A study on near-UV blue photoluminescence in graphene oxide prepared by Langmuir–Blodgett method

Highlights: • GO films were deposited on substrates using LB method and reduced into rGO at 800 °C. • The PL of GO and rGO showed the near-UV blue emission. • This blue shift and decrease in PL was due to the newly formed sp² clusters in rGO. - Abstract: The paper reports a study on a near-UV blue photoluminescence (PL) in graphene oxide (GO) films prepared by Langmuir–Blodgett (LB)-based method. GO films was reduced into reduced-graphene oxide (rGO) through thermal process at 800 °C. The surface morphology of both GO and rGO is characterized by atomic force microscope (AFM) and scanning electron microscope (SEM). X-ray photoelectron spectroscopy (XPS) analysis shows the largely restoration of graphitic domains in GO after reduction. The photoluminescence (PL) of rGO shows the near-UV blue emission, which is blueshifted along with luminescent decreased as compared to GO. This blueshift and decrease in PL is mainly due to the newly formed sp² clusters in rGO, which established percolation pathways between the sp² clusters already present