锰氧化物膜对光电解水n型硅阳极保护作用的研究

STUDIES ON PROTECTING n-Si ANODE FROM PHTOCORROSION BY COATED WITH THIN FILM OF Mn-OXIDE

利用化学沉积法,在单晶n—Si上沉积锰的氧化物膜作为保护膜,阻止了n—Si光阳极的光腐蚀。研究了脱水烧结温度对光电流起始电位的影响,分析了膜的组成和Mn的存在形式,测定了电极在碱性溶液中的光伏安特性曲线及光谱响应曲线,测量了电极在不同频率下的交流阻抗谱图,Mott—Schottky关系线性良好并推得电极的平带电位,该电极在100mw照度,0.5m KOH溶液中,连续光照110小时,稳定性良好。

Thin film of Mn-oxide was deposited on n-Si electrode by chemical deposition method, which can protect the electrode from photocorrosion. The influence of heating temperature to the onset potential was studied. The consist and the valence of Mn in the thin film was analysed and the photopolarization and wavelength response of the electrode were measured in alkali solution. Impedance were also measured at various frequencies. The Mott-Schottky plot shows a good linearity and then flat-band potential of the electrode was obtained. This electrode continuous operated for 110 hours and showed good stability under the condition of 100mw illuminance in 0.5m/L KOH solution.