贵金属沉积对Ga_(2)O_(3)光催化降解有机染料的影响

Effect of noble metal deposition on Ga_(2)O_(3)-based photocatalytic degradation of organic dyes

采用沉积沉淀法成功将Au、Ag、Pd、Rh和Ru 5种贵金属元素负载在棒状Ga_(2)O_(3)材料上,表征了负载前后催化剂的形貌结构和物化性质,并考察了其在不同光源下降解有机染料的性能。在300 W氙灯的照射下,Ag负载Ga_(2)O_(3)表现出最佳的光催化活性,反应12 min后降解83%的有机染料(IC,50 mg/L),速率常数为0.14 min^(-1);在10 W可见光照射下的速率常数可达0.084 min^(-1)。此外,Ga_(2)O_(3)-Ag催化剂对其他有机染料(MO、MB、MV和RhB,10 mg/L)也表现出良好的光降解活性。紫外可见漫反射光谱、光电流瞬态响应和光致荧光发光光谱等测试结果表明,Ag负载增强了Ga_(2)O_(3)催化剂对可见光的吸收能力,提高了光生载流子的分离效率,进而显著提升了光催化性能。

Five noble elements(Au,Ag,Pd,Rh,and Ru)were successfully loaded onto the rod-like Ga_(2)O_(3)material by the deposition-precipitation method.The surface morphology and crystal structure of catalysts were examined both before and after loading,and the photocatalytic performance were evaluated by degrading organic dyes.Ag Loading Ga_(2)O_(3)exhibited the best photocatalysis under the irradiation of 300 W Xenon lamp,degrading 83%of Indigo Carmine(IC,50 mg/L)with a rate constant of 0.14 min^(-1)after 12 min of reaction and up to 0.084 min^(-1)under the irradiation of 10 W visible light.In addition,the Ga_(2)O_(3)-Ag catalyst also showed excellent photocatalytic activity for other organic dyes(MO,MB,MV and RhB,10 mg/L).UV-vis diffuse reflectance spectroscopy,photocurrent transient response and photoluminescence luminescence spectroscopy results demonstrated that Ag loading enhanced absorption ability of visible light and increased separation efficiency of photogenerated carriers,thereby significantly improving the photocatalytic performance of Ga_(2)O_(3).