富氧空位/梯次结构CeO2的制备及光催化CO2还原

采用Ce-BTC(均苯三甲酸)为模板,通过尿素溶液浸渍合成了具有富氧空位/梯次结构的CeO₂催化剂,并用X射线衍射(XRD)、扫描电子显微镜(SEM)、透射电子显微镜(TEM)、拉曼光谱(Raman)和紫外可见漫反射(DRS)等手段对其进行了表征.结果表明,与金属有机框架(MOFs)浸渍尿素高温煅烧可以获得金属氧化物/g-C₃N₄复合材料不同,Ce-BTC/尿素体系煅烧后产品中未检测到g-C₃N₄,这可能与CeO₂的存在抑制了尿素分解产物的热缩聚过程,影响了g-C₃N₄的生成有关,但尿素的引入改变了Ce-BTC煅烧产物CeO₂的氧空位浓度,且获得梯次结构.将具有富氧空位/梯次结构的CeO₂-5用于光催化CO₂还原,催化结果表明:反应4h的CO产率可达2.06μmol/g,CH₄产率可达1.42μmol/g,性能是Ce-BTC未...     

金属有机骨架材料低温脱硝技术研究进展

金属有机骨架材料（MOFs）因其独特的结构作为催化剂应用于SCR系统表现出较好的低温脱硝效果和较强的抗SO₂、抗H₂O性能。综述了几种较典型的MOFs催化剂及其改性产物的低温催化性能,以及MOFs材料应用于SCR技术的研究进展,指出：对含有两种或两种以上金属的复合MOFs材料的深入研究,是开发稳定性更高、抗SO₂抗H₂O能力更强的MOFs催化剂的重要思路;此外,对有机组成部分进行改性,提高有机配体的热稳定性也是一个重要的研究思路。     

石墨烯量子点辅助合成Cu-MOFs及CO2吸附行为

选用一种成本低、可大规模合成的Cu基MOFs（Cu-MOFs）材料作为CO₂吸附剂,在原位合成过程中添加石墨烯量子点以调控其晶体结构.结果表明：适量石墨烯量子点的添加有利于提高Cu-MOFs的比表面积和孔体积,相比未改性MOFs材料,改性后的CO₂吸附性能有所提高,25℃,100kPa时提高了4.5%.随着温度升高,吸附容量提升越明显.改性后的MOFs对于N₂的吸附量则比未改性时更低,因此计算得到的CO₂/N₂吸附选择性也更高,增加了近一倍.综合等量吸附热的考察结果发现,尤其添加适量含N石墨烯量子点的Cu-MOFs吸附剂不仅具备了较高的吸附容量、吸附选择性,还展现了较理想的吸附热,因此兼具了较优CO₂吸附性能和较低脱附能耗的特点,为MOFs吸附剂的改性提供了一点参考价值.     

UIO-66改性聚酰胺正渗透复合膜的制备及性能研究

采用界面聚合方法将UIO-66纳米颗粒引入复合膜中制备出改性的聚酰胺复合膜,并利用傅里叶红外光谱（FT-IR）、扫描电子显微镜（SEM）、原子力显微镜（AFM）、X射线衍射光谱（XRD）和接触角仪等仪器对材料和复合膜进行测定表征.以去离子水为原料液,1mol/L氯化钠溶液为汲取液进行渗透性能测试.选取BSA及SA作为污染物进行污染实验,并利用自制探针,借助原子力显微镜（AFM）测定了污染物与膜面的微观作用力.研究发现,相较于原始的聚酰胺复合膜,当UIO-66材料的添加量为0.04wt%时,改性复合膜在FO模式下的纯水通量由10.28L/（m²·h）增大到13.67L/（m²·h）, PRO模式下纯水通量由17.68L/（m²·h）增大到20.41L/（m²·h）,渗透性能改善效果显著,并具有较好的选择性能.此外,污染实验发现相较于原始膜,改性复合膜的通量衰减趋势较缓且与污染物之间粘附力都较小,说明UIO-66改性聚酰胺复合膜的抗污染性能有所提升.     

纳米铜复合材料催化还原染料废水的研究

以铜的有机金属框架为铜源前驱物,酚醛树脂为碳源,合成了多孔碳层支撑的Cu/Cu2O/C非贵金属复合材料.负载的Cu/Cu2O颗粒粒径在40nm左右,多孔碳层的高孔隙结构有利于Cu/Cu2O颗粒与目标物充分接触.将Cu/Cu2O/C作为催化剂用于水中多种染料类污染物(邻硝基苯、亚甲基蓝和罗丹明B)的催化还原反应中,材料重复利用5次后,目标物的降解率仍在99%以上,催化剂表现出了良好的催化活性和稳定性.     

