Enhanced Photocatalytic CO₂ Reduction by Amine Functionalization of Graphitic Carbon Nitride

Abstract

Graphitic carbon nitride (g‐CN) is a promising photocatalyst for solar fuel generation, but its charge carrier mobility, charge recombination, and CO2 reduction/H2 evolution efficacy and selectivity are a strong function of the synthesis and post synthesis techniques employed. Protonation and phosphorous doping of g‐CN yield promising visible light activities, promoting enhanced CO2 reduction and hydrogen evolution. However, the amine functionalized surface chemistry of g‐CN gained little attention in open literature. Here, g‐CN and phosphorus doped g‐CN are synthesized via facile one‐pot pyrolysis and subjected to protonation post‐synthesis to quantify the influence of common strategies on surface amine content and photocatalyst activity for H2 evolution and CO2 reduction. Material characterization confirmed the exfoliation of the photocatalyst and change in the amine functionalization of the surface. The amorphous phosphorus doped g‐CN material exhibited a high number of surface amine groups, increasing the adsorption prior to reduction and enhancing selectivity for CO2 reduction.This article is protected by copyright. All rights reserved.