2015-TiO2LDH--光催化产氧--Advanced_Functional_Materials.pdfVIP

FU LL P A P ER ? 2015 WILEY-VCH Verlag GmbH Co. KGaA, Weinheim 1 electron–hole pairs generated by unfa- vorable band structure greatly limits their practical applications, which is an urgent problem to be solved as well. [ 9–11 ] There- fore, to satisfy the requirements of water splitting, the development of new mate- rials or methodologies to obtain effi cient photocatalysts with advantage of extended light response and an improved electron– hole separation effi ciency remains a tre- mendous challenge. In order to enhance the water split- ting performance, an effective way is to build elaborate hybrid semiconductors with high effi ciency of solar light utili- zation. [ 12–14 ] Recently, research interest on the nanostructured semiconduc- tors is extended to 2D inorganic solids due to their large surface area and high photocatalytic effi ciency. [ 15,16 ] Layered double hydroxides (LDHs) are 2D lay- ered anionic clays generally expressed as [M II 1 -x M III x (OH) 2 ](A n? ) x/n · m H 2 O (M II and M III are divalent and trivalent metals respectively, A n? is inter- layered anion). [ 17–20 ] Owing to their visible-light-response capa- bility and large quantum yield, transition-metal-bearing LDH materials with semiconductor properties have attracted con- siderable attention as visible-light-induced photocatalysts. [ 21–23 ] However, pristine LDHs generally suffer from poor control over particle size, morphology as well as crystalline orientation, which restricts the effi ciency of charge separation and photo- conversion capability. [ 24,25 ] Taking into account the fact that TiO 2 nanocrystal can act as a good acceptor for photogenerated elec- trons, [ 1,5 ] the hybridization of TiO 2 with LDHs would provide an effective way to enhance the charge separation and photo- catalytic effi ciency. In this regard, the resulting heterostructure material would possess the following advantages: (i) prominent full sunlight utilization will be achieved ow