Experimental Investigation of Using Coffee WasteDerived Activated Carbon Effectively as Sustainable Material for Hydrogen Storage

This study presents the synthesis and evaluation of activated carbon derived from spent coffee grounds using three distinct activation methods, namely chemical, ultrasound-assisted and surface magnetized. The characterization studies of materials are used to evaluate hydrogen storage performance under varying pressure and temperature conditions. The gravimetric measurements are employed to assess the physisorption capacities, while electrochemical techniques, such as LSV, CV, and GCD evaluate hydrogen related charge storage behavior. The activation methods affect surface morphology and elemental composition of the activated carbon samples, as confirmed by SEM and EDS analyses. Among the three, chemically activated carbon exhibits the highest hydrogen uptake , achieving 0.362 wt% at 0 ◦C and 4 kPa, which is attributed to its highly porous structure. The ultrasound-assisted and surface magnetized samples exhibitmaximum capacities of 0.357 wt%, and 0.339 wt%, respectively. This study underlines the potential of coffee waste as a sustainable carbon precursor and introduces a dual-characterization approach.