Studies On The Preparation And Photoelectrocatalytic Hydrogen Evolution Performance Of Zn In₂S₄ Based Nanostructured Film Photoelectrodes

Photoelectrocatalytic based on semiconductor materials is one of the ideal methods to use abundant solar energy and water to produce hydrogen, it has important research value and development prospects to obtain green energy and ease the energy crisis. Developing semiconductor photoelectrode materials with high efficiency, stable and low cost is the key to the realize of the photoelectrocatalytic technology. ZnIn₂S₄ is a kind of promising ternary metal sulfide photoelectric material, it has proper band gap, superior visible light adsorption ability and good stability. This paper devotes to research photoelectric catalysis based on ZnIn₂S₄. Using doping and loading methods to solve the problem that photogenerated carrier separation efficiency of ZnIn₂S₄ is low and improve the performance of photoelectrocatalytic hydrogen production.ZnIn₂S₄ film photoelectrodes prepared by hydrothermal method, using urea and Ni（NO3）2·6H2O as raw materials, ethanol and glycol as mixed solvent, the NiO loaded ZnIn₂S₄ film photoelectrodes have been prepared by alcoholthermal method. XRD results show the load of NiO can not destroy the crystal structure of ZnIn₂S₄ nano structure film photoelectrodes. NiO was loaded on the surface of ZnIn₂S₄ nanosheet which presents helminth shape. The results of EIS indicate that the load of NiO improve the interface charge transfer performance between the photoelectrode and electrolyte. ZnIn₂S₄/NiO-10% photoelectrode has the best charge transfer and hydrogen production performance. The photocurrent densities of all the NiO loaded photoelectrodes were higher than the unloaded one. The load of NiO has also enhanced the stability of the photoelectrode through the stability test.Ni-doped ZnIn₂S₄ film photoelectrodes had been prepared by a convenient hydrothermal method. The results of SEM and TEM show photoelectrodes are composed of nanosheet which perpendicular to the conductive glass substrates and present a reticulated porous structure. The results of XRD, HRTEM, EDS, XPS tests prove that comparing with undoped ZnIn₂S₄ photoelectrodes, Ni-doped ZnIn₂S₄ photoelectrodes have higher photocurrent response, and 2wt% Ni-doped ZnIn₂S₄ photoelectrode has the best hydrogen production property. EIS results imply that 2wt% Ni-doped ZnIn₂S₄ photoelectrode has the smallest interfacial charge transfer resistance. This is the reason why 2wt% Ni-doped ZnIn₂S₄ photoelectrode has the best photoelectrocatalytic performance. Otherwise, photocurrent density-time plots suggest that the stability of 2wt% Ni-doped ZnIn₂S₄ photoelectrode is better than the undoped one.The novel and efficient NiO loaded ZnIn₂S₄ film photoelectrodes and Ni-doped ZnIn₂S₄ film photoelectrodes have been prepared by hydrotherma-alcoholthermaland method hydrothermal method, respectively. The PEC and hydrogen production performance of the novel photoelectrode materials have been improved, which can offer a reference for the modification research and development of photoelectrode materials.