Carbon-based nanomaterials: Characteristics, dimensions, advances and challenges in enhancing photocatalytic hydrogen production

The majority of research in the carbon-based nanomaterials (CNMs) field has concentrated on the classification and synthesis of CNMs, with relatively few studies focusing on CNMs' roles in photocatalytic hydrogen production. CNMs have proven their potential as an effective addition to the appeal of photocatalytic hydrogen evolution because of their su-perior chemical and physical properties. This paper explores the recent advancements in photocatalytic hydrogen (H2) production utilizing CNMs. As evidenced in the literature, carbon quantum dot (CQD)-sensitized titanium dioxide (TiO2) can demonstrate to have a photocatalytic hydrogen generation activity of 472 mol g-1 h-1 and 1458 mol g-1 h-1 without and with loading metal co-catalyst (Pt). The optimum catalyst, 0.4 CQD/CdS, contributes to the highest H2 production rate of 309 mmol g-1 h-1 (apparent quantum yield of 32.6%), which is 1.5 times greater than that of bare CdS. This would significantly accelerate the hydrogen production process. There are still challenges to reaching maximum photocatalytic hydrogen production, including low hydrogen storage. The overall price of hydrogen produced via photocatalysis is also higher because of the energy needed to store the hydrogen. Even though the problem is not directly related to the usage of CNMs, this restriction generates uncertainty and limits commercial investment. Given the rising demand for energy and the trend toward green power, it is recommended that extensive industrial uses of photocatalytic hydrogen produced by employing CNMs be investigated for better and more sustainable energy frameworks.(c) 2023 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.