Publications by authors named "Xuchuan Jiang"

38 Publications

Ultrafast and efficient removal of Pb(II) from acidic aqueous solution using a novel polyvinyl alcohol superabsorbent.

Chemosphere 2021 Nov 28;282:131032. Epub 2021 May 28.

School of Chemistry and Chemical Engineering, University of Jinan, No. 336 Nanxinzhuang West Road, 250022, Jinan, PR China. Electronic address:

The direct removal of heavy metal ions from acidic wastewater is a hard problem. In this study, a novel superabsorbent, polyvinyl alcohol phosphate ester (PVAP), was designed and prepared to remove Pb(II) from acidic wastewater (pH = 3). The PVAP can absorb water and swell to reach equilibrium within 30 s, which provides the conditions for ultrafast kinetic adsorption. For 100 mg/L Pb(II) solution, the adsorption reaches equilibrium within 5 min, and the removal ratio is more than 99.9% over a wide pH range of 3-6. Adsorption kinetics and isotherm data are consistent with pseudo-second-order and Langmuir model, respectively. The calculated maximum adsorption capacity for Pb(II) is 558.66 mg/g. Thermodynamic results show that the adsorption is spontaneous and exothermic process. The removal ratio for Pb(II) of PVAP still maintains above 99% after ten recycles. The PVAP can also simultaneously remove more than 97% of other heavy metal ions (Cu(II), Cd(II), Zn(II), Co(II), and Ni(II)) from an acidic solution. Moreover, the PVAP can efficiently purify simulated acid mine heavy metal wastewater, and the results meet EPA drinking water standards. The studies of X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared (FT-IR) spectroscopy prove that the adsorption mechanism involves surface complexation. This new superabsorbent is a promising candidate for acidic heavy metal sewage disposal.
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http://dx.doi.org/10.1016/j.chemosphere.2021.131032DOI Listing
November 2021

Highly dispersed Pt species anchored onto NH-Ce-MOFs and their derived mesoporous catalysts for CO oxidation.

Nanoscale 2021 Jan;13(1):117-123

Institute for Smart Materials & Engineering, University of Jinan, Jinan 250022, P.R. China.

Simultaneously maximizing the dispersion of noble metals and demonstrating optimal activity are of significant importance for designing stable metal catalysts. In this study, highly dispersed ultrafine platinum (Pt) particles with a size of <1.5 nm anchored onto a mesoporous CeO2 structure have been synthesized by coordinating Pt ions with amino groups in NH2-Ce-MOFs, followed by high-temperature calcination. It was found that the presence of -NH2 groups in Ce-MOFs played a crucial role in anchoring Pt species with high dispersion on the MOF framework. Interestingly, the anchored Pt species were beneficial for the formation of Ce-Pt sites during the conversion from Ce-BDC to CeO2. As a result, the as-prepared catalysts held dense surface peroxo species, responsible for boosting CO oxidation at low temperatures.
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http://dx.doi.org/10.1039/d0nr05626jDOI Listing
January 2021

Development of a General Fabrication Strategy for Carbonaceous Noble Metal Nanocomposites with Photothermal Property.

Nanoscale Res Lett 2020 Jan 21;15(1):17. Epub 2020 Jan 21.

Department of Chemical Engineering, Monash University, Clayton, VIC, 3800, Australia.

This study demonstrates a simple hydrothermal method while can be generalized for controllable synthesis of noble metallic carbonaceous nanostructures (e.g., [email protected], [email protected]) under mild conditions (180-200 °C), which also provides a unique approach for fabricating hollow carbonaceous structures by removal of cores (e.g., silver) via a redox etching process. The microstructure and composition of the as-achieved nanoparticles have been characterized using various microscopic and spectroscopic techniques. Cetyltrimethylammonium bromide (CTAB), serving as a surfactant in the reaction system, plays a key role in the formation of [email protected], [email protected] nanocables, and their corresponding hollow carbonaceous nanotubes in this work. The dynamic growth and formation mechanism of carbonaceous nanostructures was discussed in detail. And finally, laser-induced photothermal property of [email protected] nanocomposites was examined. The results may be useful for designing and constructing carbonaceous metal(s) or metal oxide(s) nanostructures with potential applications in the areas of electrochemical catalysis, energy storage, adsorbents, and biomedicine. This study demonstrate a facile hydrothermal synthesis of noble metal carbonaceous nanocomposites (e.g., [email protected]) with simple procedures under mild conditions, which can be25expanded as a general method for preparing diverse carbonaceous core-shell nanoparticles. The [email protected] carbonaceous nanostructures exhibit interesting UV-Vis properties dependent upon shell thickness.
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http://dx.doi.org/10.1186/s11671-019-3242-1DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6974232PMC
January 2020

Glycothermal Synthesis of VO₂(B) Nanoparticles for Gas Sensing Application.

J Nanosci Nanotechnol 2020 03;20(3):1946-1954

Department of Chemistry Engineering, Monash University, Clayton, VIC 3800, Australia.

