Preparation Of Hydrothermal Graphene Aerogels

Since graphene was found it has provided various possibilities for applications due to its unique structure and excellent mechanical, electrical and physical properties. As a new form of 3 dimensional material, graphene aerogel servers as a promising candidate in environment remediation, catalyst support and energy storage due to its high porosity and low density. In this work, graphene oxide was prepared by using Hummers method, and graphene aerogel was prepared by hydrothermal method using graphene oxide as raw material. Also, graphene-sponge compound aerogel was prepared by mixing graphene oxide and melamine sponge. Hydrothermal process factors were compared and optimized. The application value of graphene aerogel in environmental management was studied. Some progresses in the thesis are summarized as follows.Graphene oxide was prepared by Hummers method using raw graphite powder. The inference of oxidation degree was studied compared to different amount of potassium permanganate as oxidizing agent. SEM, FTIR, Raman, conductivity text and zeta potential was used to analyze the graphene oxide. It was found that, with the increasement of potassium permanganate the oxygen-containing groups were increased along with the increase of oxidation degree. The oxidation degree no further change when the amount of potassium permanganate reach the balance.Reduced graphene oxide was prepared by hydrothermal method using graphene oxide and reducing agent. The hydrothermal time, temperature and concentration of graphene oxide was optimized. Ascorbic acid, poly dopamine, sodium dodecyl sulfate and sodium sulphide was use as reducing agent. The inference of the addition amount of reducing agent was studied. SEM, contact angel, conductivity text and Raman was used to analyze and optimize the aerogel. The adsorption ability was texted using THF, DMAc, pump oil, toluene, soybean oil and gasoline. It was found that the graphene aerogel has a great adsorption ability to different organic oils. Chloroform showed the largest amount of 132 g /g.Graphene-sponge compound aerogel was prepared by hydrothermal method using the mixture of graphene oxide and melamine. SEM, contact angle, Raman and XRD was used to characterize the structure of compound aerogel. UV-vis was used to quantitative characterize the fast adsorption ability of methylene blue. Adsorption ability under different p H values and recycle process was also studied. The thermodynamic and kinetic model was fitted. The result showed that the thermodynamic model conform to the Langmuir model and the kinetic model conform to the pseudo-second-model. It was calculated that the maximum adsorption ability reached to 286.5 mg /g. The as received aerogel shows excellent ability of adsorption and will reveal its potential in environmental management.