Interfacial engineering of Ru-doped Co3O4/CoP nanowires heterostructure as efficient bifunctional electrocatalysts for alkaline water splitting

• Low Ru incorporated Co 3 O 4 /CoP nanowires heterostructures on Ti mesh was successfully synthesized in site by a facile method. • Ru-Co 3 O 4 /CoP/TM electrodes displayed a well stability and outstanding water splitting performance. • The unique nanowire structure and synergetic cooperation between Co 3 O 4 and CoP phase can boost the water splitting kinetics. Designing a highly efficient bi-functional electrocatalyst for boosting both hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) is urgent and promising in hydrogen produce by water splitting. Here, a simple wet-chemical route followed by continuous oxidation and partial phosphorylation treatments is adopted to prepare the Ru doped Co 3 O 4 and CoP heterojunction nanowires on Ti mesh (Ru-Co 3 O 4 /CoP/TM). Benefit from the more active sites from the heterointerfaces and synergetic cooperation between Co 3 O 4 and CoP phase, the catalyst showed high electrocatalytic activity in alkaline solutions. It only required the overpotentials of 47 and 293 mV to deliver a current density of 10 mA cm −2 toward HER and OER in 1 M KOH medium, respectively. For overall water splitting (OWS), using Ru-Co 3 O 4 /CoP/TM as both the cathode and anode, it required an ultra-low cell voltage of 1.66 V to operate the current density of 20 mA cm –2 , and it also remained a robust stability during the electrocatalysis process.