Interfacial engineering of Cu2Se/Co3Se4 multivalent hetero-nanocrystals for energy-efficient electrocatalytic co-generation of value-added chemicals and hydrogen

Integrating organic upgrading and hydrogen electrolysis is recently regarded as a win-win strategy. However, it is still challenging to construct efficient robust electrocatalysts to considerably minimize their energy demand for such coupled reaction and simultaneously avoid the emission of environment-unfriendly CO2. Herein, the Cu2Se/Co3Se4 multivalent hetero-nanocrystals (CuCoSe-HNCs) are fabricated as efficient electrocatalysts through interfacial engineering, thus constructing abundant hetero-junctions on monodispersed CuCoSe-HNCs and facilitating the charge transfer at Cu–Se–Co hetero-interfaces. DFT studies reveal the multivalent CuCoSe-HNCs with hydroxylated surfaces, which possess complex species (Cu*−OOH, Co*−OOH, and SeOx) as synergistic active centers, thus effectively optimizing the surface adsorption/dissociation performance and suppress excessive oxidation to CO2. Hence, the methanol upgrading conversion to value-added formate is achieved at much low working potential (1.11V) with high faradaic efficiency (>98 %) and without CO2 emission, thus considerably decreasing the energy consumption for generating the only gas product of pure hydrogen.