Publications by authors named "Xiaobin Fan"

64 Publications

Nitrogen-carbon materials base on pyrolytic graphene hydrogel for oxygen reduction.

J Colloid Interface Sci 2021 Jun 8;602:274-281. Epub 2021 Jun 8.

Lab of Advanced Nano-structures & Transfer Processes, Department of Chemical Engineering, Tianjin University, Tianjin 300354, China; Chemistry and Chemical Engineering Guangdong Laboratory, Shantou 515031 China. Electronic address:

Hypothesis: Oxygen reduction reaction (ORR) has played a significant role in the utilization of energy nowadays. Nitrogen-doped carbon materials are seen as promising catalysts for ORR, so it is of great significance in studying the functions of different nitrogen moieties.

Experiments: The graphene hydrogel-based nitrogen-arbon materials (GH N-C) were fabricated by first obtaining a gel through hydrothermal treatment using graphene oxide (GO) as precursor, and then calcined in an ammonia atmosphere at different temperatures to form N-doped graphitized materials with divers nitrogen configuration.

Findings: GH N-C materials with tunable nitrogen configuration were synthesized by a two-step method base on graphene hydrogel. Benefiting from the 3D hydrogel structure, rich defects and optimized chemical properties, GH N-C-900 prepared by NH pyrolysis at 900 °C exhibits an excellent electrocatalytic performance toward ORR, with the onset potential of 0.947 ± 0.013 V versus RHE, half-wave potential of 0.830 ± 0.010 V versus RHE, electron transfer number of 3.61-3.99, along as methanol tolerance and superior long-term stability. Comprehensive studies have shown that there is a positive correlation between the total amount of pyrrolic-N and quaternary-N and the catalytic performance of ORR.
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http://dx.doi.org/10.1016/j.jcis.2021.06.036DOI Listing
June 2021

Bimetallic ZIF-Derived Co/N-Codoped Porous Carbon Supported Ruthenium Catalysts for Highly Efficient Hydrogen Evolution Reaction.

Nanomaterials (Basel) 2021 May 6;11(5). Epub 2021 May 6.

Lab of Advanced Nano-Structure and Transfer Process, Department of Chemical Engineering, Tianjin University, Tianjin 300354, China.

Exploring the economical, powerful, and durable electrocatalysts for hydrogen evolution reaction (HER) is highly required for practical application. Herein, nanoclusters-decorated ruthenium, cobalt nanoparticles, and nitrogen codoped porous carbon ([email protected]) are prepared with bimetallic zeolite imidazole frameworks (ZnCo-ZIF) as the precursor. Thus, the prepared [email protected] catalyst with a low Ru loading of 3.13 wt% exhibits impressive HER catalytic behavior in 1 M KOH, with an overpotential of only 30 mV at the current density of 10 mA cm, Tafel slope as low as 32.1 mV dec, and superior stability for long-time running with a commercial 20 wt% Pt/C. The excellent electrocatalytic properties are primarily by virtue of the highly specific surface area and porosity of carbon support, uniformly dispersed Ru active species, and rapid reaction kinetics of the interaction between Ru and O.
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http://dx.doi.org/10.3390/nano11051228DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8148513PMC
May 2021

Facile synthesis of iron oxide supported on porous nitrogen doped carbon for catalytic oxidation.

Sci Total Environ 2021 Sep 24;785:147296. Epub 2021 Apr 24.

School of Chemical Engineering and Technology, Tianjin University, Tianjin 300050, China. Electronic address:

Iron oxide (FeO) supported on porous nitrogen doped carbon is synthesized by a facile pyrolysis method. SiO and NaNO are used as the template and activation agent respectively for porous structure generation and large specific surface area (SSA) creation. The obtained materials show superior catalytic oxidation ability and can activate peroxymonosulfate (PMS) in a wide pH range (3-9) to degrade organic pollutants. The degradation process is a two-stage reaction, including a rapid initial decay and a following slow reaction stage. According to the free radical quenching experiments, electron paramagnetic resonance (EPR) spectroscopy analysis, and electrochemical tests, the superoxide radical (O) and singlet oxygen (O) are proved to play crucial roles in organics degradation. The high SSA (773 m g), abundant of structural defects, and synergistic effect between FeO and the nitrogen doped carbon are the key factors for the enhanced activity. The catalysts in this study can be synthesized easily and contain no toxic metals, thus should have great potential in the wastewater remediation.
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http://dx.doi.org/10.1016/j.scitotenv.2021.147296DOI Listing
September 2021

Synergistic Effect of N-Doped sp Carbon and Porous Structure in Graphene Gels toward Selective Oxidation of C-H Bond.

ACS Appl Mater Interfaces 2021 Mar 11;13(11):13087-13096. Epub 2021 Mar 11.

School of Chemical Engineering and Technology, State Key Laboratory of Chemical Engineering, Collaborative Innovation Center of Chemical Science and Engineering, Tianjin University, Tianjin 300072, People's Republic of China.

