In situ interfacial engineering of nickel tungsten carbide janus structures for highly efficient overall water splitting

The Ni2W4C-W3C Janus structures with abundant superficial Ni–W metallic bonds have been demonstrated. The inserting of Ni atoms into the W3C crystals generate a new Ni2W4C phase, making the inert W atoms in W3C be active sites in Ni2W4C for the overall water splitting.