Z型光催化剂Sb2WO6/g-C3N4的制备及光催化性能

通过水热反应合成了Sb₂WO₆改性的g-C₃N₄复合材料(Sb₂WO₆ /g-C₃N₄). 通过X射线衍射(XRD)、 扫描电子显微镜(SEM)、 紫外-可见漫散射反射光谱(UV-Vis DRS)和光致发光光谱(PL)等表征了样品的性质. 结果表明, Sb₂WO₆在g-C₃N₄的表面上生长, 并且复合材料光吸收能力有一定的增强, 光生电子-空穴的重组率降低. 通过罗丹明B(RhB)的光降解评价了Sb₂WO₆/g-C₃N₄复合材料的光催化性能. 结果表明, 模拟日光下Sb₂WO₆质量分数为10%的Sb₂WO₆/g-C₃N₄复合材料在60 min内对RhB的降解率为99.3%, 高于纯g-C₃N₄和Sb₂WO₆. Sb₂WO₆/g-C₃N₄复合材料的这种高度增强的光催化活性主要归因于强的界面相互作用促进了光生电子-空穴分离和迁移. 添加自由基清除剂的实验结果表明, ·O^2-和h⁺是光催化反应中的主要活性物质. Sb₂WO₆/g-C₃N₄复合材料在几个反应周期内表现出优异的稳定性. 根据实验结果提出了一种可能的Z型光催化机理.

Synthesis and Photocatalytic Activity of Z-Scheme Photocatalyst Sb2WO6/g-C3N4 †

Sb₂WO₆ modified g-C₃N₄(Sb₂WO₆/g-C₃N₄) composites were synthesized by hydrothermal reaction. The properties of the Sb₂WO₆/g-C₃N₄ composites were analyzed by X-ray diffraction(XRD), scanning electron microscopy(SEM), UV-Vis diffuse reflectance spectroscopy(UV-Vis DRS) and photoluminescence(PL) spectroscopy. The results indicated that the Sb₂WO₆ grew on the surface of g-C₃N₄, forming closely contacted interfaces between the Sb₂WO₆ and g-C₃N₄ components. The photocatalytic performance of Sb₂WO₆/g-C₃N₄ composites was evaluated through the photodegradation of Rhodamine B(RhB). The results showed that 99.3% of RhB was degraded by Sb₂WO₆/g-C₃N₄ composites with 10%(mass fraction) of Sb₂WO₆ in 60 min under simulated sunlight, which was much higher than that of pure g-C₃N₄ and Sb₂WO₆. This highly enhanced photocatalytic activity of the Sb₂WO₆/g-C₃N₄ composites can be mainly attributed to strong interfacial interaction promoting the photo-generated electron-hole separation and migration. The results of radical scavenger experiments showed that ·{{\mathrm{O}}_2}^{-} and h⁺ were the dominant reactive species in the photocatalytic reaction. Besides, the Sb₂WO₆/g-C₃N₄ composites showed excellent stability over several reaction cycles. Finally, a possible Z-scheme photocatalytic mechanism was proposed based on the experimental results.