Phosphorus-doped g-C₃N₄/SnS nanocomposite for efficient photocatalytic reduction of aqueous Cr(VI) under visible light

In this study, a novel phosphorus-doped g-C₃N₄/SnS (P-CN/SnS) nanocomposite for photocatalytic reduction of hexavalent chromium (Cr(VI)) in aqueous solution was successfully synthesized via a hydrothermal method. The SnS nanoparticles were loaded onto the surface of P-CN nanosheets to form tight interfaces, as confirmed by morphology observations. It was found that the P-CN/SnS nanocomposite displayed higher photocatalytic ability under visible light compared to non-composite catalysts. The unique structure of the P-CN/SnS nanocomposite provides excellent photocatalytic activity for Cr(VI), which is likely attributable to a large surface area, a wide spectral response, and the inhibition of electron-hole recombination. The best photocatalytic activity was exhibited by P-CN/SnS (30 wt% of SnS on P-CN), which completely removed Cr(VI) (100 mg/L) from solution within 60 min. Moreover, the high structural stability of the nanocomposite ensured four cycles with little activity loss. The outstanding performance of this new material provides new insights into the photocatalysis of Cr(VI).