This study represents a facile but efficient glycothermal method for synthesis of vanadium dioxide, VO₂(B) nanoparticles with various geometries from spheres to rods, flakes or their agglomeration structures, by controlling reaction conditions (e.g., vanadium resources, reducing agents and surfactants). The as-prepared VO₂(B) nanoparticles were characterized in microstructure and composition, and also examined in terms of gas sensing performance. It was found that the VO₂(B) nanoparticles exhibit a good sensitivity towards alcohols (ethanol, isopropanol, and butanol) and acetone at the optimised operating temperature of 300 °C. The gas sensing performance was further compared with other vanadium oxides investigated previously, such as V₂O, NaV₃O. The plausible gas sensing mechanism of the as-prepared nanoparticles was discussed in detail. This study would expand the family of vanadium oxides that can be made as potential sensors for applications in detecting environmental safety and human health.
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http://dx.doi.org/10.1166/jnn.2020.17167DOI Listing
March 2020

Effect of Al, Ti and Cr Doping on Vanadium Dioxide (VO2) Analyzed by Density Function Theory (DFT) Method.

J Nanosci Nanotechnol 2020 Mar;20(3):1651-1659

Department of Chemistry Engineering, Monash University, Clayton, VIC 3800, Australia.

Density function theory (DFT) method was developed and applied for fundamentally understanding the doping effect of various metals (Al, Ti and Cr) on vanadium dioxide (VO₂). The substitution doping of Al, Ti and Cr in VO₂ could lead to significant changes in electronic structure, band gap and optical property. Different from physical experiments, the DFT method could be utilized for fundamental understandings at an atomic scale. It was found via DFT calculations that: (i) Al doping caused a slightly distorted octahedron in monoclinic VO₂(M), and narrowed the band gap of VO₂(M) due to the upward shift of the valence band (VB), while Cr doping narrowed the band gap because of the downward shift of the conduction band (CB); (ii) Ti doping slightly widened the band gap of VO₂(M); and (iii) the optical reflectivity of VO₂(M) decreased after substitution doping low-valent metals (e.g., Al). This study will be beneficial for designing and controlling elemental doping to obtain metal oxide nanocomposites with unique band gap and electronic structure for thermochromic energy saving applications.
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http://dx.doi.org/10.1166/jnn.2020.17140DOI Listing
March 2020

Fluorine and tin co-doping synergistically improves the photoelectrochemical water oxidation performance of TiO nanorod arrays by enhancing the ultraviolet light conversion efficiency.

Dalton Trans 2019 Aug 19;48(32):12096-12104. Epub 2019 Jul 19.

Key Laboratory of Chemical Sensing & Analysis in Universities of Shandong, School of Chemistry and Chemical Engineering, Institute for Smart Materials & Engineering, University of Jinan, No. 336, West Road of Nan Xinzhuang, Jinan 250022, Shandong, PR China.

Fluorine and tin co-doped rutile TiO nanorod arrays are grown on fluorine-doped tin oxide substrates by a hydrothermal process and are used as photoanodes to perform photoelectrochemical water oxidation. Fluorine and tin co-doping synergistically enhances the ultraviolet light conversion efficiency of the resulting TiO, which enables its photocurrent density of photoelectrochemical water oxidation to be more than four times that of the undoped samples. Such improvement in photoelectrochemical performance is attributed to changes in the electronic structure of the rutile TiO due to fluorine and tin co-doping. It is found that introducing tin into the matrix of rutile TiO can improve the charge separation efficiency because of the enhanced migration of photogenerated electrons from the conduction band of TiO to that of SnO that occurs at local sites, while fluorine doping can greatly reduce the recombination of the photogenerated electron-hole pairs due to the presence of the Ti state that is produced to compensate for the charge difference between F ions and O ions. It is envisaged that the fluorine and tin co-doped TiO nanorod arrays described will provide valuable platforms for wide photocatalytic applications that are not merely limited to photoelectrochemical water oxidation.
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http://dx.doi.org/10.1039/c9dt01994dDOI Listing
August 2019

In situ construction of yolk-shell zinc ferrite with carbon and nitrogen co-doping for highly efficient solar light harvesting and improved catalytic performance.

J Colloid Interface Sci 2019 Oct 2;554:91-102. Epub 2019 Jul 2.

Department of Chemical Engineering, Curtin University, GPO Box U1987, Perth, WA 6845, Australia.

In this work, carbon and nitrogen co-doped yolk-shell ZnFeO nanostructures (CN-ZnFeO) were successfully synthesized through a facile self-templated method with in situ doping strategy. A series of characterizations were processed to present a comprehensive properties of the as-prepared photocatalyst samples. Doping amount could be moderated by the addition mass of dopamine, which was regarded as both the carbon and nitrogen source. And the void space between yolk and shell could be adjusted by heating rates in the calcination process of precursors. With an excellent separation efficiency of photogenerated electron-hole pairs and transfer efficiency of photogenerated electrons, the obtained CN-ZnFeO sample exhibited an enhanced visible light response than ZnFeO. And their photocatalytic performances towards gaseous 1, 2-dichlorobenzene (o-DCB) was also systematically studied. The results demonstrated that the CN-ZnFeO sample with 100 mg dopamine addition and 20 °C/min calcination heating rate exhibited the best o-DCB degradation efficiency. In situ Fourier Transform infrared (FTIR) spectroscopy was also recorded to give a detailed information of intermediate products and reveal the mechanism of photocatalytic degradation towards o-DCB. Particularly, density functional theory (DFT) calculation was used to further study the electronic structure of prepared samples to support the experimental results and especially explain the mechanism of enhanced photocatalytic activity through a proposed lattice junction. Additionally, electron paramagnetic resonance (EPR) technique was carried out to prove the reactive oxygen species involved in the photodegradation process. This work not only presents a promising strategy in photocatalyst fabrication but also provides a new sight of enhanced photocatalysis mechanism.
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http://dx.doi.org/10.1016/j.jcis.2019.07.001DOI Listing
October 2019

Holey Assembly of Two-Dimensional Iron-Doped Nickel-Cobalt Layered Double Hydroxide Nanosheets for Energy Conversion Application.

