α-Phase hematite photoelectrodes can split water. This material is nontoxic, inexpensive, and chemically stable; its low energy gap of 2.3 eV absorbs light with wavelengths lower than 550 nm, accounting for approximately 30% of solar energy. Previously, we reported polyhedral pseudocubic α-Fe₂O₃ nanocrystals using a facile hydrothermal route to increase spatial charge separation, enhancing the photocurrent of photocatalytic activity in the water-splitting process. Here, we propose a p-n junction structure in the photoanode of pseudocubic α-Fe₂O₃ to improve short carrier diffusion length, which limits its photocatalytic efficiency. We dope Zn on top of an Fe₂O₃ photoanode to form a layer of p-type semiconductor material; Sn is doped from the FTO substrate to form a layer of n-type semiconductor material. The p-n junction, n-type Fe₂O₃:Sn and p-type Fe₂O₃:Zn, increase light absorption and charge separation caused by the internal electric field in the p-n junction.

α相赤铁矿光电极可以分解水。该材料无毒，便宜且化学稳定。其2.3 eV的低能隙吸收了波长低于550 nm的光，约占太阳能的30％。此前，我们报道多面体仿立方体的α-Fe ₂ ö _3个使用容易的水热路线以增加空间电荷分离纳米晶体，提高光催化活性的光电流在水分解过程。在此，我们提出了一个pn结结构在仿立方体形状的α-Fe的光电阳极₂ ö ₃，以改善短载流子扩散长度，这限制了它的光催化效率。我们在Fe ₂ O ₃上掺杂锌光阳极形成一层p型半导体材料；从FTO衬底掺杂Sn以形成n型半导体材料层。pn结，n型Fe ₂ O ₃：Sn和p型Fe ₂ O ₃：Zn，增加了由于pn结中的内部电场引起的光吸收和电荷分离。