Single Au Atoms Anchored on Amino-Group-Enriched Graphitic Carbon Nitride for Photocatalytic CO2 Reduction.

Owing to the maximum atom-utilization efficiency and excellent catalytic properties, Au single-atom catalysts (SACs) have been extensively studied in various catalytic systems. However, the performance of Au SACs in CO2 reduction has seldom been investigated. Herein, Au single atoms on amino-group-modified graphitic carbon nitride (U-ACN) was successfully synthesized through a mild and eco-friendly urea reduction method. U-ACN showed a remarkable performance for CO2 reduction, with CO and CH4 yields 1.97 and 4.15 times higher than those of pure graphitic carbon nitride over 2.5 h visible-light irradiation. The excellent catalytic activity of U-ACN derived from the introduction of Au single atoms, which lowered the energy barrier of CH4 formation, narrowed the band gap, and hindered the recombination of charge carriers. In addition, U-ACN showed improved CO2 affinity owing to the amino groups in the catalysts introduced by urea.