Prominent roles of Ni(OH)2 deposited on ZnIn2S4 microspheres in efficient charge separation and photocatalytic H2 evolution

In this work, Ni(OH)(2)-deposited ZnIn2S4 microspheres (Ni(OH)(2)/ZnIn2S4) were fabricated using a hydrothermal process, followed by a facile in situ precipitation method. It was demonstrated that the deposition of Ni(OH)(2) on ZnIn2S4 effectively promotes the separation of charges photogenerated over ZnIn2S4, and significantly enhances photocatalytic H-2 evolution. The optimum rate of the photocatalytic H-2 evolution over the 6% Ni(OH)(2)/ZnIn2S4 composite reaches 4.43 mmol g(-1) h(-1), which is 21.1 times higher than that of the pure ZnIn2S4. Based on various characterization results and Au photo-deposition on the composite, it was proposed that the capture of the photogenerated holes by the deposited Ni(OH)(2) would be responsible for the efficient charge separation, which allows more photogenerated electrons to be left on the ZnIn2S4 for the reduction of H+ to H-2 with a higher rate.