A comparative study of two cellulosic materials i.e., cotton fabrics and bacterial cellulose nanofibers (NBC), is reported as substrates for metal organic frameworks (MOF-199), to prepare micro and nanocompistes of cellulose@MOF-199 for CO2 capture. The CO2 uptake performance was investigated using gravimetric adsorption and desorption kinetics. NBC was an efficient substrate with full coverage and uniform distribution of MOF crystals observed in NBC@MOF-199 nanocomposite. The surface area for NBC@MOF-199 and Cotton@MOF-199 were 553.4 m2.g-1 and 168.9 m2.g-1, respectively. NBC@MOF-199 showed a high adsorption capacity (2.9 mmol g-1) at ambient temperature and pressure, followed by Cotton@MOF-199 (1.2 mmol g-1). The kinetic studies revealed that the adsorption process is controlled by film diffusion at lower temperatures, and by sorption to active sites at higher temperatures. The estimated thermodynamic parameters represent a spontaneous adsorption with low activation energies of adsorption/desorption, promising a fast adsorption and facilitated regeneration adsorbent system with minimum energy costs.

Keywords