Al_(2)O_(3)/g-C_(3)N_(4)复合材料的制备、光催化性能及机理研究

Preparation,Photocatalytic Properties and Mechanism of Al_(2)O_(3)/g-C_(3)N_(4) Composites

采用高温固相复合法制备了Al_(2)O_(3)/g-C_(3)N_(4)复合光催化剂,并对不同质量比的Al_(2)O_(3)/g-C_(3)N_(4)复合光催化剂的光催化性能进行了研究。通过XRD、SEM对催化剂的组成、结构和形貌等进行了表征。在氙灯照射下,通过催化剂对有机染料罗丹明B的催化降解,评价了催化剂的光催化性能。结果表明:Al_(2)O_(3)与g-C_(3)N_(4)成功复合,Al_(2)O_(3)/g-C_(3)N_(4)复合光催化剂比单一的Al_(2)O_(3)或g-C_(3)N_(4)降解罗丹明B的速率更快,而且Al_(2)O_(3)和g-C_(3)N_(4)的质量比为3:2的光催化剂降解50 mL的100 mg·L^(-1)的罗丹明B效果最好。通过机理探究实验发现,复合物的催化降解是羟基自由基和超氧自由基起主要作用,空穴则基本没起作用。

Al_(2)O_(3)/g-C_(3)N_(4) composite photocatalyst was prepared by high-temperature solid-state composite method,and the photocatalytic properties of Al_(2)O_(3)/g-C_(3)N_(4) composite photocatalyst with different mass ratios were studied.The composition,structure and morphology of the catalyst were characterized by XRD and SEM.Under the irradiation of xenon lamp,the photocatalytic performance of the catalyst was evaluated by catalytic degradation of organic dye rhodamine B.The results showed that Al_(2)O_(3 )and g-C_(3)N_(4) were successfully compounded,and the degradation rate of rhodamine B by Al_(2)O_(3)/g-C_(3)N_(4) composite photocatalyst was faster than that by single Al_(2)O_(3) or g-C_(3)N_(4),and the photocatalyst with the mass ratio of Al_(2)O_(3)to g-C_(3)N_(4) of 3∶2 had the best degradation effect on 50 mL of 100 mg·L^(-1)rhodamine B.It was found that hydroxyl radical and superoxide radical played the main role in the catalytic degradation of the composites,while holes had little effect.