论文部分内容阅读
采用便捷的涉及电沉积和退火过程的两步法在F掺杂的氧化锡基体上制备了高品质的多晶钒酸铋(BiVO_4)薄膜,并运用扫描电镜、透射电镜、X射线衍射(XRD)、傅里叶变换红外光谱、紫外-可见光吸收光谱和拉曼光谱表征了所制薄膜的形貌和结构特征.XRD和光学分析结果表明,BiVO_4薄膜为纯相的单斜白钨矿晶相结构.将该薄膜通过电化学(EC),光化学(PC)和光电化学(PEC)过程用于水溶液中氯酸离子的多相氧化反应中.采用紫外-可见吸附光谱仪监测氯酸盐浓度的降低.结果发现,在光的照射下采用PEC法时,BiVO_4可有效催化氯酸盐的氧化.氯酸盐氧化反应级数为1级,PEC过程的反应速率常数明显高于EC和PC过程的.同时,提出了基于形成了高氯酸离子的催化氧化氯酸盐的反应机理.
High quality polycrystalline bismuth vanadate (BiVO 4) thin films were prepared on the F-doped tin oxide substrate by a convenient two-step method involving electrodeposition and annealing. The films were characterized by scanning electron microscopy, transmission electron microscopy, X-ray diffraction ), Fourier transform infrared spectroscopy (FTIR), UV-Vis absorption spectroscopy and Raman spectroscopy.The XRD and optical analysis results show that the BiVO 4 thin film is pure monoclinic scheelite crystal phase The films were used in the heterogeneous oxidation of chlorate ions in aqueous solution by electrochemical (EC), photochemical (PC) and photoelectrochemical (PEC) processes.The reduction of chlorate concentration was monitored by UV-Vis absorption spectroscopy The results showed that BiVO_4 could effectively catalyze the oxidation of chlorate when PEC was applied under light irradiation.The chlorate oxidation reaction was order 1 and the reaction rate constant of PEC was obviously higher than that of EC and PC. At the same time, a reaction mechanism based on the formation of perchlorate ion catalyzed perchlorate has been proposed.