Co_(3)O_(4)/TiO_(2) composite photocatalyst:Preparation and synergistic degradation performance of toluene

Co_(3)O_(4)/TiO_(2)复合光催化剂的制备及其对甲苯的协同降解性能

TiO_(2) nanobelts and Co_(3)O_(4)/TiO_(2) catalytic materials were prepared using the hydrothermal method.The cat-alyst was characterized by X-ray diffraction,scanning electron microscopy,transmission electron microscopy,X-ray electron spectroscopy,and fluorescence spectroscopy.At room temperature,with a relative humidity of 50.0%,the total gas flow rate of 1.0 L·min-1,the space velocity of 1.05×10^(4) h^(-1),and toluene volume concentration of 25.0µL·L^(-1),two 6 W vacuum ultraviolet lamps were used as light sources to catalyze,degrade,and mineralize toluene.The results show that the prepared catalyst is in the shape of nano-ribbons.The loading of Co_(3)O_(4) inhibits the recombina-tion of photogenerated electrons and holes and can effectively improve the catalytic performance.The Co_(3)O_(4)/TiO_(2) with a load of 6.0%Co_(3)O_(4) has the best catalytic effect.When N2 was used as a carrier gas,the degradation rate of tol-uene was only 34.7%.The toluene degradation is mainly due to the photolysis of vacuum ultraviolet light.When air was used as a carrier gas,O_(3) was produced.The Co_(3)O_(4)/TiO_(2) with a load of 6.0%and vacuum ultraviolet synergistical-ly promote toluene degradation.The highest degradation rate of toluene was 91.7%and the mineralization rate was 74.6%.The degradation rate of toluene was 2.6 times that of nitrogen as a carrier gas.

采用水热法制备TiO_(2)纳米带和Co_(3)O_(4)/TiO_(2)催化材料。通过X射线衍射、扫描电镜、透射电镜、X射线电子能谱和荧光光谱对催化剂进行表征。室温下,相对湿度为50.0%,气体总流量为1.0 L·min-1,空速为1.05×10^(4)h^(-1),甲苯的体积浓度为25.0µL·L^(-1)时,以2个6 W真空紫外光灯为光源对催化材料进行甲苯的降解和矿化研究。结果表明,所制备的催化剂为纳米带状,Co_(3)O_(4)的负载抑制了光生电子-空穴的重组,能有效提高催化性能。当以氮气作载气时,Co_(3)O_(4)负载量(质量分数)为6.0%的Co_(3)O_(4)/TiO_(2)具有最好的催化效果,甲苯的降解率仅为34.7%,甲苯的降解主要是真空紫外光的光解作用;当以空气作载气时,有O_(3)产生,Co_(3)O_(4)负载量为6.0%的Co_(3)O_(4)/TiO_(2)和真空紫外协同作用对甲苯降解率为91.7%,矿化率为74.6%,甲苯降解率是氮气作载气条件下的2.6倍。