pg-C3N4/BiOBr/Ag复合材料的制备及其光催化降解磺胺甲唑

通过简易的高温煅烧和共沉淀方法成功制备出pg-C₃N₄/BiOBr/Ag复合材料，通过XRD、SEM、TEM、XPS、UV-Vis、BET和光电流等检测手段对其进行表征，并探究了该复合材料在模拟可见光照射下对10 mg·L^-1磺胺甲唑的降解效果.结果表明，当银单质的负载比例为5%时，pg-C₃N₄/BiOBr/Ag复合材料对磺胺甲唑的降解效果最佳.与pg-C₃N₄、BiOBr单体和二元复合材料pg-C₃N₄/BiOBr相比，pg-C₃N₄/BiOBr/Ag（5%）光催化降解磺胺甲唑的效果显著提升，在30 min内降解率几乎接近100%，反应速率常数（0.2101 min^-1）是pg-C₃N₄/BiOBr的13.15倍.通过自由基猝灭实验，证明在光催化降解过程中，起主要作用的活性物质是空穴（h⁺）、超氧自由基（·O₂^-）和单线态氧（¹O₂），其中，超氧自由基（·O₂^-）贡献最大.对pg-C₃N₄/BiOBr/Ag进行多次循环实验，证明合成的材料具有良好的循环稳定性能，应用前景良好.

Preparation of pg-C3N4/BiOBr/Ag Composite and Photocatalytic Degradation of Sulfamethoxazole

A pg-C₃N₄/BiOBr/Ag composite was successfully prepared by simple high-temperature calcination and co-precipitation methods. The composite was characterized by means of XRD, SEM, TEM, XPS, UV-Vis, BET, and photocurrent analyses alongside other detection methods, and the degradation of 10 mg·L^-1 sulfamethoxazole was investigated under simulated visible light irradiation. The results showed that the pg-C₃N₄/BiOBr/Ag composite had the best degradation effect on sulfamethoxazole when the loading ratio of silver was 5%. Compared with pg-C₃N₄, BiOBr monomer, and pg-C₃N₄/BiOBr composite, the photocatalytic degradation effect of the pg-C₃N₄/BiOBr/Ag (5%) was significantly improved, and the degradation rate was almost 100% within 30 min. The reaction rate constant (0.21016 min^-1) was 13.15 times that of pg-C₃N₄/BiOBr. Through radical quenching experiments, it was shown that the main active substances in the photocatalytic degradation were holes (h⁺), superoxide radicals (·O₂^-), and singlet oxygen (¹O₂), among which superoxide radicals (·O₂^-) contributed the most. Cyclic tests of pg-C₃N₄/BiOBr/Ag showed that the synthesized material has good recyclability and application prospects.