Steering Catalytic Activity and Selectivity of CO2 Photoreduction to Syngas with Hydroxy-Rich Cu2S@ROH-NiCo2O3 Double-Shelled Nanoboxes

Simultaneous transformation of CO2 and H2O into syngas (CO and H-2) using solar power is desirable for industrial applications. Herein, an efficient photocatalyst based on double-shelled nanoboxes, with an outer shell of hydroxy-rich nickel cobaltite nanosheets and an inner shell of Cu2S (Cu2S@R-OH-NiCo2O3), is prepared via a multistep templating strategy. The high performance of Cu2S@R-OH-NiCo2O3 (7.1 mmol g(-1) h(-1) for CO; 2.8 mmol g(-1) h(-1) for H-2) is attributed to the hierarchical hollow geometry and p-n heterojunction to promote light absorption and charge separation. Spectroscopic and theoretical analyses elucidate that the R-OH-NiCo2O3 surface enhances *CO2 adsorption and lowers energy barriers for CO2-to-CO. Therefore, modulating the hydroxy contents of R-OH-NiCo2O3 can achieve broad CO/H-2 ratios from 0.51 to 1.24. This work offers in-depth insights into adjustable syngas photosynthesis and generalized concepts of selective heterogeneous CO2 photoreduction beyond cobalt-based oxides.

Automated summary

By utilizing a double-shelled nanobox photocatalyst, this study achieved the simultaneous transformation of CO2 and H2O into syngas, offering insights for adjustable syngas photosynthesis.