Li Xiaobo, Sergeyev Ivan V, Aussenac Fabien, Masters Anthony F, Maschmeyer Thomas, Hook James M
School of Chemistry, The university of Sydney, Sydney, 2006, Australia.
Bruker Biospin Corporation, 15 Fortune Drive, Billerica, MA, 01821, USA.
Angew Chem Int Ed Engl. 2018 Jun 4;57(23):6848-6852. doi: 10.1002/anie.201802278. Epub 2018 May 8.
Metal-free polymeric carbon nitrides (PCNs) are promising photocatalysts for solar hydrogen production, but their structure-photoactivity relationship remains elusive. Two PCNs were characterized by dynamic-nuclear-polarization-enhanced solid-state NMR spectroscopy, which circumvented the need for specific labeling with either C- or N-enriched precursors. Rapid 1D and 2D data acquisition was possible, providing insights into the structural contrasts between the PCNs. Compared to PCN_B with lower performance, PCN_P is a more porous and more active photocatalyst that is richer in terminal N-H bonds not associated with interpolymer chains. It is proposed that terminal N-H groups act as efficient carrier traps and reaction sites.
无金属聚合碳氮化物（PCNs）是用于太阳能制氢的有前景的光催化剂，但其结构与光活性之间的关系仍然难以捉摸。通过动态核极化增强固态核磁共振光谱对两种PCNs进行了表征，这避免了使用富含碳或氮的前体进行特定标记的需要。能够快速采集一维和二维数据，从而深入了解PCNs之间的结构差异。与性能较低的PCN_B相比，PCN_P是一种孔隙率更高、活性更强的光催化剂，其末端N-H键更丰富，且与聚合物链无关。有人提出，末端N-H基团充当有效的载流子陷阱和反应位点。
