Revealing the nontrivial topological surface states of catalysts for effective photochemical carbon dioxide conversion

TL;DR

This paper demonstrates that doping topological Os3Sn7 with Ir enhances its photocatalytic ability to convert CO2 into useful chemicals by leveraging protected surface states that improve charge separation and molecule activation.

Contribution

It introduces a simple solid-phase doping method to improve topological catalysts for CO2 reduction, combining experimental and theoretical insights.

Findings

Ir doping significantly boosts photocatalytic efficiency.

Topological surface states facilitate charge separation and CO2 activation.

Enhanced formation of reaction intermediates like *COOH and *CO.

Abstract

Topological semimetals with protected surface states mark a new paradigm of research beyond the early landmarks of band-structure engineering, allowing fabrication of efficient catalyst to harness the rich metallic surface states to activate specific chemical processes. Herein, we demonstrate a facile solid-phase method for in-situ doping of Ir at the Os sites in the Os3Sn7, an alloy with topological states, which significantly improves the photocatalytic performance for the reduction of CO2 to CO and CH4. Experimental evidence combined with theoretical calculations reveal that the nontrivial topological surface states greatly accelerate charge-separation/electron-enrichment and adsorption/activation of CO2 molecules, rendering highly efficient reaction channels to stimulate the formation of *COOH and *CO, as well CHO*. This work shows the promise of achieving high photocatalytic performances with synthesizing topological catalysts and provides hints on the design of novel topological catalysts with superior photoactivity towards the CO2 reduction reaction.