Ultra-thin carbon bridged MoC quantum dots/g-C3N4 with charge-transfer-reaction highways for boosting photocatalytic hydrogen production

• Published in: Journal of alloys and compounds Vol. 910; p. 164864
• Main Authors: Cui, Chunli, Zhang, Genrui, Yang, Yu, Wu, Tingting, Wang, Lei
• Format: Journal Article
• Language: English
• Published: Lausanne Elsevier B.V 25-07-2022; Elsevier BV
• Subjects: Carbon; Carbon nitride; Charge transfer; Electron transfer bridge; G-C3N4 nanosheets; Heterojunctions; Highway construction; Hydrogen evolution; Hydrogen production; MoC quantum dots; Nanosheets; Noble metals; Photocatalysis; Photocatalysts; Photocatalytic H2 production; Quantum dots; Surface reactions; Water splitting; MoC quantum dots; G-C3N4 nanosheets; Photocatalytic H2 production; Heterojunctions; Electron transfer bridge
• ISSN: 0925-8388; 1873-4669
• DOI: 10.1016/j.jallcom.2022.164864

Constructing heterojunction has been proved to be an efficient strategy for enhancing the photocatalytic performance of g-C3N4 by prohibiting charge recombination and providing surface active sites. Herein, a novel structure of ultra-thin carbon bridged MoC quantum dots/g-C3N4 nanosheets was constructed for the first time to facilitate carrier transfer and accelerate surface reactions. In our designed composites, a surface-to-surface contact has been formed between conductive carbon layer and g-C3N4 nanosheet via ultrasonic assembly process. Moreover, there exist strong interfaces between MoC QDs and carbon layer because of the in-situ conversion method. As to this unique structure, the ultra-thin carbon layer functions as charge separation and migration high ways while the MoC QDs perform as noble-metal-free co-catalysts consuming the surface electrons promptly. Significantly, an optimal 40 wt% MoC QDs-C/g-C3N4 photocatalyst (MCCN) is synthesized with a hydrogen evolution rate of 2989 μmol h−1 g−1, which is 69.6 and 1.7 times higher than that of pure g-C3N4 and Pt/g-C3N4, respectively. Our work provides new insights on designing highly efficient heterojunction photocatalysts for water splitting.
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•The hybrid MoC QDs-C/g-C3N4 were prepared by ultrasonic self-assembly method.•The carbon layer acts as carrier transfer bridge to speed up the separation and migration of photo-generated charge.•The MoC QDs perform as an efficient non-noble metal co-catalysts to consume electrons efficiently.•The optimized MoC QDs-C/g-C3N4 shows 69.6-fold and 1.7-fold improvement over pure g-C3N4 and Pt loaded g-C3N4.