Theoretical and Experimental Study on MIIMIII-Layered Double Hydroxides as Efficient Photocatalysts toward Oxygen Evolution from Water

• DOI: 10.1021/acs.jpcc.5b01819
• Publication Date: 2015-08-03T15:36:15Z
• Authors: Si-Min Xu; Ting Pan; Yi-Bo Dou; Hong Yan; Shi-Tong Zhang; Fan-Yu Ning; Wen-Ying Shi; Min Wei
• Keywords: Layered double hydroxides; Oxygen evolution

Recently, layered double hydroxides (LDHs) have attracted extensive attention in the field of energy storage and conversion, an in-depth understanding their semiconducting properties is rather limited. In this work, electronic (band structure, density states (DOS), band edge placement) MIIMIII-LDHs (MII = Mg, Co, Ni Zn; MIII Al Ga) were studied detail. The thermodynamic mechanism toward oxygen evolution reaction (OER) was investigated by using functional theory plus U (DFT + U) method. calculation results structure indicate that Mg Zn-based LDHs gap energies larger than 3.1 eV) are ultraviolet responsive, while Co Ni-based responsive to visible light less eV). DOS calculations reveal photogenerated hole localizes on surface hydroxyl group LDHs, facilitating oxidization a water molecule without long transportation route. placements show NiGa-, CoAl-, ZnAl-, NiAl-LDHs driving force (0.965 eV, 0.836 0.667 0.426 respectively) evolution. However, these four only CoAl-LDH can overcome barrier (0.653 via (0.836 Experimental observations MgAl-, ZnAl-LDHs further prove efficient photocatalyst (O2 generation rate: 973 μmol h–1 g–1), agreeing well with theoretical prediction. Therefore, work provides effective experimental combined method for screening possible photocatalysts, which be extended other semiconductor materials addition LDHs.