Freeze-drying synthesis of O,N-CeF_(3) with enhanced photocatalytic oxygen evolution

Drying methods have been verified to have a considerable impact on photocatalytic efficiency via altering surface area.In this study,the preparations of O,N-CeF_(3) under identical conditions using the vacuum freezing method and the oven method are compared.Surface hydroxyl,as opposed to adsorbed oxygen in CeF_(3)-O,is the main component of O faults on the surface of CeF_(3)-V.Small particle size and the doping atom defects of CeF_(3)-V allow for more efficient separation and faster migration of photogenerated charge carriers.CeF_(3)-V has an oxygen evolution rate of up to 1.4138 mmol/(g·h)and an apparent quantum yield of 90.90%at 550 nm.Energy tails are produced as a result of the doping O and N changing the intrinsic band structures.CeF_(3)-V shows a secondary conduction band potential that is sufficient for satisfying the minimal water oxidation potential simultaneously.These elucidate that defects in the states of doping O and N significantly influence CeF_(3) energy levels.Focusing on how the drying process affects the band structure and encourages carriers'separation via defects is valuable,which affects how well the photocatalysis works.