ChemSusChem 2020 Mar 8;13(6):1645-1655. Epub 2019 Aug 8.

College of Chemistry and Molecular Engineering, Qingdao University of Science and Technology, Qingdao, 266042, P.R. China.

Layered double hydroxides (LDHs) containing first-row transition metals such as Fe, Co, and Ni have attracted significant interest for electrocatalysis owing to their abundance and excellent performance for the oxygen evolution reaction (OER) in alkaline media. Herein, the assembly of holey iron-doped nickel-cobalt layered double hydroxide (NiCo-LDH) nanosheets ('holey nanosheets') is demonstrated by employing uniform Ni-Co glycerate spheres as self-templates. Iron doping was found to increase the rate of hydrolysis of Ni-Co glycerate spheres and induce the formation of a holey interconnected sheet-like structure with small pores (1-10 nm) and a high specific surface area (279 m  g ). The optimum Fe-doped NiCo-LDH OER catalyst showed a low overpotential of 285 mV at a current density of 10 mA cm and a low Tafel slope of 62 mV dec . The enhanced OER activity was attributed to (i) the high specific surface area of the holey nanosheets, which increases the number of active sites, and (ii) the improved kinetics and enhanced ion transport arising from the iron doping and synergistic effects.
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http://dx.doi.org/10.1002/cssc.201901364DOI Listing
March 2020

Normal Reference Intervals of Neutrophil-To-Lymphocyte Ratio, Platelet-To-Lymphocyte Ratio, Lymphocyte-To-Monocyte Ratio, and Systemic Immune Inflammation Index in Healthy Adults: a Large Multi-Center Study from Western China.

Clin Lab 2019 Mar;65(3)

Background: Numerous studies have shown that the hematological components of the systemic inflammatory response, including the neutrophil-to-lymphocyte ratio (NLR), the platelet-to-lymphocyte ratio (PLR), the lymphocyte-to-monocyte ratio (LMR), and the systemic immune inflammation index (SII) are efficient prognostic indicators in patients with cancers. Most of the studies did not investigate the reference intervals (RIs) of these parameters in healthy controls.

Methods: A retrospective cohort study was performed on healthy ethnic Han population aged between 18 and 79 years of age by retrieving the data from a healthy routine examination center database and laboratory infor-mation system of four participating centers in western China. By following the Clinical and Laboratory Standards Institute (CLSI), RIs of each parameter was established and validated.

Results: The analysis included 5,969 healthy subjects. We found that the individual's gender can significantly influence PLR, LMR, and SII (all p < 0.05), but not NLR (p > 0.05). Surprisingly, we also found that with an increase in age, the PLR, LMR, and SII tend to decrease, while NLR remained stable. PLR, LMR, and SII values were significantly higher in the young adults (18 - 64 years) than in old adults (65 - 79 years) (p < 0.001). The RIs of NLR, PLR (adults), PLR (old adults), LMR and SII were 0.88 - 4.0, 49 - 198, 42 - 187, 2.63 - 9.9, 142 x 109/L - 804 x 109/L, respectively.

Conclusions: Our study addresses possible variations and establishes consensus for the NLR, PLR, LMR, and SII RIs for healthy Han Chinese adults in western China. Further, established RIs can standardize clinical applications and promote the use of these indicators into the routine complete blood count report.
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http://dx.doi.org/10.7754/Clin.Lab.2018.180715DOI Listing
March 2019

Electrodeposited Vanadium Dioxide Films with Unique Optical Property.

J Nanosci Nanotechnol 2019 Jun;19(6):3597-3603

Department of Chemical Engineering, Monash University, Clayton, VIC 3800, Australia.

This study represents a facile but effective electrodeposition method to fabricate vanadium dioxide (VO₂) thin films on fluorine doped tin oxide (FTO) glass at room temperature. The film microstructure (thickness, surface structure, particle size and composition) and relevant optical properties were investigated by several advanced techniques. The pertinent variables that can affect the thin film formation and structure, such as deposition potential, time and post-treatment annealing temperature were also studied. It was found that the film thickness could be tuned from 35 to 130 nm by adjusting the potential from -1.22 to -1.35 V, and consequently leading to optical transmittance decreasing from ∼60% to ∼38% in the wavelength of 500-1000 nm, further confirmed by computational simulations using three-dimension (3D) finite-difference time-domain method. The hysteresis loop of the generated VO₂ film on FTO glass shows that the phase transition temperature from monoclinic to rutile is around 73 °C, a little higher than pure monoclinic VO₂ (∼68 °C) in this study. This proposed electrodeposition method is possible to extend into obtaining metal oxide films with tuneable surface properties for thermochromic smart devices.
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http://dx.doi.org/10.1166/jnn.2019.16093DOI Listing
June 2019

VO /TiN Plasmonic Thermochromic Smart Coatings for Room-Temperature Applications.

