Exceptional photodecomposition activity of heterostructure NiTiO3–TiO2 catalyst

Abstract

Mesoporous TiO 2 mixed with NiTiO 3 at various concentrations was synthesized by combining sol–gel and eco-friendly hydrothermal methods. The properties of the NiTiO 3 –TiO 2 (NTO–Ti) photocatalyst were characterized using Χ-ray diffraction, Raman spectroscopy, scanning electron microscopy, Fourier-transform infrared spectroscopy, Brunauer–Emmett–Teller adsorption, energy dispersive X-ray, and UV–vis absorption spectra techniques. The photocatalytic activity of NTO–Ti catalysts was assessed by way of the photodegradation of cinnamic acid (CA) under UV-A irradiation. The effects of the operating parameters, including catalyst dosage, airflow, and initial solution pH on the photodecomposition efficiency of CA were also investigated. Research results confirm that NTO–Ti heterostructure catalysts are synthesized in the crystalline phase with high crystallinity. Compared with pure TiO 2 , the NTO–Ti catalysts have a smaller particle size and average crystallite size (8.6–9.0 nm versus 34.8 nm) and lower band gap energy (3.02–3.08 eV versus 3.20 eV). The catalysts also enable a redshift in the absorption band from UV (λ = 385 nm) to UV-A light (λ = 404–412 nm). The study showed that the physicochemical and photochemical properties and the photocatalytic performance of the NTO–Ti catalysts are controlled by the NiTiO 3 loading. NTO–Ti with NiTiO 3 1.0 wt.% was found to maximize CA photodegradation. Under the most favorable conditions, CA removal of 82.8% was obtained after 120 min, which is higher than for pure TiO 2 (68.7%) and NiTiO 3 (3.8%) catalysts under the same conditions. • Mesoporous TiO 2 nanomaterials mixed with NiTiO 3 of various concentrations were synthesized. • The heterostructured NiTiO 3 -TiO 2 nanomaterials had advantages of properties and photocatalytic performance over the pure TiO 2 . • 1.0%NiTiO 3 -TiO 2 was found to be the most effective catalyst with the 120 min TOS removal efficiency of CA reached 82.8%.