N-doped carbon materials represent a type of metal-free catalyst for diverse organic synthetic reactions. However, single N-doped carbon materials perform insufficiently in the selective oxidation reaction of C-H bond compared with metal catalysts or multielement co-doped materials. There are a few reports on the application of three-dimensional (3D) carbon materials in such a reaction. Besides, the relationship between the well-developed porous structures, heteroatom doping, and their catalytic performance is unclear. In this study, 3D porous N-doped graphene aerogel catalysts with high activity and selectivity for the C-H bond oxidation under mild reaction conditions have been synthesized through a two-step method. Systematic studies on the dosage of N sources, pyrolysis temperature, and their influences on the catalytic performances have been evolved. Moreover, solid evidence of the synergistic effect of sp C atoms adjacent to the N atoms and porous structure promoting the performance has been provided in this work.
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http://dx.doi.org/10.1021/acsami.0c21177DOI Listing
March 2021

Preparation of Hollow Cobalt-Iron Phosphides Nanospheres by Controllable Atom Migration for Enhanced Water Oxidation and Splitting.

Small 2021 Apr 9;17(13):e2007858. Epub 2021 Mar 9.

School of Chemical Engineering and Technology, State Key Laboratory of Chemical Engineering, Collaborative Innovation Center of Chemical Science and Engineering, Tianjin University, Tianjin, 300072, P. R. China.

Transition metal phosphides (TMPs), especially the dual-metal TMPs, are highly active non-precious metal oxygen evolution reaction (OER) electrocatalysts. Herein, an interesting atom migration phenomenon induced by Kirkendall effect is reported for the preparation of cobalt-iron (Co-Fe) phosphides by the direct phosphorization of Co-Fe alloys. The compositions and distributions of the Co and Fe phosphides phases on the surfaces of the electrocatalysts can be readily controlled by Co Fe alloys precursors and the phosphorization process with interesting atom migration phenomenon. The optimized Co Fe phosphides exhibit a low overpotential of 225 mV at 10 mA cm in 1 m KOH alkaline media, with a small Tafel slope of 37.88 mV dec and excellent durability. It only requires a voltage of 1.56 V to drive the current density of 10 mA cm when used as both anode and cathode for overall water splitting. This work opens a new strategy to controllable preparation of dual-metal TMPs with designed phosphides active sites for enhanced OER and overall water splitting.
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http://dx.doi.org/10.1002/smll.202007858DOI Listing
April 2021

Easily Regenerated CuO/γ-AlO for Persulfate-Based Catalytic Oxidation: Insights into the Deactivation and Regeneration Mechanism.

ACS Appl Mater Interfaces 2021 Jan 5;13(2):2630-2641. Epub 2021 Jan 5.

School of Chemical Engineering and Technology, Tianjin University, Tianjin 300350, China.

In this work, γ-AlO-supported CuO (-CuO/AlO) materials are successfully synthesized using a novel impregnation-precipitation-decomposition method. The obtained -CuO/AlO catalyst shows excellent catalytic activities for bisphenol A (BPA) degradation with sodium persulfate (PDS) as an oxidant. Radical quenching tests and electron paramagnetic resonance (EPR) studies indicate that PDS activation is a combined mechanism involving both free radical and nonfree radical pathways. In a continuous large-scale degradation process, about 1.78 L of 20 ppm BPA can be completely removed within 480 min. Although -CuO/AlO can be deactivated after several reaction cycles, the catalytic activity can be regenerated after simple aerobic calcination. X-ray photoelectron spectroscopy (XPS) and Raman analysis confirm that the deactivation of -CuO/AlO should be attributed to the conversion of Cu(II) to Cu(I). The aerobic calcination could oxidize Cu(I) back to Cu(II), thus recovering the catalytic activity. In addition, the density functional technology (DFT) and temperature-programmed oxidation (TPD) results reveal that γ-AlO can not only serve as a carrier to anchor the CuO particles but also can adsorb and activate PDS by introducing more basic sites on the surface. -CuO/AlO has high activity and can be regenerated easily, thus having great potential applications for wastewater treatment.
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http://dx.doi.org/10.1021/acsami.0c19013DOI Listing
January 2021

Bamboo-like nitrogen-doped carbon nanotubes on iron mesh for electrochemically-assisted catalytic oxidation.

J Hazard Mater 2021 Apr 29;408:124899. Epub 2020 Dec 29.

School of Chemical Engineering and Technology, Tianjin University, Tianjin 300350, China. Electronic address:

In this study, bamboo-like nitrogen-doped carbon nanotubes (BN-CNTs) are successfully deposited on etched iron mesh (d-Fe) using chemical vapor deposition (CVD) method with acetonitrile as precursor. The acidic etching process is necessary for the special BN-CNTs structure formation by exposing more Fe sites. The BN-CNTs/d-Fe is then evaluated for the electrochemically-assisted PMS activation to degrade phenol. Under cyclic voltammetry (CV, 0-1 V vs. RHE) assistant, 20 ppm phenol can be degraded in 30 min with a rate constant of 0.2837 min, ~78 times more than that without CV. Some Fe species in the catalyst will be reduced at the initial stage, a two-step pseudo-first-order kinetic is thus used for the degradation curves fitting. Both the structure defects and doped nitrogen atoms are responsible for the high catalytic activity of BN-CNTs. According to the quenching tests, both radical and non-radical processes are present for PMS activation, thus obtaining enhanced organics removal efficiency. The electrochemically assistant could enhance the PMS adsorption on the electrode as well as electrons transfer between Fe and PMS, thus increasing the PMS activation efficiency. The utilization of earth-abundant Fe mesh for the fabricating free-standing electrodes provide a potential low-cost and effective strategy of waste water remediation.
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http://dx.doi.org/10.1016/j.jhazmat.2020.124899DOI Listing
April 2021

Surfactant-Free Synthesis of Ultrafine Pt Nanoparticles on MoS Nanosheets as Bifunctional Catalysts for the Hydrodeoxygenation of Bio-Oil.

