农业工程学报2016，Vol.32Issue(23)：278-283,6.DOI:10.11975/j.issn.1002-6819.2016.23.038
辐照改性银掺杂TiO2纳米管催化紫外光降解乙烯效果
Photocatalytic degradation of ethylene using titanium dioxide nanotube arrays with Ag doped and irradiated byγ-ray radiolysis
摘要
Abstract
Fruits and vegetables can produce large amounts of ethylene when stored in an enclosed storage space after harvest, which can accelerate the maturity and aging of fruits and vegetables. Due to the existence of ethylene in closed storage environment and inappropriate storage methods, a large amount of horticultural products is deteriorated, resulting in huge economic losses every year. Because of large surface area, stable chemical property, excellent charge transport characteristic and available recycling properties, TiO2 nanotube arrays (TNTAs) have been used widely in sensors, dye-sensitized solar cells, light catalytic cracking water into hydrogen, degradation of organic pollutants and other related fields. Even though the formation of TNTAs are highly ordered and vertical growth on titanium substrate, the recombination of photo-generated electrons and hole pairs at the surface of TNTAs is an issue, which seriously limits the catalytic efficiency for ethylene degradation. In order to study the influence of semiconductor materials of titanium dioxide nanotube arrays modified with Ag-doped and60Coγ-ray irradiation on photocatalytic degradation of ethylene in cold storage environment, we prepared TNTAs with anodic oxidation method followed with60Coγ-ray irradiated on it for modification. Anodic oxidation method can be used to prepare titanium dioxide nanotube arrays with different dimensions conveniently through controlling anode potential, electrolyte concentration, and temperature, which have been considered as one of the most popular ways for enhancing the photocatalytic efficiency of TiO2.Gamma rays have been observed to play a key role in inducing disruption and dislodgement of electrons and sometimes atoms within a crystal to create defects in the crystal structure. After the formation of TNTAs, silver nanoparticles were made by irradiated reduction technology and doped on TNTAs to make up the new photocatalytic material of TNTAs-Ag. The addition of Ag nanoparticles can make photo-generated electrons transfer from a higher energy level of TiO2 to the noble metal with a lower Fermi level so that the electrons and holes can be separated rapidly.Field emission scanning electron microscope (FESEM), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS) were used to analyze the characterization of the prepared semiconductor materials. Results showed that: irradiated modification can transfer amorphous crystal of TNTAs to anatase crystal. The diffraction peak of anatase crystal becomes more and more sharp and the crystal dimension becomes smaller and smaller with the increase of irradiation dose, indicating that silver particles adhered to the nozzle of TNTAs in the form of cluster deposition and it didn’t not enter internal wall after doping the surface of TNTAs. Experiments of photocatalytic degradation of ethylene with TNTAs and TNTAs-Ag under ultraviolet in simulating cold storage environment were also conducted, where rate constantK′ was chosen to represent the degradation ability of ethylene. It turned out that: optimal rate constantK′can reach up to 2.03×10-4 min-1 when TNTAs were irradiated under 20 kGy. After modifying Ag on irradiated TNTAs, the rate constantK′increased by 189.66% compared with irradiated modification separately, the constant was 5.88×10-4 min-1.关键词
纳米复合材料/乙烯/辐照/银/二氧化钛纳米管/60Co-γ射线/光催化降解Key words
nanocomposites/ethylene/irradiation/silver/titanium dioxide nanotube arrays/60Co-γ ray/photocatalytic degradation分类
轻工纺织引用本文复制引用
张全,陈雪梅,叶盛英,李利钦,崔晓雷,王熠..辐照改性银掺杂TiO2纳米管催化紫外光降解乙烯效果[J].农业工程学报,2016,32(23):278-283,6.基金项目
国家自然科学基金项目 （）
