Graphdiyne-Stabilized Silver Nanoparticles as an Efficient Electrocatalyst for CO2 Reduction

Abstract

Electrochemical CO2 reduction reaction (e-CO2RR) into high-value chemicals is a promising approach for sustainable energy research, but there remains a great challenge to develop efficient and stable catalysts. Herein, in situ synthesized uniform Ag nanoparticles (AgNPs) directly growing on the surface of 2D graphdiyne (GDY) for selectively reducing CO2 to CO with high efficiency and stability are reported. Due to the special electronic distribution of GDY, it not only serves as a template for the growth of AgNPs to prevent its aggregation, but also increases active sites and transformation of electrons through the intimate interaction between phase interface to enhance their cooperative catalytic effect, which highly improves the electrocatalytic performance of the nanocomposite. Through investigations, it is found that the Ag/GDY/CC nanocomposite electrochemically reduces CO2 to CO with Faraday efficiency up to 92.1% and current density of 25.74 mA/cm2 at the potential of −1.3 V versus reversible hydrogen electrode (RHE). Meanwhile, during catalysis, the Ag/GDY/CC composite maintains excellent stability with a high current density of ≈26 mA/cm2 (threefold higher than that of Ag/CC), unchanged for over 24 h. To the best knowledge, herein, the first experimental study of an efficient CO2 reduction electrocatalyst based on GDY is represented.