Effective adsorption of sulfamethoxazole, bisphenol A and methyl orange on nanoporous carbon derived from metal-organic frameworks

Nanoporous carbons(NPCs) derived from metal–organic frameworks(MOFs) are attracting increasing attention in many areas by virtue of their high specific surface area, large pore volume and unique porosity. The present work reports the preparation of an NPC with high surface area(1731 m~2/g) and pore volume(1.68 cm~3/g) by direct carbonization of MOF-5. We examined the adsorption of three typical contaminants from aqueous solutions, i.e., sulfamethoxazole(SMX),bisphenol A(BPA) and methyl orange(MO), by using the as-prepared NPC. The results demonstrated that NPC could adsorb the contaminants effectively, with adsorption capacity(qm) of 625 mg/g(SMX), 757 mg/g(BPA) and 872 mg/g(MO), respectively. These values were approximately 1.0-3.2 times higher than those obtained for single-walled carbon nanotubes(SWCNTs) and commercial powder active carbon(PAC) under the same conditions. With its high surface area and unique meso/macropore structure, the enhanced adsorption of NPC most likely originates from the cooperative interaction of a pore-filling mechanism, electrostatic interaction,and hydrogen bonding. In particular, the p H value has a crucial impact on adsorption, suggesting the significant contribution of electrostatic interaction between NPC and the contaminants. This study provides a proof-of-concept demonstration of MOF-derived nanoporous carbons as effective adsorbents of contaminants for water treatment.     

Development of metal organic framework-199 immobilized zeolite foam for adsorption of common indoor VOCs

Reticulated foam shaped adsorbents are more efficient for the removal of volatile organic compounds (VOCs), particularly from low VOC-concentration indoor air streams. In this study composite structure of zeolite and metal organic frameworks (MOFs), referred as ZMF, has been fabricated by immobilization of fine MOF-199 powder on foam shaped Zeolite Socony Mobil-5 (ZSM-5) Zeolitic structure, referred as ZF. The ZMF possess a uniform and well-dispersed coating of MOF-199 on the porous framework of ZF. It shows higher surface area, pore volume, and VOCs adsorption capacity, as compared to ZF-structure. Post-fabrication changes in selective adsorption properties of ZMF were studied with three common indoor VOCs (benzene, n-hexane, and cyclohexane), using gravimetric adsorption technique. The adsorption capacity of ZMF with different VOCs follow the order of benzene > n-hexane > cyclohexane. In comparison with MOF-199 and ZF, the composite structure ZMF shows improvement in selectivity for benzene from other two VOCs. Further, improvement in efficiency and stability of prepared ZMF was found to be associated with its high MOF loading capacity and unique morphological and structural properties. The developed composite structure with improved VOCs removal and recyclability could be a promising material for small to limited scale air pollution treatment units.     

超滤膜负载UiO-66@Fe3O4@UiO-66强化PPCPs去除和膜污染控制

本研究通过聚偏氟乙烯（PVDF）膜内负载具有协同吸附和催化作用的金属有机骨架（MOFs）,吸附去除水中药品及个人护理品（PPCPs）,并且达到膜滤过程中多功能材料吸附能力再生和膜污染控制的双重目的.在膜吸附方面,共混基质膜（MMMs）内MOFs材料UiO-66@Fe₃O₄@UiO-66能够有效吸附以水杨酸（SA）和邻-苯二甲酸二甲酯（DMP）为模板化合物的两种常见PPCPs.在膜催化再生方面,UiO-66@Fe₃O₄@UiO-66中的Fe₃O₄能够催化H₂O₂生成强氧化性的羟基自由基（HO·）,实现对MOFs/PVDF膜吸附能力再生和膜内污染控制的耦合.结果表明,pH=7±0.1条件下,10% MOFs/PVDF膜对0.1 mmol·L^-1 SA和DMP吸附去除率最高,它们的去除率可分别达到64.2%和46.1%.除此之外,膜内UiO-66@Fe₃O₄@UiO-66催化5 mmol·L^-1 H₂O₂,能够使膜通量和膜吸附性能恢复率分别达到91.8%和94.2%.实验设计的这种负载多功能MOFs共混基质膜的特点是它对膜吸附能力再生和膜污染控制过程的耦合.这为生化尾水深度净化过程中PPCPs去除和膜抗污染性能改善提供了新的思路.     

金属-有机框架材料去除水中重金属Cr(Ⅵ)的研究进展

金属-有机框架材料（MOFs）作为新兴的有机-无机杂化材料,兼有稳定性好、多孔、比表面积大等优点,能高效去除水中的重金属Cr（Ⅵ）。本文概括了常用的Cr（Ⅵ）去除方法,重点综述了基于不同金属的MOFs应用于Cr（Ⅵ）吸附和还原转化的影响因素和去除机理,并阐述了MOFs在去除水中Cr（Ⅵ）领域的应用价值及面临的挑战。指出,应通过后修饰、多组分混合等方法进一步提高MOFs的应用潜力。