Langmuir 2020 12 23;36(48):14710-14716. Epub 2020 Nov 23.

School of Chemical Engineering and Technology, State Key Laboratory of Chemical Engineering, Collaborative Innovation Center of Chemical Science and Engineering, Tianjin University, Tianjin 300072, People's Republic of China.

Hydrodeoxygenation (HDO) of bio-oil is a crucial step for improving the bio-fuel quality, but developing highly dispersed Pt-based catalysts with high selectivity for target alkanes remains a great challenge. This study presents a fast surfactant-free method to prepare the MoS-supported Pt catalyst for HDO. Ultrafine Pt nanoparticles with sizes of <5 nm can be readily grown on chemically exfoliated MoS nanosheets (NSs) via the direct microwave-assisted thermal reduction. The obtained Pt NPs/MoS composites show excellent catalytic performance in the conversion of palmitic acid, and the best selectivity (also the yield) of hexadecane and pentadecane is 80.56 and 19.43%, respectively.
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http://dx.doi.org/10.1021/acs.langmuir.0c02613DOI Listing
December 2020

Metal-Organic-Framework-Based Photocatalysts Optimized by Spatially Separated Cocatalysts for Overall Water Splitting.

Adv Mater 2020 Dec 4;32(49):e2004747. Epub 2020 Nov 4.

School of Materials Science and Engineering, National Institute for Advanced Materials, Nankai University, Tianjin, 300350, P. R. China.

Efficient charge separation and utilization are critical factors in photocatalysis. Herein, it is demonstrated that the complete spatial separation of oxidation and reduction cocatalysts enhances the efficacy of charge separation and surface reaction. Specifically, a [email protected] [email protected] (PUM) heterostructured photocatalyst with Pt and MnO as cocatalysts is designed for the optimization of the NH -UiO-66 photocatalyst. Compared with the pristine NH -UiO-66, [email protected] -UiO-66 (PU), and NH [email protected] (UM) samples, the PUM sample exhibits the highest hydrogen production activity. As cocatalysts, Pt favors trapping of electrons, while MnO tends to collect holes. Upon generation from NH -UiO-66, electrons and holes flow inward and outward of the metal-organic framework photocatalyst, accumulating on the corresponding cocatalysts, and then take part in the redox reactions. The PUM photocatalyst greatly prolongs the lifetime of the photogenerated electrons and holes, which favors the electron-hole separation. Furthermore, the PUM sample facilitates overall water splitting in the absence of sacrificial agents, thereby demonstrating its potential as a modification method of MOF-type semiconductors for the overall water-splitting reaction.
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http://dx.doi.org/10.1002/adma.202004747DOI Listing
December 2020

Thermal removal of partial nitrogen atoms in N-doped graphene for enhanced catalytic oxidation.

J Colloid Interface Sci 2021 Mar 20;585:640-648. Epub 2020 Oct 20.

School of Chemical Engineering and Technology, Tianjin University, Tianjin 300050, China. Electronic address:

Carbon materials are effective catalysts to activate peroxymonosulfate (PMS) for organic pollutant degradation. Both nitrogen doping and structural defects could enhance their catalytic performance for PMS activation. In this study, nitrogen-doped graphene (NG) is first synthesized by the calcination of graphene oxide (GO) with ammonium nitrate (NHNO). The obtained NG is then annealed further at a higher temperature under a N atmosphere to remove partially doped N atoms and create new structural defects. The obtained defective nitrogen-doped graphene (D-NG) can activate PMS for bisphenol A (BPA) degradation more effectively. Different annealing temperatures from 850 to 1150 °C are investigated, and D-NG synthesized at 1050 °C exhibits the highest activity. The enhanced catalytic performance is proposed to originate from the synergistic effect between doped N atoms and created structural defects. According to radical quenching, electron paramagnetic resonance (EPR), and electrochemical results, both radical and nonradical pathways are present during PMS activation, and the nonradical pathway plays the dominant role. This study provides a facile method for metal-free catalyst synthesis, which also enriches the synergistic mechanism between doped N and structural defects and thus should have great potential in wastewater remediation.
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http://dx.doi.org/10.1016/j.jcis.2020.10.043DOI Listing
March 2021

Topochemical synthesis of low-dimensional nanomaterials.

Nanoscale 2020 Nov;12(43):21971-21987

School of Chemical Engineering and Technology, State Key Laboratory of Chemical Engineering, Collaborative Innovation Center of Chemical Science and Engineering, Tianjin University, Tianjin 300072, People's Republic of China.

