Synergistic effect of cobalt in hierarchical carbon nitride nanorods (HCNNR) with promising charge transfer rate by hole scavenger for stimulating solar H2 production

• Published in: Journal of alloys and compounds Vol. 916; p. 165332
• Main Authors: Tahir, Beenish, Tahir, Muhammad, Siraj, Mohammad, Fatehmulla, Amanullah
• Format: Journal Article
• Language: English
• Published: Lausanne Elsevier B.V 25-09-2022; Elsevier BV
• Subjects: Carbon; Carbon nitride; Carbon nitrides nanorods (CNNR); Charge transfer; Charge transport; Cobalt; Cobalt cocatalyst; Current carriers; Hydrogen evolution; Hydrogen production; Mass transfer; Nanorods; Operating parameters; Parameters; Photocatalysis; Photocatalytic H2 evolution; Reagents; Sacrificial reagents; Solar energy; Synergistic effect; Photocatalytic H2 evolution; Cobalt cocatalyst; Sacrificial reagents; Operating parameters; Carbon nitrides nanorods (CNNR)
• ISSN: 0925-8388; 1873-4669
• DOI: 10.1016/j.jallcom.2022.165332

One-dimensional (1D) hierarchical carbon nitrides nanorods (HCNNRs) mediated by cobalt was designed and synthesized using a template free hydrothermal approach for improving solar light assisted H2 evolution. The performance of 1D HCNNTs was significantly enhanced compared to bulk g-C3N4 due to larger active surface area, more visible light utilization and superior charge carrier along the unidirectional flow pathways. The 2% Co/HCNNRs (1D) exhibited excellent photocatalytic efficiency and optimal H2 yield reached up to 620 µmol g−1, which is 11.27 and 17.71 folds more than it was attained with pure HCNNR and bulk g-C3N4, respectively. This reveals that 1D structure helps to accelerate charge transport, whereas, Co works as a mediator to trap electrons, thus improving photocatalytic performance. The crucial operating parameters such as sacrificial reagents, feed concentration and catalyst loading were further optimized based on highest H2 evolution. Interestingly, mass transfer, charge transfer and amount of photoinduced charges were greatly dependent on the operating parameters. Higher methanol and lower TEOA concentration were beneficial to yield highest photoactivity and stability. This work provides new approach to construct template free 1D nanorods and would be beneficial to enhance performance in other solar energy related applications.
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•1D porous graphic carbon nitride was fabricated using facile hydrothermal approach.•Higher porous structure with faster charge carrier separation was observed in 1D structure.•Using 1D Co/HCNNR, significantly higher H2 was obtained compared to bulk g-C3N4.•Catalyst loading, feed concentration and sacrificial reagents greatly affect activity and stability.