Publications by authors named "Daguang Li"

15 Publications

  • Page 1 of 1

Synchronous construction of a porous intramolecular D-A conjugated polymer via electron donors for superior photocatalytic decontamination.

J Hazard Mater 2021 Sep 29;424(Pt B):127379. Epub 2021 Sep 29.

School of Environmental Science and Engineering, Guangdong University of Technology, Guangzhou 510006, China. Electronic address:

The development of conjugated polymers with intramolecular donor-acceptor (D-A) units has the capacity to enhance the photocatalytic performance of carbon nitride (g-CN) for the removal of antibiotics from ambient ecosystems. This strategy addresses the challenge of narrowing the band gap of g-CN while maintaining its high LUMO position. For this study, we introduced the above donor units into g-CN to construct intramolecular D-A structures through the copolymerization of dicyandiamide with creatinine, which strategically extended light absorption into the green region and expedited photoelectron separation. The introduction of electron donor blocks kept the LUMO distributed on the melem, which maintained the high LUMO energy level of the copolymer with the potential to generate oxygen radicals. The as-prepared porous D-A conjugated polymer enhanced the photocatalytic degradation of sulfisoxazole with kinetic constants 5.6 times higher than that of g-CN under blue light and 15.3 times higher under green light. Furthermore, we surveyed the degradation mechanism including the effective active species and degradation pathways. This study offers a new perspective for the synchronous construction of a porous intramolecular D-A conjugated polymer to enhance water treatment and environmental remediation capacities.
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http://dx.doi.org/10.1016/j.jhazmat.2021.127379DOI Listing
September 2021

Superhigh co-adsorption of tetracycline and copper by the ultrathin g-CN modified graphene oxide hydrogels.

J Hazard Mater 2021 Sep 29;424(Pt B):127362. Epub 2021 Sep 29.

Guangzhou Key Laboratory Environmental Catalysis and Pollution Control, Guangdong Key Laboratory of Environmental Catalysis and Health Risk Control, School of Environmental Science and Engineering, Institute of Environmental Health and Pollution Control, Guangdong University of Technology, Guangzhou 510006, China.

Development of economic and efficient absorbent for the simultaneous removal of antibiotics and heavy metals is needed. In this study, a three-dimensional porous ultrathin g-CN (UCN) /graphene oxide (GO) hydrogel (UCN-GH) was prepared by co-assembling of UCN and GO nanosheets via the facile hydrothermal reaction. Characterizations indicated that the addition of UCN significantly decreased the reduction of CO and O-CO related groups of GO during the hydrothermal reaction and introduced amine groups on UCN-GH. The UCN-GH exhibited excellent ability on the co-removal of Cu(II) (q = 2.0-2.5 mmol g) and tetracycline (TC) (q = 1.2-3.0 mmol g) from water. The adsorption capacities were increased as UCN mass ratio increasing. The mutual effects between Cu(II) and TC were examined through adsorption kinetics and isotherm models. Characterizations and computational chemistry analysis indicated that Cu(II) is apt to coordinate with the amine groups on UCN than with oxygen groups on GO, which accounts for the enhanced adsorption ability of UCN-GH. In the binary system, Cu(II) acts as a bridge between TC and UCN-GH enhanced the removal of TC. The effects of pH and regular salt ions on the removal of Cu(II)/TC were examined. Moreover, the prepared UCN-GH also showed comparable co-adsorption capacities in practical water/wastewater.
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http://dx.doi.org/10.1016/j.jhazmat.2021.127362DOI Listing
September 2021

Construction of double-functionalized g-CN heterojunction structure via optimized charge transfer for the synergistically enhanced photocatalytic degradation of sulfonamides and HO production.

J Hazard Mater 2021 Aug 10;422:126868. Epub 2021 Aug 10.

School of Environmental Science and Engineering, Guangdong University of Technology, Guangzhou 510006, China. Electronic address:

Herein, supporting g-CN embedded with benzene-ring (BCN) on P-modified g-CN (PCN) successfully synthesized the homogeneous photocatalyst BCN/PCN (PBCN) via a simple thermal polymerization reaction. Under blue-light (LED) irradiation, the optimized PBCN (0.448 min) demonstrated excellent photocatalytic performance, attaining over 74 times the degradation rate for sulfisoxazole (SSZ) in contrast to non-functionalized g-CN (CN, 0.006 min). Theoretical calculations revealed that the substitution of heterocyclic rings in the g-CN triazine networks with benzene-rings enabled them to serve as electron donors, while promoting photoinduced spatial charge dissociation. Further, the carrier PCN tended to serve as electron acceptors to form electron-rich corner-phosphorous sites. Reactive species experiments demonstrate that the O˙ and h constituted the primary photocatalytic mechanism of SSZ degradation. The potential SSZ degradation routes were predicted based on the transformation products via mass spectrometry. Finally, the composite materials also exhibited excellent photocatalytic activity in the conversion of solar energy to chemical energy (HO). This study guides the rational modification of g-CN-based semiconductors to achieve green energy production and beneficial ecological applications.
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http://dx.doi.org/10.1016/j.jhazmat.2021.126868DOI Listing
August 2021

Removal of lead ions by two FeMn oxide substrate adsorbents.

