Study On Photoelectric Properties Based On Zinc Oxide Semiconductor Materials

With the development of industrial revolution,the burning of a large number of fossil fuels has caused serious energy crisis,greenhouse effect and environmental pollution,which forces people to find new ways to solve such problems.As we all know,solar energy is a kind of sustainable and clean energy.At the same time,photocatalytic technology is accepted as a new technology to produce novel energy carriers,such as hydrogen.Therefore,people began to look for suitable semiconductor materials,severing as solar catalyst to change this situation.In this process,materials selection plays an important role.Zinc is one of the most abundant elements in the earth,and zinc oxide is also simple to prepare,low cost,non-toxic and harmless,with high photoelectric conversion efficiency,so it is considered as one of the most promising photocatalytic materials.However,the large band gap and high recombination efficiency of photogenerated carriers restricted its application.Therefore,by adjusting the oxygen vacancy and constructing heterostructures,the photoelectric performance based on ZnO were studied in this paper.The details are as follows:（1）Zinc oxide with different contents of oxygen vacancy content was grown on carbon cloth by two-step method.X-ray diffraction（XRD）and scanning electron microscope（SEM）showed that the prepared sample has sheet wurtzite structure.X-ray photoelectron spectroscopy（XPS）and photoluminescence spectroscopy（PL）spectra showed that the two samples had different oxygen vacancy content.The current-time curve（I-t）shows that ZnO samples with more oxygen vacancies have a photocurrent of 280 μA/cm2,while the conventional ZnO samples have only one third of the former.In addition,electrochemical impedance spectroscopy（EIS）and Mott Schottky curve（MS）showed that ZnO samples rich in oxygen vacancies had smaller electrochemical impedance and larger carrier concentration.（2）Zinc oxide and bismuth vanadate heterojunction were synthesized by hydrothermal method.SEM results show that the heterojunction sample is flake bismuth vanadate loaded with granular zinc oxide.XPS test results reveal the existence of Zn,O,Bi and V elements.And the photocurrent response of the heterojunction samples is increased from 4 μA/cm2 to 18 μA/cm2.The photocatalytic degradation of rhodamine solution was tested,and the photocatalytic efficiency of the heterojunction sample was increased by one time after the results were obtained by mathematical conversion.（3）The heterojunction of zinc oxide and molybdenum disulfide was synthesized by hydrothermal method.The photocatalytic decomposition of aquatic hydrogen showed that the hydrogen production rate of MoS2@ZnO with few layered MoS2 reached 3.32 mmolh1g-1.The content of molybdenum disulfide was very low,and its crystal phase could not be found in XRD.Through the photoelectric chemical test,it is found that it has better photoelectric chemical properties,which breaks the dilemma that the traditional wurtzite zinc oxide cannot produce hydrogen,and provides a broader prospect for the application of zinc oxide.