Synthesis of porous, hydrophobic aerogel through the reinforcement of bamboo-shaped oxidized multi-walled carbon nanotubes in the silica matrix for oil spill cleaning

In the present work, bamboo-shaped Oxidized Multi-walled Carbon Nanotubes (O-MWCNT) synthesized through catalytic decomposition of natural gas were reinforced in a silica matrix to achieve a robust O-MWCNT-silica aerogel. The synthesized aerogel was hydrophobisized through surface modification with trimethylsilyl chloride for its application as an oil spill cleaning agent. The developed aerogel possesses high specific surface area of 795 m2/g evaluated from Brunauer–Emmett–Teller (BET) model, with a pore size of 11.2 nm. The density of the O-MWCNT-silica aerogel was 0.02 g/cc with a porosity of 87%, confirming its ultra-light and high porosity nature. Moreover, the synthesized aerogel exhibited hydrophicity, with a water contact angle of 136.2°. The sorption capacity of the aerogel investigated using motor oil projected an oil sorption capacity of about 13.72, 16.70, and 19.48 g/g at 25, 30, and 40 °C, respectively. The oil sorption kinetics revealed that the oil sorption on to the O-MWCNT-silica aerogel followed the pseudo-second-order kinetics with the particular correlation coefficients (R2) of 0.9898. Furthermore, the aerogel can be regenerated by the treatment with acetone and sustain its oil sorption capacity up to 5 regeneration cycles. Thus, the outstanding characteristics and hydrophobicity of the synthesized aerogel in this work establish itself as a capable adsorbent for oil spill cleaning. Graphical abstract: [Figure not available: see fulltext.].