Abstract Heretofore, the metal elements constituting the electrolyzed water catalysts are almost all Fe, Co, and Ni, and the accelerator elements are V, W, Ce, etc., but there is a lack of exploration for other elements. Niobium (Nb) is a promising promoter due to its complex chemical properties and the ability to react with many elements to form abundant compounds. Taking Co4N as the research case, this work incorporates Nb atoms to tune the d orbital of metallic Co4N nanowires. Experimental results and density functional theory calculations show that due to the adjustment of Nb atoms, the d-band center of Co4N moves down, which helps facilitate the desorption of H2. At the same time, abundant Co3+ active sites are generated on the surface of Nb–Co4N, which is crucial for the formation of oxygen evolution reaction (OER) intermediates (∗OOH). Nb-regulated Co4N nanosheets on the three-dimensional Ni foam (Nb–Co4N/NF) drives the current density of 20 mA cm−2 at a low overpotential of 90 mV for hydrogen evolution reaction and 273 mV for OER, respectively. This work inspires a novel idea for the rational design and synthesis of highly efficient electrocatalysts composed of novel less used elements for overall water splitting.

中文翻译：

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用新型 Nb 调节 Co4N 的电子结构以形成用于电催化整体水分解的分级多孔纳米片

摘要 迄今为止，构成电解水催化剂的金属元素几乎全部为Fe、Co、Ni，促进剂元素为V、W、Ce等，但对其他元素缺乏探索。铌 (Nb) 是一种很有前途的促进剂，因为它具有复杂的化学性质，并且能够与许多元素反应形成丰富的化合物。以 Co4N 为研究案例，这项工作结合了 Nb 原子来调整金属 Co4N 纳米线的 d 轨道。实验结果和密度泛函理论计算表明，由于 Nb 原子的调整，Co4N 的 d 带中心向下移动，有利于 H2 的解吸。同时，在 Nb-Co4N 表面生成了丰富的 Co3+ 活性位点，这对于析氧反应 (OER) 中间体 (*OOH) 的形成至关重要。三维泡沫镍 (Nb–Co4N/NF) 上的 Nb 调节 Co4N 纳米片驱动电流密度为 20 mA cm−2，析氢反应的过电位分别为 90 mV 和 OER 的过电位为 273 mV。这项工作激发了合理设计和合成高效电催化剂的新想法，该催化剂由用于整体水分解的新型较少使用元素组成。