Nanocomposites of graphene-CdS as photoactive and reusable catalysts for visible-light-induced selective reduction process  

作　　者：Siqi Liu Min-Quan Yang Nan Zhang Yi-Jun Xu 

机构地区：[1]State Key Laboratory of Photocatalysis on Energy and Environment,College of Chemistry,Fuzhou University [2]College of Chemistry,New campus,Fuzhou University

出　　处：《Journal of Energy Chemistry》2014年第2期145-155,共11页能源化学（英文版）

基　　金：supported by the National Natural Science Foundation of China(NSFC)(21173045,20903023);the Award Program for Minjiang Scholar Professorship;the Natural Science Foundation(NSF)of Fujian Province for Distinguished Young Investigator(Grant No.2012J06003);the Program for Changjiang Scholars and Innovative Research Team in Universities(PCSIRT0818);the Program for Returned High-Level Overseas Chinese Scholars of Fujian province;the Project Sponsored by the Scientific Research Foundation for the Returned Overseas Chinese Scholars,State Education Ministry

摘　　要：Graphene （GR）-CdS nanocomposites with different weight addition ratios of GR have been assembled by a facile solvothermal treatment. The GR-CdS nanocomposite photocatalyst with an appropriate ratio of GR exhibits enhanced photoactivity for selective reduction of aromatic nitro compounds to the corresponding aromatic amines in water under visible light irradiation as compared with blank-CdS. The characterization of GR-CdS nanocomposite photocatalysts by a collection of techniques discloses that： i） GR can tune the microscopic morphology of CdS nanoparticles and improve light absorption intensity in the visible light region; ii） GR scaffolds act as an electron reservoir to trap and shuttle the electrons photogenerated from CdS semiconductor under the visible light illumination; iii） the introduction of GR enhances the adsorption capacity of GR-CdS nanocomposites toward the substrates, aromatic nitro compounds. The synergistic effect of these factors should account for the photoactivity advancement of GR-CdS nanocomposites toward the probe reactions. Furthermore, because the photogenerated holes in the system are trapped by the quenching agent ammonium oxalate, the as-obtained GR-CdS photocataiyst is stable during the photocatalytic reduction reactions. A reasonable model has also been proposed to illustrate the reaction mechanism.Graphene （GR）-CdS nanocomposites with different weight addition ratios of GR have been assembled by a facile solvothermal treatment. The GR-CdS nanocomposite photocatalyst with an appropriate ratio of GR exhibits enhanced photoactivity for selective reduction of aromatic nitro compounds to the corresponding aromatic amines in water under visible light irradiation as compared with blank-CdS. The characterization of GR-CdS nanocomposite photocatalysts by a collection of techniques discloses that： i） GR can tune the microscopic morphology of CdS nanoparticles and improve light absorption intensity in the visible light region; ii） GR scaffolds act as an electron reservoir to trap and shuttle the electrons photogenerated from CdS semiconductor under the visible light illumination; iii） the introduction of GR enhances the adsorption capacity of GR-CdS nanocomposites toward the substrates, aromatic nitro compounds. The synergistic effect of these factors should account for the photoactivity advancement of GR-CdS nanocomposites toward the probe reactions. Furthermore, because the photogenerated holes in the system are trapped by the quenching agent ammonium oxalate, the as-obtained GR-CdS photocataiyst is stable during the photocatalytic reduction reactions. A reasonable model has also been proposed to illustrate the reaction mechanism.

关 键 词：graphene CDS photocatalytic selective reduction nitro compounds visible light water 

分 类 号：O643.32[理学—物理化学]