非金属B掺杂g-C3N5催化剂的制备及对亚甲基蓝的降解

Preparation of non-metallic B-doped g-C_(3)N_(5) catalyst and degradation performance of Methylene Blue

通过高温溶剂热解的方法制备B/g-C3N4催化剂,并采用X射线衍射(XRD)、扫描电子显微镜(SEM)、红外光谱(FT-IR)、紫外-可见漫反射光谱(UV-Vis DRS)、瞬态荧光光谱(PL)等对B/g-C_(3)N_(5)催化剂的晶型、官能团等进行表征。以亚甲基蓝(MB)染料溶液为模拟污染物,研究了可见光照射下不同质量比掺杂对B/g-C_(3)N_(5)光催化活性的影响。结果表明:非金属B掺杂实现了g-C_(3)N_(5)的e^(-)-h^(+)的高效分离,提高了可见光的吸收性能,光谱范围发生明显红移。当非金属B掺杂量为3%时,B/g-C3N5催化剂活性最佳,其对MB的光催化降解率达到95%,B/g-C3N5催化剂循环使用5次后其对MB的光催化降解率仍达到90%。活性自由基·O_(2)^(-)和h^(+)可将MB高效降解为CO_(2)和H_(2)O等无机小分子。

The B/g-C_(3)N_(4) catalysts are synthesized by high-temperature solvent pyrolysis,and the crystal shape and functional groups of the B/g-C_(3)N_(5) catalysts are characterized by X-ray diffraction(XRD),scanning electron microscopy(SEM),infrared spectroscopy(FT-IR),ultraviolet-visible diffuse reflectance spectroscopy(UV-vis DRS),and transient fluorescence spectroscopy(PL).The effect of doping with different mass ratios for the pho⁃tocatalytic activity of B/g-C_(3)N_(5) under visible light irradiation is investigated using Methylene Blue(MB)dye solu⁃tion as a simulated pollutant.The results show that non-metallic B doping achieves an efficient separation of e^(-)-hC_(3)N_(5) from g-C_(3)N_(5),improves the absorption performance of visible light,and the spectral range is obviously red shifted.When the non-metallic B doping is 3%,the B/g-C_(3)N_(5) catalyst has the best activity,and its photocat⁃alytic degradation rate of MB reaches 95%.The photocatalytic degradation rate of MB still reaches 90% after 5 times of recycling.The active radicals·O_(2)^(-) and h^(+) realize the efficient degradation of MB into small molecule in⁃organic substances such as CO_(2) and H_(2)O.