Preparation Of Hematite Photocatalysis Of Nanocomposite Particles And Nanoarrays

Solar energy is a promising resource to solve environmental pollution and worsening energy crisis currently. And photocatalytic materials are important for the use of solar energy. Some semiconductor materials are applied in photocatalytic degradation of organic compounds and producing hydrogen by decomposing water. As common semiconductor materials, the iron oxide and tin oxide are used widely in photocatalysis. Hematite (a-Fe2O3) is an n-type semiconductor and with a narrow band gap (about2.2eV), which means that it can absorb a large part of the solar spectrum light. It has been proved that it shows a good stability in the solution with a wide pH range (pH value>3). In addition, it has many advantages, such as low toxicity, stability and low cost. SnO2is is an important functional materials with a wide band gap (3.6eV), which is also n-type semiconductor. As a result of special optical properties and good catalytic property, gas sensitivity, photosensitivity and mechanical properties, nanostructured SnO2has attracted great attention of domestic and foreign researchers.This paper describes the synthesis of Fe2O3/SnO2composite nanoparticles and the growth of mesoporous iron oxide nanorods on the FTO glass by hydrothermal method, and then their structure and optol-electric property are studied. The contents are as follows:The first chapter introduces the research background and related work. Firstly, the photocatalytic principles and applications in the semiconductor materials are introduced, as well as the research status and progress of photocatalytic materials used in visible light range. Then the common methods for preparing iron oxides are reviewed.The second chapter introduces the methods commonly used in the preparation of semiconductor materials and the reagents and instruments used in this experiment.The third chapter is about the preparation of iron oxide and tin oxide composite nanoparticles. With and without fluorine doped tin oxide particles were deposited on the iron oxide nanoplates by hydrothermal method and then the material structure and optoeletronic properties were characterized and discussed. By investigating the influence of the amount of fluorine-dopant on the crystal lattice of tin oxide, it is found that when the molar ratio of F and Sn is1%, the fluorine-doped tin oxide can be attached to hematite tightly and formed composite nanomaterials.The fourth chapter explains how to control the morphology of iron oxide nanorods. Mesoporous iron oxide nanorods were grown on FTO glass using hydrothermal method. By changing the concentration of the starting solution of ferric chloride and urea, hydrothermal reaction time and temperature, the morphology and size of the nanorods can be regulated. The impacts of these factors on the photoelectrochemical properties of the samples were studied. It was found that the best photoelectrochemical performance can be obtained when the hydrothermal reaction time is6hours at the temperature of90℃with initial concentration of0.1M and0.3M for ferric chloride and urea, respectively.The fifth chapter is the conclusion. Problems of the experiment and future research plans are proposed.