Microwave-Hydrothermal Synthesis And Property Study Of Zn₂GeO₄Nanoscaled Photocatalysts

Semiconductor photocatalytic technology has promissing application in solar energy translation and degradation of toxic pollutants, causing intense attention in many scientific fields. The semiconductor’s quantized energy levels and the electronic transition property under light irradiation make it perfect photocatalyst. The property and activity of photocatalyst are the key factors for the development of photocatalytic technology. TiO2and its modified materials are main conventional catalysts in research and application of photocatalysis. Due to their low efficiency of solar usage and poor stability, design and synthesis of novel phtocatalysts have important significance. As one dimensional binary metal oxide semiconductor material, Zn2GeO4has larger specific surface area, high sensitivity and fast electronic transmission property. Conventional synthetic methods of Zn2GeO4nanomaterials include solid-state method, CVD process, hydrothermal route and impregnation approach etc. These methods possess many drawbacks, such as long preparation time, irregular morphology and poor dispersion of the product. Microwave-hydrothermal synthesis is a novel preparation way for nanomaterials, which is developing fast and widely used in various research fields. Herein, various morphologies of Zn2GeO4have been synthesized via microwave-hydrothermal route, and their photocatalytic activities are evaluated by the photocatalytic degradation of methyl orange.(1) Zn2GeO4nanoribbons were synthesized via a microwave-hydrothermal route, employing germanium oxide and zinc acetate as raw materials, in a binary ethylenediamine/water solvent system. The synthetic conditions was investigated and optimized. Compared to conventional hydrothermal method, the synthesis temperiture was20℃with microwave method. Moeover, the obtained Zn2GeO4nanoribbons had50.7%larger specific surface area and54.7%higher photocatalytic activity.(2) Zn2GeO4nanorods were synthesized using CTAB as template, with a good dispersion,300-700nm in length and a diameter of30～60nm. The obtained Zn2GeO4nanorods possess good phtocatalytic activity in the degradation reaction of methyl orange.(3) Zn2GeO4nanorods particles were prepared with a molar ratio of5:2.5of Zn(CH3COO)2·2H2O and GeO2. They showed superior photocatalytic property in the degradation reaction of methyl orange. The effects of reaction temperature, CTAB and viscosity of reaction solution were optimized.