2.2.6. Brunauer–Emmett–Teller (BET) Analysis

BET surface area analysis was used for porosity determination, and the nitrogen adsorption/desorption isotherms were recorded at 77 K in the relative pressure range p/p₀ = 0.005–1.0, using a NOVA2200e Gas Sorption Analyzer (Quantachrome, Boynton Beach, FL, USA). NovaWin version 11.03 software was used for data processing. Prior to adsorption measurements, the samples were degassed for 4 h at 180 °C under vacuum. The specific surface area was determined by the standard Brunauer–Emmett–Teller equation. The total pore volume was estimated from the volume adsorbed at a relative pressure p/p₀ close to unity. Pore size distribution and pore volume were obtained from the desorption branch of the isotherm by applying the Barrett–Joyner–Halenda (BJH) model.