核壳结构α-Fe2O3@Zn2SnO4的水热法制备及光电性能

α-Fe₂O₃ (带隙2.2 eV) 和Zn₂SnO₄ (带隙3.6 eV)两者都是廉价的光电材料, 然而前者光生载流子复合效率较高, 后者只有在紫外光区有光电响应. 本文采用水热法制备了核壳结构的α-Fe₂O₃@Zn₂SnO₄复合材料, 利用X射线衍射(XRD)、场发射电子扫描电子显微镜(FESEM)、X射线光电子能谱(XPS)、紫外可见吸收光谱(UV-vis)及表面光电压谱(SPS)等分析手段进行材料结构、形貌和性能表征. 结果表明, 该核壳结构复合材料的光电响应比单一组分光电响应的强度和范围都有明显的改善. 该复合材料光电响应的改善, 与水热法制备的α-Fe₂O₃@Zn₂SnO₄核壳结构有关. α-Fe₂O₃与Zn₂SnO₄复合后Fe_2p的结合能变化明显, 这可能有利于光生载流子分离.

Hydrothermal synthesis and photoelectric property of core-shell α-Fe2O3@Zn2SnO4

Both α-Fe₂O₃ (E_g=2.2 eV) and Zn₂SnO₄ (E_g=3.6 eV) are cheap materials but have weak photoelectric responses. Core-shell α-Fe₂O₃@Zn₂SnO₄ composites were synthesized hydrothermally to overcome this limitation. X-ray diffraction, field emission scanning electron microscopy, X-ray photoelectron spectroscopy, and UV-vis absorption and surface photovoltage spectroscopy were used to measure and characterize the crystal phase, morphology, and photoelectric properties of the samples. The photoelectric response of the α-Fe₂O₃@Zn₂SnO₄ composites was superior to those of α-Fe₂O₃ and Zn₂SnO₄. In α-Fe₂O₃@Zn₂SnO₄ composites the binding energy of the Fe_2P orbitals differs from α-Fe₂O₃, and the core-shell structure favors the separation of photoinduced carriers.