Over the past several decades, nanomaterials have been extensively studied owing to having a series of unique physical and chemical properties that exceed those of conventional bulk materials. Researchers have developed a lot of strategies for the synthesis of low-dimensional nanomaterials. Among them, topochemical synthesis has attracted increasing attention because it can provide more new nanomaterials by improving and upgrading inexpensive and accessible nanomaterials. In this review, we summarize and analyze many existing topochemical synthesis methods, including selective etching, liquid phase reactions, high-temperature atmosphere reactions, electrochemically assisted methods, etc. The future direction of topochemical synthesis is also proposed.
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http://dx.doi.org/10.1039/d0nr04763eDOI Listing
November 2020

Synthesis of nitrogen and sulfur doped graphene on graphite foam for electro-catalytic phenol degradation and water splitting.

J Colloid Interface Sci 2021 Feb 23;583:139-148. Epub 2020 Sep 23.

School of Chemical Engineering, The University of Adelaide, Adelaide, SA 5005, Australia.

A rational design of electrode materials with both high electron conductivity and abundant of catalytic sites is essential for high-performance electrochemical reactions. Herein, a nitrogen and sulfur co-doped graphene (SNG) anchored on the interconnected conductive graphite foam (GF) is fabricated via drop-casting and in situ annealing. The SNG flakes are tightly immobilized on the GF surface, which can provide fast electron transfer rate and large electrolyte/electrode interfaces. The [email protected] composite can be directly used as a free-standing electrode for electro-catalytic degradation of organic pollutants and overall water splitting. [email protected] significantly enhanced the electrochemical activation of peroxymonosulfate (PMS) for catalytic oxidation. During the oxygen evolution reaction (OER), the [email protected] exhibits an initial overpotential of 330 mV vs. RHE at 10 mA cm with a Tafel slope of 149 mV dec in 1 M KOH, which outperforms most of the reported metal-free catalysts. The density functional theory calculations are also used to unveil the S, N dual doping effects of carbon materials and their synergy in carbocatalysis. This study dedicates to developing multi-functional carbocatalysts for environmental and energy applications, and enables insights into carbocatalysis in electrochemistry.
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http://dx.doi.org/10.1016/j.jcis.2020.09.053DOI Listing
February 2021

A near-infrared light-mediated antimicrobial based on Ag/TiCT for effective synergetic antibacterial applications.

Nanoscale 2020 Oct;12(37):19129-19141

School of Chemical Engineering and Technology, Frontier Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (MOE), Tianjin University, Tianjin 300072, People's Republic of China.

Designing antimicrobials with high efficiency and long-term antibacterial activity is an imperative issue. We found that the antimicrobial effect of Ti3C2Tx and Ag/Ti3C2Tx could be significantly strengthened upon near-infrared light exposure. The synergistic antibacterial mode of the photothermal bactericidal effect and intrinsic bacterial activity have been revealed, which confirms that the Ti3C2Tx MXene is an excellent near-infrared light-mediated nanoplatform for antibacterial applications. To further test the antibacterial effect in practical applications, Ag/Ti3C2Tx embedded hydrogels were used as wound dressings in a wound model experiment. They exhibit outstanding bacterial inhibition and wound healing performance with near-infrared light exposure. This work inspires us to explore the MXene-based photothermal platform in terms of antibacterial application.
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http://dx.doi.org/10.1039/d0nr04925eDOI Listing
October 2020

Increasing the heteroatoms doping percentages of graphene by porous engineering for enhanced electrocatalytic activities.

J Colloid Interface Sci 2020 Oct 24;577:101-108. Epub 2020 May 24.

School of Chemical Engineering and Technology, Tianjin University, Tianjin 300350, China. Electronic address:

Graphene based materials are considered as promising catalysts towards electro-catalytic water splitting. Heteroatoms doping and structure defects creation in graphene matrix could enhance the electro-catalytic activity effectively. In this work, a nitrogen and sulfur co-doped graphene is synthesized and then activated by KOH to involve a porous structure. The atomic ratios of doped heteroatoms are found increased surprisingly. This should be due to the better thermal stability of doped heteroatoms compared with the origin carbon atoms. More carbon atoms will be removed, thus leading to the increased heteroatoms doping percentages. The increased surface area, larger heteroatoms ratios, and abundant structure defects result in the improved catalytic activity towards electrochemical oxygen evolution reaction (OER). The overpotential for OER could achieve as early as 281 mV vs. RHE at 10 mA·cm in 1 M KOH, better than most of the metal free catalysts. The obtained sample is active over a wide pH range in electrochemical hydrogen evolution reaction (HER), thus could be used as bifunctional materials for water splitting. This work provides a simple and low-cost approach to increase the ratios of doped heteroatoms, and thus should have great potential both for carbon materials synthesis and hydrogen production.
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http://dx.doi.org/10.1016/j.jcis.2020.05.089DOI Listing
October 2020

A MicroRNA Derived From Promotes Schistosomiasis Hepatic Fibrosis by Targeting Host Secreted Frizzled-Related Protein 1.

Front Cell Infect Microbiol 2020 13;10:101. Epub 2020 Mar 13.

Department of Tropical Diseases, Naval Medical University, Shanghai, China.

