在n型聚合物光催化剂中介绍的浅陷状态的光阴性能
Qiushi Ruan1, Tina Miao1,2, Hui Wang1
1Department of Chemical Engineering , University College London (UCL) , London WC1E 7JE , United Kingdom.
Journal of the American Chemical Society
|January 16, 2020
概括
这项研究通过引入缺陷来增强石墨碳化物 (g-C3N4) 作为生产的光阴极. 这种富有缺陷的g-C3N4具有显著的导电性和电荷稳定性,使其具有高效的光阴极性能.
科学领域:
- 材料科学
- 光催化
- 电化学
背景情况:
- 石墨碳化物 (g-C3N4) 是光催化的一种有前途的半导体,特别是用于H2进化.
- 它作为光电化学系统中的光阴极的应用具有挑战性,因为它具有典型的n型行为,有利于光阳极功能.
- 了解影响n型半导体作为光阴极的因素对于推进H2生产技术至关重要.
研究的目的:
- 开发一种有效的策略,将n型g-C3N4从光电极材料转化为高效的光电极.
- 研究引入的电子陷状态在增强光阴极性能中的作用.
- 在缺陷工程g-C3N4中观察到的光阴极行为背后的基本机制.
主要方法:
- 通过引入N-缺陷和C-OH终端组来合成富缺陷的g-C3N4 (def-g-C3N4).
- 使用导电性测量和开放电路光伏衰变 (OCVD) 进行电子属性的表征.
- 包括Mott-Schottky (MS) 图和短暂吸收光谱 (TAS) 探测电荷动态的光谱分析.
主要成果:
- 与原始g-C3N4相比,缺陷工程显著提高了电导率2个数量级,电荷载体寿命3个数量级.
- 在0V与RHE之间,def-g-C3N4表现出明显的光阴极行为,负光电流密度约为-10μA/cm2.
- 在微秒时间尺度上长寿命的浅陷电子被确定为光阴极性能的关键.
结论:
- 通过N-缺陷和C-OH组引入电子陷状态,有效地将n型g-C3N4转化为高效的光阴极材料.
- 增强的电荷导电性和延长的电荷载体寿命对于实现光阴极功能至关重要.
- 这项工作证明了g-C3N4作为光电化学应用的光电极和光电极候选物的双重潜力.
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