超薄SnO_2修饰Cu_2O多孔薄膜的可见光光电化学性能

Visible-light photoelectrochemical performance of porous Cu_2O thin film modified by ultrathin SnO_2 layer

在FTO(即掺杂氟的Sn O2透明导电玻璃)基底上采用两步恒流电沉积,得到厚度约500 nm的金属Cu薄膜,然后置于Sn O2溶胶中浸渍并经175°C加热氧化,制得由超薄Sn O2修饰的Cu2O多孔薄膜。利用X射线衍射(XRD)、拉曼光谱、扫描电镜(SEM)和漫反射–紫外可见光谱(UV-Vis DRS)表征了试样的结构、形貌及光学性质。通过在0.2 mol/L Na2SO4溶液中测试样品在可见光和零偏压下的光电流,分析了薄膜的光电化学性能。结果表明,超薄的Sn O2修饰层能显著增强Cu2O多孔薄膜的光电化学性能。在Sn O2溶胶中浸渍10 s所制备的超薄Sn O2修饰Cu2O多孔薄膜,其光电流密度是Cu2O未修饰薄膜的4倍。

A ca.500 nm-thick metallic Cu thin film was obtained on the surface of FTO （F-doped SnO2 transparent conductive glass） substrate by two-step galvanostatic electrodeposition, and then dipped in a SnO2 sol followed by oxidation at 175 °C to prepare a porous Cu2O thin film modified by ultrathin SnO2 layer. The structure, morphology, and optical property of the ultrathin SnO2-modified porous Cu2O thin film were characterized by X-ray diffraction （XRD）, Raman spectroscopy, scanning electron microscopy （SEM）, and diffuse reflection ultraviolet–visible spectroscopy （UV-Vis DRS）, and the photoelectro- chemical property of the thin film was analyzed via testing the photocurrent in 0.2 mol/L Na2SO4 solution under visible light and at zero bias. The results revealed that the ultrathin SnO2 layer greatly enhances the photoelectrochemical performance of the porous Cu2O thin film. The photocurrent density of the ultrathin SnO2-modified porous Cu2O thin film prepared by dipping in the SnO2 sol for 10 s is four times that of the unmodified one.