Schistosomiasis remains a serious parasitic disease, which is characterized by granulomatous inflammation and hepatic fibrosis. MicroRNAs derived from parasites can regulate host genes and cell phenotype. Here, we showed that a miRNA derived from (Sja-miR-1) exists in the hepatic stellate cells (HSCs) of mice infected with the parasite and up-regulates the expression of collagens and α-SMA by targeting secreted frizzled-related protein 1 (SFRP1). A vector-mediated delivery of Sja-miR-1 into naive mice led to hepatic fibrogenesis in the mice. Accordingly, inhibition of Sja-miR-1 in the infected mice led to reduction of the parasite-induced hepatic fibrosis. The mechanism behind the Sja-miR-1-mediated activation of HSC could be through targeting SFRP1 to regulate the Wnt/β-catenin pathway. These findings reveal that parasite-derived small non-coding RNAs are implicated in cross-species regulation of host pathological process and persistent inhibition of Sja-miR-1 may provide a therapeutic potential for the parasite diseases.
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http://dx.doi.org/10.3389/fcimb.2020.00101DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7082693PMC
June 2021

Decorated nickel phosphide nanoparticles with nitrogen and phosphorus co-doped porous carbon for enhanced electrochemical water splitting.

J Colloid Interface Sci 2020 May 11;567:393-401. Epub 2020 Feb 11.

School of Chemical Engineering and Technology, Tianjin University, Tianjin 300050, China. Electronic address:

A novel free-standing electrode consisting of nickel phosphide (NiP) nanoparticles on nitrogen and phosphorus co-doped porous carbon (NPC) are synthesized on carbon cloth (CC). Polyaniline (PANI) and nickel (Ni) are sequentially electro-deposited on the surface of CC, which are then transformed into NPC and NiP by an in-situ carbonization-phosphorization combined process. The electrode surface is distributed with large amounts of uniform macropores, which could expose more active sites and enhance the interfacial exchange with the electrolyte. The [email protected]@CC electrode delivers early overpotentials of 92 and 280 mV vs. Reversible Hydrogen Electrode (RHE) at 10 mA cm for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) in alkaline condition, respectively. The electrolytic cell with [email protected]@CC electrode both as anode and cathode can achieve 10 mA cm at a small bias of 1.54 V for the overall water splitting. Density functional theory (DFT) calculation indicates that combination with NiP and NPC can decrease Gibbs free energy for H* adsorption (ΔG) and increase charge density on the interface, thus could lead to the enhanced activity for water splitting. The free-standing and noble-metal free [email protected]@CC electrode is stable, highly active and cost effective, thus have great potential for the hydrogen production.
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http://dx.doi.org/10.1016/j.jcis.2020.02.033DOI Listing
May 2020

A schistosome miRNA promotes host hepatic fibrosis by targeting transforming growth factor beta receptor III.

J Hepatol 2020 03 16;72(3):519-527. Epub 2019 Nov 16.

Department of Tropical Infectious Diseases, Second Military Medical University, Shanghai, China. Electronic address:

Background & Aims: MicroRNAs (MiRNAs) derived from parasites, and even from plants, have been detected in body fluids and are known to modulate host genes. In this study, we aimed to investigate if the schistosome miRNAs are involved in the occurrence and progression of hepatic fibrosis during Schistosoma japonicum (S. japonicum) infection.

Methods: The presence of miRNAs from S. japonicum (sja-miRNAs) in hepatic stellate cells (HSCs) was detected by RNA sequencing. sja-miRNAs were screened by transfecting HSCs with sja-miRNA mimics. The role of sja-miR-2162 in hepatic fibrosis was evaluated by either elevating its expression in naïve mice or by inhibiting its activity in infected mice, through administration of recombinant adeno-associated virus serotype 8 vectors expressing sja-miR-2162 or miRNA sponges, respectively.

Results: We identified a miRNA of S. japonicum, sja-miR-2162, that was consistently present in the HSCs of infected mice. Transfection of sja-miR-2162 mimics led to activation of HSC cells in vitro, characterized by elevation of collagens and α-SMA. The rAAV8-mediated delivery of sja-miR-2162 to naïve mice induced hepatic fibrosis, while sustained inhibition of sja-miR-2162 in infected mice attenuated hepatic fibrosis. The transforming growth factor beta receptor III (TGFBR3), a negative regulator of TGF-β signaling, was a direct target of sja-miR-2162 in HSCs.

Conclusions: This study demonstrated that pathogen-derived miRNAs directly promote hepatic fibrogenesis in a cross-species manner, and their efficient and sustained inhibition might present a promising therapeutic intervention for infectious diseases.

Lay Summary: A schistosome-specific microRNA, sja-miR-2162, is consistently present in the hepatic stellate cells of mice infected with S. japonicum, where it promotes hepatic fibrosis in the host through cross-species regulation of host fibrosis-related genes. The efficient and sustained inhibition of pathogen-derived micRNAs may represent a novel therapeutic intervention for infectious diseases.
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http://dx.doi.org/10.1016/j.jhep.2019.10.029DOI Listing
March 2020

High-performance porous graphene from synergetic nitrogen doping and physical activation for advanced nonradical oxidation.

J Hazard Mater 2020 01 13;381:121010. Epub 2019 Aug 13.

School of Chemical Engineering, The University of Adelaide, Adelaide SA 5005, Australia.

