Tailoring the spin state of active sites in amorphous transition metal sulfides to promote oxygen electrocatalysis

Spin regulation of active sites is sparking much interest in boosting oxygen electrocatalytic performance. However, amorphous electrocatalysts, the design principle spin to promote catalytic activity remains unclear. Herein, we synthesized a series heteroatom-doped transition metal sulfides with regulated states using one-step hydrothermal process. Especially Mo-doped CoS, state Co2+ was successfully modulated low-spin state, which could optimize adsorption free energy various intermediates, improving reduction reaction kinetics. The fabricated Zn-air batteries (ZABs) delivered good cycle stability (over 100 h). large ZAB (100 cm2) exhibited high discharge voltage (1.25 V under 0.5 A) and superior overall mass-energy density (93 W h kg−1), illuminated 2.5-m light-emitting-diode ribbon for over seven days. This work provides new insight into mechanism engineering materials electrocatalysis.