Ti, Zn co-doped hematite photoanode for solar driven photoelectrochemical water oxidation  

作　　者：Quansong Zhu Chunlin Yu Xingwang Zhang 

机构地区：[1]Key Laboratory of Biomass Chemical Engineering of Ministry of Education, College of Chemical and Biological Engineering, Zhejiang University,Hangzhou310027, Zhejiang, China [2]College of Environmental and Resource Sciences, Zhejiang University,Hangzhou 310027, Zhejiang, China

出　　处：《Journal of Energy Chemistry》2019年第8期30-36,I0002,共8页能源化学（英文版）

基　　金：supported by Major Science and Technology Project of Water Pollution Control and Management(No.2017ZX07101003);Zhejiang Provincial Natural Science Foundation of China under Grant no.LR17B060003;financially supported by the Natural Science Foundation of China(Project Nos.21436007,21522606,21476201,21676246,U1462201,and 21776248)

摘　　要：Although there have been many reports of metal doping to ameliorate the drawbacks of hematite as the photoanode for water oxidation, most of them focused on monometallic doping, and only a few of them payed attention to bimetallic doping. What is worse, the synergetic mechanism between two metal dopants was not sufficiently studied, especially the density functional theory(DFT) calculation. In this work, the n-type hematite was synthesized by introducing Ti dopant into hematite through the hydrothermal method, and dipping-sintering treatment was employed to further introduce homogeneously dispersed Zn dopant into that, forming the Ti, Zn co-doped hematite. Under the optimal condition, Tidoped hematite photoanode reached approximately 2-times enhancement of the photocurrent density compared with the pristine one at 1.23 V vs. RHE, while Ti, Zn co-doped hematite anode obtained another25% elevation. UV–Vis spectroscopy, Mott–Schottky plots, EIS analysis, photo-oxidation of hole scavenger(H2O2), and DFT calculation were employed to understand the role of Ti, Zn dopant. Based on the obtained results, the synergetic mechanism of two dopants was discussed, i.e., the improvement of PEC performance of Ti, Zn co-doped hematite photoanode was possibly attributed to greater carrier density and improved charge separation efficiency at the surface of hematite. This work provides new strategy and understanding of the improvement of PEC performance of hematite by doping engineering.Although there have been many reports of metal doping to ameliorate the drawbacks of hematite as the photoanode for water oxidation, most of them focused on monometallic doping, and only a few of them payed attention to bimetallic doping. What is worse, the synergetic mechanism between two metal dopants was not sufficiently studied, especially the density functional theory（DFT） calculation. In this work, the n-type hematite was synthesized by introducing Ti dopant into hematite through the hydrothermal method, and dipping-sintering treatment was employed to further introduce homogeneously dispersed Zn dopant into that, forming the Ti, Zn co-doped hematite. Under the optimal condition, Tidoped hematite photoanode reached approximately 2-times enhancement of the photocurrent density compared with the pristine one at 1.23 V vs. RHE, while Ti, Zn co-doped hematite anode obtained another25% elevation. UV–Vis spectroscopy, Mott–Schottky plots, EIS analysis, photo-oxidation of hole scavenger（H2O2）, and DFT calculation were employed to understand the role of Ti, Zn dopant. Based on the obtained results, the synergetic mechanism of two dopants was discussed, i.e., the improvement of PEC performance of Ti, Zn co-doped hematite photoanode was possibly attributed to greater carrier density and improved charge separation efficiency at the surface of hematite. This work provides new strategy and understanding of the improvement of PEC performance of hematite by doping engineering.

关 键 词：PHOTOELECTROCHEMICAL water oxidation HEMATITE TI ZN CO-DOPING DFT calculation 

分 类 号：O4[理学—物理]