Design And Performance Study Of Nanomaterials That Used For Energy Production And Storage

Energy crisis is a major issue for humanity. There are two effective means to solve this problem:the production of clean energy and the manufacture of highly efficient energy storage devices. Based on the two ways for dealing with the energy crisis, nanomaterials and its applications in the fields of energy production and energy storage are talked in this paper. Specific details as follows:1. Research on catalytic materials of photoelectrocatalytic water splitting refered to production of clean energy.This part is mainly about synthesis of the Si nanowires arrays (Si NWs) and its performance for photoelectrocatalytic water splitting. In this section, the metal-assisted chemical etching method was employed to fabricate different types (p type and n type) of Si NWs, followed by the Pt deposition outside. The resulting Si NWs/Pt was used as photocatalysts for water splitting. It showed that the Si NWs/Pt exhibited much enhanced photo-electrochemical properties relative to the pristine Si NWs and planar Si due to the high surface roughness of Si NWs and the addition of Pt catalyst. More importantly, we have also studied the relationship between the type of Si substrates and the type of the photoelectrocatalytic reaction (Oxygen Evolution Reaction, OER and Hydrrogen Evolution Reaction, HER), and found that different types of Si NWs/Pt showed different enhancement for OER and HER under illumination. These big differences were coursed by the various band gap structures of the different types of Si.2. Research on electrode materials for supercapacitor related to the manufacture of highly efficient energy storage devices.Morphology and phase evolution of CoAl layered double hydroxides in an alkaline environment with enhanced pseudocapacitive performance were studied in this part. In this work, the CoAl-LDH nanoplates were prepared by nucleation/crystallization separation and hydrothermal method, and it can be transformed to porous CoAl-LDH composites by treating the CoAl-LDH in the high concentrate basic solution for different time. XRD, SEM, TEM, porous structure and specific area analyse were used to analyze the morphology, composition and the transformation process of the CoAl-LDH and its composites. It showed that the CoAl-LDH nanoplates could be transformed to porous CoAl-LDH/Co(OH)2 composites, and finally converting to CoOOH nanoparticle by prolonging the soaking time in the basic solution. And the electrochemical performances of the CoAl-LDH and its composites that treated in the basic solution for different time were investigated, in order to find the relationship between the supercapacitive performance and the morphology and composition. Results showed that CoAl-LDH treated in high concentrated basic solution within a short time (1h) showed the best pseudocapacitance performance, remarkable rate capability and excellent cycling stability no mater what synthetic methods were used. This improvement is attributed to the complex materials of Co(OH)2/CoAl-LDH and its porous structure.