Multi-Purpose Improvements in Catalytic Activity for Li-Ion Deposited TiO₂, SnO₂, and CeO₂ Nanoparticles through Oxygen-Vacancy Control

Controlling the number of oxygen vacancies (V_os) in metal-oxide nanoparticles (MO NPs; TiO₂, SnO₂, and CeO₂) using Li-ions has been shown to endow MO NPs with improved photocatalytic and electrocatalytic properties. Increasing the number of V_os in nanostructures provides a foundation for efficient multi-use catalyst designs that facilitate biomass oxidation reactions and improve electrocatalytic activity. Herein, the trends in the properties of MO-based catalysts are investigated with varying amounts of V_os achieved by Li-ion deposition. The controlled introduction of V_os into MO NPs tunes the band structures and surface chemistry, leading to enhanced activities of the NPs as photocatalysts for the selective oxidation of 2,5-hydroxymethylfurfural and as electrocatalysts for acidic hydrogen evolution. It is believed that Li-ion deposition in the MO matrix provides a novel approach for optimizing oxide-based catalyst defect engineering, thereby enabling more efficient biomass conversion and water splitting. These findings contribute significantly to the field of multi-purpose catalysis and are expected to inspire new catalyst designs for a more sustainable future. The results provide a pathway for the facile and efficient engineering of surface defect structures on catalytic metal oxide NPs toward designing high-performance photocatalysts.