Unveiling deoxygenation thermokinetics for controlling electrical transport and water removal from freestanding graphene oxide paper: Differential scanning calorimetry and thermomechanical analyzer study

This work reports on deoxygenation thermokinetics involved in preparing freestanding deoxygenated graphene oxide paper (DGOP) and the degree of deoxygenation-electrical transport correlation. The differential scanning calorimetry (DSC) and thermomechanical analyzer (TMA) for dimensional change study revealed that the manifestation of graphene oxide paper (GOP) into DGOP is associated with the activation energy of 153.8 kJ/mol with releasing gaseous moieties in the range of 210–230 °C. With variation in deoxygenation temperature ranging from 50 to 250 °C, DGOP is altered from dark brown to black, indicating the thermal reduction of DGOP. Upon increasing the annealing temperature, the hydrophobicity and electrical conductivity of DGOP are significantly increased. DGOP-250 exhibited superhydrophobicity and electrical conductivity of 102.2° and 4.5 S/cm, respectively. Understanding the underlying controlled-thermokinetics in converting GOP into DGOP with DSC and TMA helps in fine-tuning the structural modification associated electrical transport and hydrophobicity, which is desirable for practical applications.