高可见光响应型单斜介孔BiVO_4的合成与表征

Synthesis and Characterization of Highly Visible-light Active Monoclinic Mesoporous BiVO_4

利用纳米铸造法,以立方有序介孔分子筛MCM-48为硬模板,550℃成功制备了结晶良好的纯相单斜介孔BiVO4.采用XRD、TEM、BET及UV-Vis光谱分析对样品的结构进行了表征,结果表明:与水热法制备的大颗粒样品相比,"纳米铸造"介孔BiVO4的平均孔径为16.8nm,孔体积为0.1 cm2/g,比表面积高达22.9 m2/g,有效减少了光生电子和空穴复合的几率,在可见光范围内表现出优良的可见光催化活性,90min内对乙基黄原酸钾的光催化降解率高达78%.

Ordered nanocrystalline mesoporous BiVO4 with pure phase was successfully synthesized at 550℃ via nanocasting using cubic MCM-48 molecular sieves as hard template.The long-range ordered mesostructure was characterized by XRD,TEM,BET as well as UV-Vis spectrophotometer.Compared with the BiVO4 synthesized by conventional hydrothermal method,the nanocasting mesoporous BiVO4 has the average pore diameter of 16.8nm,pore volume of 0.1 cm3/g and specific surface area up to 22.9 m2/g.The structure decreases the recombination of optical excitation electrons and holes efficiently,so the mesoporous BiVO4 has an excellent photocatalytic activity in the visible light region.As a result,the photocatalytic efficiency of mesoporous BiVO4 for xanthate in 90min reaches 78%.