Adv Mater 2018 Mar 19;30(10). Epub 2018 Jan 19.

Department of Physics and Materials Science, City University of Hong Kong, Tat Chee Avenue, Kowloon, 999077, Hong Kong, China.

Vanadium dioxide/titanium nitride (VO /TiN) smart coatings are prepared by hybridizing thermochromic VO with plasmonic TiN nanoparticles. The VO /TiN coatings can control infrared (IR) radiation dynamically in accordance with the ambient temperature and illumination intensity. It blocks IR light under strong illumination at 28 °C but is IR transparent under weak irradiation conditions or at a low temperature of 20 °C. The VO /TiN coatings exhibit a good integral visible transmittance of up to 51% and excellent IR switching efficiency of 48% at 2000 nm. These unique advantages make VO /TiN promising as smart energy-saving windows.
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http://dx.doi.org/10.1002/adma.201705421DOI Listing
March 2018

Drops on a Superhydrophobic Hole Hanging On under Evaporation.

ACS Omega 2017 Sep 27;2(9):6211-6222. Epub 2017 Sep 27.

Department of Mechanical & Aerospace Engineering, Laboratory for Optics and Applied Mechanics and Department of Chemical Engineering, Monash University, Clayton, VIC 3800, Australia.

Drops with larger volumes placed over a superhydrophobic (SH) surface with a hole do not fall through unless they are evaporated to a size that is small enough. This feature offers the ability to preconcentrate samples for biochemical analysis. In this work, the influence of pinning on the behavior of drops placed on a 0.1 mm thick SH substrate with a 2 mm diameter hole as they evaporated was investigated. With 16 μL of water dispensed, the sessile drop component volume was initially higher than that of the overhanging drop component and maintained this until the later stages where almost identical shapes were attained and full evaporation was achieved without falling off the hole. With 15 μL of water dispensed, the volume of the sessile drop was initially higher than that of the overhanging drop component but the liquid body was able to squeeze through the hole after 180 s due to the contact line not having sufficient pinning strength when it encountered the edge of the hole. This resulted in the liquid body either falling through the hole or remaining pinned with an oval-like shape. When it did not fall-off, the liquid body had volume and contact angle characteristics for the sessile drop and overhanging drop components that were reversed. In the later stages, however, nearly identical shapes were again attained and full evaporation was achieved without falling off the hole. The effects of pinning, despite the substrate being SH, offer another path toward achieving practical outcomes with liquid bodies without the need for chemical surface functionalization. Similarities and differences could be seen in the behavior of a sessile drop on a SH plate that was inclined at 30° to the horizontal and evaporated.
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http://dx.doi.org/10.1021/acsomega.7b01114DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6644627PMC
September 2017

Seedless Synthesis of Monodispersed Gold Nanorods with Remarkably High Yield: Synergistic Effect of Template Modification and Growth Kinetics Regulation.

Chemistry 2017 Mar 1;23(14):3291-3299. Epub 2017 Feb 1.

Department of Chemical Engineering, Monash University, Clayton, Victoria, 3800, Australia.

Gold nanorods (AuNRs) are versatile materials due to their broadly tunable optical properties associated with their anisotropic feature. Conventional seed-mediated synthesis is, however, not only limited by the operational complexity and over-sensitivity towards subtle changes of experimental conditions but also suffers from low yield (≈15 %). A facile seedless method is reported to overcome these challenges. Monodispersed AuNRs with high yield (≈100 %) and highly adjustable longitudinal surface plasmon resonance (LSPR) are reproducibly synthesized. The parameters that influence the AuNRs growth were thoroughly investigated in terms of growth kinetics and soft-template regulation, offering a better understanding of the template-based mechanism. The facile synthesis, broad tunability of LSRP, high reproducibility, high yield, and ease of scale-up make this method promising for the future mass production of monodispersed AuNRs for applications in catalysis, sensing, and biomedicine.
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http://dx.doi.org/10.1002/chem.201605617DOI Listing
March 2017

Nanoarchitectured Design of Porous Materials and Nanocomposites from Metal-Organic Frameworks.

Adv Mater 2017 Mar 27;29(12). Epub 2016 Dec 27.

International Center for Materials Nanoarchitectonics (MANA), National Institute for Materials Science (NIMS), 1-1 Namiki, Tsukuba, Ibaraki, 305-0044, Japan.

The emergence of metal-organic frameworks (MOFs) as a new class of crystalline porous materials is attracting considerable attention in many fields such as catalysis, energy storage and conversion, sensors, and environmental remediation due to their controllable composition, structure and pore size. MOFs are versatile precursors for the preparation of various forms of nanomaterials as well as new multifunctional nanocomposites/hybrids, which exhibit superior functional properties compared to the individual components assembling the composites. This review provides an overview of recent developments achieved in the fabrication of porous MOF-derived nanostructures including carbons, metal oxides, metal chalcogenides (metal sulfides and selenides), metal carbides, metal phosphides and their composites. Finally, the challenges and future trends and prospects associated with the development of MOF-derived nanomaterials are also examined.
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http://dx.doi.org/10.1002/adma.201604898DOI Listing
March 2017

Dual-Phase Transformation: Spontaneous Self-Template Surface-Patterning Strategy for Ultra-transparent VO Solar Modulating Coatings.

ACS Nano 2017 01 28;11(1):407-415. Epub 2016 Dec 28.

