A tunable azine covalent organic framework platform for visible light-induced hydrogen generation.
A tunable azine covalent organic framework platform for visible light-induced hydrogen generation.
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DOI：
10.1038/ncomms9508
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发表时间：
2015-09-30
影响因子：
16.6
通讯作者：
Lotsch BV
中科院分区：
文献类型：
--
作者：
Vyas VS;Haase F;Stegbauer L;Savasci G;Podjaski F;Ochsenfeld C;Lotsch BV
水的光催化还原放氢有望成为一种可持续的无碳能源。共价有机骨架(COF)是一类有趣的新型光催化材料，它结合了与光催化过程相关的三个关键特征，即结晶性、孔隙率和可调性。在这里，我们从含氮量不同的肼和三苯基芳醛合成了一系列水和光稳定的2D-azine连接的COF。前体中的电子和空间变化转移到生成的骨架中，从而导致随着骨架中氮含量的增加而逐渐增强的光诱导放氢。我们的结果表明，通过在分子水平上合理地设计COF，可以精确地调节其结构和光电性质，从而提高其光催化活性。这有望激发人们对这些光功能框架的进一步兴趣，在这些框架中，合理的超分子工程可能会导致新的材料应用。光催化还原水制氢是一种很有吸引力的能源，但催化剂往往很昂贵，而且几乎没有改进的空间。在这里，作者们展示了共价有机骨架可以被调节以获得最佳的光催化性能。
Hydrogen evolution from photocatalytic reduction of water holds promise as a sustainable source of carbon-free energy. Covalent organic frameworks (COFs) present an interesting new class of photoactive materials, which combine three key features relevant to the photocatalytic process, namely crystallinity, porosity and tunability. Here we synthesize a series of water- and photostable 2D azine-linked COFs from hydrazine and triphenylarene aldehydes with varying number of nitrogen atoms. The electronic and steric variations in the precursors are transferred to the resulting frameworks, thus leading to a progressively enhanced light-induced hydrogen evolution with increasing nitrogen content in the frameworks. Our results demonstrate that by the rational design of COFs on a molecular level, it is possible to precisely adjust their structural and optoelectronic properties, thus resulting in enhanced photocatalytic activities. This is expected to spur further interest in these photofunctional frameworks where rational supramolecular engineering may lead to new material applications. Production of hydrogen via the photocatalytic reduction of water is an attractive source of energy, but the catalysts are often expensive and possess little room for modification. Here, the authors show that covalent organic frameworks can be tuned for optimal photocatalytic performance.