Built-In Electric Fields and Interfacial Electron Modulation: Enhancement of Oxygen Reduction Reaction in Alkaline Seawater

The development of an electrocatalyst for oxygen reduction reaction (ORR) in a seawater electrolyte is the key to realizing the utilization of marine resources and application of Zn-air batteries (ZABs). Exploring the adsorption and desorption behavior of oxygen can guide the design of catalysts fundamentally and improve the catalytic performance. On this basis, WC and Co on nitrogen-doped carbon (WC-Co@NC) with an interfacial built-in electric field (BEF) is designed as an ORR catalyst. The theoretical calculation certifies that the BEF of WCCo connections promote charge separation and directional migration, thus realizing the oxygen adsorption equilibrium and speeding up the process of ORR. These give WC-Co@NC a high half-wave potential of 0.872 V, and the alkaline seawater-based ZAB with WC-Co@NC as the air cathode has a peak power density of 188.8 mW cm-2 and excellent stability. This work can provide a basis for the rational design of the cathode of alkaline seawater-based ZAB, and can also give a new direction for the utilization of seawater resources. WC and Co on nitrogen-doped carbon (WC-Co@NC) is designed as an oxygen reduction reaction (ORR) catalyst in alkaline seawater. Characterization and calculation certify that the interfacial built-in electric field of WCCo connections promotes charge separation and directional migration, thus realizing oxygen adsorption equilibrium and speeding up the process of ORR. These make alkaline seawater-based zinc io batteries with WC-Co@NC as the air cathode exhibit excellent performance.image