Preparation of WO3/ZnO Composite Photocatalyst and Its Photocatalytic Performance

A series of WO3/ZnO composite photocatalysts with different WO3 concentrations were prepared by a precipitation-grinding method followed by calcination at different temperatures. The prepared samples were characterized by N2 physical adsorption, X-ray diffraction, scanning electron microscopy, Fourier transform infrared spectroscopy, UV-visible spectroscopy, and photoluminescence spectroscopy. The photocatalytic activity of the samples was evaluated by photocatalytic degradation of acid orange II under UV light (λ = 365 nm) irradiation. The results showed that at the optimal calcination temperature of 600 °C, the WO3/ZnO composite photocatalyst with 2 wt% concentration of WO3 showed about doubled photocatalytic activity compared to pure ZnO. The increase in the photocatalytic activity could be attributed to the coupling of WO3, which suppressed the growth of ZnO particles, increase of the surface area and increased amount of surface OH groups of the sample. The presence of WO3 also restrained the recombination rate of e−/h+ pairs.

摘要：采用沉淀-研磨法制备了一系列不同 WO3 含量的 WO3/ZnO 复合光催化剂, 应用 N2 物理吸附、X 射线衍射、扫描电镜、傅里叶变换红外光谱、紫外-可见光谱和光致发光谱等手段对催化剂进行了表征, 并以 λ = 365 nm 的紫外光为光源, 评价了该催化剂光催化降解酸性橙 II 的活性, 考察了 WO3 的复合对 WO3/ZnO 样品光催化性能的影响. 结果表明, 当复合 2%WO3, 并于 600 °C 焙烧时, 所制备的 WO3/ZnO 催化剂活性最高, 比纯 ZnO 的提高了约一倍. 合适的煅烧温度可以提高催化剂结晶度, 而 WO3 的复合可抑制 ZnO 晶粒的长大, 提高催化剂比表面积和改善催化剂表面羟基数量, 并可抑制光生电子与光生空穴的复合, 从而显著提高其光催化脱色活性.

The addition of WO3 to ZnO can effectively separate its photo generated e−/h+ pairs to increase its photocatalytic activity.Figure optionsDownload as PowerPoint slide