Photochromic Properties And Special Morphology Of AgNbO₃

Since the industrial revolution, a rapid progress of the human society has been obtained and the living standard was increasingly improved. However, a rapid reduction of the total amount of coal has been occurred with the social progress, so is the oil and natural gas; At the same time, the amount of CO2?CO and freon emission increased rapidly, which has hurt the ecological balance deeply. What is the worse, it is extremely difficult to repair. In total, the two problems, energy shortage and environmental pollution, should be treated with more caution..Photocatalytic technology, which could make use of the solar energy, attract the gaze of people. The key of photocatalytic technology is semiconductor, which could product the excited electron-hole pair under illumination, so then split water or degrade the organics. This green technology, which has important application prospects in the field of energy and environment, has become the research focus of scientists. Through the efforts of countless scientific workers, photocatalytic technology has a rapid development, with more and more photocatalytic materials, better and better photocatalytic performance. However, there still are many problems to solve, such as the large band gap. To semiconductor, the larger the band gap, the shorter the wavelength of light absorption, in other words, most semiconductor could only absorb the ultraviolet, which only accounts 5% in the sunshine. The development of visible light photocatalytic materials has become a new hot spot in the photocatalytic technology.In the last couple of decades, a variety of photocatalysts have been reported to exhibit activities for organic compound degradation and water splitting, [1-3] [1-3] such as titanate, niobate, tantalate, tungstate and vanadate. Among the photocatalytic materials, the silver-based photocatalytic material was well-known for its excellent optical absorption, which was due to the unique delectronic configuration and surface plasmon resonance effect of Ag nanoparticles. There are many kinds of silver-based visible photocatalysts, which can be divided into three elements and multiple elements according to the elements. The catalyst of the three elements is mainly composed of Ag and O, the other element is changeable and the proportion is different. The silver-based photocatalytic material still has many defects, such as the poor stability. inthispaper,wedidsomestudiesonsilver-basedphotocatalysts,inordertoimprovethephotocatalyticperformance.specificcontentsareasfollows:?1?The research on the stability of the silver-based photocatalysts. Ag Nb O₃ was prepared by solid phase synthesis, which was used as the photocatalyst in the degradation experiment of iso-propyl alcohol. Comparing the macroscopic appearance, UV-Vis absorption spectroscopy, X- ray diffraction pattern, micro- morphology, X- ray photoelectron spectroscopy of Ag Nb O₃ before and after the experiment, we discuss the theory and analyze the results in detail. In addition, we have done a series of experiments with Ag₂Nb₄O₁₁/Ag_1.7Sb₂O_5.85/Ag₃PO₄ as the photocatalysts by the same method, in order to sum up the stability of the silver-based photocatalysts.?2?One-dimensional silver niobate was prepared and researched. At first, the Ag nanowires were prepared by the chemistry method, then was used as the raw materials and the templates in the preparation of the one-dimensional silver niobate, which has a larger specific surface area. Morphology and structure of the product were characterized with the help of the Ultraviolet visible spectrophotometer, X- ray diffraction and field emission scanning electron microscope. The photocatalytic performance was characterized by the degradation of Rhodamine B and 2,4-Dichlorophenol. Comparing Ag Nb O₃ prepared by the traditional solid phase synthesis, the line-shape silver niobate shows the better photocatalytic performance.