农业工程学报Issue(20)：286-292,7.DOI:10.3969/j.issn.1002-6819.2013.20.037
利用60Co-γ射线辐照使TiO2改性后对乙烯的催化降解效果
Photoelectrocatalytic degradation of ethylene with TiO2 modified by 60Coγ-ray irradiation
摘要
Abstract
Horticultural products are abundant in China. However, a large amount of them were deteriorated due to the lack of appropriate storage and transport technology, resulting in a huge waste. Ethylene gas is one of the main reasons which cause the deterioration of horticultural products in storage. Nanometer TiO2 photoelectrocatalysis technology is a new technique developed in recently. TiO2, under UV light, can degrade organics such as ethylene, so it provides a potentially effective method for keeping free products. However, in practical applications, the mutual composite happens easily, which shorts the lives of the carriers and limits the application of TiO2. The only solution for this problem is to decrease the compositing rate of photoinduced electrons and the holes by modifying the nanometer-sized TiO2. Developing modified method is also a hot topic of researchers here in China and abroad. 60Co-γ ray irradiation reduction technique can modify TiO2 and make it more activity for the catalytic degradation of organics. In order to investigate the effect of TiO2, irradiated by 60Co-γray and loaded with activated carbon fibers (ACF), on photoelectrocatalytic degradation of ethylene in the environment of cold storage, the TiO2/ACF photoelecrorcatalysis materials was deposited with nano-Ag (Ag-TiO2/ACF) and irradiated by 60Co-γray. The effects of 60Co-γray irradiation modified TiO2 (10, 15, 20, 25, 30, 40 kGy) on the photoelectrocatalytic degradation rate of ethylene were investigated in a simulated cold storage environment for horticultural product. X-ray diffractometer and X-ray photoelectron spectroscopy were used to characterize the prepared TiO2. Results from X-ray diffraction showed that: the crystal size has reduced. The percent of anatase decreased from 84.97%in pure TiO2 to 82. 98%in TiO2 treated with a 40 kGy irradiation dose. Result of X-ray photoelectron spectroscopy indicated that the amount of Ti3+, hydroxyl oxygen which have better catalytic activity increased after irradiation. The percentage of Ti3+in total Ti element rose from barely detected to 3.1%. The hydroxyl oxygen increased from 18.83% to 35.8%. Both X-ray diffraction and X-ray photoelectron spectroscopy results favored the separation rate of electron-hole, the redox ability and catalytic activity of TiO2. The apparent rate constant for photoelectrocatalysis degradation of ethylene was increased as irradiation dose increased up to 25 kGy due to the promotion of catalytic activity of TiO2. However, when the irradiation dose reached 30 kGy, the solution of TiO2 formed precipitate which reduced the specific surface of TiO2 and decreased the apparent rate constant.关键词
TiO2/辐照/乙烯/60Co-γ射线Key words
titanium dioxide/irradiation/ethylene/60Coγ-ray分类
农业科技引用本文复制引用
郑森鸿,叶盛英,黄迅,沈生文..利用60Co-γ射线辐照使TiO2改性后对乙烯的催化降解效果[J].农业工程学报,2013,(20):286-292,7.基金项目
国家自然科学基金资助项目 （）
