Phosphorus-Mediated Selenium Dual Atoms for Bifunctional Oxygen Reactions and Long-Life Low-Temperature Energy Conversion

Abstract

Rapid kinetics and stable atom configuration of the catalysts are essential and greatly sought after for bifunctional oxygen reactions and energy conversion devices, but remain unsatisfactory. Herein, the Se dual atoms structure consisting of the periodically arranged Se-P-Se configurations within graphitic nitrogen carbon framework (P-Se dual atoms-NC) is constructed by P directionally mediated single atoms deposition strategy. The in situ/ex situ experiments combining the theoretical calculations reveal that both the inter-site distance effect of the adjacent Se atoms in the NC and the Se-P binding effect endow P-Se dual atoms-NC with a stable atom configuration and ultra-durable lifespan, and the locally polarized electronic micro-environment built by P 2p-Se 3d-C 2p orbital hybridization and the electrons transfer significantly promotes H₂O-O₂ coupling, boosts the adsorption/desorption of O-intermediates and accelerates the electron transport kinetics. Moreover, the adjacent Se atoms with a periodically arranged structure could provide more sites for the absorption and conversion of reactants. Thus, the as-prepared catalyst exhibits the top-level bifunctional activity with an ultra-low potential difference (ΔE) of 0.58 V and delivers the outstandingly low-temperature specific capacity of 796.41 mAh g_Zn⁻¹ and the ultra-durable lifespan over 1000 h for assembled zinc-air batteries at −40 °C.