Synergetic effect of metal-doped GO and TiO₂ on enhancing visible-light-driven photocatalytic hydrogen production from water splitting

Abstract

Although titanium dioxide (TiO2) is frequently used as photocatalyst, but its wide band gap decreases its catalytic activity in the visible light. To improve the visible light activity, Cobalt (Co) and Nickel (Ni)-doped Graphene oxide (GO) supported TiO2 were fabricated. The characterization results showed that the successfully doping of the Co and/or Ni on the GO as well as the incorporation TiO2 in the nanocomposite catalyst. The photon-induced evolution of H2 was remarkably enhanced when Ni and Co doped GO was introduced. Furthermore, the optimum ratio of GO:Ni:TiO2 in the hybrids was 10:1:2, while the higher TiO2 ratio would decrease the hydrogen production performance and photocatalytic activity. In contrast, the catalytic activity and H2 production rate were increased by increasing the TiO2 ratio in the GO:Co:TiO2 nanocomposite catalyst and the highest performance was obtained at ratio of 10:1:5, respectively. The remarkably boosted photocatalytic performance under visible (solar) light may be mainly assigned to the synergetic effect of Ni/Co and GO supported TiO2.