Surface-exposed single-Ni atoms with potential-driven dynamic behaviors for highly efficient electrocatalytic oxygen evolution

• Main Authors: Zhao, Yafei, Lu, Xue Feng, Fan, Guilan, Luan, Deyan, Gu, Xiaojun, Lou, David Xiong Wen
• Other Authors: School of Chemical and Biomedical Engineering
• Format: Article
• Language: English
• Published: 2023
• Subjects: Science::Chemistry; Electrocatalysis·; Hollow S/N-Doped Carbon Spheres
• Online Access: https://hdl.handle.net/10356/166123
• Institution: Nanyang Technological University

Trapping the active sites on the exterior surface of hollow supports can reduce mass transfer resistance and enhance atomic utilization. Herein, we report a facile chemical vapor deposition strategy to synthesize single-Ni atoms decorated hollow S/N-doped football-like carbon spheres (Ni SAs@S/N-FCS). Specifically, the CdS@3-aminophenol/formaldehyde is carbonized into S/N-FCS. The gas-migrated Ni species are anchored on the surface of S/N-FCS simultaneously, yielding Ni SAs@S/N-FCS. The obtained catalyst exhibits outstanding performance for alkaline oxygen evolution reaction (OER) with an overpotential of 249 mV at 10 mA cm−2, a small Tafel slope of 56.5 mV dec−1, and ultra-long stability up to 166 hours without obvious fading. Moreover, the potential-driven dynamic behaviors of Ni-N4 sites and the contribution of the S dopant at different locations in the matrix to the OER activity are revealed by the operando X-ray absorption spectroscopy and theoretical calculations, respectively.