2D Ti3C2 decorated Z-scheme BiOIO3/g-C3N4 heterojunction for the enhanced photocatalytic CO2 reduction activity under visible light

The development of photocatalytic technology can not only reduce CO2 emissions, but also realize the effective utilization of solar energy, thus alleviating the global energy crisis. In this work, BiOIO3/g-C3N4 Z-scheme heterojunction modified by Ti3C2 nanosheets was designed and fabricated through hydrothermal method and electrostatic self-assembly strategy. The g-C3N4/BiOIO3/Ti3C2 (4 wt%) photocatalytic system exhibited the optimal photocatalytic efficiency, reaching 5.88 and 1.55 μmol/g/h for CO and CH4, respectively, and the CO production rate was 6.6 folds as high as that of bare g-C3N4. Various characterization techniques were utilized to research the physicochemical properties of as-prepared photocatalysts. Z-scheme heterojunction formed between g-C3N4 and BiOIO3 and the decorating of 2D Ti3C2 co-catalyst were responsible for the boosted photocatalytic behavior. Z-scheme heterojunction could prevent the recombination of charge carriers, the co-catalyst Ti3C2 acted as electron sink could achieve quick shift of photo-induced electrons and supply numerous active sites for photocatalytic reaction.