A comparative study of sol-gel and green synthesized CuCr2O4 nanoparticles as an electrode material for enhanced electrochemical hydrogen storage.

Renewable energy sources, such as hydrogen play a crucial role in developing sustainable technologies. Hydrogen is one of the best candidates for future energy transition. Today, hydrogen storage techniques have become an important and debated issue in many countries. This study represents the first attempt to prepare CuCr 2 O 4 nanoparticles using two different methods (sol-gel and green) and compare their performance as an electrocatalyst in electrochemical hydrogen storage. The tetragonal crystal structure, spherical shape, purity, and mesoporous features of the sample were studied using X-ray diffraction (XRD), Fourier transform infrared (FT-IR), field emission scanning electron microscopy (FESEM), energy dispersive X-ray (EDS), and Brunauer-Emmett-Teller (BET) techniques. Additionally, the hydrogen storage performance of CuCr 2 O 4 nanoparticles was investigated using cyclic voltammetry (CV), and charge-discharge chronopotentiometry (CP) in a 3 M KOH alkaline medium. The result revealed that the specific capacitance values of CuCr 2 O 4 nanoparticles in sol-gel and green methods were obtained to be 2427 and 1503 Fg-1, respectively. The discharge capacities of CuCr 2 O 4 nanoparticles in sol-gel and green methods after 11 cycles were calculated to be 4304 and 3011 mAh/g, respectively. The superior hydrogen storage capability of CuCr 2 O 4 nanoparticles in the sol-gel method can be attributed to its high porosity. [Display omitted] • CuCr 2 O 4 nanoparticles were synthesized using the sol-gel and green methods. • Study of crystal structure, morphological, and electrochemical properties of the samples. • CuCr 2 O 4 showed excellent hydrogen storage capacity of 4304 and 3011mAh/g in the sol-gel and green methods, respectively. • A promising material for hydrogen storage applications. [ABSTRACT FROM AUTHOR]