Sci Total Environ 2021 Jun 6;773:145670. Epub 2021 Feb 6.

School of Environmental Science and Engineering, Guangdong University of Technology, Guangzhou, Guangdong 510006, China.

Lead pollution has become a global concern due to its ubiquity and persistence. This study describes two FeMn oxide substrate adsorbents, namely, FeMn binary oxides (FMBO) and mesoporous FeMn binary oxide (MFMBO) covered with tannic acid film ([email protected] and [email protected]), for the treatment of Pb in water. The characterization results showed that TA was successfully coated onto the surfaces of FMBO and MFMBO. The maximum capacities of Pb on [email protected] and [email protected] were 322.08 and 357.14 mg g, respectively, which were twice those of FMBO and MFMBO. The adsorption of Pb on the adsorbents was a spontaneous, endothermic process with increasing disorder through thermodynamics studies. An overall mechanism was proposed for Pb adsorption, the improved adsorption performance of [email protected] and [email protected] is ascribed to the mesoporous characteristics and the introduction of hydroxyl groups. Further investigation indicated the adsorption of Pb could be attributed to electrostatic interactions on [email protected] and [email protected], and cation exchange existed through the formation of these internal surface complexes. The Pb-loaded adsorbents could be effectively desorbed in a dilute hydrochloric acid solution, promoting recycling and reuse of the regenerated adsorbents. These results warrant the promising application of [email protected] and [email protected] for the removal of Pb, and this work first proposed TA film-modified FMBO and MFMBO to improve its adsorption capacity in the application of environmental remediation.
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http://dx.doi.org/10.1016/j.scitotenv.2021.145670DOI Listing
June 2021

Nonthermal and reversible control of neuronal signaling and behavior by midinfrared stimulation.

Proc Natl Acad Sci U S A 2021 03;118(10)

Department of Neurology, Huashan Hospital, State Key Laboratory of Medical Neurobiology, Institute for Translational Brain Research, MOE Frontiers Center for Brain Science, Fudan University, Shanghai 200032, China

Various neuromodulation approaches have been employed to alter neuronal spiking activity and thus regulate brain functions and alleviate neurological disorders. Infrared neural stimulation (INS) could be a potential approach for neuromodulation because it requires no tissue contact and possesses a high spatial resolution. However, the risk of overheating and an unclear mechanism hamper its application. Here we show that midinfrared stimulation (MIRS) with a specific wavelength exerts nonthermal, long-distance, and reversible modulatory effects on ion channel activity, neuronal signaling, and sensorimotor behavior. Patch-clamp recording from mouse neocortical pyramidal cells revealed that MIRS readily provides gain control over spiking activities, inhibiting spiking responses to weak inputs but enhancing those to strong inputs. MIRS also shortens action potential (AP) waveforms by accelerating its repolarization, through an increase in voltage-gated K (but not Na) currents. Molecular dynamics simulations further revealed that MIRS-induced resonance vibration of -C=O bonds at the K channel ion selectivity filter contributes to the K current increase. Importantly, these effects are readily reversible and independent of temperature increase. At the behavioral level in larval zebrafish, MIRS modulates startle responses by sharply increasing the slope of the sensorimotor input-output curve. Therefore, MIRS represents a promising neuromodulation approach suitable for clinical application.
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http://dx.doi.org/10.1073/pnas.2015685118DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7958416PMC
March 2021

Integration of oxygen vacancies into BiOI via a facile alkaline earth ion-doping strategy for the enhanced photocatalytic performance toward indometacin remediation.

J Hazard Mater 2021 Jun 24;412:125147. Epub 2021 Jan 24.

