Nanocomposites for Adsorption of NOₓ and SOₓ Gases

Nitrogen oxides (NOₓ) and sulfur oxides (SOₓ) air pollution is still a major environmental and health issue, making efficient removal technologies more necessary than ever. In this work, we present the synthesis and characterization of a series of newly developed nanocomposite adsorbents with the ability to adsorb both SOₓ and NOₓ under simulated flue gas conditions. Three various composites were prepared: an activated carbon–MgO hybrid (AC–MgO), a multi-component hybrid of carbon nanotubes mixed with Tio₂, Cuco, and zeolite, and a graphene oxide–CEOs₂ composite. To verify their nature, the samples were characterized by surface area measurements (BET analysis), crystal structure determination (XRD), and morphology imaging (SEM). Laboratory-scale fixed-bed reactor adsorption experiments at room temperature confirmed that the CNT/Tio₂/Cuco/zeolite composite showed the highest efficiency, removing approximately 92% of NOₓ (≈140 mg/g) and 95% of SOₓ (≈150 mg/g). The AC–MgO and GO–CEO₂ systems also showed high efficiencies with 75–90% removal (60–100 mg/g). Microscopy showed that the oxide nanoparticles were uniformly distributed within the carbon architectures, and diffraction data confirmed the expected crystalline phases. Collectively, the results suggest the promise of these nanocomposites as low-temperature, low-cost alternatives for the removal of flue gases, and the data here provide valuable information regarding the influence of material structure on adsorption performance.