近日，广东工业大学环境健康与污染控制研究院、环境科学与工程学院安太成教授团队题为《Near-infrared light induced adsorption-desorption cycle for VOCs recovery by integration of metal-organic frameworks with graphene oxide nanosheets》的学术论文在Environ. Sci.: Nano (2022,https://doi.org/10.1039/D2EN00103A)杂志上接受发表。论文的第一作者为刘宏利副教授，第二作者为硕士研究生李宁云，通讯作者为安太成教授。该研究工作主要是基于MOF较大的VOCs吸附容量和氧化石墨烯纳米片（GO）良好的光热效应，提出了在GO纳米片表面生长MIL-101制备GO@MIL-101吸附剂。发现该吸附剂不仅对工业排放典型VOC乙酸乙酯表现出优异的吸附能力，而且在UV-vis-NIR光照射下可使被吸附的乙酸乙酯快速脱附，通过原位漫反射红外光谱、VOCs程序升温脱附和吡啶红外光谱等技术，系统阐明了乙酸乙酯在GO@MIL-101表界面上的吸附和光热脱附的微观机制。

论文链接：https://pubs.rsc.org/en/content/articlelanding/2022/en/d2en00103a

吸附法因具有操作工艺简单、低成本及可回收VOCs等优点等，已成为净化工业排放VOCs的有效技术之一。金属有机骨架材料（MOFs）作为一类新型多孔材料，因其具有较大的比表面积和高的孔隙率，已展现出比其他多孔材料更优异的VOCs吸附能力。然而，由于MOFs导热系数较低，如何有效地脱附被吸附的VOCs，实现MOFs基吸附剂的再生仍是目前亟待解决的科学难题。在此，我们将MOF前体与GO进行预配位，利用简单的一步水热法在GO纳米片上均匀地生长MIL-101。制备的复合吸附剂的吸附、脱附结果表明：GO@MIL-101不仅继承了MIL-101优异的乙酸乙酯吸附能力，而且在UV-vis-NIR光照50秒的时间内，吸附剂表面温度迅速升高至130 °C，UV-vis-NIR光照60 min即可完全实现所吸附乙酸乙酯的脱附。机理研究表明：GO@MIL-101复合吸附剂主要通过物理吸附和少量的化学原理来吸附捕获乙酸乙酯；随后在光照下，具有优异光热转化能力的GO可将吸收的光能转化成热能并转移到MIL-101上，这些热能随后通过其有序配体和金属离子分布到整个MIL-101表面，由于每个MIL-101纳米颗粒内部的传热距离较短，可以有效缓解MIL-101固有导热性能差的缺点。同时由于MIL-101较低的导热系数，可有效减少热量向周围环境的损失，致使热量可以聚集在MOF内产生局部高温，最终促进被吸附VOCs的快速脱附。该研究主要是希望利用取之不尽的太阳能为脱附驱动力，将为高效、低能耗、可持续的资源化净化或者回收VOCs提供新的发展方向。

Graphical Abstract：

论文英文摘要：

Metal-organic frameworks are appealing candidates for adsorption of VOCs from contaminated air due to their outstanding capturing capacities, but the traditional regeneration methods of used MOFs adsorbents often suffer from great energy-penalty. Herein, a near-infrared light induced desorption of VOCs from a photodynamic GO@MIL-101 nanocomposite adsorbent was attempted by the integration of MIL-101 with GO nanosheets. MIL-101 uniformly and closely grown on GO nanosheets not only rendered it inherit excellent VOC adsorption capability of MIL-101, but also enabled it to manifest strong light-harvesting in whole UV-vis-NIR region. More importantly, GO nanosheets could serve as “nanoheaters” to convert incident light into thermal energy upon exposure to UV-vis or UV-vis-NIR light, and then the localized thermal energy would rapidly transfer and distribute to MIL-101 located on GO nanosheets, thus making GO@MIL-101 nanocomposites reach higher surface temperatures compared to pure MIL-101 and GO counterparts regardless of UV-vis irradiation or UV-vis-NIR irradiation. Eventually, such light induced localized heat would trigger the complete release of adsorbed ethyl acetate from GO@MIL-101 nanocomposites. Distinct from traditional thermal swing desorption, this light induced VOC release could not only mitigate the drawback of MOF on inferior thermal conductivity, but also would provide a potentially low energy strategy for highly efficient regeneration of MOF-based adsorbents powered by naturally abundant solar light without the other energy input.