Electrochemical approach to the surface characterization of mechanochemically synthesized alumina-supported cobalt applicable in glucose sensing

The main goals of this study are: (i) employ the electrochemical methods as alternative methods for aluminasupported cobalt (Co-A) surface characterization; (ii) investigate the electro-catalytic activity of different cobalt phases toward glucose, and (iii) implement the mechanochemical approach for the synthesis of the fourth generation of glucose sensing materials. Co3O4 and alumina were either manually grinded (Co3O4-A) or ballmilled (CoAl2O4-A) with different amounts of cobalt in CoAl2O4-A. The final products were characterized by XRF, LDPSA, XRD, and TPR. The electrodes were prepared in the form of the carbon paste electrode and tested in supporting electrolyte (1 M NaOH) as well as in a glucose-containing solution. The CV, EIS, and chronoamperometry were used for electrochemical measurements. TPR revealed the formation of CoAl2O4 during the ball milling process. Different cobalt phases significantly affected the electrochemical responses. Higher activity of CoAl2O4-A toward glucose oxidation in comparison with Co3O4-A was ascribed to tetrahedral Co2+ ion acting as the active site in glucose oxidation. In addition, results convinced employing the scarcely employed mechanochemical synthesis protocols for obtaining glucose-sensing materials. Finally, it was proven that electrochemical techniques can be harnessed as alternative, new, powerful methods for Co-A surface characterization.

Automated summary

The main goals of this study were to characterize aluminasupported cobalt using electrochemical methods, investigate the electro-catalytic activity of different cobalt phases towards glucose, and synthesize glucose sensing materials using mechanochemical approach. The study found that CoAl2O4-A exhibited higher activity towards glucose oxidation compared to Co3O4-A, due to the involvement of tetrahedral Co2+ ion as the active site. The study also demonstrated the effectiveness of mechanochemical synthesis protocols for obtaining glucose-sensing materials. Furthermore, the study highlighted the potential of electrochemical techniques as powerful alternative methods for Co-A surface characterization.