Department of Chemical Engineering, Monash University , Clayton, VIC 3800, Australia.

Dual-phase transformation has been developed as a template-free surface patterning technique in this study. Ordered VO honeycomb structures with a complex hierarchy have been fabricated via this method, and the microstructures of the obtained VO(M) coatings are tunable by tailoring the pertinent variables. The VO(M) honeycomb-structured coatings have excellent visible light transmittance at 700 nm (T) up to 95.4% with decent solar modulating ability (ΔT) of 5.5%, creating the potential as ultratransparent smart solar modulating coatings. Its excellent performance has been confirmed by a proof-of-principle demonstration. The dual-phase transformation technique has dramatically simplified the conventional colloidal lithography technique as a scalable surface patterning technique for achieving high-performance metal oxide coatings with diverse applications, such as catalysis, sensing, optics, electronics, and superwettable materials.
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http://dx.doi.org/10.1021/acsnano.6b06152DOI Listing
January 2017

Superwettability Strategy: 1D Assembly of Binary Nanoparticles as Gas Sensors.

Small 2017 Jan 20;13(4). Epub 2016 Jun 20.

Department of Chemical Engineering, Faculty of Engineering, Monash University, Wellington Road, VIC, 3800, Australia.

Binary 1D nanowires consisting of both SnO nanoparticles and Au nanorods are fabricated through a "substrate-particle solution template" assembling method, which shows highly enhanced gas sensitivity toward acetone under ambient conditions.
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http://dx.doi.org/10.1002/smll.201601087DOI Listing
January 2017

Carbon-Coated Gold Nanorods: A Facile Route to Biocompatible Materials for Photothermal Applications.

ACS Appl Mater Interfaces 2015 Nov 13;7(46):25658-68. Epub 2015 Nov 13.

Department of Chemical Engineering, Monash University , Clayton, Victoria 3800, Australia.

Gold nanorods and their core-shell nanocomposites have been widely studied because of their well-defined anisotropy and unique optical properties and applications. This study demonstrates a facile hydrothermal synthesis strategy for generating carbon coating on gold nanorods ([email protected]) under mild conditions (<200 °C), where the carbon shell is composed of polymerized sugar molecules (glucose). The structure and composition of the produced core-shell nanocomposites were characterized using advanced microscopic and spectroscopic techniques. The functional properties, particularly the photothermal and biocompatibility properties of the produced [email protected], were quantified to assess their potential in photothermal hyperthermia. These [email protected] were tested in vitro (under representative treatment conditions) using near-infrared (NIR) light irradiation. It was found that the AuNRs produced here exhibit exemplary heat generation capability. Temperature changes of 10.5, 9, and 8 °C for [email protected] were observed with carbon shell thicknesses of 10, 17, and 25 nm, respectively, at a concentration of 50 μM, after 600 s of irradiation with a laser power of 0.17 W/cm(2). In addition, the synthesized [email protected] also exhibit good biocompatibility toward two soft tissue sarcoma cell lines (HT1080, a fibrosarcoma; and GCT, a fibrous histiocytoma). The cell viability study shows that [email protected] (at a concentration of <0.1 mg/mL) core-shell particles induce significantly lower cytotoxicity on both HT1080 and GCT cell lines, as compared with cetyltrimethylammonium bromide (CTAB)-capped AuNRs. Furthermore, similar to PEG-modified AuNRs, they are also safe to both HT1080 and GCT cell lines. This biocompatibility results from a surface full of -OH or -COH groups, which are suitable for linking and are nontoxic Therefore, the [email protected] represent a viable alternative to PEG-coated AuNRs for facile synthesis and improved photothermal conversion. Overall, these findings open up a new class of carbon-coated nanostructures that are biocompatible and could potentially be employed in a wide range of biomedical applications.
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http://dx.doi.org/10.1021/acsami.5b07975DOI Listing
November 2015

Hydrothermal Synthesis of Silver Vanadium Oxide (Ag0.35V2O5) Nanobelts for Sensing Amines.

Nanoscale Res Lett 2015 Dec 21;10(1):411. Epub 2015 Oct 21.

Department of Chemical Engineering, Monash University, Clayton, VIC, 3800, Australia.

A simple hydrothermal method for the synthesis of Ag0.35V2O5 nanobelts with the assistance of sodium dodecyl sulfate (SDS) is reported in this study. The experimental variables that may affect the nanoparticle structures were investigated. And several advanced techniques, such as TEM, HRTEM, X-ray diffraction (XRD), were used to characterize the morphology and composition of the as-prepared nanobelts. The mechanism of the formation and growth of Ag0.35V2O5 nanobelts was also investigated and discussed. The results show that SDS, as a weak reducing agent, plays a crucial role in the formation of Ag0.35V2O5. According to N2 sorption isothermals, the as-prepared Ag0.35V2O5 nanobelts are found to exhibit relative high surface area. The gas sensing performance of the Ag0.35V2O5 nanobelts towards organic amine was tested. It is found that the nanobelts show superior sensitivity of amine(s) to V2O5 particles, lower detection limit (5 ppm), and higher selectivity of amine versus ammonia at an optimized working temperature of ~260 °C. Moreover, the density functional theory (DFT) simulation was conducted to better understand the sensing mechanism. These findings may be useful in designing promising materials to detect amine gases for medical or food industrial applications.
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http://dx.doi.org/10.1186/s11671-015-1119-5DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4614852PMC
December 2015

Direct Hydrothermal Synthesis of Carbonaceous Silver Nanocables for Electrocatalytic Applications.

