Hierarchical CuS@ZnIn₂S₄ Hollow Double-Shelled p–n Heterojunction Octahedra Decorated with Fullerene C₆₀ for Remarkable Selectivity and Activity of CO₂ Photoreduction into CH₄

In this work, a hollow double-shelled architecture, based on n-type ZnIn2S4 nanosheet-coated p-type CuS hollow octahedra (CuS@ZnIn2S4 HDSOs), is designed and fabricated as a p–n heterojunction photocatalyst for selective CO2 photoreduction into CH4. The resulting hybrids provide rich active sites and effective charge migration/separation to drive CO2 photoreduction, and meanwhile, CO detachment is delayed to increase the possibility of eight-electron reactions for CH4 production. As expected, the optimized CuS@ZnIn2S4 HDSOs manifest a CH4 yield of 28.0 μmol g–1 h–1 and a boosted CH4 selectivity up to 94.5%. The decorated C60 both possesses high electron affinity and improves catalyst stability and CO2 adsorption ability. Thus, the C60-decorated CuS@ZnIn2S4 HDSOs exhibit the highest CH4 evolution rate of 43.6 μmol g–1 h–1 and 96.5% selectivity. This work provides a rational strategy for designing and fabricating efficient heteroarchitectures for CO2 photoreduction.