ZnIn2S4 nanosheet growth on amine-functionalized SiO2 for the photocatalytic reduction of CO2

Abstract

The photocatalytic reduction of CO₂ into valuable fuels and sustainable energy has a promising future, yet remains a challenge due to low charge separation efficiency and inadequate active sites. We find that ZnIn₂S₄-loaded secondary amine-functionalized organic silica (ZnIn₂S₄/NH–SiO₂) was effective for visible-light driven CO₂ photocatalytic reduction. The ZnIn₂S₄/NH–SiO₂ with 40% ZnIn₂S₄ content achieves a CO production rate of 1304.8 μmol g⁻¹ h⁻¹ at room temperature, which is about 3 times higher than that of pristine ZnIn₂S₄. The thin ZnIn₂S₄ nanosheet accelerates the separation of photogenerated electron pairs, and the amine groups on ZnIn₂S₄/NH–SiO₂ act as active sites for adsorption and activation of CO₂, hence facilitating the photoreduction of CO₂.