Constructing Bridging Heterointerfaces of PtCo/Co₉S₈ for Enhancing Oxygen Electrocatalysis in Zn–Air Batteries

Abstract

Constructing heteronanostructures is an essential approach for integrating multiple functionalities into one single entity. Here, PtCo/Co 9 S 8 composites with bridging heterointerfaces are synthesized using an ultrafast hightemperature shock strategy. The oxygen electrocatalysis of PtCo/Co 9 S 8 is remarkably enhanced by constructing the well-coupled Pt−Co−S interfaces in the composites, in which the Co acts as the bridging linkage. PtCo/Co 9 S 8 composites show efficient bifunctional activities toward oxygen evolution and reduction reactions (OERs and ORRs). The OER overpotential (10 mA cm −2 ) and ORR half-wave potential reach 284 and 832 mV, respectively. The rechargeable aqueous zinc−air battery (ZAB) using PtCo/Co 9 S 8 composites as air cathodes achieves high power density (262.5 mW cm −2 ) and long-term cycling life (more than 1000 cycles). Moreover, the assembled flexible solid-state ZAB can power electronic devices well. The theoretical results suggest that the catalytic sites of Co and Pt in the bridging interfaces could impressively optimize the adsorption/desorption/transformation of O* to OH*, thus lowering the ΔG and facilitating the ORR process. This work provides an extremely promising strategy to develop bridging heterointerfaces for their application in energy storage and conversion systems.

Electrospinning-derived transition metal/carbon nanofiber composites as electrocatalysts for Zn-air batteries

“…This expansion in surface area not only increases the number of effective active sites but also accelerates the catalytic reactions by facilitating more rapid interactions. 91–93 The diversification of active sites can be realized by incorporating various metal species and heteroatoms, such as forming additional metal-N structures or constructing pyridinic N and pyrrolic N configurations. Synergistic interactions between metal–metal and metal–heteroatom also contribute to advancing the reaction processes.…”