花状Pt/Bi2WO6微米晶合成、表征及其高可见光催化性能

利用水热-光化学沉积法合成了一系列粒径为1.5~2μm的花状Pt/Bi2WO6微米晶.采用X射线衍射仪（XRD）、N2物理吸附、扫描电子显微镜（SEM）、透射电子显微镜（TEM）、紫外可见漫反射光谱（DRS）、X射线光电子能谱（XPS）和傅里叶变换红外光谱（FT-IR）等手段进行表征.在可见光照射下（λ＞420 nm），进行了光催化降解染料酸性橙Ⅱ的性能测试.表征和测试结果表明，这些多尺度花状Pt/Bi2WO6复合微米晶，在水溶液中进行光催化降解反应具有优越的性能.此外，沉积1%的Pt 纳米粒子可使光催化活性显著提高，为Bi2WO6的2.8倍.沉积的Pt纳米粒子由于产生表面等离子体的共振吸收，增强对可见光的吸收能力，同时降低了光生电子（e-）和空穴（h+）的复合，促进·OH 自由基的产生，因此能在很大程度上提高光催化活性.此外，这种特殊结构的Pt/Bi2WO6微米晶有利于在水溶液中进行分离和回收，提高催化剂的利用效率.

Synthesis,characterization offlower-like Pt/Bi 2WO6 microcrystals and high visible lightphotocatalytic performance

A series of 1.5~2 μmPt/Bi2WO6 composite microflowers were synthesized by a hydrothermal synthe-sis combination with photo-deposition method. The as-synthesized microflowers were characterized by powder X-ray diffraction (XRD), N2-physical adsorption, scanning electron microscopy (SEM), transmission electron microscopy (TEM), UV-VIS diffuse reflectance spectra (DRS), X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared (FT-IR).The photocatalytic performance of the catalysts was evaluated by the con-secutive photocatalytic degradation of acid orange II dye under visible light (λ > 420 nm) irradiation. The re-sults show that these hierarchical Pt/Bi2WO6 composite microflowers have superior texture property in aqueous photocatalytic reactions. Moreover, the deposition of optimal amount of 1 % Pt brings about 2.8 times increase in activity. The deposited Pt NPs over Bi2WO6 nanosquares enhance the visible light absorption due to the sur-face plasmon resonance absorption and decrease the recombination rate of e-/h+pairs and promote ·OH radi-cals production, hence largely boosting the photocatalytic activity. Moreover, the unique hierarchical structures of Pt/Bi2WO6 microflowers benefit their separation and recycle in aqueous photocatalytic reactions, andutiliza-tion efficiency of the catalyst has been improved.