State Key Laboratory of Fine Chemicals, School of Chemical Engineering, Dalian University of Technology, Dalian 116024, China.
Institute of Functional Textiles and Advanced Materials, College of Textiles and Clothing, State Key Laboratory of Bio-Fibers and Eco-Textiles, Qingdao University, Qingdao 266071, China.
Inorg Chem. 2023 May 29;62(21):8347-8356. doi: 10.1021/acs.inorgchem.3c00876. Epub 2023 May 18.
Accomplishing a green hydrogen economy in reality through water spitting ultimately relies upon earth-abundant efficient electrocatalysts that can simultaneously accelerate the oxygen and hydrogen evolution reactions (OER and HER). The perspective of electronic structure modulation via interface engineering is of great significance to optimize electrocatalytic output but remains a tremendous challenge. Herein, an efficient tactic has been explored to prepare nanosheet-assembly tumbleweed-like CoFeCe-containing precursors with time-/energy-saving and easy-operating features. Subsequently, the final metal phosphide materials containing multiple interfaces, denoted CoP/FeP/CeO, have been synthesized via the phosphorization process. Through the optimization of the Co/Fe ratio and the content of the rare-earth Ce element, the electrocatalytic activity has been regulated. As a result, bifunctional Co3Fe/Ce0.025 reaches the top of the volcano for both OER and HER simultaneously, with the smallest overpotentials of 285 mV (OER) and 178 mV (HER) at 10 mA cm current density in an alkaline environment. Multicomponent heterostructure interface engineering would lead to more exposed active sites, feasible charge transport, and strong interfacial electronic interaction. More importantly, the appropriate Co/Fe ratio and Ce content can synergistically tailor the d-band center with a downshift to enhance the per-site intrinsic activity. This work would provide valuable insights to regulate the electronic structure of superior electrocatalysts toward water splitting by constructing rare-earth compounds containing multiple heterointerfaces.
通过喷水来实现真正的绿色氢能经济最终依赖于丰富的高效电催化剂，这种电催化剂可以同时加速氧气和氢气的析出反应（OER 和 HER）。通过界面工程调节电子结构的观点对于优化电催化性能具有重要意义，但仍然是一个巨大的挑战。在此，探索了一种高效策略，用于制备具有节能、省时和易于操作特点的纳米片组装的滚草状含 CoFeCe 的前体。随后，通过磷化过程合成了含有多个界面的最终金属磷化物材料，记为 CoP/FeP/CeO。通过优化 Co/Fe 比和稀土 Ce 元素的含量，调节了电催化活性。结果表明，双功能 Co3Fe/Ce0.025 在碱性环境中，在 10 mA cm 的电流密度下，OER 和 HER 的过电位最小，分别为 285 mV 和 178 mV。多组分异质结构界面工程将导致更多暴露的活性位点、可行的电荷传输和强的界面电子相互作用。更重要的是，适当的 Co/Fe 比和 Ce 含量可以协同调整 d 带中心向下移动，以增强每个位点的固有活性。这项工作为通过构建含有多个异质界面的稀土化合物来调节优越电催化剂的电子结构以实现水分解提供了有价值的见解。
