Abstract Morphological and structural modifications are effective ways to improve the photocatalytic performance of polymeric carbon nitride (CN), a promising photocatalyst for industrial application, but research on simultaneous morphological control and covalent bond insertion in CN and relevant structure-function relationships are still rare. Herein, sp2-carbon linked CN (C-CN) porous nanotubes were simply synthesized by first using polyethyleneimine as the template and modifying agent, and exhibit an enlarged specific surface area, enhanced visible light absorption and charge separation, originating from the sp2-C introduced impurity level in the bandgap, and thus improved photocatalytic H2 evolution activity under visible light irradiation, compared with the bulk CN. Interestingly, the photoactivity of C-CN at wavelengths of 400 and 420 nm is lower than CN because of the sp2-C insertion induced reduction of amino groups which are active sites for H2 evolution. That is, the photoactivity enhancement of C-CN is λ-dependent. This work elucidates the sp2-C linked structure-performance relationship of C-CN, and may direct future research on atom-linked mesoporous CN-based photocatalysts.

中文翻译：

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sp2-碳连接的聚合氮化碳多孔纳米管的软模板合成与增强的光催化析氢

摘要 形态和结构修饰是提高聚合氮化碳（CN）光催化性能的有效途径，聚合氮化碳（CN）是一种有前景的工业应用光催化剂，但在 CN 中同时进行形态控制和共价键插入以及相关的结构 - 功能关系的研究仍然很少。在此，首先以聚乙烯亚胺为模板和改性剂简单合成了 sp2-碳连接的 CN（C-CN）多孔纳米管，并表现出更大的比表面积，增强的可见光吸收和电荷分离，源自 sp2-C与块状 CN 相比，在带隙中引入了杂质能级，从而提高了在可见光照射下的光催化析氢活性。有趣的是，C-CN 在 400 和 420 nm 波长的光活性低于 CN，因为 sp2-C 插入诱导氨基减少，氨基是 H2 释放的活性位点。也就是说，C-CN 的光活性增强是依赖于 λ 的。这项工作阐明了 C-CN 的 sp2-C 连接结构-性能关系，并可能指导未来对原子连接介孔 CN 基光催化剂的研究。