Nanchang Hangkong University

About: Nanchang Hangkong University is a education organization based out in Nanchang, China. It is known for research contribution in the topics: Microstructure & Alloy. The organization has 7004 authors who have published 5270 publications receiving 62162 citations. The organization is also known as: Nanchang Aviation University.

Synthesis and efficient visible light photocatalytic H2 evolution of a metal-free g-C3N4/graphene quantum dots hybrid photocatalyst

Abstract: In this work, we report a systematic study of the relationship between photocatalytic properties of hydrogen evolution and structures and morphologies of g-C 3 N 4 prepared by different precursors (urea, melamine and dicyandiamide). The photocatalytic performances of H 2 production are affected by the method and degree of polymerization, the degree of protonation, and the morphology of g-C 3 N 4 prepared by different precursors. Furthermore, a novel metal-free N-GQDs/g-C 3 N 4 catalyst was designed and synthesized, which shows much better photocatalytic activity for H 2 evolution from water splitting than that of g-C 3 N 4 due to the unique and multiple roles of N-GQDs. A mechanism is put forth to explain the roles of N-GQDs and the detailed enhancement of photocatalytic performance of the N-GQDs/g-C 3 N 4 .

Recent advances in precious metal-free bifunctional catalysts for electrochemical conversion systems

Abstract: There remains a grand challenge to develop sustainable and pollution-free energy to replace the current dominant but gradually “depleting” fossil fuels. Electrochemical energy conversion presents a promising “bridge” to mitigate energy shortage issues and minimize the ecological implications by synergy with the ever-increasing sustainable energies (e.g., wind and solar). It thus calls for exploring high-activity, low-cost, and long-durability electrocatalysts to facilitate the electrochemical reactions involved in electrochemical energy conversion systems. This review focuses on summarizing the recent progress in the development of bifunctional electrocatalysts for several important electrochemical redox reactions which are critical to implement conversion between electrical energy and chemical energy, especially for bifunctional electrocatalysts applied in a single electrochemical conversion system, including water electrolyzers with the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER), zinc–air batteries with the OER and oxygen reduction reaction (ORR), and fuel cells with small molecule (e.g., glucose, urea, and hydrazine hydrate) oxidation reactions (MOR) and the ORR. Special emphasis has been placed on investigating the progress of electrocatalyst synthesis and strategies for improving the electrocatalytic performance and the associated devices' performance in terms of activity, stability, power density etc. We also put forward the major challenges and prospects in the development of bifunctional electrocatalysts for potential applications in a variety of energy devices.

Fabrication of platinum-deposited carbon nitride nanotubes by a one-step solvothermal treatment strategy and their efficient visible-light photocatalytic activity

Abstract: A series of platinum nanoparticles-deposited carbon nitride nanotubes (Pt/C 3 N 4 NTs) was fabricated by a simple one-step solvothermal treatment strategy using graphite carbon nitride (g-C 3 N 4 ) and chloroplatinic acid (H 2 PtCl 6 ·6H 2 O) as precursors. The morphology, porosity, phase and chemical structure, and optical and electronic properties of Pt/C 3 N 4 NTs were well characterized. Compared with bulk g-C 3 N 4 , the as-prepared Pt/C 3 N 4 NTs exhibited efficient photocatalytic activity toward hydrogen evolution from water-splitting and aqueous p -chlorophenol degradation under visible-light irradiation ( λ > 420 nm) as a result of their unique tubular nanostructure and the synergic effect of Pt nanoparticles. Subsequently, the activities of simultaneous hydrogen evolution with organic pollutant degradation were also tested using as-prepared Pt/C 3 N 4 NTs under the representative organic pollutants p -chlorophenol, p -nitrophenol, methylene blue, or rhodamine B as electron donors. Finally, the photocatalytic mechanisms in three different photocatalytic systems were discussed.

One‐Pot Synthesis, Characterization, and Enhanced Photocatalytic Activity of a BiOBr–Graphene Composite

Abstract: Herein, a chemically bonded BiOBr–graphene composite (BiOBr–RG) was prepared through a facile in situ solvothermal method in the presence of graphene oxide. Graphene oxide could be easily reduced to graphene under solvothermal conditions, and simultaneously BiOBr nanoplates with pure tetragonal phase were grown uniformly on the graphene surface. The structure and photoelectrochemical properties of the resulting materials were characterized by transmission electron microscopy (TEM), X-ray diffraction (XRD), Fourier-transform infrared (FTIR) spectroscopy, Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), and impedance and photocurrent action measurements. The combination of BiOBr and graphene introduces some properties of graphene into the photocatalysis reaction, such as excellent conductivity, adsorptivity, and controllability. A remarkable threefold enhancement in the degradation of rhodamine B (RhB) was observed with as-prepared BiOBr–RG as compared with pure BiOBr under visible light (λ>420 nm). The enhanced photocatalytic activity could be attributed to the great adsorptivity of dyes, the extended photoresponse range, the negative shift in the Fermi level of BiOBr–RG, and the high migration efficiency of photoinduced electrons, which may effectively suppress the charge recombination.

Synthesis and characterizations of metal-free Semiconductor/MOFs with good stability and high photocatalytic activity for H 2 evolution: A novel Z-Scheme heterostructured photocatalyst formed by covalent bonds

Abstract: To solve serious energy and environmental crises caused by rapid industrial development, the formation of Z-scheme heterostructured photocatalysts is a promising approach for efficient and scalable H2 production from water splitting due to wide absorption range, high charge-separation efficiency and strong redox ability of the Z-scheme heterostructured photocatalysts. In this study, we combined the MOFs of NH2-MIL-125(Ti) with g-C3N4 functionalized by benzoic acid (CFB) to synthesize a novel composite catalyst of CFB/NH2-MIL-125(Ti) (CFBM) by covalent bonds for the first time. The benzoic acid in the CFBM acts as electron mediator to well separate photogenerated electrons and holes, leading to excellent photocatalytic performance of photocatalytic hydrogen generation from water splitting under visible light irradiation. Experimental results show that the H2 production rate of the 10CFBM is 1.123 mmol·h−1·g−1, which is about 6 times of the NH2-MIL-125(Ti). Meanwhile, the simple physical mixture of NH2-MIL-125(Ti) with 10 wt% g-C3N4 and the 10wt%g-C3N4/MOFs heterostructured catalyst all show much smaller H2 evolution rate and worse stability than that of the 10CFBM. Finally, we proposed a possible mechanism to well explain the improved photocatalytic performance of the Z-scheme photocatalytic system based on the results of different characterizations. The present work gives a good example to develop a novel Z-scheme heterostructured system with good stability and high photocatalytic activity for H2 evolution and puts forward a new synthetic strategy to prepare metal-free semiconductor/MOFs formed by covalent bonds.