Fabrication ternary dual electron transfer Ag2MoO4/SrWO4/g-C3N4 heterojunction photocatalyst for the highly efficient visible-light-driven degradation of tetracycline

Abstract

The construction of new electron transfer channels is essential to improve the photocatalyst activity. Herein, a novel Ag2MoO4/SrWO4/g-C3N4 photocatalyst with dual electron transfer channels was constructed by one-step precipitation method. The obtained photocatalysts were characterized using XRD, SEM, FT-IR, TEM, Uv-vis and PL. Under visible light, the photocatalyst was evaluated for its ability to degrade tetracycline (TC). The characterization results presented that the olive sphere-like SrWO4 and the nanosphere-like Ag2MoO4 were uniformly dispersed on the surface and pores of g-C3N4, forming a heterostructure and thereby heterojunctions, which promoted the internal electron transfer. The degradation experiments showed that the Ag2MoO4/SrWO4/g-C3N4 improved degradation efficiency of TC under visible light relative to monomeric and binary materials. In addition, the 20AMO/8SW/CN maintained 92.19 % degradation of TC after four cycles of experiments, showing excellent reusability. During the photocatalytic process, ·O2-, h+, and ·OH promoted the degradation of TC. Combining with the energy band structure analysis, it was found that a novel dual electron transfer channel had been constructed among Ag2MoO4, SrWO4 and g-C3N4, which markedly enhanced photocatalytic efficiency. The work provides a potential approach for developing efficient and stable photocatalysts.