Cu nanoparticles decorating rGO nanohybrids as electrocatalyst toward CO 2 reduction

Cu-based composites with different compositions and construction can seriously influence its electrocatalytic performance toward CO2 reduction reaction (CO2RR). Herein, we report a microwave-assistant route to prepare Cu nanoparticles decorating reduced graphene oxide (CuNPs/rGO) nanohybrids, which are characterized by a variety of techniques, demonstrating that Cu nanoparticles coupling with CuxO nanoparticles were uniformly anchored on the surface of rGO, as well as the existence of grain boundaries. The CuNPs/rGO composites are studied as electrocatalyst for CO2RR and show a favorable electrocatalytic activity toward CO2RR with an onset potential of −0.9 V, corresponding to about only 190 mv overpotential for CO generation. Besides with a small amount of HCOOH (<5%), H2 and CO are the main CO2 reduction products with a tunable ratio of from 1.16:1 to 6.38:1 by changing the applied potentials. The gaseous products with various ratio of H2 to CO can be potentially used as syngas to produce more valuable products in industry. This work demonstrates a simple, facile and effective way to improve the electrocatalytic CO2RR performance of Cu-based composites.