School of Environmental Science and Engineering, Guangdong University of Technology, Guangzhou 510006, China. Electronic address:

Bismuth oxyiodide (BiOI) has garnered intense attention in the field of photocatalysis for environmental remediation; however, it suffers from a high electron-hole recombination rate. In this study, for the first time, we report on a facile strategy for the creation of oxygen vacancies in BiOI via strontium (Sr) doping. The as-prepared 0.45-SrBiOI demonstrated significantly enhanced photocatalytic degradation of indometacin under visible light exposure, which was almost 10 folds higher than pristine BiOI. This augmented photocatalytic performance was ascribed to the accelerated separation of charge carriers by oxygen vacancies, as well as Sr ion trapping electrons. Reactive species determination experiments revealed that O, O, and h were the dominant active species. Finally, potential indometacin degradation pathways were proposed based on the identification of degradation by-products and theoretical calculations. This study offers new perspectives for the synthesis of highly efficient and cost effective BiOI-based photocatalysts, and provides a promising strategy toward advanced environmental remediation.
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http://dx.doi.org/10.1016/j.jhazmat.2021.125147DOI Listing
June 2021

High Color-Purity Red, Green, and Blue-Emissive Core-Shell Upconversion Nanoparticles Using Ternary Near-Infrared Quadrature Excitations.

ACS Appl Mater Interfaces 2021 Jan 12;13(3):4402-4409. Epub 2021 Jan 12.

State Key Laboratory on Integrated Optoelectronics, College of Electronic Science and Engineering, Jilin University, Changchun, Jilin 130012, China.

Development of multicolor-emitting upconversion nanoparticles (UCNPs) is of significant importance for applications in optical encoding, anti-counterfeiting, display, and bioimaging. However, realizing the orthogonal three-primary color (TPC) upconversion luminescence in a single nanoparticle remains a huge challenge. Herein, we have rationally designed core-multishell-structured NaYF UCNPs through regulating the dopant concentration, composition of luminescent layers, and shell position and thickness, which are capable of emitting red, green, and blue luminescence with high color purity in response to ternary near-infrared quadrature excitations (1560/808/980 nm). Moreover, their high color purity is well retained with varying excitation power densities. This orthogonal TPC emissions property of such UCNPs endows them with great promise in the field of security. As a proof-of-concept, we have demonstrated the feasibility of combining such UCNPs with MnO nanosheets for information encryption and decryption. This work not only offers a new way to achieve TPC upconversion luminescence at a single nanoparticle level but also broadens the scope of application for security protection.
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http://dx.doi.org/10.1021/acsami.0c19902DOI Listing
January 2021

Photoelectrochemical immunosensor for sensitive detection of alpha-fetoprotein based on a graphene honeycomb film.

J Colloid Interface Sci 2020 Nov 16;580:583-591. Epub 2020 Jul 16.

State Key Laboratory on Integrated Optoelectronics, College of Electronic Science and Engineering, Jilin University, Changchun, Jilin 130012, China. Electronic address:

Alpha-fetoprotein (AFP) in adult serum often appears in early liver cancer. Therefore, early detection of an abnormal elevation of AFP concentration is important for the early diagnosis and treatment of primary liver cancer. In this work, a photoelectrochemical (PEC) electrode was fabricated for AFP-sensitive detection based on a reduced graphene oxide (rGO) honeycomb structure. After layer-by-layer bioconjugation, the immunoassay graphene electrode was modified with anti-AFP antibodies (Ab). Meanwhile, polymer nanoparticles (PFBT dots) were prepared via a nanoprecipitation method. In addition, the AFP was modified by using the PFBT dots and glucose oxidase (GOD), which formed a fluorescent probe (AFP-PFBT-GOD). By the competitive linkage of AFP and AFP-PFBT-GOD onto the anti-AFP modified honeycomb structure electrode, an immunosensor for AFP detection was obtained. During the PEC test, the electrons produced by the catalytic reaction of glucose and GOD can scavenge the photogenerated holes on the PFBT dots, which can reduce the recombination of photogenerated holes and electrons on the PFBT dots. The PEC immunosensor based on a rGO honeycomb structure exhibited a linear detection range of 0.05-100 ng/mL with a detection limit of 0.05 ng/mL. The excellent detection performance of the graphene PEC biosensor provides an opportunity for the early diagnosis of primary liver cancer.
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http://dx.doi.org/10.1016/j.jcis.2020.07.064DOI Listing
November 2020

Synthesis of a carbon dots modified g-CN/SnO Z-scheme photocatalyst with superior photocatalytic activity for PPCPs degradation under visible light irradiation.

J Hazard Mater 2021 01 21;401:123257. Epub 2020 Jun 21.

