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采用一步式阶跃电压加压方法,在NH4F/(NH4)2SO4电解质溶液中对W片进行阳极氧化处理制备了WO3多孔薄膜,通过后续热处理温度的控制,制备了性能规律性变化的WO3多孔纳米薄膜材料.用场发射扫描电镜(FE-SEM)、X射线衍射(XRD)分析等手段考察了热处理温度对氧化钨晶体结构和形貌影响的规律,在450°C以下的煅烧温度下,薄膜保持50-100nm孔径;通过对光电化学性质、光催化降解甲基橙动力学行为的研究,考察了不同热处理温度对WO3多孔薄膜光电转换性能影响的规律.研究表明,450°C煅烧处理后的WO3薄膜在500W氙灯光源照射及1.2V偏压下,光电流密度达到5.11mA·cm-2;340及400nm单色光辐射下光电转换效率(IPCE)值分别达到87.4%及22.1%.电化学交流阻抗谱显示,450°C煅烧处理后的WO3薄膜表现出最佳的导电率及最小的界面电荷转移电阻.实验结果证明,高结晶度的多孔结构是WO3薄膜具有高光电转换效率的主要因素,控制热处理温度是实现薄膜具有高孔隙率、完整结晶度、低电阻的重要手段.
The WO3 porous film was prepared by anodic oxidation of NH4F / (NH4) 2SO4 electrolyte solution by a one-step step voltage pressurization method. WO3 porous nanocrystals with varying regularity of properties were prepared by the subsequent heat treatment temperature control The influence of heat treatment temperature on the crystal structure and morphology of tungsten oxide was investigated by means of field emission scanning electron microscope (FE-SEM) and X-ray diffraction (XRD). The film was maintained at a calcination temperature below 450 ° C 50-100nm pore size.The photocatalytic degradation of methyl orange by the photoelectrochemical properties and photocatalytic degradation of WO3 porous film was investigated.The results show that the WO3 The photocurrent density reached 5.11mA · cm-2 under 500W xenon lamp illumination and 1.2V bias voltage, and reached 87.4% and 22.1% respectively at 340 and 400nm monochromatic light irradiation.The electrochemical AC The impedance spectra showed that the WO3 films calcined at 450 ° C showed the best conductivity and the lowest interfacial charge transfer resistance.The experimental results show that the porous structure with high crystallinity is a kind of WO3 thin film with high photoelectric conversion The main factor for efficiency, the control of heat treatment temperature is to achieve a film with high porosity, complete crystallinity, low resistance, an important means.