2020年04月22日

    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硕士生丁心和刘宏利老师等人在MOFs纳米片阵列光催化降解典型VOCs方面取得新进展，研究成果以“In situ growth of well-aligned Ni-MOF nanosheets on nickel foam for enhanced photocatalytic degradation of typical volatile organic compounds”为题发表在Nanoscale杂志上。该工作首次将MOFs纳米片阵列应用于光催化降解VOCs，表现出优异的可见光降解活性和催化剂稳定性，系统探究了该催化剂高效降解VOCs的作用机制及可能的降解路径。

    光催化氧化技术被认为是最具应用前景的VOCs治理技术之一，但目前仍面临可见光催化效率低和催化剂易失活的问题。本文首次尝试以泡沫镍为MOFs纳米片的基底和牺牲模板，通过简单的溶剂热法，一步制备出在泡沫镍表面紧密、垂直均匀生长的Ni-MOF纳米片阵列 (Ni-MOF/NF)。研究结果表明：多孔泡沫镍载体和Ni-MOF纳米片阵列可使催化剂表面暴露更多的催化活性位点和光吸收位点，并可提供快速的扩散和电子传输通道；而且Ni-MOF纳米片与具有良好导电性泡沫镍间的紧密界面接触，可进一步加速光生电子的传输。这些因素协同作用提高了分子的传质扩散、光的吸收和光生载流子的分离，致使催化剂表面产生大量强氧化性自由基 (如，•OH、•O2-)，且可被反应底物分子快速消耗，减少中间产物在催化剂表面的累积，因此提高了催化剂的光催化活性和抗失活性能。进一步通过PTR-ToF-MS、吸附和光催化表面动力学调控等手段推导了Ni-MOF/NF光催化降解VOCs的可能反应路径。该研究不仅提供了一种简单制备MOFs纳米片阵列的方法，也为MOFs在光催化降解VOCs方面的应用提供了新思路。

    论文英文摘要

    ABSTRACT：Exploitation of highly efficient catalysts for photocatalytic degradation of volatile organic compounds (VOCs) under visible light irradiation is highly desirable yet challenging. Herein, well-aligned 2D Ni-MOF nanosheet arrays vertically grown on porous nickel foam (Ni-MOF/NF) without lateral stacking was successfully prepared via a facile in-suit solvothermal strategy. In this process, Ni foam could serve as both skeletons to vertically support the Ni-MOF nanosheets and self-sacrificial templates to afford Ni ions for MOF growth. The Ni-MOF/NF nanosheet arrays with highly exposed active sites and light harvesting centres as well as fast mass and e‒ transport channels exhibited excellent photocatalytic oxidation activity and mineralization efficiency to typical VOCs emitted form paint spray industry, which was almost impossible for its three-dimensional (3D) bulk Ni-MOF counterparts. A mineralization efficiency of 86.6% could be achieved at 98.1% of ethyl acetate removal. The related degradation mechanism and possible reaction pathways were also attempted based on the electron paramagnetic resonance (EPR) and online Time-of-Flight Mass Spectrometer (PTR-ToF-MS) results.

    论文链接：https://doi.org/10.1039/D0NR01027H