Solar-driven hydrogen production from a water-splitting cycle based on carbon-TiO2 nano-tubes

This study illustrates the structuring of the TiO2 within carbon nano-tubes to enhance the solar-driven production of hydrogen (S-DPOH) via water splitting. The newly developed Carbon-TiO2 nano-tubes (C-Ti-NTs) aimed at improving the practical applications of TiO2 composites under natural solar irradiation conditions, enhancing the absorption of UV and VIS-light, reduces the required bandgap energy and decreases the chance for photoinduced-charges recombination. The C-Ti-NTs were prepared using an alkaline hydrothermal method, characterized using different state of art techniques and tested for the S-DPOH via water splitting. Adding a carbon layer on the surface of TiO2 nano-tube with a thickness of similar to 1 nm reduced the bandgap of the C-Ti-NTs <= 0.88 eV, improved the quantum efficiency under UV light to 100%, enhanced the absorption capacity under VIS-light and extremely suppressed the charge recombination. The S-DPOH achieved a cumulative production of hydrogen (CPOH) during 50 h of solar irradiation of 43.75 mmol at a rate R-POH'of H-2 production of 38.66 +/- 0.655 mmol/h.g, which is 1.5 folds higher than the maxim rate reported for pure TiO2-based photocatalyst. The obtained results confirmed the contribution of TiO2 for the production of hydrogen, which is expected to open a new insight towards the importance of architectural design and band engineering in the practical development of sustainable solar energy harvesting applications. (C) 2021 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.

Automated summary

This study focuses on enhancing the production of hydrogen through water splitting by structuring TiO2 within carbon nano-tubes. The findings show that carbon-TiO2 nano-tubes have improved UV and VIS-light absorption, reduced bandgap energy, and suppressed charge recombination, resulting in higher hydrogen production compared to pure TiO2 photocatalyst.