Surface‐Exposed Single‐Ni Atoms with Potential‐Driven Dynamic Behaviors for Highly Efficient Electrocatalytic Oxygen Evolution

Abstract

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.

Construction of a S and Fe co-regulated metal Ni electrocatalyst for efficient alkaline overall water splitting

“…To seek alternative catalysts for precious metals, exploration of transition metal based catalysts including single-atom catalysts, [8][9][10][11] alloys, 1,12 phosphides, [13][14][15][16][17] oxides, 18,19 (oxy) hydroxides, [20][21][22] suldes, 23,24 etc., has never stopped. Transition metals with excellent conductivity have attracted extensive attention.…”

Atomically dispersed Fe/Co dual site electrocatalysts derived from covalent triazine frameworks for boosting oxygen reduction

“…To understand the electrocatalytic activity of these samples, the electrochemical active surface areas (ECSAs) were measured. 54–56 From Fig. S10,† the double-layer capacitance ( C dl ) of Fe/Co–N–C is 28.24 mF cm −2 , and the corresponding ECSA is 706 cm 2 , while the ECSA of Fe–N–C and Co–N–C are 322 and 291 cm −2 , respectively, indicating the excellent mass transfer capacity derived from the synergistic catalysis of dual metal sites.…”

Challenges and Perspectives of Single-Atom-Based Catalysts for Electrochemical Reactions

“…They used the CdS balls covered with 3-aminophenol/formaldehyde resin as precursors, and then gas-migrated Ni single atoms diffused on the exterior surface. 56 After severe steps to remove the original CdS framework, the carbon spheres doped with a high-density Ni single atom were obtained. Nanoframe structures are also efficient strategies to increase the utilization of metal sites.…”