Preparation Of New Carbon Based 2D Nano-materials For Energy Storage And Conversion

Carbon-based two-dimensional (2D) nanomaterials have been arising much focus and interests of more and more scientists. Owing to the unique physical and chemical properties of 2D nano-materials, they have shown great potential used in electrochemical energy storage and conversion fields and there were many reports. The length of 2D nano-materials is unlimited and exceeds nano-scale thickness, which can result in speeding up electronic transition rate and volume. There are three main preparation methods:mechanical exfoliation, self-assembly and template method. Among these three methods, the third method template method is the most commonly used owing to the easy operation and controllable structure. However, the synthesis of carbon-based 2D nano-materials is hard to control and feeble function. This thesis introduced the synthesis of different structure of carbon-based 2D nano-materials. by template method, meanwhile the characterization and application were also tested. The main detailed are described as follows:(1) Two-dimensional molybdenum disulfide/graphene hybrids wrapped in carbonized polyaniline (MCGs) have been constructed by the in-situ growth of molybdenum trisulfide nanoparticles on polyaniline decorated graphene oxide nanosheets and the following carbonization. When the resulting hybrids were used as the anode materials in lithium-ion batteries, the carbonized polyaniline can effectively prevent the pulverization of MoS2 caused by the inner-plane volume expansion. It turns out that MCG-600, the sample thermally treated at 600?, manifests a capacity of 785 mA h g-1 after 300 cycles with the current density of 200 mA g-1 and the capacity is 724 mA h g-1 even at a highly current density of 1 A g-1.(2) MgAl-LDH act as the template and coated with polydopamine uniformly (LDH@PDA), then the MgAl-LDH were etched in acid solution, hollow polydopamine 2D structure were obtained (HPDA). After that, HPDA was carbonized to form hollow carbon sheets (HCS). Additionally, filtration of HPDA to form hollow carbon film (HCF) were used as electrode material in supercapacitor. In acid condition and three electrode system, the specific capacity is 150 F g-1 under the current rate of 0.5 A g-1. After 1000 cycles the capacity can still maintain the original level at a current rate of 1A g-1.