Surface polarization enables high charge separation in TiO_(2) nanorod photoanode  

作　　者：Wei Ma Keke Huang Xiaofeng Wu Meng Wang Shouhua Feng 

机构地区：[1]State Key Laboratory of Inorganic Synthesis and Preparative Chemistry,NMAC International Joint Laboratory,College of Chemistry,Jilin University,Changchun,130012,China

出　　处：《Nano Research》2021年第11期4056-4062,共7页纳米研究（英文版）

基　　金：The work was supported by the National Natural Science Foundation of China(Nos.21801090,21831003,21671076,and 21621001).

摘　　要：Poor charge separation efficiency of semiconductors often stands in the way of photoelectrochemical (PEC) water splitting realization. In this report, a surface polarized TiO_(2) photoanode is obtained via −OH moiety decoration, which achieves a fundamentally improved charge separation efficiency of about 94% at 1.23 VRHE. Detailed data shows that these hydroxyls with electric dipoles polarize the surface, inducing substantial electric field in the surface region, and elevating band edges so as to form a homojunction within TiO_(2). Such serves as the direct driving force for the photogenerated charge separation and migration. Moreover, these hydroxyls also facilitate water oxidation kinetics. Without typical doping or cocatalyst, surface polarized TiO_(2) photoanode delivers a considerably increased photocurrent density of about 1.41 mA·cm^(−2) at 1.23 VRHE (AM 1.5 G) and a cathodic shift on onset potential over 200 mV. This report highlights new opportunities to modulate charge separation by surface polarization for the construction of robust photoanodes.

关 键 词：TiO_(2)nanorod HYDROXYLS surface polarization charge separation photoelectrochemical water splitting 

分 类 号：O62[理学—有机化学]