Effect of nickel on hydrogen storage behaviors of carbon aerogel hybrid

Limited conventional energy resources and serious environmental calamities have motivated researchers to find new and efficient sources of energy. The considerable efforts devoted to this end include the development of bio-diesel, solar cells, coal liquefaction/ gasification technologies, and fuel cells. Hydrogen is considered by many an ideal energy source owing to its renewable and clean energy characteristics. In addition, it mostly produces water, which is eco-friendly compared to the byproducts of many other energy sources [1-6]. To use hydrogen as an energy source, various hydrogen storage methods such as the use of metal hydrides, liquefied hydrogen, and adsorption of hydrogen in porous materials have been studied [7-14]. The adsorption of hydrogen in porous materials is particularly suitable for hydrogen storage, which is critical for suitably utilizing hydrogen energy, owing to the reversibility and stability of this method. To date, the wide ranging attempts to develop hydrogen storage mechanisms include studies on carbon materials [15-17], metal-organic frameworks, and zeolites [18-21]. Carbon materials offer many advantages for hydrogen storage, such as easy preparation, suitable surface functional groups, low mass density, thermal stability, and hydrophobicity [22-24]. Carbon aerogels (CAs) in particular have been recognized as potential hydrogen storage materials because of their suitable structural properties, controllable mass densities, high specific surface areas, and mesopore volumes. However, it is necessary to modify the surfaces of carbon materials in order to reach the hydrogen storage capacities determined by the US Department of Energy (DOE).