Efficient and clean energy storage and conversion devices are essential for future social development.However,the slow oxygen reduction reaction(ORR)and oxygen evolution reaction(OER)considerably limit the energy efficiency and operating life of metal-air batteries,fuel...MORE Efficient and clean energy storage and conversion devices are essential for future social development.However,the slow oxygen reduction reaction(ORR)and oxygen evolution reaction(OER)considerably limit the energy efficiency and operating life of metal-air batteries,fuel cells and water splitting devices.Preparing inexpen...