Yang Beibei, Du Yanyan, Shao Mengjiao, Bin Duan, Zhao Qiyuan, Xu Yufeng, Liu Baohong, Lu Hongbin
Department of Chemistry and Chemical Engineering, Nantong University, Nantong 226000, China.
Department of Chemistry and Chemical Engineering, Nantong University, Nantong 226000, China.
J Colloid Interface Sci. 2022 Jun 15;616:803-812. doi: 10.1016/j.jcis.2022.02.119. Epub 2022 Feb 26.
Water splitting is considered as a promising candidate for renewable and sustainable energy systems, while developing efficient, inexpensive and robust bifunctional electrocatalysts for the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) still remains a challenge. Herein, the well-designed RuCoP nanoparticles embedded in nitrogen-doped polyhedron carbon (RuCoP@CN) composite is fabricated by in-situ carbonization of Co based zeolitic imidazolate framework (ZIF-67) and phosphorization. Ru-substituted phosphate is proved to be imperative for the electrochemical activity and stability of individual catalysts, which can efficiently yield the active electronic states and promote the intrinsic OER and HER activity. As a result, a current density of 10 mA cm is achieved at a cell voltage as low as 1.60 V when the RuCoP@CN electrocatalyst applied for the overall water splitting, which is superior to the reported RuO and Pt/C couple electrode (1.64 V). The density functional theory (DFT) calculations reveal that the introduction of Ru and P atoms increase the electronic states of Co d-orbital near the Fermi level, decreasing the free energy of the hydrogen adsorption and HO dissociation for HER and the rate-limiting step for OER in alkaline media.
水分解被认为是可再生和可持续能源系统的一个有前景的候选方案，然而，开发用于析氢反应（HER）和析氧反应（OER）的高效、廉价且耐用的双功能电催化剂仍然是一个挑战。在此，通过钴基金属有机框架（ZIF-67）的原位碳化和磷化制备了嵌入氮掺杂多面体碳（RuCoP@CN）复合材料中的精心设计的RuCoP纳米颗粒。事实证明，Ru取代的磷酸盐对于单个催化剂的电化学活性和稳定性至关重要，它可以有效地产生活性电子态并促进本征OER和HER活性。结果，当RuCoP@CN电催化剂用于全水解时，在低至1.60 V的电池电压下实现了10 mA cm的电流密度，这优于报道的RuO和Pt/C耦合电极（1.64 V）。密度泛函理论（DFT）计算表明，Ru和P原子的引入增加了费米能级附近Co d轨道的电子态，降低了HER中氢吸附和OH解离的自由能以及碱性介质中OER的速率限制步骤。
