Synthesis of NiFe2O4/TiO2-Ag+ S-scheme photocatalysts by a novel complex-assisted vapor thermal method for photocatalytic hydrogen production

This work aims to design and develop a photocatalyst with the main three properties: i) reduced bandgap for solar activation of the photocatalyst, ii) retarded e(-)/ h(+) recombination rate for the enhanced photocatalytic activity, iii) magnetic separability from the reaction medium. In this study, NiFe2O4/TiO2-Ag( )(+)photocatalysts were synthesized to modify the structural properties of TiO2. Firstly, NiFe2O4 nanoparticles were synthesized by a conventional co-precipitation method, then in the presence of NiFe2O4 nanoparticles, TiO2 was synthesized by a novel complex-assisted vapor thermal (VT) method via slow hydrolysis of Ti-complex. After the best wt% amount of NiFe2O4 in the NiFe2O4/TiO2 had been determined for photocatalytic activity, Ag+ was added by wet-impregnation. The photocatalysts were characterized by X-ray diffraction (XRD), UV-vis Diffuse Reflectance Spectroscopy (DRS), Photoluminescence Spectroscopy (PL), vibrating sample magnetometer analysis (VSM), transmission electronic microscopy (TEM), and X-ray photoelectron spectroscopy (XPS).