Carbon dots with aggregation induced quenching effect and solvatochromism for the detection of H2O in organic solvents

In this work, a type of carbon dots (CDs) which can be well dispersed in organic solvents but precipitated in neutral aqueous solution was synthesized by using one-step hydrothermal heating treatment of o-phenylenediamine in H2SO4 solution. Although the emissions of the CDs in different organic solvents are excitation independent, solvatochromism is observed for the CDs since the emission wavelength is red shifted with an increase in the polarity of solvents. The optical properties suggest that the emission of the CDs is controlled by molecular state. According to aggregation induced quenching effect and solvatochromism caused by an increase in the solvent polarity with the content of H2O increasing, detection methods of H2O in the organic solvents were developed by using the CDs as a probe. The spiked H2O in acetone and methanol could be recovered in the range of 98.2% to 101.7%, which indicates that the as-proposed method has a high potential for the determination of H2O in organic solvents.