Small 2015 Aug 25;11(29):3557-67. Epub 2015 Mar 25.

School of Materials Science and Engineering, The University of New South Wales, Sydney, NSW, 2052, Australia.

This study demonstrates a facile but efficient hydrothermal method for the direct synthesis of both carbonaceous silver ([email protected] core-shell) nanocables and carbonaceous nanotubes under mild conditions (<180 °C). The carbonaceous tubes can be formed by removal of the silver cores via an etching process under temperature control (60-140 °C). The structure and composition are characterized using various advanced microscopic and spectroscopic techniques. The pertinent variables such as temperature, reaction time, and surfactants that can affect the formation and growth of the nanocables and nanotubes are investigated and optimized. It is found that cetyltrimethylammonium bromide plays multiple roles in the formation of [email protected] nanocables and carbonaceous nanotubes including: a shape controller for metallic Ag wires and [email protected] cables, a source of Br(-) ions to form insoluble AgBr and then Ag crystals, an etching agent of silver cores to form carbonaceous tubes, and an inducer to refill silver particles into the carbonaceous tubes to form core-shell structures. The formation mechanism of carbonaceous silver nanostructures depending upon temperature is also discussed. Finally, the electrocatalytic performance of the as-prepared [email protected] nanocables is assessed for the oxidation reduction reaction and found to be very active but much less costly than the commonly used platinum catalysts. The findings should be useful for designing and constructing carbonaceous-metal nanostructures with potential applications in conductive materials, catalysts, and biosensors.
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http://dx.doi.org/10.1002/smll.201401854DOI Listing
August 2015

Crystal plane-dependent gas-sensing properties of zinc oxide nanostructures: experimental and theoretical studies.

Phys Chem Chem Phys 2014 Jun 7;16(23):11471-80. Epub 2014 May 7.

School of Materials Science and Engineering, The University of New South Wales, Sydney, NSW 2052, Australia.

The sensitivity of a metal oxide gas sensor is strongly dependent on the nature of the crystal surface exposed to the gas species. In this study, two types of zinc oxide (ZnO) nanostructures: nanoplates and nanorods with exposed (0001) and (10̄10) crystal surfaces, respectively, were synthesized through facile solvothermal methods. The gas-sensing results show that sensitivity of the ZnO nanoplates toward ethanol is two times higher than that of the ZnO nanorods, at an optimum operating temperature of 300 °C. This could be attributed to the higher surface area and the exposed (0001) crystal surfaces. DFT (Density Functional Theory) simulations were carried out to study the adsorption of ethanol on the ZnO crystal planes such as (0001), (10̄10), and (11̄20) with adsorbed O(-) ions. The results reveal that the exposed (0001) planes of the ZnO nanoplates promote better ethanol adsorption by interacting with the surface oxygen p (O2p) orbitals and stretching the O-H bond to lower the adsorption energy, leading to the sensitivity enhancement of the nanoplates. These findings will be useful for the fabrication of metal oxide nanostructures with specifically exposed crystal surfaces for improved gas-sensing and/or catalytic performance.
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http://dx.doi.org/10.1039/c4cp01279hDOI Listing
June 2014

Plasmonic "pump-probe" method to study semi-transparent nanofluids.

Appl Opt 2013 Aug;52(24):6041-50

Nanofluids have been increasingly used in a wide range of thermal applications. Although these applications can benefit greatly from investigating the behavior of nanoparticles under different heating scenarios, there is a lack of experiments that can achieve this. To overcome this challenge, an optical "pump-probe"-type experiment is suggested in this paper. In experiments of this type, a set of "pumping" nanoparticles are specifically selected to absorb laser radiation. These particles represent a flexible tool for volumetric heating. A second set of "probing" nanoparticles can be tailored to scatter a separate optical probing signal. This work presents a selection procedure for nanoparticles of both types. The selection procedure is then demonstrated for a specific example where the pump and probe wavelengths are of 980 and 532 nm, respectively. Gold nanorods with diameters of 10 and a length of 58 nm are selected as the "most suitable" absorbing particles, while silver nanospheres with a diameter of 110 nm are selected as the "most suitable" scattering particles. These particles are synthesized and shown to experimentally match the desired optical properties. Overall, this paper proposes and demonstrates an approach by which it is possible to design and fabricate particles for a wide range of optical studies in semi-transparent nanofluids.
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http://dx.doi.org/10.1364/AO.52.006041DOI Listing
August 2013

Bimetallic Ag-Au nanowires: synthesis, growth mechanism, and catalytic properties.

Langmuir 2013 Jun 31;29(23):7134-42. Epub 2013 May 31.

School of Materials Science and Engineering, The University of New South Wales, Sydney, NSW 2052, Australia.

