Graphdiyne/copper sulfide heterostructure for active conversion of CO2 to formic acid

Abstract

The synthesis of electrocatalysts with high selectivity, activity, and stability for the CO₂ reduction reaction (CO₂RR) is a promising and sustainable route to convert CO₂ into value-added chemicals at room temperatures and pressures. Here we report a new heterostructured electrocatalyst of graphdiyne/copper sulfide (GDY/CuS_x) via the controlled in situ growth of GDY on the surface of CuS_x. Our results show that the introduction of GDY can effectively induce the formation of mixed-valence Cu(I, II) and incomplete charge transfer between the GDY and Cu atoms, which enhance the conductivity, produce new active sites, and finally result in a higher catalytic performance. In addition, the GDY grown on the surface of the catalysts endows the sample with a high long-term stability. Benefitting from above advantages, GDY/CuS_x shows a high CO₂-to-formate conversion performance with a high faradaic efficiency (FE) and long-term stability at room temperatures and ambient pressures.