Preparation And Researches On The Photocatalytic Property Of The CdS Intercalation's CdS/H₄Nb₆O₁₇ Compound

Since the beginning of the 20th century, energy crisis and environmental pollution caused by the quick development industry civilization have been important problems that people must resolve them right away. The solar energy which covers more than 99% of the total energy in globe is used as a kind of reproducible resource, and it has many advantages that all other energies can't comparing to. Therefore to develop and make use of the solar energy is an important method to resolve the problem of world energy crisis and environment pollution. Nano-photocatalysis technique opens a vast and applicable foreground which no matter what in the aspect of making use of the solar energy and in managing the environment pollution synthetically. However the key to realize the technique is the acquirement of high efficient photocatalyst. Oxide semiconductor TiO2 is the common catalyst, but the wide band gap (3.2eV) limits its improvement of photocatalytic properties. And other single semiconductor's disadvantages also restrain their applications in the photocatalytic realm. So the study and use of compound powders and thin films get more and more regards. Among them the double layered structure nanocompound semiconductor become the focus of study by their high photocatalytic efficiency, fast reaction speed etc. It has been confirmed that the potassium niobate (K4Nb6O17) is an excellent semiconductor photocatalyst. Its special construction consists in the ion K+ in the interlayer can be replaced by other cations, which providing vast space of modifying the material.The tasks of this thesis are following. To synthesize potassium niobate K4Nb6O17 through the high temperature solid reaction. To make CdS/K4Nb6O17 powder on the base of the K4Nb6O17 powder which by the courses of ion exchanging, amine intercalation, sulfuration etc. To obtain CdS/K4Nb6O17 thin film through the same course of making CdS/K4Nb6O17 powder on the base ofK4Nb3O17 thin film on the quartz which made by the spin coating and after heat treatment. To make experiments with additives (Na2SO3, 0.1mol/l) of photocatalytically decomposing water into H2 and O2 to evaluate the photocatalytic activities of the catalyst KNb6O17 powder, CdS/K4Nb6O17 powder, K4Nb6O17 film, CdS/K4Nb6O17 film. The crystalline structures of the midst powder and film productions were investigated by using the X-Ray Diffraction(XRD). The compared surface area of the K4Nb6O17 powder and CdS/KtNbeOn powder were compared by the BET apparatus. The absorption threshold of CdS/K4Nb6O17 powder and film were measured by the UV-VIS spectrophotometer. At last it can elicit the following conclusions, (1) The solid reaction and the reaction condition are,(2) The compared surface area of the CdS/K4Nb6O17 powder is bigger than powder; (3) The absorption threshold of CdS/K4Nb6O17 powder and were 2.21eV, 2.17eV respectively; (4) The ratio of hydrogen production of photocatalyst K4Nb6O17 powder, CdS/H4Nb6O17 powder, K4Nb6O17film, CdS/H4Nb6O17 film correspond 2.15, 2.43, 0.633, 1.15mmol.g-1.h-1 respectively.