Исследования физико-химических свойств аблированных наночастиц диоксида церия при фотокаталитическом процессе

Abstract

Purpose of the study. Investigation of the antioxidant properties of nanodispersed solutions of ablated particles of cerium dioxide under conditions of oxidative degradation of an organic dye methylene blue during a photocatalytic reaction, depending on their size characteristics and the pH-environment of solutions. Methods. The ablated cerium dioxide nanoparticles were characterized using scanning electron microscopy; a study was carried out in the visible and ultraviolet ranges of the absorption spectra of the samples using an optical spectrophotometer. The antioxidant activity of ablated nanoparticles in the oxidative photocatalytic reaction was studied using the example of the organic dye methylene blue, depending on the size composition of cerium dioxide nanoparticles and the pH environment of the systems. Cerium dioxide nanoparticles with pronounced antioxidant properties have been obtained by laser ablation. Results. Scanning electron microscopy revealed that cerium dioxide particles agglomerate in an aqueous solution. After the centrifugation process, the number of agglomerates in the upper layers of the solution with a nanometer size of the order of 10 nm increases. Dependences of the antioxidant activity of cerium dioxide nanoparticles on their size characteristics have been determined. The data obtained during the research indicate the highest antioxidant properties of solutions with cerium dioxide nanoparticles, which were centrifuged at a speed of 13400 rpm. With an increase in the pH-medium of solutions, the intensity of the process of inactivation of reactive oxygen species formed during the photocatalytic reaction increases. Conclusion. Cerium dioxide nanoparticles ablated by pulsed laser radiation are new nanomaterials that are antioxidants capable of inactivating reactive oxygen species in oxidative processes of a photocatalytic reaction. These properties of cerium dioxide nanoparticles are determined by the content of defects of the oxygen vacancy type on their surface.