A comparison study of three green syntheses based on MCM-41 nanocatalyst for removal of toxic BTES vapors from the gas stream

Utilizing waste resources to produce materials that lessen environmental pollution is one of the current directions for sustainable development. In this study, we discuss the potential efficacy of nanoparticles (MCM-41, Co-MCM-41, and ALV-TiO 2 /Co-MCM-41) in eradicating noxious benzene, toluene, ethylbenzene, styrene (BTES) vapors. The nanoparticles MCM-41 and Co-MCM-41 were made using pure Nano-silica extracted from rice husk. Additionally, Aloe vera extract was used to create the nanoparticles ALV-TiO 2 /Co-MCM-41. The sol-gel method was used to create MCM-41, and Co-MCM-41 nanoparticles, and the doping method to prepare ALV-TiO 2 /Co-MCM-41 nanocomposites. The same conditions were used for all experiments and the analysis of nanoparticle structure. According to the BET results, the nanoparticles' average pore size is between 5.6 and 14.9 nm, and their specific surface areas range from 207.4 to 793.8 m 2 / g. In the physical adsorption mode, the properties of prepared nanoparticles were investigated, and the results showed that all three nanoparticles have significant removal capacity for BTES gas. They showed the highest theoretical successful adsorption capacity (MCM-41: 95.85 %, Co-MCM-41: 97.35 %, and ALV-TiO 2 /Co-MCM-41: 100 %) in the first run. These materials' high capacity for toxic BTES vapor adsorption by the nanoparticles and highly reusable nature (up to 14 consecutive cycles) demonstrate their efficacy in the removal of toxic gases in relevant industries. • Rice husk waste is used to create MCM-41, Co-MCM-41, and ALV-TiO 2 /Co-MCM-41. • Effective sorbents for the removal of BTES were MCM-41, Co-MCM-41, and ALV-TiO 2 /Co-MCM-41. • Doping increases the physicochemical properties and absorption of ALV-TiO 2 /Co-MCM-41. • High regeneration efficiency above 90 % using N 2 inert gas.