Luminescence spectra of reduced graphene oxide obtained by different initial heat treatments under microwave irradiation

摘要

When solid-state graphene is exposed to microwave irradiation, it often emits intense luminescence; however, whether the luminescence spectra of reduced graphene oxide (RGO) remains the same at different temperatures is not known. In this study, the luminescence spectra of RGO prepared by different initial heat treatments were measured and studied under microwave irradiation. The results showed spectral characteristics that varied with the initial heat treatment temperature. In particular, a new spectral line appeared at 670 nm, whose intensity increased with increasing initial heat treatment temperatures above 500 degrees C. Besides, the other notable difference in the spectra is the change in the spectral lines at 588 and 765 nm (769 nm) with the initial heat treatment temperature, and the luminescence spectrum of RGO-400 exhibited the weakest intensity at 588 and 765 nm (769 nm). We speculate that these changes may have affected the results of the microwave reduction. Further studies indicate that an initial heat treatment of 400 degrees C facilitated the preparation of high-quality graphene with smaller defects, larger domain size, and higher conductivity with microwave irradiation. Overall, this study is helpful for the preparation of high-quality graphene samples by microwave reduction.