农业工程学报
農業工程學報
농업공정학보
2013年
20期
286-292
,共7页
郑森鸿%叶盛英%黄迅%沈生文
鄭森鴻%葉盛英%黃迅%瀋生文
정삼홍%협성영%황신%침생문
TiO2%辐照%乙烯%60Co-γ射线
TiO2%輻照%乙烯%60Co-γ射線
TiO2%복조%을희%60Co-γ사선
titanium dioxide%irradiation%ethylene%60Coγ-ray
为了解60Co-γ射线辐照且以活性炭纤维(activated carbon fiber,ACF)为载体所负载Ag沉积的TiO2的半导体材料(Ag-TiO2/ACF)对光催化降解冷藏环境中乙烯的影响,在模拟园艺产品的冷藏环境中,研究了不同辐照剂量下的TiO2对乙烯的降解,并利用X射线衍射仪(XRD)及X-射线光电子能谱(XPS)对所制备的光催化材料进行相关的表征分析。表征结果表明:随着辐照剂量的增加,总体上锐钛矿的含量及尺寸减小,Ti3+及羟基氧含量提高,这些变化能使TiO2的催化活性增强。乙烯降解试验结果表明,当辐照剂量小于25 kGy时,乙烯降解速率随辐照剂量的提升而提高;当辐照剂量大于25 kGy时,乙烯降解速率随辐照剂量的提升而下降,可能是辐照能量过高导致TiO2粒子聚集沉淀,催化能力下降。研究结果为 TiO2光催化技术的进一步应用提供了参考。
為瞭解60Co-γ射線輻照且以活性炭纖維(activated carbon fiber,ACF)為載體所負載Ag沉積的TiO2的半導體材料(Ag-TiO2/ACF)對光催化降解冷藏環境中乙烯的影響,在模擬園藝產品的冷藏環境中,研究瞭不同輻照劑量下的TiO2對乙烯的降解,併利用X射線衍射儀(XRD)及X-射線光電子能譜(XPS)對所製備的光催化材料進行相關的錶徵分析。錶徵結果錶明:隨著輻照劑量的增加,總體上銳鈦礦的含量及呎吋減小,Ti3+及羥基氧含量提高,這些變化能使TiO2的催化活性增彊。乙烯降解試驗結果錶明,噹輻照劑量小于25 kGy時,乙烯降解速率隨輻照劑量的提升而提高;噹輻照劑量大于25 kGy時,乙烯降解速率隨輻照劑量的提升而下降,可能是輻照能量過高導緻TiO2粒子聚集沉澱,催化能力下降。研究結果為 TiO2光催化技術的進一步應用提供瞭參攷。
위료해60Co-γ사선복조차이활성탄섬유(activated carbon fiber,ACF)위재체소부재Ag침적적TiO2적반도체재료(Ag-TiO2/ACF)대광최화강해랭장배경중을희적영향,재모의완예산품적랭장배경중,연구료불동복조제량하적TiO2대을희적강해,병이용X사선연사의(XRD)급X-사선광전자능보(XPS)대소제비적광최화재료진행상관적표정분석。표정결과표명:수착복조제량적증가,총체상예태광적함량급척촌감소,Ti3+급간기양함량제고,저사변화능사TiO2적최화활성증강。을희강해시험결과표명,당복조제량소우25 kGy시,을희강해속솔수복조제량적제승이제고;당복조제량대우25 kGy시,을희강해속솔수복조제량적제승이하강,가능시복조능량과고도치TiO2입자취집침정,최화능력하강。연구결과위 TiO2광최화기술적진일보응용제공료삼고。
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.