MoS2/g-C3N4复合光催化剂的构建及其可见光催化性能研究

本研究通过水热合成法和超声法成功构建MoS₂/g-C₃N₄复合型光催化剂。通过X射线粉末衍射（XRD）、扫描电子显微镜（SEM）、红外光谱（IR）以及紫外-可见吸收光谱（UV-Vis）表征技术对复合型催化剂的物理化学特性进行分析。以光催化降解罗丹明B（RhB）为探针反应，探究可见光下不同质量比的MoS₂/g-C₃N₄复合型光催化剂对RhB光催化降解性能的影响。实验结果表明，当MoS₂负载量为30%，光催化降解80 min时，10 mg/L的RhB溶液的降解率为96.7%。MoS₂/g-C₃N₄复合催化剂相比于纯的g-C₃N₄，MoS₂降解RhB的效果有显著地提高。光催化降解性能的提升归因于两半导体间MoS₂和g-C₃N₄异质结界面构筑，有效地抑制光生电子（e^-）和空穴（h⁺）的复合，从而提高复合型光催化剂MoS₂/g-C₃N₄的光催化性能。

PREPARATION OF MoS2/g-C3N4 COMPOSITE PHOTOCATALYST AND ITS VISIBLE LIGHT CATALYTIC PERFORMANCE

In this study, hydrothermal synthesis and ultrasonic method were used to construct MoS₂/g-C₃N₄composite catalyst. The structure of the composite catalyst was characterized by X-ray powder diffraction (XRD), scanning electron microscopy (SEM), infrared spectroscopy (IR) and UV-Vis. The photocatalytic degradation of Rhodamine B (RhB) was investigated by using MoS₂/g-C₃N₄ composite catalyst with different mass ratio as a probe. The results showed that the degradation rate of 10 mg/L RhB solution was 96.7% when MoS₂load was 30% and photocatalyzed for 80 min. Compared with pure g-C₃N₄, MoS₂/g-C₃N₄composite catalyst significantly improved the degradation effect of MoS₂ on RhB. The improvement of photocatalytic degradation performance can be attributed to the fact that the heterojunction interface of MoS₂ and g-C₃N₄ between the two semiconductors effectively inhibits the recombination of photogenerated electrons (e^-) and holes (h⁺). Finally, by reasoning the photocatalytic degradation mechanism of the composite photocatalyst, the charge transfer mechanism of MoS₂/g-C₃N₄ is the same as that of type II heterojunction, so it can be concluded that the composite belongs to type II heterojunction.