Preparation of Carbon Nanotube-Sulfur Nanohybrid Materials with Elemental Sulfur as a Feedstock

Based on the concept of green chemistry and synthesis of new functional materials, elemental sulfur is employed as the feedstock for the preparation of nanohybrid materials of carbon nanotubes (CNT) and sulfur. Referring to the radical reaction-based inverse vulcanization process, 2 reaction routes are conducted in this work. In the first approach elemental sulfur is directly reacted with CNTs through the addition reaction between sulfur radicals and the CC bonds of CNT surfaces. The obtained CNT-sulfur nanohybrids possess 23.2 wt % polysulfide segments chemically bonded to the outer surfaces of CNTs. The second route involves 2-step reactions, including the incorporation of poly-(glycidyl methacrylate) (PGMA) to CNTs through a surface-initiated atom transfer radical polymerization followed by an inverse vulcanization reaction between the PGMA-functionalized CNTs and elemental sulfur. 31.3 wt % polysulfide segments are chemically bonded to the PGMA-functionalized CNTs. The CNT-sulfur nanohybrids are subjected to metal ion absorption. The sample from route 2 exhibits an absorption capacity of 16 mg g^-1 for Fe³⁺, which is several times higher than the values reported for sulfur polymers from inverse vulcanization. The inverse vulcanization-like process provides an effective platform for the synthesis of CNT-sulfur nanohybrids exhibiting high absorption capacity for metal ions.