Synergistic Size and Electronic Engineering of Cr 3 C 2 @C(N x ) Nanoparticles Via Arc‐Discharge for
Enmin Lv, Yilong Wang, Hongtao Yu, Hao Zhang, Xuefeng Zhang, Xinglong DongABSTRACT
Developing efficient non‐precious oxygen reduction reaction (ORR) catalysts is essential for advancing zinc‐air batteries (ZABs). This work presents a one‐step synthesis of core‐shell Cr 3 C 2 @C nanoparticles (NPs) via DC arc‐discharge plasma. Precise regulation of cooling dynamics achieves a switch from growth‐dominated to nucleation‐dominated regimes, enabling controlled preparation of nanoparticles with distinct sizes. The liquid‐nitrogen‐cooled Cr 3 C 2 @C ln NPs exhibit smaller size and higher surface area, leading to enhanced ORR performance. Subsequent nitrogen doping at 700 °C produces Cr 3 C 2 @C ln (N x ) catalysts with precisely tuned nitrogen content (0.65–1.24 at.%). The optimized Cr 3 C 2 @C ln (N 1.13 ) demonstrates outstanding ORR activity with a half‐wave potential ( E 1/2 ) of 0.81 V and superior kinetics, surpassing commercial Pt/C. In situ optical emission spectroscopy (OES) monitors the plasma state and electron temperature, providing fundamental insights into nucleation mechanisms. Density functional theory (DFT) calculations reveal that nitrogen doping optimizes the p ‐band center of carbon and significantly reduces the energy barrier of the rate‐determining step (RDS) (*OH desorption). When applied in both liquid and solid‐state flexible zinc‐air batteries (FZABs), the Cr 3 C 2 @C ln (N 1.13 )‐based cathode delivers exceptional performance, achieving high power densities (230.64 and 164.83 mW·cm −2 , respectively) and remarkable cycling stability. This study offers an efficient strategy for designing high‐performance transition metal carbide electrocatalysts through synergistic control of size and electronic structure.