چكيده به لاتين
Hydrogen is the cleanest, durable and acceptable energy carrier that does not have the adverse effects of fossil fuels on the environment. Despite the significant advantages of hydrogen, there are still many disadvantages in its use, the most important of which are the high production costs and storage challenges. One of the best methods of hydrogen storage is its surface adsorption in hexagonal boron nitride (h-BN) nanostructures. In this research, by using two different approaches of using/not using ultrasound energy with the help of an ultrasonic probe, the effective factors on the construction of monolithic boron nitride aerogel (BN Aerogel) by sol-gel and freeze-drying method was investigated. Then, the prepared samples were calcined in four different heat treatment modes (neutral atmospheres of argon gas and nitrogen gas and at two maximum temperatures of 1300°C and 1400°C). In the following, the selected samples were characterized by various methods. In this regard, phase investigation using X-ray diffraction (XRD) analysis, chemical bonds investigation using Fourier transform infrared (FT-IR) and Raman spectroscopic analyses, microstructural investigation using Scanning Electron Microscope (SEM) analysis and investigation of gas absorption and desorption behavior (applicable properties) were also done with the help of Brunoer-Emmett Teller (BET) analysis. In the end, among all the prepared samples, P0A14 aerogel, whose initial hot and transparent sol did not receive ultrasound energy and was calcined in a neutral atmosphere of argon gas (Ar) with a maximum temperature of 1400°C for a duration of 3h, It has the highest amount of hexagonal boron nitride (h-BN) phase synthesized in its homogeneous, three-dimensional (3D), porous and integrated (monolithic) nanostructure and includes the strongest stretching and bending bonds of boron-nitrogen (B-N), With the formation of separated, bent, twisted, intertwined nanoribbons, with uniform dimensions and grown along the length, finally, with a specific surface area of 158 m2g-1, total porosity volume of 0.71cm3g-1 and plane holes, A shape with an average diameter of about 18nm and also, the smallest difference between the absorption and desorption curves of nitrogen gas, was determined as the best final sample.