Porous nitrogen-doped reduced graphene oxide (NRGO) is successfully synthesized from graphene oxide via the combination of CO activation and nitrogen doping with ammonia. The performances of the carbon materials are evaluated by catalytic activation of perroxymonosulfate (PMS) for phenol degradation. The effect of the treatment sequence of CO activation and nitrogen doping on the catalytic activity of the derived product is investigated. The material obtained by CO activation-nitrogen doping (P-NRGO) shows better activity than the one obtained from nitrogen doping-CO activation (N-PRGO). The activation mechanisms are also investigated by radical scavenging test, and the P-NRGO/PMS system is unveiled to rely on the nonradical oxidation pathway. The turnover frequencies (TOFs) of these RGOs are also calculated, and the P-NRGO has the largest TOF of 58.39. Based on the analysis of synthesis method and catalytic activity, it is proposed that new catalytic sites are generated on P-NRGO. Density functional theory (DFT) calculations also illustrated that the most reactive sites are the structure vacancies with two nitrogen atoms, which is consistent with the results. The conclusion in this study provides new insights into the synergistic effect of N-doping and structural defects of carbon materials and the induced nonradical pathway in advanced oxidation.
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http://dx.doi.org/10.1016/j.jhazmat.2019.121010DOI Listing
January 2020

Bifunctional Graphene-Based Metal-Free Catalysts for Oxidative Coupling of Amines.

ACS Appl Mater Interfaces 2019 Sep 20;11(35):31844-31850. Epub 2019 Aug 20.

Lab of Advanced Nano Structures & Transfer Processes, Department of Chemical Engineering , Tianjin University , Tianjin 300354 , P. R. China.

Graphene oxide (GO), an emerging material ornamented with oxygen-containing functional groups, is becoming a promising alternative for various applications. The piranha solution treatment of GO can increase oxygen-containing functional groups and result in improved graphene oxide (IGO), as well as restore the functional groups lost because of the reaction. It is found that GO can oxidize the amine to the corresponding imine in the absence of oxygen and a catalyst, and the obtained IGO even shows higher activity. In addition, the piranha solution can partially restore the reactivity of GO after the reaction. The different roles of oxygen-containing functional groups in the oxidative coupling reaction are investigated. A possible reaction mechanism for the oxidation of benzylamine to -benzylidene benzylamine is also proposed.
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http://dx.doi.org/10.1021/acsami.9b08741DOI Listing
September 2019

Butyllithium-Treated TiCT MXene with Excellent Pseudocapacitor Performance.

ACS Nano 2019 Aug 5;13(8):9449-9456. Epub 2019 Aug 5.

School of School of Chemical Engineering and Technology , Tianjin University , Tianjin 300072 , China.

MXenes, a family of two-dimensional (2D) transition-metal carbide and nitride materials, are supposed to be promising pseudocapacitive materials because of their high electronic conductivity and hydrophilic surfaces. MXenes, prepared by removing the "A" elements of their corresponding MAX phases by hydrofluoric acid (HF) or LiF-HCl etching, possess abundant terminal groups like -F, -OH, and -O groups. It has been proven that the MXenes with fewer -F terminal groups and more -O groups showed a higher pseudocapacitor performance. In organic reactions, -OH and -X (X = halogen) groups could turn to ether groups in strong nucleophilic reagent. Inspired by that, herein, we report an -butyllithium-treated method to turn the -F and -OH terminal groups to -O groups on the TiCT MXenes. Two types of TiCT MXenes prepared by either HF or LiF-HCl etching were systematically investigated, and a comparison with the traditional KOH/NaOH/LiOH-treated method was also carried out. It is found that most of the -F terminal groups on the TiCT MXenes can be successfully removed by -butyllithium, and abundant -O terminal groups were formed. The -butyllithium-treated TiCT MXenes show promising applications in high-performance pseudocapacitors. A record high capacitance of 523 F g at 2 mV s was obtained for the -butyllithium-treated TiCT MXenes, and 96% capacity can remain even after 10 000 cycles.
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http://dx.doi.org/10.1021/acsnano.9b04301DOI Listing
August 2019

Heterostructure engineering of Co-doped MoS coupled with MoCT MXene for enhanced hydrogen evolution in alkaline media.

Nanoscale 2019 Jun;11(22):10992-11000

School of Chemical Engineering and Technology, State Key Laboratory of Chemical Engineering, Collaborative Innovation Center of Chemical Science and Engineering, Tianjin University, Tianjin 300072, China.

The hydrogen evolution reaction (HER) in alkaline media is key for the cathodic reaction of electrochemical water splitting, but it suffers sluggish kinetics due to the slow water dissociation process. Here, we present a simple strategy to enhance the HER activity in alkaline media by engineering Co-doped MoS2 coupled with Mo2CTx MXene. The improved HER activity might be ascribed to the synergistic regulation of water dissociation sites and electronic conductivity. Co doping could effectively regulate the electronic structure of MoS2 and further improve the intrinsic activity of the catalyst. Mo2CTx MXene served as both the active and conductive substrate to facilitate electron transfer. As a result, the Co-MoS2/Mo2CTx nanohybrids showed dramatically enhanced HER performance with a low overpotential of 112 mV at a current density of 10 mA cm-2 and exhibited excellent long-term stability in alkaline media.
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http://dx.doi.org/10.1039/c9nr02085cDOI Listing
June 2019

TiO nanorod arrays decorated with exfoliated WS nanosheets for enhanced photoelectrochemical water oxidation.

