Liu Pengfei, Wang Chongwu, Wang Lijie, Wu Xuefeng, Zheng Lirong, Yang Hua Gui
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.
School of Electrical and Electronic Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore, Singapore 639798.
Research (Wash D C). 2020 Feb 24;2020:5473217. doi: 10.34133/2020/5473217. eCollection 2020.
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 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.
赤铁矿光阳极中电荷分离不足导致的光电化学（PEC）性能不佳，严重限制了其应用。在大区域内进行能带弯曲的梯度掺杂被认为是一种很有前景的策略，由于内置电场，这种策略有助于提高电荷转移能力。在此，我们开发了一种合成策略来制备梯度Ti掺杂的超薄赤铁矿光电极，并系统地研究了其PEC性能。所制备的电极（从表面到基底的掺杂水平为1.5 - 6.0%）在相对于可逆氢电极（RHE）为1.23 V时，光电流约为1.30 mA/cm²，这比均匀掺杂的赤铁矿电极高出近100%。电化学测量进一步证实了由内置电场引起的能带弯曲所导致的电荷转移性能增强。这种梯度掺杂策略应该具有适应性，可应用于各个领域的其他功能材料。
