关键词: 溶胶－凝胶法, 催化剂, 光催化, 制氢, 镍氧化物负载

Abstract:

A novel kind of photocatalyst,namely NiO_x-loading Fe /K₂La₂Ti₃O₁₀,was prepared by means of sol-gelmethod and impregnation method,and the photocatalytic activity of the product for hydrogen generation from watersplitting was investigated. Then,the photocatalyst samples were characterized and analyzed by means of SEM,XRD,UV-vis DRS and XPS. The results show that the prepared catalysts with layered structure are sensitive to visiblelight,and that,after the loading of NiO_x,the photocatalytic activity increases to 477.3 μmol /g ( calculated asthe hydrogen production after 6 hours of accumulation) ,the band-edge absorption value has a blue shift,the directforbidden gap widens and the redox ability of electron-hole pairs improves. Moreover,as for the photoca-talyticmechanism,lanthanum in the compound serves as the main electron donor,the loading of NiO_x provides addedactive sites for reactant adsorbing,and the NiO groups on the surface produce captures of free electrons,thus promotingthe reduction of H⁺ on the catalyst surface.With this action,the reduced nickel in bulk produces capturesof photo-induced electrons and transfers them to the surface timely,thus decreasing the recombination ratio of electronsand holes.

Key words: sol-gel method, catalyst, photocatalysis, hydrogen production, nickel oxide loading