g-C3N4-W18O49复合光催化剂的制备及其光催化机理研究

Preparation and Photocatalytic Mechanism of g-C_3N_4-W_(18)O_(49) Composite Photocatalyst

通过简单的溶剂热法成功制备出了g-C_3N_4-W_(18)O_(49)复合光催化剂,采用XRD、SEM、TEM以及PL对所得催化剂的物相结构及形貌和光学性能进行了表征,通过降解甲基橙和光解水产氢实验研究所得催化剂的催化性能及其催化机理。由实验可知,W_(18)O_(49)的含量为50%时所得g-C_3N_4-W_(18)O_(49)复合光催化剂的降解性能最好,其降解率比纯g-C_3N_4纳米片提高48%;为进一步研究复合光催化剂的电子-空穴传输机理,我们又进行了光解水制氢实验。结果表明:单一的W_(18)O_(49)无产氢活性,它的复合明显降低了g-C_3N_4的产氢速率,说明复合结构中光生电子是从g-C_3N_4传递到了W_(18)O_(49),表现出明显的Ⅱ型异质结复合特征,而不是部分文献所提出的Z型方式。

g-C3N4-W18O49 composite photoeatalyst was successfully prepared by simple solvothermal method. The phase structure, morphology and optical properties of the obtained catalyst were characterized by XRD, SEM, TEM and PL. The catalytic performance of the catalyst and its catalytic mechanism were studied by degradation of methyl orange and water splitting hydrogen production. It was found that the degradation performance of g-C3N4-W18O49 photocatalyst was the best when the content of W18049 was 50% , and the degradation rate was 48% higher than that of pure g-C3N4 nanosheets. In order to further study the electron-hole transfer mechanism, the photolysis of hydrogen production experiments were carried out. The results show that the single W18 049 has no hydrogen production activity, and with its recombination obviously reduces the hydrogen production rate of g-C3N4, indicating that the photo-generated electrons in the composite structure are transferred from g-C3N4 to W18 049, showing obvious heterojunetion complex type II , rather than some of the literature presented by the Z- way.