It was also explored that with enhancing the annealing duration, the content of both pyrrolic and pyridinic nitrogen decreases but the content of quaternary nitrogen . . From XPS investigations, it is clear that the intensity of pyridinic nitrogen is lower than quaternary nitrogen when the annealing was carried out at 300 °C while the intensity of quaternary nitrogen is higher than pyridinic nitrogen if the thermal annealing is performed at 700 °C. Huan et al. prepared the N-doped GO by thermal annealing of GO/RGO with ammonia gas at three various reaction conditions . XPS investigations of N-doped GO and N-doped RGO revealed that only the peaks corresponding to both pyridinic and pyrrolic nitrogen moieties are obtained at 700 °C while the intensity of quaternary nitrogen commences at 800 °C and its intensity is relatively higher compared to pyrrolic nitrogen for N-doped RGO when annealed at 900 °C. Hence it is apparently inferred that the formation of quaternary nitrogen is more pronounced if the annealing is carried out at 900 °C. In another literature, the N-doped graphene was prepared by thermal annealing method using urea as the dopant with various annealing temperatures and durations . They have demonstrated that both the content of nitrogen and the electrical conductivity initially rises with increase in temperature and attained the maximum value at 500 °C but then reduces with further increment in temperature. the N-doped graphene by thermal annealing of GO with melamine with three various compositions at 700 °C under N2 flow for 30 minutes and evaluated its application as electrocatalysts for ORR applications . Among the three various weight ratios of melamine and GO, the one which contains the quantity of dopant three times greater compared to GO at 700 °C has shown the excellent performance towards ORR.