n-型多孔Si/TiO2纳米线异质结构的制备及光电化学性能

采用光辅助电化学腐蚀法制备了n-型多孔硅衬底, 再采用水热法在其表面生长TiO₂纳米线制得了三维n-型多孔Si/TiO₂纳米线异质结构. 通过X射线衍射、 扫描电子显微镜和X射线能量散射等表征证实了n-型多孔Si/TiO₂纳米线异质结构的形成. 紫外-可见漫反射光谱测试结果表明, n-型多孔硅与TiO₂纳米线的复合提高了紫外-可见波段的光吸收. 光电性能测试结果表明, 3个样品中n-型多孔Si/TiO₂纳米线异质结作为光电极的光电流最高, 这说明n-型多孔Si/TiO₂纳米线作为光电极具有更高的光电化学分解水性能.

Preparation and Photoelectrochemical Properties of n-Type Macroporous Si/TiO2 Nanowire Heterostructure†

n-Type macroporous silicon as substrate material was prepared by photo-assisted electrochemical etching. The TiO₂ nanowire cover layer on macroporous silicon was prepared by hydrothermal method. Thus, n-type macroporous Si/TiO₂ nanowire heterostructure was obtained. The formation of n-type macroporous Si/TiO₂ nanowire heterostructure was confirmed by X-ray diffraction(XRD), scanning electron microscope(SEM), energy dispersive X-ray detector(EDX). The UV-Vis diffusion reflectance spectra showed that n-type macroporous Si/TiO₂ nanowire heterostructure had the strongest absorption among the four tested samples. The photoelectric performance tests showed that n-type macroporous Si/TiO₂ nanowire heterostructure had higher photocurrent than the n-type macroporous Si and the n-type Si/TiO₂ nanowire. The results showed that n-type macroporous Si/TiO₂ nanowire heterostructure as photoanode improved the performance of photoelectrochemical water splitting.