Preparation and photocatalytic degradation of Sulfamethoxazole by g-C3N4 nano composite samples

Graphite-carbon nitride (g-C3N4) was prepared by thermocondensation, and g-C3N4/BiVO4 material (GCB) and g-C3N4/CNTs composite material (GCC) were prepared by doping different contents of BiVO4 and carbon nanotubes (CNTs) with g-C3N4 samples, respectively. Then, BiVO4, CNTs, and g-C3N4 samples with different contents were doped to prepare ternary composite material (GCBC). In the performance experiment, Sulfamethoxazole (SMZ) was used as degradation material to evaluate the photocatalytic performance of the prepared samples, and the degradation reaction kinetics equation, quadric cycle stability experiment, free radical capture, and intermediates identification were studied. The intermediates of photocatalytic degradation of SMZ were analyzed by high-performance liquid chromatography-mass spectrometry. From the experimental data, it can be seen that for SMZ solution, when the reaction time T = 0 min and retention time rt = 7.53 min, there is a peak corresponding to the substance with m/z [M + H](+) of 254, which is judged as SMZ. At 20, 40, and 60 min, rt was 2.00, 7.06, and 9.57 min, indicating the presence of intermediates in the photocatalytic process. Experimental analysis shows that there are three intermediates of SMZ degradation by composite sample GCBC. In this work, three kinds of composite materials were successfully prepared, and a variety of characterization, SMZ as pollutants, test the photocatalytic performance of composite materials (GCB, GCC, and GCBC) samples, and elucidated the cyclic stability of the material, active species capture, and photocatalytic degradation mechanism.