Electroactive Li incorporated cobalt oxide nanostructures for photocatalytic applications

A successful attempt has been made to synthesize nanostructured cobalt oxides at different weight percentage of lithium ions via rapid and facile microwave combustion method. The dopant has a high influence on Co₃O₄ nanostructure which has been well-studied by various spectroscopic and microscopic analytical tools such as Fourier Transform Infrared Spectroscopy (FT-IR), Powder X-ray Diffractometry (XRD) and Field Emission Scanning Electron Microscopy (FESEM). The synthesized nanostructures exhibit an optical band gap in the range of 3.099–3.211 eV. Cyclic voltammetry studies indicate that doping Li into nanostructured cobalt oxide increases the peak currents of oxidation and reduction peaks, thereby reducing the potential (E_O − E_R) between the peaks. Amongst the samples studied, 1 wt% Li doped cobalt oxide has shown the best surface electrochemical activity. The sample reported a decrease in charge transfer resistance with a simultaneous increase in its capacitance. At the same time, the synthesized samples also manifest appreciative photocatalytic activity. The doped samples exhibit selective photocatalytic degradation of CV and MV2B dyes which are cationic in nature; the degradation of anionic dye ARS could not be achieved. Nevertheless, these nanostructured materials offer encouraging electrochemical results coupled with photocatalytic applications paving new dimensions for future research in this direction. (paper)