Control Strategy on Two-/Four-Electron Pathway of Water Splitting by Multidoped Carbon Based Catalysts

Overall photocatalytic water splitting can proceed through a four-electron or two-electron/two-step pathway. However, it is challenging to manipulate the two- or four-electron pathway. Here, we present a carbon-based nanostructure codoped with nitrogen, sulfur, and a transition metal that exhibits reliable photocatalytic ability and satisfactory photostability in water splitting without the need for sacrificial agents. Note that in the present system the transition-metal-doped structure (M = Cr, Cd, Fe, Zn) as a photocatalyst splits water into H₂ and O₂ through a two-electron pathway while the structure on doping with rare-earth (Re) elements (M = Re = Sm, Ce, Eu, Pr, Er) acts as a photocatalyst via a four-electron pathway and carbon dots work herein as an electron acceptor and a reduction cocatalyst.