Enhanced photocatalytic performance of Ni-ZnO/Polyaniline composite for the visible-light driven hydrogen generation

NixZn1-xO/Polyaniline hybrid photocatalysts are synthesized and used for the experiments of hydrogen production from water-splitting under visible irradiation. XRD, UV-Vis absorption and SEM-EDX are used to characterize the prepared materials. It is shown that the Ni2+ amount doped into ZnO controls its morphology and enhances its photoactivity for H2 generation. Polyaniline (PANI) is shown to sensitize ZnO and to extend its light absorption toward the visible region. The hybrid photocatalyst with 10 mol. % Ni2+ and 10 wt. % PANI shows the maximum photocatalytic H2 production for 1 h of visible irradiation: ∼558 μmole while only ∼178 μmole in the presence of pure ZnO. Additives such as sacrificial electron donors are found to play a key role in the improvement of H2 evolution. Thus, the hydrogen photoproduction efficiency increases in the following order: thiosulfate > sulfide > propanol. All the obtained results show that Ni-ZnO/PANI hybrid photocatalyst is a good candidate to promote the H2 production using visible/solar lights.