Conversion of laboratory paper waste into useful activated carbon: a potential supercapacitor material and a good adsorbent for organic pollutant and heavy metals

In this study, laboratory tissue paper and hardboard waste were utilized to synthesize activated carbon (AC). The structure, morphology, zeta potential and particle size of the synthesized AC is investigated using X-ray diffraction, scanning electron microscopy-energy dispersive spectroscopy, Fourier-transform infrared spectroscopy, Raman spectroscopy, zeta seizer and particle size analysis techniques. The synthesized AC is used as an adsorbent for removal of Methylene blue (MB) and chromium ion from aqueous solution. AC adsorption efficiency is analyzed using a UV–Vis spectrophotometer. The adsorption capacity of the tissue paper derived activated carbon (T-AC) is greater than that of the hardboard derived activated carbon (H-AC). MB adsorption by T-AC and H-AC data fitted well to the Langmuir isotherm model. The thermodynamic parameters such as Gibbs free energy (∆G), enthalpy change (∆H) and entropy change (∆S) are calculated for both the T-AC and H-AC adsorbents. Moreover, the dye adsorbed T-AC and H-AC exhibit good specific capacitance value of about 260 Fg ⁻¹ and 155 Fg ⁻¹ at a constant current density of 0.5 Ag ⁻¹ . The specific capacitance is maintained to an extent of 92% and 71% even after 1000 cycles for T-AC and H-AC respectively. It is encouraging that the results obtained have opened up ways of utilizing laboratory waste materials for producing materials useful in environmental remediation and energy storage sectors.