Barrer Centre, Department of Chemical Engineering, Imperial College London , South Kensington Campus, London SW7 2AZ, U.K.
Department of Materials, Imperial College London , South Kensington Campus, London SW7 2AZ, U.K.
ACS Nano. 2017 Oct 24;11(10):10003-10011. doi: 10.1021/acsnano.7b04219. Epub 2017 Sep 18.
Production of biocompatible and stable porous materials, e.g., boron nitride, exhibiting tunable and enhanced porosity is a prerequisite if they are to be employed to address challenges such as drug delivery, molecular separations, or catalysis. However, there is currently very limited understanding of the formation mechanisms of porous boron nitride and the parameters controlling its porosity, which ultimately prevents exploiting the material's full potential. Herein, we produce boron nitride with high and tunable surface area and micro/mesoporosity via a facile template-free method using multiple readily available N-containing precursors with different thermal decomposition patterns. The gases are gradually released, creating hierarchical pores, high surface areas (>1900 m/g), and micropore volumes. We use 3D tomography techniques to reconstruct the pore structure, allowing direct visualization of the mesopore network. Additional imaging and analytical tools are employed to characterize the materials from the micro- down to the nanoscale. The CO uptake of the materials rivals or surpasses those of commercial benchmarks or other boron nitride materials reported to date (up to 4 times higher), even after pelletizing. Overall, the approach provides a scalable route to porous boron nitride production as well as fundamental insights into the material's formation, which can be used to design a variety of boron nitride structures.
如果要将氮化硼等生物相容性和稳定的多孔材料用于解决药物输送、分子分离或催化等挑战，那么生产具有可调谐和增强多孔性的多孔氮化硼等材料是前提条件。然而，目前人们对多孔氮化硼的形成机制以及控制其多孔性的参数知之甚少，这最终阻碍了充分发挥该材料的潜力。在此，我们使用多种易于获得的具有不同热分解模式的含氮前体制备了具有高表面积和微/介孔的氮化硼，通过一种简单的无模板方法。气体逐渐释放，形成分级孔、高表面积（>1900 m/g）和微孔体积。我们使用 3D 断层扫描技术重构孔结构，从而可以直接观察介孔网络。此外，还使用成像和分析工具对材料进行了从微观到纳米尺度的表征。这些材料的 CO 吸收量与商业基准或迄今为止报道的其他氮化硼材料（高达 4 倍）相当或超过（即使在压片后）。总的来说，该方法为多孔氮化硼的生产提供了一种可扩展的途径，并为材料的形成提供了基本的见解，可用于设计各种氮化硼结构。
