Preparation And Characterization Of SnO₂-Based Phthalocyanine Sensitized Nanomaterials Used As Photocatalyst

SnO₂ is one of the most promising semiconductor materials and its band gap is 3.6 eV. The photocatalytic activity of SnO₂ is limited only to the UV region, and hence solar energy can not be effectively harnessed. Metal phthalocyanine (MPc) is used to be sensitizer early and is one of the excellent dyes. It is known that metal phthalocyanine has excellent chemical, light and thermal stability and possesses intensive absorption in visible light and near-IR region (Q-band: 600-800nm). The general methods for the modification were deposition of CoPc dye layers on inorganic semiconductor powders by mixing, dipping and modifying with chemical synthesis. However, these general methods have a common question. In this paper, CoPc/SnO₂ was first synthesized by an in-situ method based on SnO₂ nano-powers, the results of a systematic investigation of synthesis and characterization of the CoPc/SnO₂ have been given, and the sensitive mechanism for photocatalysis is tried to be discussed. The main results are as follows:1,Using tin chloride (SnCl₄·5H₂O) as starting materials, the preparation conditions of SnO₂ nano-powers synthesized by the Sol-Gel methods and ammonia coprecipitation, the crystallite size of SnO₂ we got is around 4～5nm.2,Taking Co (II) as template, CoPc/SnO₂,CoTSPc/SnO₂,CoTNPc/SnO₂ was synthesized using an in-situ method through the cyclotetramerization of dicyanobenzene, 4-sulfdicyanobenzene, 4-nitrodicyanobenzene on the surface of Sn(OH)₄ nanoparticles. There is strong interaction of Co-O band between organic and inorganic side and stability was improved.3,In the CoPc/SnO₂ nanocomposite, there was no crystal of CoPc formed on the surface of SnO₂ and the CoPc exist with the form of monolayer when the molar ratio≤8mol% or surface coverage(θ)≤1.4,The numbers of binding sites for CoPc/SnO₂ nanocomposite prepared with in-situ method are around 1.2, the binding constants are all in 104 orders. The Wonderful force didn't play a primary part between organic and inorganic side in the CoPc/SnO₂ nanocomposite, that's to say, pH values of SnO₂ particles has a weak effect on the combined equilibrium constance, and Co-O band plays an deciding part.