▎ 摘　　要

Different sizes of graphene oxide with tunable fluorescence colours were prepared by continuous chemical oxidation with multi-walled carbon nanotubes (MWCNTs) as precursor. The photoluminescence of as-prepared GO was attributed to fluorescence according to their luminescence lifetimes. The as-prepared GO exhibit colourful fluorescence, which can be tuned by the level of oxidation. It is found that the fluorescence emission can be bathochromically shifted with the increase of pH value, and the fluorescence can be strongly quenched by usual heavy metal ions except for Cd2+.