Method for preparing fluorescent nitrogen-doped carbon nanodots from compost humic acid and application thereof

Abstract

The invention relates to a method for preparing fluorescent nitrogen-doped carbon nanodots by taking compost humic acid as a raw material. The preparation method comprises the following steps: uniformly mixing humic acid and a hydrogen peroxide aqueous solution at room temperature, carrying out hydrothermal reaction, and naturally cooling to room temperature to obtain a reaction solution; carryingout ultrasonic treatment, centrifugation and separation on the reaction liquid at room temperature to obtain supernatant; enabling the supernatant to pass through a water system microporous filter membrane, dialyzing, intercepting to obtain a carbon nano point aqueous solution with the molecular weight of more than 3500Da, and freeze-drying to obtain the solid nitrogen-doped carbon nanodots. According to the invention, high-value recycling of sludge can be realized, and the provided nitrogen-doped carbon nanodot synthesis method is convenient, green and efficient. The prepared nitrogen-dopedcarbon nanodot has high quantum dot yield and high fluorescence emission and can be applied to rapid detection of metal ions, and shows high selectivity and sensitivity for detection of Fe < 3 + >, and the Fe < 3 + > detection effect can be visualized by using an induction strip of a nitrogen-doped carbon nanodot matrix.

Description

technical field [0001] The invention relates to carbon nanomaterials, specifically a preparation method for synthesizing a blue fluorescent nitrogen-doped carbon nanodot from compost humic acid, and its application to Fe 3+ detection. Background technique [0002] As a new class of environmentally friendly carbon nanomaterials, carbon nanodots have excellent optical properties. Compared with traditional semiconductor quantum dots and organic fluorescent dyes, carbon nanodots have the advantages of high water solubility, low toxicity, high photostability, easy synthetic modification and good biocompatibility. Generally, there are two routes for preparing carbon nanodots: top-down and bottom-up. The top-down method mainly "transforms" large-scale carbon sources into carbon nanoparticles through physical and chemical methods. The top-down method often uses abundant natural biomass as raw material, so it is greener and more economical than the bottom-up method. [0003] Pate...

AI Technical Summary

Problems solved by technology

The carbon nano-dots invented by the patent CN106629663A pair Fe 3+ The detection limit is 52nmol / L, and in Cu 2+ In the presence of the environment, its effect on Fe 3+ The detection will be affected by Cu 2+ Interference, indicating that the fluorescence detection sensitivity is not high

[0006] It can be seen that the low yield of quantum dots, poor fluorescence properties, low sensitivity, high energy consumption, and uneconomical are still obvious shortcomings of the existing technology

Images