Improving Photocatalytic Hydrogen Production with Sol–Gel Prepared NiTiO₃/TiO₂ Composite

This study presents a comprehensive investigation into the synthesis, characterization, and photocatalytic performance of NiTiO₃/TiO₂ nanocomposites for solar hydrogen production. Through a carefully optimized sol–gel method, we synthesized a heterojunction photocatalyst comprising 99.2% NiTiO₃ and 0.8% anatase TiO₂. Extensive characterization using XRD, Raman spectroscopy, FTIR, UV–visible spectroscopy, photoluminescence spectroscopy, and TEM revealed the formation of an intimate heterojunction between rhombohedral NiTiO₃ and anatase TiO₂. The nanocomposite demonstrated remarkable improvements in optical and electronic properties, including enhanced UV–visible light absorption and an 85% reduction in charge carrier recombination compared to pristine NiTiO₃. Crystallite size analysis showed a reduction from 53.46 nm to 46.35 nm upon TiO₂ incorporation, leading to increased surface area and active sites. High-resolution TEM confirmed the formation of well-defined interfaces between NiTiO₃ and TiO₂, with lattice fringes of 0.349 nm and 0.249 nm corresponding to their respective crystallographic planes. Under UV irradiation, the NiTiO₃/TiO₂ nanocomposite exhibited superior photocatalytic performance, achieving a hydrogen evolution rate of 9.74 μmol min−1, representing a 17.1% improvement over pristine NiTiO₃. This enhancement is attributed to the synergistic effects of improved light absorption, reduced charge recombination, and efficient charge separation at the heterojunction interface. Our findings demonstrate the potential of NiTiO₃/TiO₂ nanocomposites as efficient photocatalysts for solar hydrogen production and contribute to the development of advanced materials for renewable energy applications.