In-situ construction of metallic Ni3C@Ni core–shell cocatalysts over g-C3N4 nanosheets for shell-thickness-dependent photocatalytic H2 production

By Rongchen Shen, Kelin He, A. Zhang, Neng Li, Y. Ng, Peng Zhang, Jun Hu, Xin Li. 2021

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Abstract Herein, we designed the shell-thickness-controlled Ni3C@Ni/g-C3N4 photocatalysts with intimate Schottky-junctions by an in situ high-temperature transformation strategy. Meanwhile, we found that the cocatalysts with optimized Ni shell-layer thickness of 15 nm could achieve the best visible-light photocatalytic H2-production performance of 11.28 μmolh−1, with an apparent quantum yield (AQY) of 1.49 % at 420 nm, which was 16 times higher than that of Ni3C/g-C3N4. Moreover, an excellent stability is achieved. The well-defined density functional theory (DFT) calculations indicate that the “TOP_C1” sites of Ni3C@Ni can exhibit the H adsorption and Gibbs free energies of -0.07eV and 0.18 eV, respectively, which should be hydrogen-evolution active sites instead of two “HOLLOW” sites. Interestingly, the intimate Schottky-junctions, could hinder rapid charge recombination, increase reactive sites, boost catalytic kinetics and passivate unstable surface of Ni3C, thus achieving shell-thickness-dependent hydrogen evolution. Therefore, the Ni3C@Ni core–shell cocatalysts will open a new avenue for robust solar fuel production.

Subfields: Materials Chemistry, Renewable Energy, Sustainability and the Environment

View Paper: https://www.semanticscholar.org/paper/1121aa6ebef88775571e83f503d6b2fa60cfe3c0