Polyacrylonitrile-loaded bismuth (Bi) porous carbon materials for efficient adsorption of iodine vapour

Bismuth-based materials are regarded as green materials for dealing with radioactive iodine. However, the sole use of Bi has problems such as agglomeration. Dispersing Bi in the matrix material to overcome the disadvantage of Bi’s easy agglomeration to prepare Bi-based composites with low cost and high adsorption capacity is an urgent need for iodine gas capture. Here, five kinds of Bi-containing polyacrylonitrile (PAN) porous carbon materials (Bi/PAN-P) were prepared by thoroughly mixing Bi as adsorbent with contents of 10 wt%, 20 wt%, 30 wt%, 40 wt% and 50 wt%, PAN as the matrix and dimethyl sulfoxide (DMSO) as the solvent, and then carbonizing. The results show that the Bi loaded on Bi/PAN-P is uniformly distributed and the material is mainly mesoporous. It has a rapid adsorption rate for gaseous iodine, reaching more than 50 % of the maximum adsorption capacity within the first 90 min, and its speed far exceeds the adsorption rate of pure PAN carbon materials. Especially when the Bi content is 30 wt%, the iodine adsorption capacity reaches 4057 mg/g, which is about 20 times that of commercial silver exchange zeolite. Based on experimental and model simulation results, the adsorption of iodine by Bi/PAN-P mainly through chemical adsorption.