Nitrogen adsorption/desorption isotherms at -196°C were measured with a Micromeritics ASAP 2020 V4.04 surface area and porosity analyzer. A pre-treatment of vacuum exposure for only one hour was performed to avoid any interactions with the mesoporous sample. By applying the BET (Brunauer-Emmett-Teller) method, the specific surface area of the samples was calculated. The pore size distribution was determined by using the BJH (Barrett-Joyner-Halenda) method with the ASAP 2020 V4.04 software accompanied with the analysis equipment.