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.

Simultaneous photoreduction of Uranium(VI) and photooxidation of Arsenic(III) in aqueous solution over g-C 3 N 4 /TiO 2 heterostructured catalysts under simulated sunlight irradiation

Abstract: In the present work, the hererostructured catalysts of g-C3N4/TiO2 were synthesized and well characterized by XRD, SEM, TEM, Raman, UV–vis diffuse reflectance spectra, PL, Mott-Schottky, and XPS. Simultaneous photoreduction of Uranium(VI) and photooxidation of Arsenic(III) was firstly achieved over the g-C3N4/TiO2 catalysts. And the experimental results show that the removal rate of U(VI) decreases with the increase of As(III) concentration, whereas the photooxidation rate of As(III) to As(V) increases with the increase of As(III) concentration. Noteworthily, the photoreduction of U(VI) to U(IV) and photooxidation of As(III) to As(V) was confirmed by XPS analysis in time-scale. The experimental results of free radical capture and quantitative test indicate that holes, hydroxyl radical and superoxide radical are the major active species for photooxidation of As(III), while U(VI) was reduced to U(IV) by the photogenerated electrons. Furthermore, a possible mechanism was proposed to well explain the improved photocatalytic performance of the g-C3N4/TiO2 and the competitive relationship between photoreduction of U(VI) and photooxidation of As(III). The present work develops a heterostructured catalyst for potential application to the simultaneous removal of U(VI) and As(III), and makes clear the effect of photooxidation of As(III) on photoreduction of U(VI) for the first time.

Silver Single Atom in Carbon Nitride Catalyst for Highly Efficient Photocatalytic Hydrogen Evolution.

Abstract: Single atom catalysts (SACs) with the maximized metal atom efficiency have sparked great attention. However, it is challenging to obtain SACs with high metal loading, high catalytic activity, and good stability. Herein, we demonstrate a new strategy to develop a highly active and stable Ag single atom in carbon nitride (Ag-N2 C2 /CN) catalyst with a unique coordination. The Ag atomic dispersion and Ag-N2 C2 configuration have been identified by aberration-correction high-angle-annular-dark-field scanning transmission electron microscopy (AC-HAADF-STEM) and extended X-ray absorption. Experiments and DFT calculations further verify that Ag-N2 C2 can reduce the H2 evolution barrier, expand the light absorption range, and improve the charge transfer of CN. As a result, the Ag-N2 C2 /CN catalyst exhibits much better H2 evolution activity than the N-coordinated Ag single atom in CN (Ag-N4 /CN), and is even superior to the Pt nanoparticle-loaded CN (PtNP /CN). This work provides a new idea for the design and synthesis of SACs with novel configurations and excellent catalytic activity and durability.

Removal of Antimonite (Sb(III)) and Antimonate (Sb(V)) from Aqueous Solution Using Carbon Nanofibers That Are Decorated with Zirconium Oxide (ZrO2)

Abstract: Zirconium oxide (ZrO2)-carbon nanofibers (ZCN) were fabricated and batch experiments were used to determine antimonite (Sb(III)) and antimonate (Sb(V)) adsorption isotherms and kinetics. ZCN have a maximum Sb(III) and Sb(V) adsorption capacity of 70.83 and 57.17 mg/g, respectively. The adsorption process between ZCN and Sb was identified to be an exothermic and follows an ion-exchange reaction. The application of ZCN was demonstrated using tap water spiked with Sb (200 μg/L). We found that the concentration of Sb was well below the maximum contaminant level for drinking water with ZCN dosages of 2 g/L. X-ray photoelectron spectroscopy (XPS) revealed that an ionic bond of Zr-O was formed with Sb(III) and Sb(V). Based on the density functional theory (DFT) calculations, Sb(III) formed Sb-O and O-Zr bonds on the surface of the tetragonal ZrO2 (t-ZrO2) (111) plane and monoclinic ZrO2 planes (m-ZrO2) (111) plane when it adsorbs. Only an O-Zr bond was formed on the surface of t-ZrO2 (111) plane and m-ZrO2 (111) plane for Sb(V) adsorption. The adsorption energy (Ead) of Sb(III) and Sb(V) onto t-ZrO2 (111) plane were 1.13 and 6.07 eV, which were higher than that of m-ZrO2 (0.76 and 3.35 eV, respectively).