Facile Synthesis of MAX Modified Graphitic Carbon Nitride Nanocomposite for Stimulating Hydrogen Production Through Photocatalytic Water Splitting

Abstract

Photocatalytic hydrogen production has been considered a promising strategy for developing green, sustainable, and clean energy resources to substitute non-renewable fossil fuels. A widely studied graphitic carbon nitride (g-C₃N₄) has garnered research attention due to their commercial availability and excellent photochemical efficiency to drive hydrogen generation through water splitting process. Undesirable recombination of photocarriers, higher electrostatic potential barriers, and low solar absorbance in a single g-C₃N₄ photocatalyst impede their efficiency in the energy conversion field. Several alternatives have been proposed over decades to improve the photocatalytic efficiency of g-C₃N_4. Among them, noble metal integration has been denoted as the most promising technique to maximize solar efficiency. Less availability and non-economical, however, limit their functionality surpasses their unique SPR characteristics. In this study, a novel composite of V₂AlC MAX/g-C₃N₄ that exhibits the same functionality as those of noble metals was fabricated via a sol-gel method, and their efficiency enhancement was investigated using a liquid slurry photoreactor system. The optimal 10% loading of V₂AlC exhibits maximum hydrogen generation up to 196.25 µmol g^-1 h^-1, which is 2.8-fold higher than pure g-C₃N₄. The photoactivity enhancement observed was due to the intimate contact formed between V₂AlC with g-C₃N₄, accelerating the migration of the photogenerated charges. The electrons confinement due to the induced Schottky junction hamper the recombination of and maximizes the separation of the photocarriers. The prepared sample was characterized by XRD, PL analysis, and SEM. The successful integration of V₂AlC with g-C₃N₄ was affirmed by XRD analysis as the characteristics peaks of both materials are present in the composite. The stacked irregular structure of V₂AlC/g-C₃N₄ highly indicates that a tight interface contact was formed between both semiconductors. This study provides new insight into newly developed V₂AlC MAX-based g-C₃N₄ for clean energy systems and unravels their potential in solar energy applications.