Laboratory of Theoretical and Computational Chemistry, Institute of Theoretical Chemistry, Jilin University, Changchun 130023, People's Republic of China.
Phys Chem Chem Phys. 2019 Jan 23;21(4):1773-1783. doi: 10.1039/c8cp06011h.
Inspired by the fascinating result that NbN-related species can possess a similar electronic structure to noble metal atoms (e.g. Pt), in this work we have proposed for the first time a new strategy, through embedding the transition metal (TM) Nb atom in the in-plane cavity of g-C3N4, for constructing the nonprecious Nb-C3N4 configuration comprising the NbN unit exhibiting noble-metal-like characteristics. Our computed results reveal that embedding Nb can significantly improve the catalytic activity for the hydrogen evolution reaction (HER) of g-C3N4, and even that the formed Nb-C3N4 can exhibit a considerably high HER catalytic activity over a wide range of hydrogen coverage. Similarly, such a high HER activity can also be observed in the analogous V- or Ta-doped g-C3N4 systems. Furthermore, a series of new hybrid systems TM-C3N4@G (TM = V, Nb or Ta) is constructed by coupling the single-layered TM-C3N4 with graphene, and all of them can also possess a considerably high HER catalytic activity over a wide range of hydrogen coverage. Moreover, all these composite TM-C3N4 and TM-C3N4@G systems possess high structural stability and metallic conductivity. Thus, all of them can be viewed as a new class of promising HER catalysts, and this work can also provide new strategies for designing low-cost and high-performance electrocatalysts.
受 NbN 相关物种具有类似于贵金属原子（如 Pt）的电子结构这一迷人结果的启发，本工作首次提出了一种新策略，即将过渡金属（TM）Nb 原子嵌入 g-C3N4 的面内腔中，构建包含具有贵金属特性的 NbN 单元的非贵金属 Nb-C3N4 构型。我们的计算结果表明，嵌入 Nb 可以显著提高 g-C3N4 对析氢反应（HER）的催化活性，甚至形成的 Nb-C3N4 在较宽的氢覆盖范围内也具有相当高的 HER 催化活性。同样，在类似的 V 或 Ta 掺杂 g-C3N4 体系中也可以观察到这种高 HER 活性。此外，通过将单层 TM-C3N4 与石墨烯耦合，构建了一系列新的混合体系 TM-C3N4@G（TM = V、Nb 或 Ta），它们在较宽的氢覆盖范围内也都具有相当高的 HER 催化活性。此外，所有这些复合 TM-C3N4 和 TM-C3N4@G 体系都具有高的结构稳定性和金属导电性。因此，它们都可以被视为一类有前途的新型 HER 催化剂，本工作也为设计低成本、高性能电催化剂提供了新策略。