School of Environmental Science and Engineering, Guangdong University of Technology, Guangzhou, 510006, China. Electronic address:

As an emerging carbon nanomaterial, carbon dots (CDs) have superior prospects for applications in the area of photocatalysis due to their unique optical and electronic properties. In this study, a novel CDs modified g-CN/SnO photocatalyst (CDs/g-CN/ SnO) was successfully synthesized by the thermal polymerization. Under visible light irradiation, the resulting CDs/g-CN/SnO photocatalyst exhibited excellent photocatalytic activity for the degradation of indomethacin (IDM). It was demonstrated that a 0.5 % loading content of CDs led to the highest IDM degradation rate, which was 5.62 times higher than that of pristine g-CN. This improved photocatalytic activity might have been attributed to the unique up-conversion photoluminescence (PL) properties and efficient charge separation capacities of the CDs. Moreover, the combination of g-CN with SnO improved the separation of photoinduced carriers and augmented the specific surface area. Reactive species (RSs) scavenging experiments and electron spin resonance (ESR) revealed that superoxide radical anions (O) and photogenerated holes (h) played critical roles during the photocatalytic process. The results of the detection of HO and ESR confirmed that CDs/g-CN/ SnO was a Z-scheme heterojunction photocatalyst. Further, HRAM LC-MS/MS was employed to identify the byproducts of IDM, and the major IDM degradation pathways of the CDs/g-CN/SnO photocatalyst were proposed. This study provides new ideas for the design of novel CDs modified photocatalysts for environmental remediation.
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http://dx.doi.org/10.1016/j.jhazmat.2020.123257DOI Listing
January 2021

Ultrathin AgWO-coated P-doped g-CN nanosheets with remarkable photocatalytic performance for indomethacin degradation.

J Hazard Mater 2020 06 19;392:122355. Epub 2020 Feb 19.

School of Environmental Science and Engineering, Guangdong University of Technology, Guangzhou, 510006, China.

As a metal-free photocatalyst, the photocatalytic activity of graphitic carbon nitride (g-CN) remains restricted due to an insufficient visible-light absorption capacity, the rapid recombination of photoinduced carriers, and low surface area. Consequently, P-doped g-CN (PCN) was successfully prepared via a single -step thermal polymerization technique using phytic acid biomass and urea, which exhibited remarkable photocatalytic activity for the degradation of indometacin (IDM). The IDM degradation rate was 7.1 times greater than that of pristine g-CN (CN). Furthermore, AgWO was loaded onto the surface of the PCN, which formed a Z-scheme heterostructure that promoted the separation of photogenerated carriers. According to analyses of the chemical binding states of PCN, P atoms replaced carbon atoms in the CN framework. According to electron localization function analysis, the low ELF values of P-N facilitated the transfer of photoelectrons. The results of active species scavenging experiments confirmed that superoxide radicals were the primary active species in the photocatalytic degradation system. Finally, the photocatalytic degradation pathways of IDM were predicted through the identification of by-products and IDM reaction sites.
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http://dx.doi.org/10.1016/j.jhazmat.2020.122355DOI Listing
June 2020

Expression and association of IL-21, FBXL20 and tumour suppressor gene PTEN in laryngeal cancer.

Saudi J Biol Sci 2019 Dec 16;26(8):2048-2051. Epub 2019 Aug 16.

Department of Clinical Laboratory, the First Hospital of Jilin University, Changchun 130000, China.

Objective: To study the expression of three genes IL-21, FBXL20 and tumour suppressor gene PTEN in laryngeal cancer; analyse the differences in their expression in laryngeal cancer and adjacent tissues; by using pEGFP-N1-IL21 and pGPU/GFP/Neo-FBXL20 expression vectors, to analyse the characteristics in their expression in laryngeal cancer cells outside the body as well as the associations among them.

Methods: The expression of the three genes in laryngeal cancer and adjacent tissues from 30 cases and in normal laryngeal tissues from 20 healthy persons was detected with the RT-PCR; laryngeal cancer cell line (HEp-2 cells) transfection was also performed with the pEGFP-N1-IL21 and pGPU/GFP/Neo-FBXL20 expression vectors we constructed, to detect the mRNA expression of the three genes. Cell proliferation, apoptosis and cell cycle were measured by the MTT assay.

Results: The results of RT-PCR showed that the expression of IL-21 and FBXL20 was up-regulated in laryngeal cancer, while the expression of tumour suppressor gene PTEN was significantly decreased (p < 0.01). In HEp-2 cells transfected with pGPU/GFP/Neo-IL-21 and pGPU/GFP/Neo-FBXL20 expression vectors, the mRNA expression of PTEN was restored to some extent (p < 0.05); in addition, the ability of HEp-2 cells in proliferation and invasion was also reduced.

