Interface engineering of Co nanoparticles decorated by Ir confined in N-doped carbon nanotubes for flexible Zn-air batteries and pH-universal overall water splitting

To alleviate the crisis of energy shortages,the scalable fabrication of highly efficient electrocatalysts is highly sought after for metal-air batteries and pH-universal overall water splitting.Hereby,an in situ construction to achieve Co@Ir nanoparticles in N-doped carbon nanotubes has been explored,which were directly fabricated by the pyrolysis and galvanic replacement.The interface engineering of Co@Ir core-shell structures could enhance interfacial and synergistic effects,achieving the tailorable electrocatalytic activities for oxygen reduction reaction,oxygen evolution reaction and hydrogen evolution reaction.Co@Ir-NT demonstrates the outstanding stability for overall water splitting under pH-universal conditions.Co@Ir-NT-based r-ZABs display a high power density of295.1 mW·cm-2 and a ultralong cycle stability over 2000continuous charge-discharge cycles,and Co@Ir-NT-based F-ZABs maintain the similar performance at different bending angles,suggesting its promising potential in the application of wearable electronics.The corresponding theoretical calculations also indicate that Co@Ir core-shell structure could improve the adsorption capacity and facilitate the breakage of O-O band.Hence,this work might be helpful for developing multifunctional catalysts for metalair batteries and water splitting under pH-universal conditions.