Green sol-gel auto-combustion synthesis, characterization and investigation of the electrochemical hydrogen storage properties of barium cobalt oxide nanocomposites with maltose

Abstract

Barium cobalt oxide nanocomposites (Ba₂Co₉O₁₄/Co₃O₄ NCs) as potential hydrogen storage material fabricated by sol-gel auto-combustion method using maltose as reductant, for the first time. Three different ratios of Ba:maltose were applied, including 1:5.5, 1:11 and 1:22 for morphological engineering. X-Ray diffraction (XRD), Energy-dispersive X-ray spectroscopy (EDS), Fourier-transform infrared spectroscopy (FT-IR), along with Field Emission Scanning Electron Microscopy (FE-SEM) and Transmission electron microscopy (TEM) images was applied for study the composition and structure of as-prepared samples. Also, the magnetic, optical and electrochemical properties of optimum sample were inquired using VSM, DRS and CV techniques. The porosity and surface properties of NCs were checked by Brunauer-Emmett-Teller (BET) measurements. FE-SEM micrographs of all maltose assisted-synthesis products showed formation of hexagonal nanoparticles on the surfaces of the microplates. According to FE-SEM, HRTEM and XRD results, 1:22 ratio of Ba:maltose and calcination process of 900 °C for 4 h, was selected as optimum condition. The electrochemical hydrogen sorption capability of obtained Ba₂Co₉O₁₄/Co₃O₄ NCs was studied according to chronopotentiometry charge-discharge procedures in KOH medium and performed 1100 mAh/g discharge capacity. Based on the obtained results, Ba₂Co₉O₁₄/Co₃O₄ NCs can be promising compounds to improve the electrochemical performance of hydrogen storage.