Long Jiang, NDSU Department of Mechanical Engineering

Carbonaceous materials have been widely used to produce electrodes used in energy storage devices such as supercapacitors and batteries. Activated carbon, a traditional carbonaceous material that is commonly used in commercial storage devices, only offers limited energy densities due to its low electrical conductivity and low accessible surface area. Carbon nanosheets, exhibiting large, open and flat adsorption surfaces and high conductivity, can achieve superior energy storage performance.

In this research, we produced carbon nanosheets from an aqueous mixture of DDGS, glucose and graphene oxide using an integrated one-pot hydrothermal and microwave irradiation process. During the process, carbon nanosheets were induced to grow by graphene oxide using DDGS and glucose as the carbon sources. The mixture was first pre-carbonized in an autoclave at ~ 200 oC under self-generated pressure for 20 hours.  The product was freeze dried and then subjected to short term microwave irradiation to increase its degree of carbonization and promote the growth of carbon nanosheets.  The final product was made into electrodes of supercapacitors and tested for its electrochemical properties. The effects of the concentrations of graphene oxide, DDGS and glucose, autoclave temperature and treatment time, and microwave irradiation strength and time on the structure of the produced carbon nanosheets and their electrochemical properties were studied.