Biomass-derived carbon deposited TiO(2) nanotube photocatalysts for enhanced hydrogen production

In this study, titanium oxide nanotubes (TiO(2)NTs) were deposited on the surface of activated carbon (AC) by varying the wt% of AC. The physicochemical properties of synthesized TiO(2)NTs–AC nanocomposites were analysed by various characterization techniques such as XRD, FT-IR, Raman, DRUV-vis, HR-TEM, XPS, PL, and N(2) physisorption. The FT-IR, EDX, and XPS analyses proved the existence of interaction between AC and TiO(2)NTs. This study found that as the content of AC increases, the surface area and pore volume increase while the energy bandgap decreases. The TiO(2)NTs–AC nanocomposite with 40% AC exhibited a surface area of 291 m(2) g(−1), pore volume of 0.045 cm(3) g(−1) and half pore width = 8.4 Å and had a wide band gap energy (3.15 eV). In addition, the photocatalytic application of the prepared nanocomposites for photocatalytic H(2) production was investigated. The H(2) was produced via photo-reforming in the presence of a sacrificial agent (methanol) under sunlight irradiation. It was found that the prepared TiO(2)NTs–AC nanocomposite with 40% AC acted as an efficient photocatalyst for aqueous-methanol reforming under various optimization conditions. Approximately 18 000 μmol(−1) hydrogen gas was produced via aqueous-methanol reforming under optimized conditions (catalyst dose = 100 mg, temperature = 25 °C, time = 12 hours, vol. of methanol = 20% (v/v), and pH = 7). The reusability of the TiO(2)NTs–AC nanocomposite was also investigated for 5 consecutive cycles, and the results suggested only a slight decline in efficiency even after the fifth cycle. This study demonstrates the ability of an activated carbon deposited TiO(2)NT catalyst to produce hydrogen effectively under sunlight.