Preparation of Z‐type heterojunction SiCf/g‐C3N4 composites with enhanced photocatalytic degradation of tetracycline under visible light

Abstract

Novel visible light‐driven silicon carbide‐based composites were prepared via in situ deposition of g‐C3N4 on fibrous SiC. The X‐ray diffractometry, scanning electron microscopy, transmission electron microscopy, and X‐ray photoelectron spectrometer characterization showed that a Z‐type heterojunction was formed. According to the UV diffuse reflectance spectroscopy and (αhv)1/2 versus hv plots, it was demonstrated that the addition of g‐C3N4 extended the light absorption of the sample in visible light, narrowing its band gap. The EIS plots and PL spectra showed an increase in the efficiency of the charge carriers' mobility of the sample and a decrease in the recombination of its photogenerated electron–hole pairs. The photocatalytic degradation experiments showed that using a 0.03‐g·L−1 suspension concentration and a pollutant concentration of 10 mg·L−1, the degradation rate under visible light irradiation was 100 and 3.6 times higher than that of bare SiCf and g‐C3N4, respectively. The possible photocatalytic mechanism was proposed based on reactive species capture experiments and electron paramagnetic resonance showing that ·O2− and e− were the active entities.