Ultrathin Hematite Photoanode with Gradient Ti Doping

Pengfei Liu; Chongwu Wang; Lijie Wang; Xuefeng Wu; Lirong Zheng; Hua Gui Yang

doi:10.34133/2020/5473217

Ultrathin Hematite Photoanode with Gradient Ti Doping

Research (Wash D C). 2020 Feb 24:2020:5473217. doi: 10.34133/2020/5473217. eCollection 2020.

Authors

Pengfei Liu¹, Chongwu Wang², Lijie Wang¹, Xuefeng Wu¹, Lirong Zheng³, Hua Gui Yang¹

Affiliations

¹ Key Laboratory for Ultrafine Materials of Ministry of Education, Shanghai Engineering Research Center of Hierarchical Nanomaterials, School of Materials Science and Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai 200237, China.
² School of Electrical and Electronic Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore, Singapore 639798.
³ Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China.

Abstract

The poor photoelectrochemical (PEC) performance derived from insufficient charge separation in hematite photoanode crucially limits its application. Gradient doping with band bending in a large region is then considered as a promising strategy, facilitating the charge transfer ability due to the built-in electric field. Herein, we developed a synthetic strategy to prepare gradient Ti-doped ultrathin hematite photoelectrode and systematically investigated its PEC performance. The as-synthesized electrode (1.5-6.0% doping level from the surface to the substrate) delivered a photocurrent of about 1.30 mA cm^-2 at 1.23 V versus the reversible hydrogen electrode (RHE), which is nearly 100% higher than that of homogeneously doped hematite electrode. The enhanced charge transfer property, induced by the energy band bending due to the built-in electric field, has been further confirmed by electrochemical measurements. This strategy of gradient doping should be adaptable and can be applied for other functional materials in various fields.