Facile synthesis of ultra-light graphene aerogels with super absorption capability for organic solvents and strain-sensitive electrical conductivity

- Ultra-light graphene aerogels (GA and CGA) were fabricated through a facile and mild approach.
- The novel approach was low cost and more viable for industry with ammonia solution as single reducing agent.
- The GAs showed highly repeatable compressibility.
- The GAs exhibited excellent absorption performance for organic solvents.
- The GAs demonstrated superior strain-sensitive electrical conductivity.

A novel ultra-light graphene aerogel with highly repeatable compressibility was successfully synthesized via a low cost and viable approach. In specific, the graphene aerogel exhibited a super absorption capacity for oil and various organic solvents up to 350 times of its own mass after thermal annealing, which was much higher than the most reported absorption materials, and excellent reusable properties in absorption-combustion, absorption-distillation, and absorption-squeezing cycles. In addition to the excellent absorption capabilities, the unique graphene aerogels also possessed other significant performances, such as ideal hydrophobicity, satisfactory fire-resistance, and strain-sensitive electrical conductivity. More importantly, in comparison with the usual reduction temperature for GO, e.g. 180 °C, our fabrication approach only involved a relatively low temperature (90 °C), at which the successfully reducing GO with ammonia solution was realized assisted by freeze-drying and thermal annealing. The viable method and unique performance advantages endow the resulting graphene aerogels with important and broad applications such as oil absorption, energy devices and pressure sensitive sensors.