Rechargeable sodium-carbon dioxide (Na-CO2) batteries have been proposed as a promising CO2 utilization technique, which could realize CO2 reduction and generate electricity at the same time. They suffer, however, from several daunting problems, including sluggish CO2 reduction and evolution kinetics, large polarization, and poor cycling stability. In this study, a rambutan-like Co3O4 hollow sphere catalyst with abundant oxygen vacancies was synthesized and employed as an air cathode for Na-CO2 batteries. Density functional theory calculations reveal that the abundant oxygen vacancies on Co3O4 possess superior CO2 binding capability, accelerating CO2 electroreduction, and thereby improving the discharge capacity. In addition, the oxygen vacancies also contribute to decrease the CO2 decomposition free energy barrier, which is beneficial for reducing the overpotential further and improving round-trip efficiency. Benefiting from the excellent catalytic ability of rambutan-like Co3O4 hollo
Oxygen vacancies boost performance of aqueous zinc ion batteries, study finds
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Developing a superbase-comparable oxynitride catalyst
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Defect engineering is considered as an effective idea for regulating the electronic structure and surface geometric structure of both metal- and carbon-based electrocatalysts. Furthermore, those defects can also be regarded as efficient active sites or collaborate with the surrounding environment to offer unique physical/chemical properties and interactions between active centers and host/support materials. In this regard, a serial of practical defect engineering methods has been developed for the preparation of electrocatalysts for various electrocatalytic processes, including nitrogen reduction reaction (NRR), hydrogen reduction reaction (HER), oxygen reduction reaction (OER), and oxygen reduction reaction (ORR). Comparing with state-of-the-art noble metal catalysts, our fabricated catalysts are much lower in costs but in higher electrocatalytic performances.
Firstly, we adopted a Fe doping strategy to modify the surface atomic structure of W18O49 for effective NRR electrocatalysis a