Construction of a red phosphorus-molybdenum dioxide electron-rich interface for efficient photocatalytic reduction of carbon dioxide

Abstract

Developing efficient catalysts to enhance photoreduction carbon dioxide (CO₂) into hydrocarbon fuels is a great challenge. As metallic material, molybdenum dioxide (MoO₂) has very high conductivity and charge density, which make it a promising candidate as photocatalyst. However, its photocatalytic activity is limited by the serious charge recombination. How to effectively make full use of the metallic MoO₂ for photocatalytic CO₂ reduction is still a critical issue. The potential effective way to solve this problem is to introduce appropriate auxiliary catalysts to construct electron-rich interfaces. In this study, red phosphorus (P) is dispersed on MoO₂ nanoparticles to construct electron-rich interfaces which can serve as the active site for photocatalytic CO₂ reduction. The results show that the reduction of CO₂ by pure MoO₂ only produces carbon monoxide (CO) and methane (CH₄). However, with the aid of red P, the P-MoO₂ photocatalyst can produce ethylene (C₂H₄) with the yield of 5.43 μmol h^-1 g^-1, and the CO and CH₄ yields are also significantly improved. Experimental results and density functional theory (DFT) calculations indicate that photogenerated carriers can migrate from MoO₂ to the interface, and the reduction of CO₂ occurs at the interface. This study provides a significant insight for the design of efficient photocatalysts by using metallic photocatalysts.

Keywords: Carbon dioxide reduction; Electron-rich interface; MoO(2); Photocatalysis; Red phosphorus.