A facile synthetic approach for TiO2@NiO core‐shell nanoparticles using TiO2@Ni(OH)2 precursors and their photocatalytic application

The current study presents a simple and an efficient chemical method for the synthesis of TiO2@NiO core‐shell nanoparticles (CSNPs) as photocatalyst for effective degradation of rhodamine B (RhB) in aqueous solution upon sunlight irradiation. First, TiO2 spheres were synthesized using a wet chemical method. Then, TiO2@Ni(OH)2 precursors were prepared via homogeneous precipitation and TiO2@NiO core‐shell nanoparticles were obtained on calcination of the precursors. The synthesized precursors and the TiO2@NiO CSNPs were analyzed using XRD, FT‐IR, FESEM and DRS. XRD data shows the presence of both TiO2 and NiO phases in the TiO2@NiO samples. FE‐SEM and TEM analyses confirm coating of NiO NPs on TiO2 spheres with varying shell thickness (40 nm to 170 nm). Optical studies reveal that TiO2@NiO CSNPs possess band gap of about ∼3.7 eV. Photoluminescence (PL) results show lower recombination rate of e− and h+ pairs in the TiO2@NiO CSNPs. XPS studies confirm the presence of different elements in the TiO2@NiO CSNPs. Magnetic investigations reveal ferromagnetic behavior of the core‐shell NPs at 5 K. The TiO2@NiO CSNPs were explored as photocatalyst for the degradation of rhodamine B in water under natural sunlight. The TiO2@NiO CSNPs exhibit better photocatalytic activity compared to TiO2 and NiO nanoparticles.