Two-Dimensional Forms of Robust CO$_2$ Reduction Photocatalysts

TL;DR

This paper explores two-dimensional monolayer materials as promising, stable, and selective photocatalysts for CO$_2$ reduction using sunlight, expanding the potential candidates for efficient carbon-neutral energy solutions.

Contribution

It identifies and evaluates specific 2D monolayer materials, such as SiAs, ZnTe, and ZnSe, as viable photocatalysts for CO$_2$ reduction, highlighting their stability and light absorption properties.

Findings

SiAs, ZnTe, and ZnSe monolayers can absorb visible light effectively.

These monolayers favor CO production in CO$_2$ reduction.

The study expands the chemical space for 2D photocatalysts.

Abstract

Novel photoelectrocatalysts that use sunlight to power the CO$_2$ reduction reaction will be crucial for carbon-neutral power and energy-efficient industrial processes. Scalable photoelectrocatalysts must satisfy a stringent set of criteria, such as stability under operating conditions, product selectivity, and efficient light absorption. Two-dimensional materials can offer high specific surface area, tunability, and potential for heterostructuring, providing a fresh landscape of candidate catalysts. From a set of promising bulk CO$_2$ reduction photoelectrocatalysts, we screen for candidate mono-layers of these materials, then study their catalytic feasibility and suitability. For stable monolayer candidates, we verify the presence of visible-light band gaps, check that band edges can support CO$_2$ reduction, determine exciton binding energies, and compute surface reactivity. We find for SiAs, ZnTe, and ZnSe monolayers, visible light absorption is possible, and reaction selectivity biases towards CO production. We thus identify SiAs, ZnTe, and ZnSe monolayers as targets for further investigation, expanding the chemical space for CO$_2$ photoreduction.