Liu Wei, Yanase Takashi, Iwasa Nobuhiro, Mukai Shin, Iwamura Shinichiro, Nagahama Taro, Shimada Toshihiro
Division of Applied Chemistry, Faculty of Engineering, Hokkaido University, Kita 13 Nishi 8, Kita-Ku, Sapporo, Hokkaido 060-8628, Japan.
Division of Applied Chemistry, Faculty of Engineering, Hokkaido University, Kita 13 Nishi 8, Kita-Ku, Sapporo, Hokkaido 060-8628, Japan.
J Colloid Interface Sci. 2020 May 1;567:369-378. doi: 10.1016/j.jcis.2020.02.031. Epub 2020 Feb 11.
Two-dimensional (2D) graphitic carbon nitride (g-CN) nanoplates (CNNP) have become a hot research topic in photocatalysis due to their small thickness and large specific surface area that favors charge transport and catalytic surface reactions. However, the wide application of 2D g-CN nanoplates prepared by ordinary methods suffers from increased band gaps with a poor solar harvesting capability caused by the strong quantum confinement effect and reduced conjugation distance. In this paper, a facile approach of exfoliation and the following fast thermal treatment of the bulk g-CN is proposed to obtain a porous few-layered g-CN with nitrogen defects. Due to the preferable crystal, textural, optical and electronic structures, the as-obtained porous CNNP demonstrated a significantly improved photocatalytic activity towards water splitting than the bulk g-CN and even the 3 nm-thick CNNP obtained by sugar-assisted exfoliation of the bulk g-CN. The difference in the enhancement factors between the HO splitting and organic decomposition has revealed the effect of N defects. This study offers insightful outlooks on the scalable fabrication of a porous few-layered structure with a promoted photocatalytic performance.
二维（2D）石墨相氮化碳（g-CN）纳米片（CNNP）因其厚度小、比表面积大，有利于电荷传输和催化表面反应，已成为光催化领域的研究热点。然而，通过常规方法制备的二维g-CN纳米片，由于强量子限域效应和共轭距离减小导致带隙增大，太阳能捕获能力较差，其广泛应用受到限制。本文提出了一种简便的剥离方法，并对块状g-CN进行快速热处理，以获得具有氮缺陷的多孔少层g-CN。由于具有较好的晶体、织构、光学和电子结构，所制备的多孔CNNP对水分解的光催化活性比块状g-CN甚至通过块状g-CN的糖辅助剥离获得的3nm厚的CNNP都有显著提高。析氢反应和有机分解之间增强因子的差异揭示了氮缺陷的影响。该研究为可扩展制备具有增强光催化性能的多孔少层结构提供了深刻见解。
