Boosting visible-light-driven photocatalytic H2 evolution of C/Znln2S4 hollow tubes by Ni doping

An n-type nickel-doped carbon indium zinc sulfur (Ni/CZIS) hollow tube structure photocatalyst was synthesized for the first time through a simple solvothermal combination with an oil bath. Then it was characterized by a series of tests such as SEM, TEM, XRD, XPS, photoelectric properties and so on. The results showed that the addition of nickel acetate in the oil bath achieved uniform doping of nickel atoms and partially replaced the positions of zinc. The optimized Ni/CZIS material had lower overpotential, broadened the light absorption region, promoted photo-induced carrier separation and better hydrophilicity. Thus it showed an excellent visible-light photocatalytic hydrogen production rate (3035.75 μmol/g/h) and cyclic stability. In view of density functional theory calculations, Ni atomic doping narrowed the band gap width, changed the positions of the valence and conduction bands, and also generated a new hybridization level near the Fermi level. This energy level provided a new electronic channel for photo-generated electrons, facilitated the transfer of electrons and suppressed the recombination of carrier, thereby enhancing the photocatalytic hydrogen production performance.