Interfacial coupling effects in g-C3N4/InxSb2−xS3 heterojunction for enhanced photocatalytic activity under visible light

A series of In x Sb 2− x S 3 nanosheets modified g-C 3 N 4 (In x Sb 2− x S 3 -TCN) heterojunctions with different g-C 3 N 4 contents were fabricated by an in situ deposition method. All the In x Sb 2− x S 3 -TCN composites were applied as photocatalysts in Cr(VI) polluted water treatment and the results displayed that In x Sb 2− x S 3 -TCN could effectively remove Cr(VI) under visible light through synergistic effects of adsorption and photocatalytic reduction. Especially, In x Sb 2− x S 3 -TCN-70 (70 mg g-C 3 N 4 ) exhibited the most excellent adsorption and photocatalytic reduction performance among all composites, which possessed a high equilibrium adsorption capacity of 12.45 mg/g in a 30.0 mg/L Cr(VI) aqueous solution, and reduced Cr(VI) to Cr(III) within 10 min under visible light irradiation. DRS and PL results indicated that the interfacial coupling effect between g-C 3 N 4 and In x Sb 2− x S 3 enhanced the utilization efficiency of visible light and suppressed photoinduced carrier recombination, which improved the photocatalytic activity of composites. Moreover, the photocatalyst exhibited satisfactory reduction activity and good stability after 5 cycles of Cr(VI) adsorption-photoreduction.