Coordination confinement pyrolysis to hollow sea urchin shaped composite with embedded ultrasmall Co/Ni alloy for overall water splitting. (19th January 2022)

• Record Type: Journal Article
• Authors: Wang, Xiaoyu; Li, Qingqing; Hu, Jinsong; Zhou, Chuihui; Yang, Sixin; Huang, Xinhua
• Is Part Of: International journal of hydrogen energy. Volume 47:Number 6(2022)
• Page Start: 3699
• Page End: 3708
• Publication Date: 2022-01-19
• Subjects: Metal-organic frameworks derivatives -- Energy conversion and catalysis -- Electrocatalysis -- Overall water splitting -- Hydrogen evolution reaction; Hydrogen as fuel -- Periodicals; Hydrogène (Combustible) -- Périodiques; Hydrogen as fuel; Periodicals; 665.81
• DOI: 10.1016/j.ijhydene.2021.10.243
• Languages: English
• ISSNs: 0360-3199

Abstract

Abstract: Electrocatalytic water splitting has been extensively studied for producing clean fuels in energy conversion and utilization. However, the huge challenge is remaining existence for developing efficient and low-cost non-noble metal electrocatalysts. Herein, an efficient hollow sea urchin-shaped water-splitting catalyst was prepared by coordination confinement pyrolysis strategy, in which the superminiature Co/Ni alloy ( ca . 5 nm) was embedded into the nanorods assembly unit successfully. This as-synthesized catalyst not only reveals satisfactory catalytic efficiencies with 70 and 296 mV overpotentials for HER and OER at the current density of 10 mA cm −2, but also demonstrates the total stabilities for HER, OER, and over water splitting after long-term electrolytic process with the negligible potentials increase by 2.8%, 2.9%, and 1.8%. Therefore, the catalyst integrates the advantages of superminiature Co/Ni alloy particles, hollow structure, and slender nanorods, which could provide a new route to design and prepare other efficient electrocatalysts. Graphical abstract: In this study, coordination confinement pyrolysis method was introduced to produce an efficient bifunctional electrocatalyst with inherited hollow sea urchin shaped morphology, in which the ultra-small Co/Ni alloy with ca . 5 nm in size were embedded into the nanorods assembly unit. The catalyst not only realizes the satisfying catalytic efficiencies with overpotentials of 70 and 296 mV for HER and OER at the current density of 10 mA cm −2, but also delivers all right stability for HER, OER and over water splitting after long-term electrolytic process, with the negligible potentials increase by 2.8%, 2.9% and 1.8%. Image 1 Highlights: Hollow sea urchin shaped electrocatalyst with ultrasmall Co/Ni alloy was prepared by coordination confinement pyrolysis. The ultrasmall Co/Ni alloy embedded on nanorods offer numerous active sites and accelerates the mass transfer. The electrocatalyst realizes overpotentials of 70 mV and 296 mV for HER and OER at the current density of 10 mA cm −2 . Electrocatalytic mechanisms were studied by XPS, TEM, XPS, UPS, Raman, et al.