Construction of visible light-driven ternary S-scheme melamine sponge MS/TpTt/ZIS heterojunction photocatalysts for enhanced photocatalytic pollutant removal and hydrogen evolution

Charge separation critical for improving photocatalytic performance. But single semiconductor cannot realize efficient charge separation and transport. Little research has been reported on using melamine foam (MS) as a carrier. Herein, we have successfully synthesized a heterojunction MS/TpTt/ZnIn₂S₄-x% (MTZIS-x%) photocatalysis with MS as the carrier by solvothermal method. It was found the degradation rate of MO over MTZIS-3 % could reach almost 100 %, and the biotoxicity tests showed that degraded residual liquid of MO was almost non-biological toxicity. Moreover, the ptotocatalytic H₂ evolution rate of MTZIS-3 % reached to 11523.64 µmol g⁻¹h⁻¹, which was 7.02, 11.91 and 13.19 times than that of ZIS, MS/TpTt and COF-TpTt. And the evolution rate of photoreduction CO₂ to CO was 501.55 µmol g⁻¹ h⁻¹. The excellent photocatalytic property was owing to the S-scheme band structure facilitated the separation of electron-hole efficiently and retained the highly reducing electrons. This work provided a theoretical reference for the construction of efficient new heterojunction photocatalysts using MS as a carrier.