Preparation of highly functionalized carbon nanoparticles using a one-step acid dehydration of glycerol

Abstract

In this paper, we report the low-cost synthesis of a highly functionalized carbon material synthesized through controlled acid dehydration of glycerol. Physical properties were investigated using scanning and transmission electron microscopy, X-ray diffraction, thermogravimetric analysis, and dynamic light scattering. Chemical properties were determined using elemental analysis, acid-base titration, uv–vis spectroscopy, fluorescence spectroscopy, Raman spectroscopy, Fourier transform infrared spectroscopy, and X-ray photoelectron spectroscopy. The acid dehydration temperature during synthesis was varied and at moderate temperatures (160 °C), highly functionalized fluorescent carbon nanoparticles (hydrodynamic radius < 100 nm) containing sulfonic acid (2.6 mmol/g), carboxylic acid (2.5 mmol/g), and hydroxyl (5.8 mmol/g) functional groups were produced. Freeze-dried material prepared at this temperature could be easily dispersed in a wide range of polar solvents with sonication. The potential application as a catalyst was demonstrated and the carbon showed enhanced ability to catalyze oleic acid esterification compared to commercial catalysts. The synthesized carbon also demonstrated considerable capacity, rivaling current graphene oxide-based materials, to remove methylene blue, cadmium, and lead from contaminated water, demonstrating its potential as a nano-adsorbent for water purification. Overall, the process shown here provides a simple method to produce large quantities of a functionalized carbon nanomaterial having many potential applications.