黄铜基底上铜/锌复合氧化物薄膜的制备及光电化学性能研究

Preparation of copper/zinc composite oxide film on brass and study on its photoelectrochemical properties

通过草酸腐蚀和热氧化在α-黄铜基底上制备出铜/锌复合氧化物薄膜,探究了草酸质量分数(0.1%~15.0%)和加入少量(0.1%~5.0%)乙酸对复合氧化膜光电化学性能的影响。利用扫描电镜、X射线衍射、透射电镜、X射线光电子能谱等手段分析了复合薄膜的形貌、结构和表面化学特性。在0.1 mol/L Na_2SO_4电解液中测试了复合薄膜在零偏压下的可见光光电流响应。结果表明,经60°C的10.0%草酸腐蚀及300°C热氧化可制备出光电化学性能较好的氧化物薄膜,零偏压下的阴极光电流密度为19μA/cm^2。氧化膜中有纳米片和微米颗粒两种组织结构。10.0%草酸+1.0%乙酸的溶液腐蚀后热氧化制备的样品中由于微米颗粒的裂解而增大了氧化膜的比表面积,因此在零偏压下的阴极光电流密度增大到42μA/cm^2。

Cu/Zn composite oxide thin films were prepared by thermal oxidation on α-brass substrates etched in oxalic acid solution. The effects of the mass fraction of oxalic acid（0.1-15.0 wt.%） and the addition of a small amount（0.1-5.0 wt.%） of acetic acid on the photoelectrochemical performance of the composite film were studied. The morphology, microstructure, and surface chemical characteristics of the oxide films were analyzed by scanning electron microscopy, X-ray diffraction, transmission electron microscopy, and X-ray photoelectron spectroscopy. The photocurrent responses of the oxide films at zero bias under visible light irradiation were tested in 0.1 mol/L Na2 SO4 electrolyte. The results showed that the oxide film prepared by etching in 10.0 wt.% oxalic acid solution at 60 °C followed by thermal oxidation at 300 °C produces a cathodic photocurrent density of 19 μA/cm-2 at zero bias, showing good photoelectrochemical performance. The oxide films are composed of nanosheets and microparticles. The cathodic photocurrent density on the oxide film prepared by etching in a solution comprising oxalic acid 10.0 wt.% and acetic acid 1.0 wt.% was increased to 42 μA/cm-2, which could be attributed to the increase in specific surface area of the oxide film caused by the cracking of microparticles.