Hydrogen storage in pt/carbon nanotube sheets

Three types of self-assembled carbon nanotube (CNT) sheets, for example, carboxylic functionalized multi-walled CNTs (MWNTs-COOH), pure multi-walled CNTs (MWNTs), and pure single-walled CNTs (SWNTs), were prepared as substrates by ambient environment vacuum filtration of suspensions of the nanotubes. To enhance hydrogen storage on the CNTs, platinum particles were deposited on the three types of CNT sheets using two processes: electrodeposition (ED) using a DC power source and electrochemical deposition under cyclic voltammetry (CV). To verify platinum deposition on the surface of the CNT sheets, a Scanning Electron Microscope (SEM) was used to obtain images, and Energy Dispersive X-ray (EDX) spectroscopy was used to determine the percentage of platinum particles coated on the CNT sheets. Hydrogen was produced and stored on the surface-modified CNT and pristine CNT sheets by cyclic voltammetry in alkaline electrolytic solution (6 N KOH). The hydrogen storage capacity in the electrochemically treated samples was evaluated using temperature-programmed desorption (TPD) measurement