Enhanced iodine capture by nano-copper particles modified benzimidazole-based molded porous carbon

Abstract

Capturing toxic radioactive iodine represents a critical issue for the safe development of nuclear energy. Replacing expensive silver with copper is a promising method for capturing iodine. Here, porous carbon with a high specific surface area and well-developed porosity was synthesized using benzimidazole as a carbon precursor and potassium hydroxide as an activator. Nano-copper particles were doped into porous carbon to further enhance the iodine adsorption performance. The results demonstrate that nano-copper loaded porous carbon improves the adsorption rate of iodine vapor, and the saturation adsorption capacity in cyclohexane and aqueous solutions increased from 767 and 2735 mg/g to 1490 and 2878 mg/g, respectively. Additionally, copper-loaded porous carbon demonstrates excellent regeneration performance, retaining over 90 % of its adsorption capacity after three cycles. Phenolic resin was used as a binder to prepare molded porous carbon to meet transportation and practical use requirements. With a binder ratio of 8 wt%, the compressive strength reached 12.5 MPa. The molded porous carbon exhibited adsorption capacities of 4765 mg/g for iodine vapor, 418 mg/g for iodine in cyclohexane, and 2069 mg/g for iodine in water, maintaining high iodine adsorption performance.