Silicon-doped carbon nanotubes: a potential resource for the detection of chlorophenols/chlorophenoxy radicals

Abstract
Chlorinated phenols and chlorophenoxy radicals are known as predominant precursors for forming polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/PCDF), which are highly carcinogenic and persistent organic pollutants (POPs). Density functional theory (DFT) calculations have been carried out to explore the potential possibility of carbon nanotubes (CNTs) serving as the resource for detecting and/or adsorbing these PCDD/PCDF precursors. Based on the calculated results on a pristine (8, 0) CNT and a Si-doped (8, 0) CNT with and without the presence of a 2-chlorophenol (2-CP)/2-chlorophenoxy radical (2-CPR), the typical representative of chlorophenols/chlorophenoxy radicals, we propose that pristine carbon nanotubes (CNTs) may be unsuitable for the desired applications due to their poor capability for catching chlorinated phenols/chlorophenoxy radicals, on the other hand, Si-doped CNTs are expected to be a potential resource for detecting and/or adsorbing (concentrating) these PCDD/PCDF precursors. The present results provide a guide to the relevant experimentalists, who are exploring novel applications of CNT-based materials in nanoscience and nanotechnology, and/or searching for suitable resources for detecting chlorophenols/chlorophenoxy radicals.