Green synthesis of porous Cu2ZnSnS4/g-C3N4 heterostructured for promoted photocatalytic degradation of trichloroethylene

Accelerating the photo-induced carrier separation in semiconducting materials under visible-light exposure is a great challenge in effective organic pollutant degradation. Herein, a mesoporous Cu2ZnSnS4/g-C3N4 heterojunction was synthesized through a facile sol-gel approach with hard and soft templates leading to a high-surface area material. TEM analysis showed spherical Cu2ZnSnS4 nanocrystals (5 nm in diameter) with a high and uniform distribution on the g-C3N4 nanosheets. The Cu2ZnSnS4/g-C3N4 photocatalyst (3%) showed photo catalytic trichloroethylene (TCE) degradation to Cl- and CO2 of approximately 100% in an aqueous medium. The optimal rate for this photocatalyst was approximately 7.754 mu mol L-1.min(-1), which was 4 and similar to 5.75 folds higher than that of bare Cu(2)ZnSnS(4)and g-C3N4, respectively. Moreover, the apparent rate constant of 3% Cu2ZnSnS4/g-C3N4 was 7.6 and 4.1 times higher than that of bare g-C3N4 and Cu2ZnSnS4, respectively. Recycling experiments confirmed that the Cu2ZnSnS4/g-C3N4 photocatalyst exhibited remarkably stable photocatalytic activity and could be recycled five times. This work provides a novel insight into the design and preparation of visible-light-based photocatalysts with high and stable photocatalytic efficiency.