Preparation of PrCoO₃/CuO nanocomposites on the g-C₃N₄ substrate for performance comparison of hydrogen storage capacity

Electrode materials for electrochemical hydrogen storage (EHS) based on PrCoO₃ Perovskite, CuO, and Graphitic carbon nitride were produced through the sol-gel process. Field Emission Scanning Electron Microscopes showed the formation of flower-like structures assembled with the presence of PrCoO₃ nanoparticles on the scaly-shaped CuO on the g-C₃N₄ nanosheets as substrate. The effect of natural fuel of Japanese parsnip was compared against using maleic acid in the sol-gel synthesis of PrCoO₃. The Japanese parsnip led to the formation of bulk cubic structures, but the maleic acid causes the formation of nanoparticles with an average size of 54 nm. Also, X-ray diffraction for synthesized perovskite-based samples shows the pure phase of PrCoO₃ for the calcined sample at 700 °C. However, the resultant samples at 600 and 800 °C have impurity phases of PrO₂ and Co₃O₄. Three-electrode cells were collected and galvanostatic cycling was applied at a charge-discharge current of 1 mA and cyclic voltammograms of hydrogen adsorption/desorption procedures were investigated. The hydrogen storage capacity for PrCoO₃/CuO (800 mAhg⁻¹) and PrCoO₃/CuO/g-C₃N₄ (1200 mAhg⁻¹) was compared by pristine PrCoO₃ nanostructures (450 mAhg⁻¹). The performance improvements of PrCoO₃/CuO/g-C₃N₄ possibly will contribute to endorsing its usage in the electrochemical hydrogen storage field.