| Semiconductor photocatalysis is a new type of advanced oxidation technology(AOP),which is driven by rich and green solar energy.And excites semiconductors with a suitable band gap width through photon absorption,thus generating high-energy free electrons and holes,and inducing chemical reactions together with the derived reactive free radicals.Photocatalysis technology can be applied to mineralization of organic pollutant,reduction of heavy metal ion,new energy hydrogen or preparation of liquid fuel,so it is a potential project to handle with the growing global energy crisis and environmental problems,and then achieving sustainable development of society.At present,photocatalysis is mainly used as an independent technology,and it is rarely used in conjunction with other new technologies.The integration of the photocatalytic technology into the friction layer surface of the triboelectric nanogenerators(TENGs),which not only expands the photocatalytic technology in cleaning applications,but also gives the TENG device a self-recovering function for output performance.In addition,we have fully explored the properties of some photocatalytic materials,and have proposed that couple photo-excited properties with ferroelectricity of semiconductors to degrade volatile organic compunds(VOCs)after electret treatment.In this thesis,we will mainly carry out work from the following three aspects:1.Integrate the mineralization function of photocatalysis technology into the friction interface of TENG,and develop the self-cleaning function of TENG by utilizing the characteristics of photocatalysis with degrading organic pollutants efficiently through sunlight.By loading the optimized Ti O2 nanoparticles(NPs)photocatalyst on the PDMS polymer sponge,the simulated pollutants are degraded under ultraviolet irradiation,and the friction layer surface can be self-cleaned.After testing with different simulated substrates multiple cycles,the removal efficiency of contaminants on the surface of the friction layer remained above 80%,so showed good universal applicability.The proposed strategy based on the self-cleaning effect of semiconductor photocatalysis technology on the polymer surface can not only realize the "defense" of the polymer surface,but also contribute to promoting the functional development and long-term use of electronic skin and wearable devices.2.To study the effect of self-cleaning function on the electrical performance of TENG devices.By studying the change of the output capacity of ordinary TENG before and after being contaminated,the strategy of photocatalytic self-cleaning function to restore the energy output of TENG device is proposed.Based on the optimized dielectric layer of Ti O2 NPs loading,when the organic pollutants on the friction layer is mineralized,meanwhile,the energy output of the TENG device recovers from the significant decrease after contamination to 92% of the original level performance.In addition,after the degradation of pollutants,the output performance of TENG devices has good repeatability.This part of the work is based on the previous work of self-cleaning the surface of the photocatalytic polymer,and the photocatalysis has slightly improved the energy output of TENG,and it also helps the performance recovery of contaminated devices.Due to the diversity of photocatalytic materials and dielectric materials,we believe that this strategy can be easily extended to other fields,especially in the field of self-driven nano-systems,electronic skin and wearable devices.3.It is proposed that ferroelectricity regulate semiconductor surface energy level,surface adsorption and carrier transport in bulk phase,and apply it to the mineralization of VOCs.Compared with the original ferroelectric semiconductor,the polarized ferroelectric phase Pb Ti O3 will have a more severe energy level tilt,higher carrier separation rate/faster mobility in the bulk phase,and it also shows enhanced the adsorption of polar toluene gas molecules.By designing the energy band and interface reaction process of semiconductors,it is expected to achieve efficient purification of photocatalytic VOCs. |
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