FORMATION AND CHARACTERIZATION OF POROUS ANODIZED ALUMINUM OXIDE SYNTHESIZED ELECTROCHEMICAL WITH GRAPHENE OXIDE

Abstract

Purpose of the research: studying the effect of addition of carbon nanosized modifier graphene oxide on the formation of a porous film during the electrochemical oxidation of aluminum.

Methods: UV-VIS spectra of graphene oxide suspension were obtained using a spectrophotometer, the thermogravimetric characteristics of anodized alumina were determined using a thermal analyzer, the surface characteristics were determined by the low-temperature nitrogen sorption-desorption method, the surface was calculated by the BET method, the morphology and ultrastructure of the surface were determined using electron microscope.

Results: the possibility of using carbon materials for the electrochemical oxidation of aluminum was shown. The obtained electron micrographs indicate the effect of the inserted carbon modifier (graphene oxide) on the morphology of resulting oxide. As a result of this process we observe the formation of the cellular surface of the aluminium oxide with smaller pores compared with sample after synthesis without the modifier.

It was shown that the addition of graphene oxide (0.25%) in the oxalic acid (0,3М) electrolyte effects on the stability of the anodizing process, the specific surface area of the sample of anodized aluminum synthesized with graphene oxide is determined as 35.5 m³/g, and it is three times higher than sample without modifier. According to sorption studies, it could be noted that the presence of nanosized graphene oxide in oxalic acid electrolyte leads to the formation of honey-comb pores with a smaller radius (22 nm), while the total volume of micropores increases. The obtained results allow us to conclude that graphene oxide as modifier is promising material for the preparation of anodized aluminum oxide matrices. In the future, these matrices could be used in processes of solutions and gases separation.

Conclusions: The addition of graphene oxide into the electrolyte changes structure of porous anodized aluminum oxide and has shown the possibility of controlling the porosity of films.