Silver-gold (Ag-Au) bimetallic nanowires were controllably synthesized by a newly developed wet-chemical method at room temperature. The Ag nanowires and Au nanoparticles were sequentially formed by reduction with vanadium oxide (V2O3) nanoparticles so as to form Ag-Au bimetal, in which the Ag nanowires show a diameter of ~20 nm and length up to 10 μm. A few unique features were noted in our new approach: it was rapid (within a few minutes), controllable in shape and size, reproducible, and there was no need for any surface modifiers. The formation and growth mechanisms of these Ag-Au bimetallic nanostructures driven by lattice match and a unique reducing agent (V2O3) have been proposed in this study. Moreover, the application of such bimetallic nanoparticles for catalytic reduction of 4-nitrophenol to 4-aminophenol was performed, and they exhibit catalytic properties superior to those of the Ag nanowires, Au nanoparticles, and Ag-Pd bimetallic nanostructures prepared under the reported conditions. These Ag-Au bimetallic nanoparticles have potential to be highly efficient catalysts for the reduction of 4-nitrophenol. This study may lead to new path for the generation of other bimetallic nanostructures with excellent catalytic efficiency.
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http://dx.doi.org/10.1021/la400753qDOI Listing
June 2013

Feasibility of nanofluid-based optical filters.

Appl Opt 2013 Mar;52(7):1413-22

University of New South Wales, Sydney, New South Wales, Australia.

In this article we report recent modeling and design work indicating that mixtures of nanoparticles in liquids can be used as an alternative to conventional optical filters. The major motivation for creating liquid optical filters is that they can be pumped in and out of a system to meet transient needs in an application. To demonstrate the versatility of this new class of filters, we present the design of nanofluids for use as long-pass, short-pass, and bandpass optical filters using a simple Monte Carlo optimization procedure. With relatively simple mixtures, we achieve filters with <15% mean-squared deviation in transmittance from conventional filters. We also discuss the current commercial feasibility of nanofluid-based optical filters by including an estimation of today's off-the-shelf cost of the materials. While the limited availability of quality commercial nanoparticles makes it hard to compete with conventional filters, new synthesis methods and economies of scale could enable nanofluid-based optical filters in the near future. As such, this study lays the groundwork for creating a new class of selective optical filters for a wide range of applications, namely communications, electronics, optical sensors, lighting, photography, medicine, and many more.
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http://dx.doi.org/10.1364/AO.52.001413DOI Listing
March 2013

Large-surface mesoporous TiO2 nanoparticles: synthesis, growth and photocatalytic performance.

J Colloid Interface Sci 2012 Dec 25;387(1):74-83. Epub 2012 Jul 25.

School of Materials Science and Engineering, The University of New South Wales, Sydney, NSW 2052, Australia.

This study demonstrates a facile and effective method to generate mono-dispersed titanium dioxide spheres at ambient conditions. The size of the colloids can be controlled from 60 to 500 nm by optimizing experimental parameters (e.g., concentration, time, and temperature). Anatase TiO(2) can be obtained through titanium glycolate colloids generated in acetone via two ways: water boiling approach and calcination at a high temperature of 500°C. Particle characteristics (shape, size, and size distribution) were measured by advanced techniques, including transmission electron microscope (TEM), thermo-gravimetric analysis (TGA), UV/Vis absorption spectrum, nitrogen gas adsorption and desorption isotherms Brunauer-Emmett-Teller (BET) surface area measurement, and X-ray diffraction technique (XRD). The possible mechanism of nucleation and growth of such colloids was discussed. The role of acetone in the formation and growth of titanium glycolate colloids was also investigated by Fourier transform infrared (FT-IR) spectroscopy. Finally, the photocatalysis performance of such anatase TiO(2) particles was tested and proved to be efficient in degradation of organic dyes (e.g., phenolphthalein and methly orange).
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http://dx.doi.org/10.1016/j.jcis.2012.06.080DOI Listing
December 2012

A facile and highly sensitive probe for Hg(II) based on metal-induced aggregation of ZnSe/ZnS quantum dots.

Nanoscale 2012 Aug 4;4(16):4996-5001. Epub 2012 Jul 4.

State Key Laboratory of Fine Chemical, School of Environmental Science and Technology, Dalian University of Technology, Dalian, 116024, China.

Sensitive and selective detection strategies for toxic heavy metal ions, which are rapid, cheap and applicable to environmental and biological fields, are of significant importance. As a result of specific interaction between thiol(s) used as ligands and heavy metal ions, the photoluminescence intensity of quantum dots (QDs) in PBS buffer solution was quenched and the aggregation of QDs was formed at the same time. Herein, we present water-soluble, low toxic QDs, ZnSe/ZnS, which were applied for ultrasensitive Hg(2+) ion detection with a low detection limit (2.5 nM). In addition, a model has been proposed to explain the aggregation of QDs in the presence of heavy metal ions such as Hg(2+) ions.
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http://dx.doi.org/10.1039/c2nr31238gDOI Listing
August 2012

Deposition of gold nanoparticles on β-FeOOH nanorods for detecting melamine in aqueous solution.

J Colloid Interface Sci 2012 Feb 15;367(1):204-12. Epub 2011 Oct 15.

School of Materials Science and Engineering, University of New South Wales, Sydney, NSW 2052, Australia.