Conclusions: IL-21 and FBXL20 genes are important in the occurrence and development of laryngeal cancer; the expression of PTEN gene can suppress laryngeal cancer, and there's a certain association among IL-21, FBXL20 and PTEN.
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http://dx.doi.org/10.1016/j.sjbs.2019.08.013DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6923488PMC
December 2019

One-step synthesis of phosphorus/oxygen co-doped g-CN/anatase TiO Z-scheme photocatalyst for significantly enhanced visible-light photocatalysis degradation of enrofloxacin.

J Hazard Mater 2020 03 8;386:121634. Epub 2019 Nov 8.

School of Environmental Science and Engineering, Guangdong University of Technology, Guangzhou, 510006, China.

Anatase TiO nanoparticles coated with P and O co-doped g-CN were prepared via a single-step procedure. The resulting POCN/anatase TiO demonstrated remarkable performance in the degradation of enrofloxacin (ENFX). The photocatalytic activity of this heterojunction was 28.9 and 3.71 times better than that of the CN and anatase TiO, respectively. The microtopography of the POCN/anatase TiO was revealed in this study. Co-doping with P and O increased the visible light adsorption capacity of the g-CN, whereas the anatase TiO nanoparticles enhanced the adsorption properties of the ENFX and the separation of the photoinduced carriers of the POCN/anatase TiO. The O and h were the main reactive oxidative species in the photocatalytic degradation of ENFX. The results of the detection of HO and ESR confirmed that POCN/anatase TiO was a type Z-scheme photocatalyst. Finally, the ENFX degradation pathways were estimated through the detection of by-products.
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http://dx.doi.org/10.1016/j.jhazmat.2019.121634DOI Listing
March 2020

Zn-Alloyed CsPbI Nanocrystals for Highly Efficient Perovskite Light-Emitting Devices.

Nano Lett 2019 03 11;19(3):1552-1559. Epub 2019 Feb 11.

Department of Materials Science and Engineering, and Centre for Functional Photonics (CFP) , City University of Hong Kong , Kowloon , Hong Kong SAR.

We alloyed Zn into CsPbI perovskite nanocrystals by partial substitution of Pb with Zn, which does not change their crystalline phase. The resulting alloyed CsPbZnI nanocrystals exhibited an improved, close-to-unity photoluminescence quantum yield of 98.5% due to the increased radiative decay rate and the decreased non-radiative decay rate. They also showed an enhanced stability, which correlated with improved effective Goldschmidt tolerance factors, by the incorporation of Zn ions with a smaller radius than the Pb ions. Simultaneously, the nanocrystals switched from n-type (for CsPbI) to nearly ambipolar for the alloyed nanoparticles. The hole injection barrier of electroluminescent LEDs was effectively eliminated by using alloyed CsPbZnI nanocrystals, and a high peak external quantum efficiency of 15.1% has been achieved.
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http://dx.doi.org/10.1021/acs.nanolett.8b04339DOI Listing
March 2019

Improved Upconversion Luminescence in Water-Soluble Yb3+/Er3+ Codoped LaF3 Nanoparticles Through Ca2+ Doping.

J Nanosci Nanotechnol 2016 Apr;16(4):3883-5

Monodisperse water-soluble LaF3: Yb3+/Er3+ nanocrystals (NCs) have been successfully fabricated via a fast, facile, and environmentally-friendly polyol process with polyvinylpyrrolidone (PVP) as an amphiphilic surfactant. The obtained NCs with a small size of 18 nm can be well dispersed in hydrophilic solutions. Meanwhile, their upconversion (UC) luminescence intensity was increased through Ca2+ doping due to the decrease of symmetry around rare earth ions.
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http://dx.doi.org/10.1166/jnn.2016.11824DOI Listing
April 2016

Effects of Gd element and SiC particles on microstructures of Cf/Mg composites.

Micron 2014 Sep 25;64:1-5. Epub 2014 Mar 25.

School of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150001, China. Electronic address:

In present work, Cf/Mg-8Gd and SiC+Cf/Mg-8Gd composites were fabricated by squeeze infiltration method. Gd2O3 coating layers were found on the surface of the carbon fibers in these two kinds of the composites, while GdC2 precipitations were found in the hybrid reinforced composite only. Owing to this phenomenon, the coating layer in SiC+Cf/Mg-8Gd composite (88 nm) was much thinner than the one without the SiC particles (160 nm). The Gd2O3 coating layer formed on the surface of carbon fibers can improve the wettability between carbon fibers and magnesium alloy.
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http://dx.doi.org/10.1016/j.micron.2014.03.007DOI Listing
September 2014
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