Liquid‐Phase Synthesis of Hydrophilic Luminescent Carbon Dots Using Porous Silica as a Nanotemplate

Abstract

Herein, nanoporous silica monoliths are used as a morphological template for liquid‐phase synthesis of luminescent carbon nanodots. Two kinds of sol–gel‐derived porous silica samples with the average nanopore sizes of 40 and 7 nm are infiltrated with sucrose/dimethyl sulfoxide solution followed by thermolysis at 170–180 °C. Thermal treatment causes the formation of carbon moieties that are, afterward, extracted into water. The obtained aqueous solutions of carbon dots show intense photoluminescence. The observed emission and excitation bands are strongly affected by the morphology of nanoporous silica template. Larger pore size of silica nanotemplate results in the red shift of the emission and excitation bands.

Photoluminescence quantum yield of carbon dots: emission due to multiple centers versus excitonic emission

“…Synthesis of CDs by thermal decomposition of sucrose (referred to as CD2) was performed following the procedure described in our previous work. 23 The advantage of this method is the use of a solvent with a high boiling point, i.e. , dimethyl sulfoxide (DMSO, T b = 189 °C), which allow us to avoid autoclaving.…”

“…Synthesis of CDs by thermal decomposition of sucrose (referred to as CD2) was performed following the procedure described in our previous work. 23 The advantage of this method is the use of a solvent with a high boiling point, i.e., dimethyl sulfoxide (DMSO, T b = 189 °C), which allow us to avoid autoclaving. In brief, a solution of sucrose (C 12 H 22 O 11 ) in DMSO with a sucrose concentration of 200 mmol l −1 was thermally treated in an open quartz vessel on a laboratory furnace with a ceramic coating at a temperature of 170-180 °C for 5 minutes.…”