Preparation And Application Research Of High-Performance Composite Materials For Solar Energy Utilization Technology

The employment of solar energy has garnered significant global interest due to its numerous benefits.Firstly,solar energy constitutes a form of clean energy,generating no pollutants during utilization and demonstrating environmental compatibility.Secondly,solar energy is highly renewable,representing an unending source of green energy.In recent years,as the worldwide energy crisis has intensified,scientific researchers have persistently investigated the application of solar energy across various domains.Two prominent research trajectories within the solar energy field include organic solar cells and solar-driven seawater desalination.Organic solar cells employ organic semiconductor materials to facilitate the conversion of light into electricity.In comparison to conventional silicon-based solar cells,these organic cells exhibit reduced production costs and enhanced flexibility.Solar-driven desalination employs the conversion of solar energy into heat to propel water evaporation,ultimately achieving seawater desalination.This method boasts environmental protection,energy conservation,and cost-effectiveness.This master’s thesis concentrates on these two solar energy utilization technologies,attaining efficient solar energy utilization through meticulous material design and fabrication.The primary research findings encompass the development and application of high-performance composite materials for solar energy utilization technology.（1）A high-performance polyimide（PI）/ZnO composite（PI-ZnO）was prepared via introducing ZnO nanocrystals to an elaborately designed PI with both hydrogen bonds and abundant carboxyl groups（PI-COOH）,where the fabrication cost of the PI-COOH was reduced by using common solvent under air atmosphere.The PI-ZnO showed outstanding solvent-resistant,mechanical,thermal,and UV filtering properties.An untra-flexible OSCs with an optimal PCE of 13.55%was constructed based on the Ag NWs semi-embedded ultrathin flexible transparent composite electrode（FTE,～6μm）.The ultra-flexible OSCs showed outstanding mechanical stability（PCE decreased by less than 5%after 4000 bending cycles at a small bending radius of 1 mm）and superior UV light stability（PCE decreased by only～3%after UV light irradiation for 6 h）.（2）With the exponentially rapid development of solar-driven interfacial evaporation,evaporators with both the high evaporation efficiency and recyclability are highly desirable to alleviate resource waste and environmental problems,but remain challenging.Here,a monolithic evaporator was developed based on a dynamic disulfide vitrimer（covalently crosslinked polymer network with associative exchangeable covalent bonds）.Two types of solar absorbers,carbon nanotubes and oligoaniline were simultaneously introduced to enhance the optical absorbing.A high evaporation efficiency of 89.2%,ranking top-level among the monolithic polymer-based evaporators,was achieved at 1 sun(1 k W·m^-2).When the evaporator was applied to solar desalination,drinkable water with low ion concentrations satisfying the drinkable water levels of World Health Organization and a high output(8.66 kg·m^-2,8 h in one day),revealing great potential for practical seawater desalination.Moreover,high-performance film material was obtained from the used evaporator via simple hot-pressing,indicating excellent fully close-hoop recyclability of the evaporator here.This work provides a promising platform for high-efficiency and recyclable solar-driven interfacial evaporators.