CTF stabilizes truncated octahedral Cu2O nanocrystals and SnO2 nanoparticle assisted photocatalytic CO2 reduction in hybrid ternary Cu2O/SnO2/CTF nanostructures

Abstract

Efficient CO₂ conversion into value-added chemicals using visible light has been one of the prime focuses, given the potential of directly harnessing photon energy for chemical energy. Photocatalytic CO₂ reduction reaction (CO₂RR) suffers from several challenges, including low CO₂ adsorption onto the catalyst surface, limited number of efficient photocatalytically generated electrons in the conduction band (CB) of semiconductors, their short lifetime, and multiple proton-coupled electron transfer reactions. Herein, we demonstrate an approach for the efficient conversion of CO₂ into CO (40.33 μmol g⁻¹ h⁻¹) with a minimal amount of CH₄ (1.03 μmol g⁻¹ h⁻¹) using Cu₂O/SnO₂/CTF hybrid nanocatalysts. The synthesized truncated octahedral Cu₂O nanocrystals were deposited with smaller (∼10 nm) SnO₂ nanoparticles. The porous covalent triazine-based framework (CTF) was then deposited onto the surface of Cu₂O/SnO₂ by a simple reflux method to synthesize Cu₂O/SnO₂/CTF hybrid nanocatalysts. The CTF coating on Cu₂O/SnO₂ was found to shift electronic band positions of Cu₂O which was ascribed for facile charge separation for enhanced CO₂RR.