J Colloid Interface Sci 2019 Jun 14;545:282-288. Epub 2019 Mar 14.

State Key Laboratory of Chemical Engineering, School of Chemical Engineering and Technology, Collaborative Innovation Center of Chemical Science and Engineering, Tianjin University, Tianjin 300354, China. Electronic address:

A novel three-dimensional (3D) photoanode consisting of TiO nanorod arrays (TiO NAs) coated by exfoliated WS nanosheets was fabricated for enhanced photoelectrochemical water oxidation. Mixed phase WS nanosheets with 1 T percentage of 55% were exfoliated by the lithium insertion, which were then coated on the top of TiO NAs by a drop-casting method. By optimizing the loading amount of WS, a maximum photocurrent of ∼1.8 mA/cm could be obtained at +1.8 V vs. RHE under AM 1.5 irradiation (100 mW/cm), which is 2.3 times higher compared to the pure TiO NAs (0.8 mA/cm). The enhanced photo-activity should be attributed to the presence of the mixed phase WS nanosheets, which have excellent charge transport ability and can accept photogenerated holes for water oxidation.
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http://dx.doi.org/10.1016/j.jcis.2019.03.041DOI Listing
June 2019

Reversible intercalation and exfoliation of layered covalent triazine frameworks for enhanced lithium ion storage.

Chem Commun (Camb) 2019 Jan;55(10):1434-1437

Faculty of Chemical Engineering, The Higher Educational Key Laboratory for Phosphorus Chemical Engineering of Yunnan Province, Kunming University of Science and Technology, Kunming 650500, China.

We report that layered covalent triazine frameworks (CTF-1) can be rapidly and reversibly intercalated with either an oxidizing or a non-oxidizing acid based on the acid-base driven mechanism. The obtained CTF-1 intercalated compounds can be readily reacted with nitronium ions and spontaneously exfoliated into 1-2 layered functionalized CTF-1 nanosheets (f-CTF-1) with a high yield of 42%. The f-CTF-1 shows a 2.5 to 3.8 times increase in specific capacitance and much better rate performance when used as an LIB anode.
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http://dx.doi.org/10.1039/c8cc10262gDOI Listing
January 2019

3D self-supported Ni(PO)-MoO nanorods anchored on nickel foam for highly efficient overall water splitting.

Nanoscale 2018 Dec 27;10(47):22173-22179. Epub 2018 Nov 27.

Lab of Advanced Nano Structures & Transfer Processes, Department of Chemical Engineering, Tianjin University, Tianjin 300354, P. R. China.

Electrolyzing water as a sustainable energy source is a promising and appealing method to resolve the environmental crisis. Developing efficient and stable bifunctional electrocatalysts for the hydrogen evolution reaction (HER) and the oxygen evolution reaction (OER) is crucial and challenging in the overall water splitting process. Herein, we report the synthesis of Ni(PO)-MoO nanorods anchored on nickel foam (Ni(PO)-MoO/NF) within a two-step strategy and their application as a bifunctional water splitting electrocatalyst. The results show that the optimal Ni(PO)-MoO/NF electrodes exhibit superior catalytic activity with robust durability and ultralow overpotentials of 86 mV for HER and 234 mV for OER to achieve 10 mA cm (η) in alkaline solution. The favorable performance of the obtained catalyst is attributed mainly to the synergetic effect between Ni(PO) and MoO, as well as the self-supporting porous conductive substrate. As a result, the integrated Ni(PO)-MoO/NF electrodes deliver η at a small potential of 1.47 V for overall water splitting, highlighting a promising application as a bifunctional electrocatalyst.
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http://dx.doi.org/10.1039/c8nr07577hDOI Listing
December 2018

Magnetic Au-Ag-γ-Fe₂O₃/rGO Nanocomposites as an Efficient Catalyst for the Reduction of 4-Nitrophenol.

Nanomaterials (Basel) 2018 Oct 25;8(11). Epub 2018 Oct 25.

Lab of Advanced Nano-structures & Transfer Processes, Department of Chemical Engineering, Tianjin University, Tianjin 300354, China.

In this paper, a facile route has been developed to prepare magnetic trimetallic Au-Ag-γ-Fe₂O₃/rGO nanocomposites. The impact of the preparation method (the intensity of reductant) on the catalytic performance was investigated. The nanocomposites were characterized by transmission electron microscopy (TEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The prepared nanocomposites show fine catalytic activity towards the reduction reaction of 4-nitrophenol (4-NP). The nanocomposites also have superparamagnetism at room temperature, which can be easily separated from the reaction systems by applying an external magnetic field.
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http://dx.doi.org/10.3390/nano8110877DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6266811PMC
October 2018

Decoration of CuO photocathode with protective TiO and active WS layers for enhanced photoelectrochemical hydrogen evolution.

Nanotechnology 2018 Dec 1;29(50):505603. Epub 2018 Oct 1.

School of Chemical Engineering and Technology, Tianjin University, Tianjin 300050, People's Republic of China.

