Composites synthesized from iron(III) citrate and carbon spheres, and activated with potassium compounds were prepared and then characterized using XRD, SEM, and low-temperature nitrogen adsorption methods. The adsorption properties of the composites toward carbon dioxide were assessed using CO2 uptake measurement, as well as by measuring their selectivity toward carbon dioxide, given their further application as photocatalysts for the reduction of this gas. The effect of changing preparation conditions on the structural and adsorption properties of the material was assessed. The potential strength of such material is a synergistic effect between the high adsorption capacity related to the microporosity of carbon spheres combined with the catalytic properties of iron particles.
Keywords: adsorption; carbon dioxide; carbon spheres; iron modification; potassium activation.