Scalable and clean exfoliation of graphitic carbon nitride in NaClO solution: enriched surface active sites for enhanced photocatalytic H2 evolution
Scalable and clean exfoliation of graphitic carbon nitride in NaClO solution: enriched surface active sites for enhanced photocatalytic H2 evolution
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NaClO 溶液中石墨碳氮化物的可扩展且清洁的剥离：富集表面活性位点以增强光催化 H-2 析出
DOI：
10.1039/c7gc03704j
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发表时间：
2018-03-21
期刊：
影响因子：
9.8
通讯作者：
Kang, Shifei
中科院分区：
文献类型：
--
作者：
Cui, Lifeng;Liu, Yanfei;Kang, Shifei
石墨氮化碳（g-C3N4）作为一种有前途的可见光驱动的无金属半导体光催化剂引起了广泛的关注。 g-C3N4光催化过程中光生载流子的传输和转化受到表面活性位点不足和电荷分离效率低的限制。作为一种自上而下的策略，将层状堆积的块状 g-C3N4 剥离成纳米片被广泛认为是一种适用的途径，但在可扩展和清洁合成方面仍然具有挑战性。在此，通过在 NaClO 溶液中使用简单的水热方法解决了这一挑战，其中涉及碱金属离子嵌入和块状 g-C3N4 氧化剥离的协同效应。高活性的 g-C3N4 纳米片很容易在实验室中制造出几十克的重量，并且这个简单的过程可以很容易地扩展到公斤的规模。水热处理形成了定向电子转移的垂直通道，并获得了具有显着分级孔隙率和良好亲水性的超薄多孔g-C3N4纳米片。多孔g-C3N4纳米片具有高比表面积（170.7 m(2) g(-1)）、窄带隙（2.55 eV）、大量暴露边缘和优异的电子传输能力。这些多孔 g-C3N4 纳米片的平均 H-2 演化速率是块状 g-C3N4 的 9 倍。这种绿色、简便且可扩展的合成少层 g-C3N4 纳米片的方法为设计和制造其他功能性二维材料提供了新的策略。
Graphitic carbon nitride (g-C3N4) has attracted wide attention as a promising visible-light-driven metal-free semiconductor photocatalyst. The transportation and transformation of photogenerated carriers during the photocatalytic process of g-C3N4 are restricted by the insufficient surface active sites and low charge separation efficiency. As a top-down strategy, the exfoliation of layer-stacked bulk g-C3N4 into nanosheets is widely recognized as an applicable route, yet still challenging in terms of scalable and clean synthesis. Herein, this challenge was tackled via a simple hydrothermal method in NaClO solution, in which the synergetic effect of alkaline metal ion intercalation and the oxidative exfoliation of bulk g-C3N4 was involved. Highly active g-C3N4 nanosheets were easily made in the laboratory in tens of grams and this simple process could readily be extended to the scale of kilograms. The hydrothermal treatment created vertical channels for directional electron transfer and obtained ultrathin holey g-C3N4 nanosheets with remarkable hierarchical porosity and good hydrophilicity. The holey g-C3N4 nanosheets exhibit a high specific surface area (170.7 m(2) g(-1)), a narrow band gap (2.55 eV), a large number of exposed edges, and superior electron transport ability. These holey g-C3N4 nanosheets have an average H-2 evolution rate 9 times that of bulk g-C3N4. This green, facile and scalable method to synthesize few-layer g-C3N4 nanosheets affords a new strategy to design and fabricate other functional 2D materials.