Holey Graphitic Carbon Nitride Nanosheets with Carbon Vacancies for Highly Improved Photocatalytic Hydrogen Production
Holey Graphitic Carbon Nitride Nanosheets with Carbon Vacancies for Highly Improved Photocatalytic Hydrogen Production
复制标题
具有碳空位的多孔石墨氮化碳纳米片可显着提高光催化产氢能力
DOI：
10.1002/adfm.201503221
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发表时间：
2015-11-25
影响因子：
19
通讯作者：
Yang, Quan-Hong
中科院分区：
文献类型：
--
作者：
Liang, Qinghua;Li, Zhi;Yang, Quan-Hong
二维石墨氮化碳纳米片由于其许多有趣的性质在光催化领域引起了广泛的关注。然而，GCN纳米片的光催化性能仍然受到光催化过程中活性位点有限和聚集现象严重的制约。本文报道了一种在NH3气氛下对块状GCN （BGCN）进行热处理，制备具有丰富面内孔的多孔GCN （HGCN）纳米片的简单方法。这些形成的平面内空穴不仅使GCN纳米片具有更多暴露的活性边缘和跨平面扩散通道，大大加快了质量和光生电荷的转移，而且还提供了许多边界，从而减少了聚集。与BGCN相比，合成的HGCN具有更高的比表面积，达到196 m2 g−1，同时带隙扩大到2.95 eV。此外，HGCN还被证明具有碳空位的自修饰，这使得HGCN在近红外区域具有更宽的光吸收，更高的供体密度和更长的载流子寿命。因此，HGCN具有更高的光催化制氢速率，几乎是BGCN的20倍。
2D graphitic carbon nitride (GCN) nanosheets have attracted tremendous attention in photocatalysis due to their many intriguing properties. However, the photocatalytic performance of GCN nanosheets is still restricted by the limited active sites and the serious aggregation during the photocatalytic process. Herein, a simple approach to produce holey GCN (HGCN) nanosheets with abundant in‐plane holes by thermally treating bulk GCN (BGCN) under an NH3 atmosphere is reported. These formed in‐plane holes not only endow GCN nanosheets with more exposed active edges and cross‐plane diffusion channels that greatly speed up mass and photogenerated charge transfer, but also provide numerous boundaries and thus decrease the aggregation. Compared to BGCN, the resultant HGCN has a much higher specific surface area of 196 m2 g−1, together with an enlarged bandgap of 2.95 eV. In addition, the HGCN is demonstrated to be self‐modified with carbon vacancies that make HGCN show much broader light absorption extending to the near‐infrared region, a higher donor density, and remarkably longer lifetime of charge carriers. As such, HGCN has a much higher photocatalytic hydrogen production rate of nearly 20 times the rate of BGCN.