Impact of surface hydroxylation in MgO-/SnO-nanocluster modified TiO_2 anatase(101) composites on visible light absorption, charge separation and reducibility

作     者：Stephen Rhatigan Michael Nolan 

作者机构：Tyndall National Institute University College Cork 

出 版 物：《Chinese Chemical Letters》 (中国化学快报（英文版）)

年 卷 期：2018年第29卷第6期

页      面：757-764页

核心收录：

学科分类：081705[工学-工业催化] 07[理学] 08[工学] 0817[工学-化学工程与技术] 070205[理学-凝聚态物理] 080501[工学-材料物理与化学] 0805[工学-材料科学与工程（可授工学、理学学位）] 0703[理学-化学] 0702[理学-物理学] 

基　　金：support from Science Foundation Ireland through the US-Ireland R&D Partnership Program (No. SFI 14/US/ E2915) the European Commission through COST Action CM1104 "Reducible Metal Oxides, Structure and Function" funded by SFI by the SFI and Higher Education Authority funded Irish Centre for High End Computing 

主　　题：Photocatalyst Titania Visible-light absorption Surface modification Charge separation Surface hydroxylation Oxygen vacancy formation 

摘      要：Surface modification with metal oxide nanoclusters has emerged as a candidate for the enhancement of the photocatalytic activity of titanium dioxide. An increase in visible light absorption and the suppression of charge carrier recombination are necessary to improve the efficiency. We have studied Mg4O4 and Sn4O4 nanoclusters modifying the（101） surface of anatase TiO2 using density functional theory corrected for on-site Coulomb interactions（DFT ＋ U）. Such studies typically focus on the pristine surface, free of the point defects and surface hydroxyls present in real surfaces. We have also examined the impact of partial hydroxylation of the anatase surface on a variety of outcomes such as nanocluster adsorption, light absorption, charge separation and reducibility. Our results indicate that the modifiers adsorb strongly at the surface, irrespective of the presence of hydroxyl groups, and that modification extends light absorption into the visible range while enhancing UV activity. Our model for the excited state of the heterostructures demonstrates that photoexcited electrons and holes are separated onto the TiO2 surface and metal oxide nanocluster respectively. Comparisons with bare TiO2 and other TiO2-based photocatalyst materials are presented throughout.