A carbon-coated g-C₃N₄ nanotube (C-TCN) was constructed via the concurrent thermal polymerization of urea and carbonization of glucose. When the mass ratio of glucose to urea was 1/30, after the precursors were concurrently recrystallized from water, partially dried, and heated at 550 °C for 2 h, the carbon/g-C₃N₄ hybrid (TCN-200) with high nanotube content could be successfully prepared, the diameter of which was in the range of 45–80 nm. The formation mechanism of C-TCN was proposed as follows. As the cocrystal of urea and glucose could form a stacked layered structure because of hydrogen bonding, the newly formed carbon dots (CDots) originated from the carbonization of glucose might uniformly distribute on the surface of g-C₃N₄ layers that originated from the thermal polymerization of urea, and CDots could hinder the aggregation of g-C₃N₄ layers to form nanosheets like bulk g-C₃N₄ (BCN). With the increase of CDots, the adjacent CDots tended to interact and aggregate on the surface of g-C₃N₄ layers, which will drive the g-C₃N₄ layers to crimp and finally form nanotubular structures. With TCN-200 as the electrode material of the supercapacitor, its specific capacitance is ∼2 times that of BCN, owing to the synergistic advantages of highly conductive carbon and nanotubular structures. This facile one-step dual in situ method can afford a guidance for further studies of some TCN-based functional composites.

中文翻译：

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超级电容器应用的碳涂层石墨氮化碳纳米管

通过同时进行尿素的热聚合和葡萄糖的碳化来构建碳包覆的gC ₃ N ₄纳米管（C-TCN）。当葡萄糖与尿素的质量比为1/30时，将前体同时从水中重结晶，部分干燥并在550°C加热2小时后，碳/ gC ₃ N ₄杂化物（TCN-200）具有较高的可以成功制备纳米管含量，其直径在45–80 nm范围内。提出了C-TCN的形成机理。由于尿素和葡萄糖的共晶体可以通过氢键形成堆叠的层状结构，因此源自葡萄糖碳化的新形成的碳点（CDots）可能均匀地分布在gC的表面上源于尿素的热聚合反应的₃ N ₄层和CDots可能阻碍gC ₃ N ₄层的聚集，从而形成纳米片，如块状gC ₃ N ₄（BCN）。随着CDots的增加，相邻的CDots倾向于在gC ₃ N ₄层的表面上相互作用并聚集，这将驱动gC ₃ N ₄层卷曲，最后形成纳米管结构。使用TCN-200作为超级电容器的电极材料，由于高导电碳和纳米管结构的协同优势，其比电容约为BCN的2倍。这种简便的一步双原位方法可为进一步研究某些基于TCN的功能复合材料提供指导。