Optimized oxygen deficient mesoporous barium doped cobalt oxide: A wonder material for green energy generation and storage

Abstract

Electrochemical energy conversion and storage systems are presently playing a lead role in the global energy platform. This study reports the fabrication of a Hydroelectric Cell (HEC) via the synthesis of oxygen-deficient barium-doped Co3O4 multifunctional material using a solid-state method for green electrical energy generation and storage applications. Different analytical methods were used to characterize the material. The Transmission and Scanning Electron micrographs of pure Co3O4 and Ba- Co3O4 revealed that doping with Barium metal into Co3O4 causes a change in morphology from a spherical shape to a sheet-like structure. The UV–vis spectroscopy indicates that the doping enhanced the band gap of Co3O4 from 1.65 to 2.52 eV and Brunauer Emmett Teller's investigation shows an increase in specific surface area from 8 m2/g to 13 m2/g. Further, an increase in oxygen deficiency due to Ba doping was confirmed with Photoluminescence spectroscopy, Electron Paramagnetic Resonance, and X-ray photoelectron spectroscope. The short circuit current of barium-doped HEC increased by 13 folds as compared to the undoped cell from 1.7 mA/cm2 to 21.6 mA/cm2, and its peak power increased by 18 times from 12.5 W/m2 to 227 W/m2. The power obtained from Ba-doped HEC is higher than typical solar panels of the same area and HEC has an edge over solar cells that it needs no light to produce energy therefore it can be used in the dark also. The specific capacitance of pure Co3O4 was 282.01 F/g which increased to 451.83 F/g after Ba doping. Moreover, the charge–discharge stability studies have established that the Ba- Co3O4 has a remarkable specific capacitance retention capability of 95% even after 2000 continuous charge-discharge cycles. Since this process involves water splitting, therefore hydrogen gas is produced as a byproduct that can be used for further energy generation. Thus, this material has enormous potential for application in the field of electrical energy generation, storage, and hydrogen gas production.