The Preparation Of Porous Carbon And Flow Electrode And Its Application In Capacitive Deionization

Capacitive deionization (CDI) is a novel desalination technology which is appeared after the multi-stage flash, electrodialysis and reverse osmosis. The advantage of CDI includes low energy consumption, high efficiency and no secondary pollution, etc., it is a kind of new technology developed in recent years. The technology is based on the theory of electric double layer(EDL), by applying an electrostatic field between the two electrode plates, the ions in the solution move to the electrode with the reverse charge. Regulation of the material structure and synthesis of new material is the core of capacitive deionization technology. This paper focuses on regulation and synthetic materials, and the realationship between desalination performance and structure, surface properties about carbon materials was also studied, the main contents are as follows:(1) Carbon aerogel was prepared by the sol-gel polymerization with formaldehyde and resorcinol as raw materials and ionic liquids as template, followed by carbonization and activation. The adding of ionic liquid can control pore structure, simplify the preparation process and shorten the production cycle of carbon aerogel. The nitrogen adsorption, scanning electron microscopy and transmission electron microscopy were used to characterize its pore structure and morphology; electrochemical workstation and plate desalination equipment analyzed the performance of electrochemical properties and desalination. The results showed that:the prepared carbon aerogel electrode have good electrochemical properties(the specific capacitance value can reach 88 F g-1 under 2 mV s-1 in 1 mol L-1 NaCl solution), high absorption capacity(7.5 mg g-1) and excellent cycle performance.(2) In order to simplify the preparation technology of the desalination electrode and increase the recycling number. Based on flate desalination device, a new type of flow capacitive desalination was proposed and a flow desalination device was designed in this chapter. The flow electrode made by carbon materials was tested first to determine the experiment parameters, including voltage, flow rate and the concentration of salt solution and graphene oxide picking emulsions(GPEs) was prepared as a kind of new material; polarizing microscope and viscosity analyzer were used to observe the morphology and viscosity of the GPEs and the flow desalination equipment tested desalination performance The results showed that:GPEs has strong stability, good fluidity and high desalination capacity (9.3 mg g-1).