A CuO based multi-layered photocathode was fabricated with a layer-by-layer assembly method for enhanced photoelectrochemical (PEC) hydrogen evolution. Au was first electrodeposited on the fluorine-doped tin oxide glass to decrease the electrochemical impedance of the CuO photocathode. A layer of TiO was then coated to increase the light-to-electricity energy conversion efficiency and the chemical stability by forming a p-n junction with CuO. Exfoliated WS nanosheets obtained from lithium insertion were then coated as the electron acceptor to facilitate the hydrogen evolution. This photocathode is effective for PEC hydrogen evolution, and a photocurrent of -10 mA cm can be obtained at -0.33 V versus RHE in a phosphorus buffer (pH = 6.0) under visible light (λ ≥ 420 nm, 100 mW cm) on the optimized photocathode.
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http://dx.doi.org/10.1088/1361-6528/aae569DOI Listing
December 2018

Hierarchical Cobalt Borate/MXenes Hybrid with Extraordinary Electrocatalytic Performance in Oxygen Evolution Reaction.

ChemSusChem 2018 Nov 12;11(21):3758-3765. Epub 2018 Oct 12.

School of School of Chemical Engineering and Technology, State Key Laboratory of Chemical Engineering, Collaborative Innovation Center of Chemical Science and Engineering, Tianjin University, Tianjin, 300072, P.R. China.

Oxygen evolution reaction (OER) is a key reaction for many renewable energy storage and conversion techniques. Developing efficient non-precious metal-based electrocatalysts for OER has attracted increasing attention. Herein is reported a strategy to fabricate hierarchical cobalt borate/Ti C T MXene (Co-B /Ti C T ) hybrid through fast chemical reactions at room temperature. This interesting hierarchical structure of Co-B /Ti C T hybrid is beneficial for exposing more active sites, improving mass diffusion, and charge-transfer pathways for electrochemical reaction. Moreover, a strong interaction between Co-B and Ti C T ensures efficient charge transfer and facilitates the electrostatic attraction of more anionic intermediates for a fast redox process. Consequently, the hierarchical Co-B /Ti C T hybrid shows extraordinary OER catalytic activity to deliver a current density of 10 mA cm at an overpotential of 250 mV, and a Tafel slope of about 53 mV dec .
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http://dx.doi.org/10.1002/cssc.201802098DOI Listing
November 2018

Correction: TiCT nanosheets as photothermal agents for near-infrared responsive hydrogels.

Nanoscale 2018 09;10(36):17409

School of Chemical Engineering & Technology, State Key Laboratory of Chemical Engineering, Collaborative Innovation Center of Chemical Science and Engineering, Tianjin University, Tianjin, 300072, China.

Correction for 'Ti2C3Tx nanosheets as photothermal agents for near-infrared responsive hydrogels' by Changyu Yang et al., Nanoscale, 2018, 10, 15387-15392.
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http://dx.doi.org/10.1039/c8nr90190bDOI Listing
September 2018

TiCT nanosheets as photothermal agents for near-infrared responsive hydrogels.

Nanoscale 2018 Aug;10(32):15387-15392

School of Chemical Engineering & Technology, State Key Laboratory of Chemical Engineering, Collaborative Innovation Center of Chemical Science and Engineering, Tianjin University, Tianjin, 300072, China.

Poly(N-isopropylacrylamide) (PNIPAM) is broadly applicable in many fields due to its temperature-induced phase transition property. Herein, a facile method to incorporate exfoliated Ti2C3Tx nanosheets in the PNIPAM network is reported. Due to compatibility, stability and photothermal properties of the incorporated Ti2C3Tx nanosheets, the obtained MXene/PNIPAM composite hydrogel shows excellent photothermal properties, expanding the pure thermal-responsive property of the PNIPAM hydrogel. Based on the smart composite hydrogel, remote light-control of the microfluidic pipeline is also demonstrated.
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http://dx.doi.org/10.1039/c8nr05301dDOI Listing
August 2018

Partially Etched Ti AlC as a Promising High-Capacity Lithium-Ion Battery Anode.

ChemSusChem 2018 Aug 16;11(16):2677-2680. Epub 2018 Jul 16.

School of School of Chemical Engineering and Technology, State Key Laboratory of Chemical Engineering, Collaborative Innovation Center of Chemical Science and Engineering, Tianjin University, Tianjin, 300072, China.

MXenes, a family of two-dimensional transition-metal carbide and nitride materials, are thought to be promising materials in energy storage because of their high electronic conductivity, hydrophilic surfaces, and low diffusion barriers. MXenes are generally prepared by removing the "A" elements (A=Al, Si, Sn, etc.) from their corresponding MAX phases by using hydrofluoric acid (HF) and other etching agents, although these "A" elements usually have great volumetric and gravimetric capacities. In a study of the etching progress of Ti AlC and evaluation of their anode performance in lithium-ion batteries, a partially etched sample (0.5 h-pe Ti C T ) is found to have much higher capacity (160 mAh g , 331.6 mAh cm at 1C) when compared with the fully etched Ti C T (110 mAh g , 190.3 mAh cm at 1C). Moreover, a 99 % capacity retention was observed even after 1000 cycles in the 0.5 h-pe Ti C T anode. This interesting result can be explained, at least in part, by the alloying of the residual Al during lithiation.
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http://dx.doi.org/10.1002/cssc.201801200DOI Listing
August 2018
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