Application Of Semiconductor Thin Film Electrodes In Photo Assisted Energy Battery And Research On Photoelectric Properties

Energy is the power source and important survival basis for the sustainable development of human society.In recent years,the research of new energy has attracted great attention all over the world.Renewable energy,including solar energy,wind energy and tidal energy is becoming a promising alternative to traditional fossil fuels.Therefore,it is imperative to develop low-cost and large-scale energy conversion technology and new energy storage system.By preparing semiconductor photoelectric materials with different high catalytic activity to replace precious metal materials as electrodes,and introducing solar energy into the field of energy cells,the collaborative conversion from solar energy to chemical energy to electric energy is realized while improving the chemical reaction kinetics.In this thesis,a series of work has been carried out on the photoelectrode used in photocatalytic fuel cell(PFC)and photo assisted metal air cell.The main work of this paper is as follows:1.Photocatalytic methanol fuel cells were constructed by using a double-chamber H-type battery with a proton exchange membrane,a quartz window and four different photoanode materials:ZnO,BiVO4,Ti O2 and Ti O2/Sr Ti O3.The effect of temperature on the performance of photocatalytic methanol fuel cell was investigated by electrochemical test methods,including linear sweep Voltammetry,AC impedance and polarization curve test through the intermittent operation of the system at different temperatures.Under low temperature conditions,the photocatalytic fuel cells still have good photoelectrochemical output characteristics.In 5?,the short-circuit current and output power of ZnO photoanode can reach0.91 m A/cm~2 and 0.079 m W/cm~2 under illumination,which are 9 times and 3 times higher than that based on Pt anode,respectively.In addition,as the temperature increasing,the anode photocatalytic activity,the photocurrent density and the battery output power gradually increase,while the load transfer resistance decreases.The research results show that the photocatalytic methanol fuel cell system can adapt to low temperature working scenarios and has application value in some special environments.2.Using FTO conductive glass as substrate,ZnO/CuO composite was prepared by hydrothermal and scraping method as photoelectric anode(air electrode)of photo assisted Zn-air battery.Using zinc sheet as metal electrode,an efficient and stable zinc air secondary battery with dual functional characteristics of oxygen reduction reaction(ORR)and oxygen evolution reaction(OER)was constructed.Under the condition of simulated sunlight,the low charging potential and high discharging potential of about 1.50 V and 1.28 V are realized by constant current charging and discharging respectively,and the short-circuit current and open circuit Voltage reach49 m A/cm~2 and 0.9 V,respectively.We found that this bifunctional characteristic comes from the valence state change mechanism of Cu,which means that ZnO/Cu2O and ZnO/CuO play the role of photocatalysis in the process of charging and discharging,respectively.This work provides a simple and effective method for the development of integrated single cell photo assisted zinc air battery.At the same time,the charge transfer mechanism in this process is further studied.