Tuning the CO₂ Reduction Activity of Graphitic Carbon Nitride via the Capping-Agent-Free Involvement of Ag Nanocrystals

In this work, a facile method to tune the carbon dioxide (CO₂) reduction reaction (CRR) activities of graphitic carbon nitride (GCN) was developed via the capping-agent-free involvement of a trace amount of Ag nanocrystals with a decreased size. After the optimization of experimental conditions, the CRR performance investigation confirms that Ag-GCN-0.2 exhibited a superior CRR performance, achieving a faradaic efficiency (FE) of more than 72 ± 1% for CO in a wide potential range from −0.6 to −1.1 V (vs reversible hydrogen electrode (RHE)) and a max FE of 89 ± 1% at an overpotential of 0.9 V with a constant current density and a well-maintained microstructure even after 12 h of electrolysis. This work provides a new route to tune the catalytical performance of GCN and pave the way for the rational design, synthesis, and accurate estimation of the GCN-based catalysts, which will be synthesized on a large scale and utilized in industries.