Low energy liquid plasma for direct reduction and formation of rGO-aminopyridine hybrid for electrical and environmental applications

The present works demonstrate the formation of reduced graphene oxide (r-GO) and aminopyridine (r-GO-(AmPy)_n) hybrid by submerged liquid plasma process. Raman spectra shows the ID/IG ratio of GO, r-GO and r-GO-(AmPy)_n are 2.2, 1.91 and 2.0, respectively. The decrease in ID/IG ratio of r-GO clearly indicate the reduction of oxygen functional groups and restoration of sp² network in r-GO domain. The pyridinic and pyrrolic functional group present in rGO-(AmPy)_n hybrids shows a distinct redox peaks in cyclic voltameter at the scan rates of 5, 10 and 25 mV/s. The r-GO-(AmPy)_n hybrid displayed an excellent electrochemical performance with a high specific capacitance of 418, 400 and 381 F/g at the current densities of 0.1, 0.2 and 0.3 A/g, respectively. Electro chemical generation of H₂O₂ at the rGO-(AmPy)_n surface was evaluated and found to be 0.72 mmol for the fixed reaction time of 60 min. Similarly, conversion of H₂O₂ to [rad]OH radical with a coated Fe₃O₄ plate catalyst was found to be 0.15 mmol. A H₂O₂/[rad]OH radicals generated in the electrochemical cell was used for the degradation of methyl parathion. During the degradation (7.5 mg/L), two intermediates like methylparaoxon, and p-nitrophenol were identified by the Gas Chromatography and Mass Spectrometer analysis.