Morphology-controllable ZnO catalysts enriched with oxygen-vacancies for boosting CO2 electroreduction to CO

Electrochemical CO2 reduction (ECR) is a promising approach to realize carbon neutral and energy sustainability, which is still impeded by the low selectivity and activity for application. Defect engineering of electrocatalysts, especially oxygen vacancy introduction into metal oxide materials has been proved to be an effective strategy to satisfy thermodynamic condition and improve kinetics for ECR. Herein, we synthesize oxygen vacancy-enriched ZnO nanoparticle catalysts for efficient ECR through electrospinning technique using particular precursor. Characterizations reveal that the utilization of Zn(CH3COO)2 precursor contributes to the generation of oxygen vacancies in ZnO catalysts which enhances CO2 adsorption and stabilizes the intermediate. In a flow cell configuration, a current density of 150 mA cm−2 and a CO Faradic efficiency > 80% can be obtained for ZnO nanoparticle catalysts (p-ZnO-800), which is meaningful for industry. •The morphology of ZnO catalyst is affected by electrospinning precursor.•Reasonable selection or modification of metallic salt of electrospinning precursor is a promising method to obtain more defects.•Oxygen vacancies enhance the performance of CO2 reduction.