Impact of oxygen vacancy density in modified cobalt oxide nanoparticles on the efficiency of visible-light photocatalysis

This study demonstrates enhanced photocatalysis on cobalt oxide nanoparticles (CoO NPs) by increasing the surface density of oxygen vacancies (Vos), achieved through base treatment and subsequent Li ion deposition. Surface Li-ion-doped CoO NPs exhibited significantly improved biomass oxidation capabilities. Li doping effectively scavenged oxygen from CoO NPs, resulting in a substantial increase in Vos and modifications to the surface structure. The induced surface defects, combined with energy engineering, enhanced the photocatalytic oxidation of biomolecules, such as 2,5-hydroxymethylfurfural. This study serves as a proof of concept, highlighting the potential of purpose-driven and mechanism-specific surface modification and defect engineering techniques, while emphasizing the need for their development and appropriate application.