ZnS modified N, S dual-doped interconnected porous carbon derived from dye sludge waste as high-efficient ORR/OER catalyst for rechargeable zinc-air battery

Facile and rational design of high-efficient oxygen reduction reaction (ORR)/oxygen evolution reaction (OER) bifunctional electrocatalysts is significant for rechargeable Zinc-air batteries. In this study, ZnS modified N, S dual-doped interconnected porous carbon (ZnS/NSC) derived from the dye sludge waste is successfully fabricated via a facile ZnCl2-assisted pyrolysis process. The effect of ZnCl2 and carbonization temperature on the microstructure and electrocatalytic performance is systematically investigated. By virtue of the synergistic effect between ZnS nanoparticles and N, S dual-doped porous carbon network, the obtained catalyst ZnS/NSC calcined at 1000 °C exhibits a decent bifunctional electrocatalytic performance with potential gap (ΔE=EOER,10-EORR,1/2) of 0.76 V comparable with commercial electrocatalysts (Pt/C and RuO2). In addition, a rechargeable zinc-air battery employed ZnS/NSC-1000 as the air cathode also displays the favorable electrochemical performance, in which the power density is 125 mW cm-2, the specific capacity is 763.27 mAh g-1 and the cycling stability at 10 mA cm-2 is more than 85 h, indicating a promising application prospect in rechargeable Zinc-air batteries.