A trifunctional Ni-N/P-O-codoped graphene electrocatalyst enables dual-model rechargeable Zn-CO2/Zn-O-2 batteries

摘要

Sustainable energy and environmental developments require exploring multi-functional energy conversion and storage, such as metal-air batteries, water splitting and CO2 electro-reduction, which is bottlenecked by the lack of multi-functional electrocatalysts. Herein, we designed and synthesized a Ni-N and P-O codoped graphene (NiPG) nanomaterial for trifunctionally electrocatalyzing the oxygen evolution reaction (OER), oxygen reduction reaction (ORR), and carbon dioxide reduction reaction (CDRR). Beyond the known role of P-O and Ni-N units for the OER/ORR and CDRR, separately, the P-O unit, which expressed high activity in the HER, was found to suppress the competitive HER towards enhanced CDRR on NiPG over Ni-N doped graphene, firstly. Besides, the Ni-N unit also promoted the OER/ORR over P-O doped graphene. Based on this trifunctional NiPG electrocatalyst, we realized dual-model Zn-CO2/Zn-O-2 batteries, switched by supplying CO2 or O-2. This work provides the novel design of multifunctional electrocatalysts and dual-model batteries for the versatile application demands of energy conversion and storage.