This study demonstrates a facile but efficient approach to deposit metallic (gold) nanoparticles on β-FeOOH nanorods to obtain Au/β-FeOOH nanocomposites without the assistance of any polymers or surfactants at ambient conditions. In this method, a strong reducing agent (NaBH(4)) can be used to extensively produce Au nanoparticles, converting β-FeOOH into Fe(3)O(4) and depositing gold particles onto magnetic Fe(3)O(4) simultaneously. The microstructure, composition, and chemical properties of the obtained nanocomposites are characterized by various advanced techniques, including transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray diffraction (XRD), and UV-vis spectroscopy. Moreover, the Au/β-FeOOH nanocomposite can be used to detect trace melamine using UV spectrum in the ultraviolet wavelength range (190-260 nm), in which the nanocomposites show a higher sensitivity toward melamine due to the promotion of symmetry-forbidden bands (n→π(*)) of melamine molecules and also avoid the disturbance of commercial products containing solid colloids or food colorings that distort visual spectrum during the detection of chemical sensing. The deposition mechanisms and their sensing detection toward melamine are discussed.
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http://dx.doi.org/10.1016/j.jcis.2011.10.024DOI Listing
February 2012

Molecular dynamics study on Au/Fe3O4 nanocomposites and their surface function toward amino acids.

J Phys Chem B 2011 Oct 22;115(40):11693-9. Epub 2011 Sep 22.

School of Materials Science and Engineering, University of New South Wales, Sydney NSW 2052, Australia.

The deposition of gold nanoparticles on the magnetite (Fe(3)O(4)) surface is demonstrated through a molecular dynamics method. The simulated results show that an intermediate layer composed by such as a surfactant, polymer, or silica plays a key role in the formation of core/shell Fe(3)O(4)/Au nanostructures. The functional groups of the intermediate layer are crucial factors in depositing gold onto the Fe(3)O(4) surface via nonbonding interactions, in which the van der Waals and columbic forces will determine the strength of interaction toward the gold and iron oxide. Such interactions can affect the stability of the metal-coated nanocomposites and hence the functional properties. The nanocomposite is further investigated on the surface adsorption of amino acids (e.g., cysteine), which may be useful for functional exploration in biomedical applications.
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http://dx.doi.org/10.1021/jp206532pDOI Listing
October 2011

One-step approach for the synthesis and self-assembly of silver nanoparticles.

J Nanosci Nanotechnol 2010 Nov;10(11):7643-7

School of Materials Science and Engineering, University of New South Wales, Sydney, NSW 2052, Australia.

This study demonstrates a facile approach for one-step synthesis and self-assembly of silver nanoparticles at ambient conditions. It was found that pyrogallol acid (PYA) can play multiple roles in the proposed synthesis, including a reducing agent, a stabilizer, and a linking agent for assembly. Silver ions can be readily reduced by PYA at room temperature due to its powerful reducing capability. The capability in shape and size control can be evidenced by TEM images. A third function of PYA in this case is to link the generated silver particles into chains through the action of hydrogen bonding, which leads to a new plasmon resonance emerges in the longer wavelength region centered at approximately 650 nm. These results may be useful for shape-controlled synthesis and self-assembly of other metallic nanoparticles. The self-assembly structures would be imposed more functional applications in the areas of optics, plasmonics, biomedicine labeling and ionic sensing.
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http://dx.doi.org/10.1166/jnn.2010.2763DOI Listing
November 2010

Low dimensional silver nanostructures: synthesis, growth mechanism, properties and applications.

J Nanosci Nanotechnol 2010 Dec;10(12):7829-75

School of Materials Science and Engineering, University of New South Wales, Sydney, NSW 2052, Australia.

This work presents a review of the recent advances on the low-dimensional (LD) silver nanostructures (e.g., one-dimensional nanorods and nanowires, and two-dimensional nanoplates and nanodisks). First, the methods, either physical or chemical, for the synthesis of silver LD nanostructures are introduced. Then, the use is discussed of advanced experimental techniques (e.g., transmission electron microscope, high-resolution transmission electron microscope, scanning electron microscope, atomic force microscope, ultraviolet-visible and Raman spectra) and theoretical techniques at different time and length scales from quantum mechanics (e.g., ab initio simulation and density function theory) to molecular dynamics method for understanding the principles of governing particle growth, as well as discrete dipolar approximate method for understanding the optical properties of different shapes and sizes of silver LD nanostructures. Subsequently, the functional applications of the LD silver nanostructures in different areas such optical, electronic, and sensing, particularly for those related to surface plasma resonance are summarized based on the recent findings. Finally, some perspectives and comments for future investigation of silver nanostructures are also briefly discussed.
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http://dx.doi.org/10.1166/jnn.2010.3568DOI Listing
December 2010

A Two-Step Hydrothermal Synthesis Approach to Monodispersed Colloidal Carbon Spheres.

Nanoscale Res Lett 2009 May 21;4(9):971-976. Epub 2009 May 21.

This work reports a newly developed two-step hydrothermal method for the synthesis of monodispersed colloidal carbon spheres (CCS) under mild conditions. Using this approach, monodispersed CCS with diameters ranging from 160 to 400 nm were synthesized with a standard deviation around 8%. The monomer concentration ranging from 0.1 to 0.4 M is in favor of generation of narrower size distribution of CCS. The particle characteristics (e.g., shape, size, and distribution) and chemical stability were then characterized by using various techniques, including scanning electron microscopy (SEM), FT-IR spectrum analysis, and thermalgravity analysis (TGA). The possible nucleation and growth mechanism of colloidal carbon spheres were also discussed. The findings would be useful for the synthesis of more monodispersed nanoparticles and for the functional assembly.
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http://dx.doi.org/10.1007/s11671-009-9343-5DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2894148PMC
May 2009
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