Photocatalyst Engineering for Water-Based CO2 Reduction Under Visible Light Irradiation to Enhance CO Selectivity: A Review of Recent Advances

Abstract

Among greenhouse gases, carbon dioxide (CO2) is major constituent causing severe climate change. Therefore, it is imperative to seek solutions that will subside CO2 concentration in the atmosphere. One of the best approaches is photocatalytic CO2 reductions into useful molecules (Carbon monoxide (CO), Methane (CH4) and Hydrogen (H-2)). This unique route could remediate both environmental and energy crises simultaneously. However, the overall photoconversion and selectivity for CO production have been severely constrained by poor light absorption and competitive side reactions (water splitting and hydrogenation). Here, authors have given insights on current state of structural engineering-based CO evolution via CO2 photoreduction under visible irradiation. Moreover, different structural modifications including elemental doping, facet engineering heterojunctions, surface defects, and co-catalyst introduction methods have been discussed thoroughly to improve CO selectivity and production.