(常州大學(xué) 江蘇省先進(jìn)催化與綠色制造協(xié)同創(chuàng)新中心，常州 213164)
摘 要: 以硝酸鐠、硝酸鐵、檸檬酸為主要原料，提純后的凹凸棒石(ATP)作為載體，采用溶膠-凝膠-浸漬法制備碳量子點(diǎn)(CQDs)修飾PrFeO3/ATP復(fù)合材料。采用X射線衍射(XRD)、透射電子顯微鏡(TEM)、紫外可見漫反射譜(UV-Vis DRS)及傅里葉變換紅外光譜(FT-IR)等對復(fù)合材料的形貌結(jié)構(gòu)進(jìn)行表征，考察不同CQDs負(fù)載量對復(fù)合材料光催化氧化脫硝性能的影響。結(jié)果表明：CQDs的引入顯著提高了復(fù)合材料的脫硝性能，當(dāng)CQDs負(fù)載量為4%(質(zhì)量分?jǐn)?shù))時，CQDs/PrFeO3/ATP復(fù)合材料對NO的光氧化活性最高，轉(zhuǎn)化率達(dá)到85%。提出可能的機(jī)理在于：PrFeO3受到可見光的照射激發(fā)產(chǎn)生的電子從價帶躍遷至導(dǎo)帶，光生電子迅速遷移到CQDs上并產(chǎn)生超氧自由基，空穴仍然留在PrFeO3的價帶，二者具有強(qiáng)氧化性將NO氧化成 。CQDs的引入促進(jìn)了光生電子與空穴的分離，同時擴(kuò)展了復(fù)合材料的光譜吸收范圍，凹凸棒石表面的微孔結(jié)構(gòu)也有利于NO氣體的吸附增加其與活性組分的接觸，這種協(xié)同效應(yīng)使得復(fù)合材料的光催化脫硝性能得到提高。
關(guān)鍵字: 稀土鈣鈦礦；凹凸棒石；碳量子點(diǎn)；光氧化脫硝
（Advanced Catalytic and Green Manufacturing Collaborative Innovation Center, Changzhou University, Changzhou 213164, China）
Abstract:By CQDs-(Carbon quantum dots) modified PrFeO3/attapulgite (ATP) composites were prepared by sol-gel/ impregnation method using ATP as support, Pr(NO3)3, Fe(NO3)3 and citric acid as raw materials. The morphology and structure of the composites were characterized by X-ray diffractometer(XRD), transmission electron microscope(TEM), UV-Vis diffuse reflectance spectroscope(UV-Vis DRS) and Fourier transform infrared spectroscope(FT-IR). The photocatalytic denitrification was investigated with different mass ratios of CQDs. The results show that the incorporation of CQDs remarkably promotes the photocatalytic activity of the composite. When the loading amount of the carbon quantum dots is 4% (mass fraction), the NO conversion rate of the composite reaches the highest of 85%.The mechanism is put forward as follows, under visible light irradiation, the PrFeO3 is excited where the electrons jump from the valence band to the conductive band, and the electrons quickly migrate to the CQDs forming super oxygen radicals, while the holes remain in the valence band of PrFeO3, both of them had super oxidation property and further oxidized NO to . The CQDs not only facilitate the separation of photogene rated electrons and holes, but also extend the spectrum absorption range of the composites. Such synergistic effect is expected to improve the photocatalytic denitration performance of the products.
Key words: rare earth perovskite; attapulgite; carbon quantum dots; photocatalytic oxidation denitration
