Non-trivial Topological Surface States Regulation of 1T-OsCoTe$_2$ Enables Selective C-C Coupling for Highly Efficient Photochemical CO$_2$ Reduction Toward C$_{2+}$ hydrocarbons

TL;DR

This paper reports the synthesis and characterization of 1T-OsCoTe2, a topological semimetal that exhibits high selectivity and efficiency in photocatalytic CO2 reduction to C3 hydrocarbons, with insights into its electronic structure and reaction mechanism.

Contribution

It introduces 1T-OsCoTe2 as a novel topological semimetal catalyst with enhanced CO2 reduction performance and elucidates the role of Os atoms in facilitating electron transfer and reaction kinetics.

Findings

71.2% selectivity for C3H8 production

54.6% internal quantum efficiency at 380 nm

Os atoms accelerate CO2 conversion via electron bridging

Abstract

Despite ongoing research, the rational design of nontrivial topological semimetal surface states for the selective photocatalytic CO$_2$ conversion into valuable products remains full of challenges. Herein, we present the synthesis of 1T-OsCoTe$_2$ for the photoreduction upgrading of CO$_2$ to tricarbon alkane C$_3$H$_8$,by the integration of experimental work and theory calculation. Experimental studies suggested a high electron based selectivity of 71.2% for C$_3$H$_8$ and an internal quantum efficiency of 54.6% at 380 nm. In-situ X-ray photoelectron spectroscopy and X-ray absorption fine structure spectroscopy demonstrated that Co and Os atoms coordinated with Te atoms enable an efficient Os-Te-Co electron transfer to activate the generation of *CH$_3$,*CHOCO and *CH$_2$OCOCO. Density functional theory calculations further confirmed Os-Te-Co electron bridging on the improved CO$_2$ conversion kinetics. To our knowledge, this is the first report suggesting the role of Os atoms in accelerating the photocatalytic CO$_2$ conversion activity of the topological semimetal 1T-OsCoTe$_2$.