Wang Yang, Liu Xueqin, Zheng Cunchuan, Li Yinchang, Jia Songru, Li Zhen, Zhao Yanli
Faculty of Materials Science and chemistry China University of Geosciences Wuhan 430074 P. R. China.
Division of Chemistry and Biological Chemistry School of Physical and Mathematical Sciences Nanyang Technological University 21 Nanyang Link Singapore 637371 Singapore.
Adv Sci (Weinh). 2018 Apr 15;5(6):1700844. doi: 10.1002/advs.201700844. eCollection 2018 Jun.
Rapid recombination of photoinduced electron-hole pairs is one of the major defects in graphitic carbon nitride (g-CN)-based photocatalysts. To address this issue, perforated ultralong TiO nanotube-interlaced g-CN nanosheets (PGCN/TNTs) are prepared via a template-based process by treating g-CN and TiO nanotubes polymerized hybrids in alkali solution. Shortened migration distance of charge transfer is achieved from perforated PGCN/TNTs on account of cutting redundant g-CN nanosheets, leading to subdued electron-hole recombination. When PGCN/TNTs are employed as photocatalysts for H generation, their in-plane holes and high hydrophilicity accelerate cross-plane diffusion to dramatically promote the photocatalytic reaction in kinetics and supply plentiful catalytic active centers. By having these unique features, PGCN/TNTs exhibit superb visible-light H-generation activity of 1364 µmol h g (λ > 400 nm) and a notable quantum yield of 6.32% at 420 nm, which are much higher than that of bulk g-CN photocatalysts. This study demonstrates an ingenious design to weaken the electron recombination in g-CN for significantly enhancing its photocatalytic capability.
光生电子 - 空穴对的快速复合是石墨相氮化碳（g-CN）基光催化剂的主要缺陷之一。为了解决这个问题，通过在碱溶液中处理g-CN和TiO纳米管聚合杂化物，采用基于模板的方法制备了穿孔超长TiO纳米管交错的g-CN纳米片（PGCN/TNTs）。由于去除了多余的g-CN纳米片，穿孔的PGCN/TNTs实现了电荷转移迁移距离的缩短，从而抑制了电子 - 空穴复合。当PGCN/TNTs用作光催化产氢的光催化剂时，其面内空穴和高亲水性加速了跨平面扩散，从而在动力学上显著促进光催化反应并提供丰富的催化活性中心。凭借这些独特特性，PGCN/TNTs表现出1364 μmol h g（λ > 400 nm）的出色可见光产氢活性以及在420 nm处6.32%的显著量子产率，远高于块状g-CN光催化剂。这项研究展示了一种巧妙的设计，可削弱g-CN中的电子复合，从而显著提高其光催化能力。
