Hematite (α-Fe₂O₃) is a very attractive photoanode material for photoelectrochemical (PEC) water oxidation application due to its remarkable chemical stability and appropriate bandgap. However, the low charge separation efficiency, poor conductivity, and sluggish water oxidation kinetics still severely limit its expected performance. In this study, we constructed a photo-electrodeposited amorphous nickel-borate (Ni-B_i) thin layer on Ti-doped α-Fe₂O₃ photoanode. The fabricated heterostructure photoanode developed a built-in electric field, which will accelerate charge transport and improve the water oxidation kinetics significantly, resulting in the greatly enhanced photocurrent density of about 348% at 1.23 V vs. reversible hydrogen electrode (RHE) and the improvement of onset potential advance of ~ 80 mV. The surface morphology of samples was characterized with field-emission scanning electron microscope (FE-SEM) and high-resolution transmission electron microscope (HRTEM). The Mott–Schottky (M-S) and electrochemical impedance spectroscopy (EIS) results confirmed the donor density and the conductivity of photoanodes with Ti-doping and Ni-B_i coated. This work provides a novel strategy to develop various heterojunction photoanodes for practical PEC application of α-Fe₂O₃.

赤铁矿（α-的Fe ₂ ö ₃）是用于光电化学（PEC）水氧化应用非常有吸引力的光电阳极材料由于其显着的化学稳定性和适当的带隙。但是，低的电荷分离效率，较差的电导率和缓慢的水氧化动力学仍然严重限制了其预期性能。在这项研究中，我们构建了光电沉积非晶态镍硼酸盐（镍-B_我）在薄层的Ti掺杂的α-Fe ₂ ö ₃光电阳极。所制造的异质结构光阳极产生了一个内置电场，该电场将加速电荷传输并显着改善水的氧化动力学，从而导致与可逆氢电极（RHE）相比，在1.23 V时光电流密度大大提高了约348％，并且得到了改进发病电位提前约80 mV。用场发射扫描电子显微镜（FE-SEM）和高分辨率透射电子显微镜（HRTEM）对样品的表面形貌进行表征。Mott–Schottky（MS）和电化学阻抗谱（EIS）结果证实了掺杂Ti和Ni-B _i的光阳极的施主密度和电导率涂层的。这项工作提供了开发各种异质结光电阳极为的α-Fe的实际应用PEC的新策略₂ ö ₃。