Using hydrogen peroxide to mediate through a one-step hydrothermal method for the fast and green synthesis of N-CDs

A facile and green approach for preparation of photoluminescent nitrogen-doped carbon dots (N-CDs) is reported, using cheap and extensively available cocoon silk as raw material. The use of H2O2 leads to the enhanced formation of N-CDs. The N-CDs have been synthesized in a short time (50 minutes), and have a high fluorescence quantum yield (24.0%). A small amount of H2O2 solution plays a vital role in shortening the reaction time, which is a brand new way to synthesize N-CDs with the help of H2O2, with both reactants and products being environmentally friendly. The prepared N-CDs are collected by removing the insoluble materials through simple filtration rather than dialysis. As far as we know, this is the first report of N-CDs being synthesized simply with the help of H2O2 solution. The prepared N-CDs solution is sensitive to pH changes, which means they have promise for application in the pH detection area.