Photocatalytic hydrogen production by ternary heterojunction composites of silver nanoparticles doped FCNT-TiO_2

摘要

Silver nanoparticles doped with FCNT-TiO_2 heterogeneous catalyst were prepared via one-step chemical reduction process and their efficacy was tested for hydrogen production under solar simulator. Crystallinity, purity, optical properties, and morphologies of the catalysts were examined by X-ray diffraction, Raman spectroscopy, UV-visible diffuse reflectance spectra, and transmission electron microscopy. The chemical states and interface interactions were studied by X-ray photoelectron spectroscopy and Fourier transform infrared spectroscopy. The optimized catalyst showed 19.2 mmol/(g h) of hydrogen production, which is 28.5 and 7 times higher than the pristine TiO_2 nanoparticles and FCNT-TiO_2 nanocomposite, respectively. The optimized catalyst showed stability up to 50 h under the solar simulator irradiation. The natural solar light irradiated catalyst showed -2.2 times higher hydrogen production rate than the solar simulator irradiation. Aplausible reaction mechanism of Ag NPs/FCNT-TiO_2 photocatalyst was elucidated by investigating the beneficial co-catalytic role of Ag NPs and FCNTs for enhanced hydrogen production.