Electrodeposited cobalt phosphide superstructures for solar-driven thermoelectrocatalytic overall water splitting

We demonstrate solar-driven thermoelectrocatalytic water splitting using unique cobalt phosphide (Co₂P) sheet-on-leaf superstructures. Co₂P is synthesized through a one-step room-temperature electrodeposition technique that precludes the release of toxic PH₃ gas, where the in situ process warrants electron and mass transfer between Co₂P and the underlying substrate for effective electrocatalytic reactions. Facilitated by thermionic energy harvested from sustainable solar irradiance conversion, the electrocatalytic behaviours of Co₂P are remarkably increased. These superstructures are endowed with a higher electrical conductivity and electrochemical surface area, reduced activation energy and enhanced solar-to-heat conversion efficiency to accelerate electrocatalysis.