New Findings for the Much‐Promised Hematite Photoanodes with Gradient Doping and Overlayer Elaboration

• DOI: 10.1002/solr.202100701
• Publication Date: 2022-01-22T19:48:06Z
• Authors: Kai-Hang Ye; Peng Hu; Kuiliang Liu; Songtao Tang; Duan Huang; Zhan Lin; Shanqing Zhang; Yongchao Huang; Hongbing Ji; Shihe Yang
• Keywords: Overlayer; Oxygen evolution; Photocurrent; Reversible hydrogen electrode

Herein, it is demonstrated that gradient Ti doping coupled with an overlayer of NiFeO x on hematite can markedly improve the photoelectrochemical (PEC) water‐splitting efficiency hematite‐based photoanodes, which are prized from sustainability considerations but have met daunting challenges. First, has effectively lowered onset potential while maintaining high photo‐generated charge separation and transmission. Second, layer not only substantially reduces surface trap states, also significantly enhances oxygen evolution kinetics photoanodes as catalyst, resulting in a further improvement potential. Consequently, TiO 2 double electrode stack design, remarkable photocurrent density 4.49 mA cm −2 achieved at 1.23 V versus reversible hydrogen (RHE) for /(Grad Ti)‐Fe O 3 /TiO photoanode without any hole scavenger, delivering applied bias photo‐to‐current up to 0.58% 1 RHE. This multipronged attack improving PEC revitalizes great promise sheds light design development next‐generation photoelectrodes.