Enhanced light driven CO2 conversion based on silver bismuth sulfide hollow octahedrons coated with amorphous metal–organic frameworks

Abstract

Ternary sulfides have been widely studied for photocatalytic applications recently due to their flexible chemical composition and feasible band structure regulation. Theoretical research indicates huge potential of AgBiS₂ in photocatalysis despite the lack of experimental data. Herein, single crystalline AgBiS₂ hollow octahedrons were developed for CO₂ photoreduction with amorphous ZIF-67 frameworks as outer layers. The predominant exposure of (111) planes and central cavities endowed AgBiS₂ hollow octahedrons with sufficient light harvesting and electron transfer capability. The core–shell AgBiS₂@ZIF-67 heterostructure significantly facilitated the separation of photogenerated carriers on the interface and electron accumulation around the active sites, further inducing stronger electrostatic attraction between ZIF-67 and ruthenium bipyridine complexes as photosensitizers. In consequence, AgBiS₂@ZIF-67 heterostructures with medium thickness of outer layers exhibited the optimum photocatalytic efficiency towards CO₂ photoreduction with the average CO and H₂ production rates of 2.27 mmol g_cat⁻¹ h⁻¹ and 0.78 mmol g_cat⁻¹ h⁻¹, which qualified AgBiS₂ hollow octahedrons as a universal platform for cocatalyst loading in heterogeneous catalysis.