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

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 H-2 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.