MoO3/g-C3N4复合材料的制备及光催化性能

以三聚氰胺和四水合钼酸铵为前驱体,采用水热法制备了MoO₃/g-C₃N₄复合光催化剂。利用X-射线衍射仪（XRD）、红外光谱仪（FT-IR）、扫描电子显微镜（SEM）、X射线光电子能谱仪（XPS）及紫外-可见漫反射仪（DRS）等对制备的样品进行了表征。表征结果显示,棒状的三氧化钼负载在层状C₃N₄表面,复合材料的光吸收能力有一定的增强。材料可见光催化降解亚甲基蓝（MB）溶液的实验表明,三氧化钼和g-C₃N₄所复合产生的异质结具有较好的吸收光强度及催化降解性能,尤其是5%（质量分数）MoO₃/g-C₃N₄复合材料光催化降解率最好,达到95.7%,高于纯三氧化钼和g-C₃N₄。自由基与空穴捕获实验表明,·O₂^-是光催化反应中的主要活性物种。MoO₃/g-C₃N₄复合材料在4个循环周期内表现出了优异的稳定性。

Preparation and photocatalytic property of MoO3/g-C3N4 composite

Using melamine and ammonium molybdate tetrahydrate as precursors,a novel MoO₃/g-C₃N₄ composite photocatalyst was prepared by hydrothermal method.The samples were characterized by X-ray diffraction（XRD）,infrared spectroscopy （FT-IR）,scanning electron microscopy（SEM）,X-ray photoelectron spectroscopy（XPS） and ultraviolet-visible diffuse reflectometer（DRS）.Characterization results showed that the optical absorption of the composites was enhanced when the rodlike MoO₃ was loaded on the layered g-C₃N₄ surface.The experiment of photocatalytic degradation of methylene blue（MB） solution by material visible light showed that the heterojunction produced by MoO₃ and g-C₃N₄ had better absorption light intensity and catalytic degradation performance,especially the 5%（mass fraction） MoO₃/g-C₃N₄ composite photocatalytic degradation rate was the best,reaching 95.7%,higher than that of pure MoO₃ and g-C₃N₄.Free radical and hole trapping experiments show that ·O₂^- was the main substance in photocatalytic reaction.The MoO₃/g-C₃N₄ composite exhibited excellent stability in four reaction cycles.