Chemical modifications of Polyheptazine-imides : carbon-nitride-based semiconductors with improved structure and electronic properties for full photochemical water splitting and novel photocatalytic reactions

聚庚嗪酰亚胺的化学修饰：具有改进结构和电子性能的氮化碳基半导体，可实现完全光化学水分解和新型光催化反应

• 批准号: 322755296
• 负责人: Professor Dr. Markus Antonietti
• 金额: --
• 依托单位: National Natural Science Foundation of China
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2017
• 资助国家: 德国
• 起止时间: 2016-12-31 至 2021-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/322755296?language=en
• 关键词: Chemical; modifications; Polyheptazine; imides; carbon

The direct splitting of water into H2 and O2 on semiconductor-based photocatalysts is an ideal methodology for the sustainable utilization of solar energy. Coupling water splitting photocatalysis with organic transformations expands applications beyond fuel generation to organic synthesis providing reduction or oxidation equivalents without consumption of fossil resources. Recently, the class of graphitic carbon nitride polymers with their semiconductive, Pi-conjugated electronic features has attracted intense research interests, due to its metal-free, low-cost, stable, and sustainable properties for artificial photosynthesis. This effect was discovered by two of the contributors of this joint proposal. Although significant progress on water half-splitting reactions has been made ever since, the direct water splitting releasing H2 and O2 stoichiometrically has however been rarely realized. This is mainly limited by the large activation barrier to evolve O2 and a still non-optimal semiconductor band structure with insufficient overpotentials. To address the above issues achieving overall water splitting on graphitic carbon nitride, optimizations on both thermodynamic and kinetic aspects are addressed. To achieve this goal, a joint project composed by a Chinese part and a German part is proposed, in which the Chinese group (Wang) focuses on the kinetic control of photocatalytic reactions to facilitate gas release, and one of the German groups (Antonietti) majors in the thermodynamic issues to facilitate water splitting. The thermodynamically and kinetically optimized catalysts are in addition applied to advanced organic photocatalysis, which will be performed by the second German group (König) having a broad expertise in this area. The ideal complementary expertise will allow to improving the overall water splitting to produce hydrogen fuel by graphitic carbon nitride photocatalysts and utilize the added-value of the developed catalysts for photoredox organic synthesis coupled with the water splitting reaction.

在光催化剂上直接将水分解为H2和O2是太阳能可持续利用的理想方法。将水裂解催化转化与有机转化相结合，将应用范围从燃料产生扩展到有机合成，提供了还原或氧化当量，而不消耗化石资源。近年来，具有π共轭电子特性的石墨碳氮聚合物因其不含金属、成本低、稳定性好、可持续性好等优点而成为人工光合作用的研究热点。这一效应是由这一联合提案的两个贡献者发现的。尽管从那时起，水半裂解反应已经取得了重大进展，但是直接水裂解以化学计量方式释放H2和O2却很少实现。这主要是由大的激活势垒演变O2和仍然是非最佳的半导体能带结构与不足的过电位的限制。为了解决在石墨碳氮化物上实现总体水裂解的上述问题，解决了热力学和动力学方面的优化。为了实现这一目标，提出了一个由中国部分和德国部分组成的联合项目，其中中国小组（王）专注于光催化反应的动力学控制，以促进气体释放，德国小组之一（Antonietti）专注于热力学问题，以促进水分解。此外，经过化学和动力学优化的催化剂还将应用于先进的有机合成，这将由在该领域拥有广泛专业知识的第二家德国集团（König）进行。理想的互补专业知识将允许通过石墨氮化碳光催化剂改善整体水裂解以生产氢燃料，并利用所开发的催化剂的附加值用于光氧化还原有机合成与水裂解反应。

项目成果

Optimizing Optical Absorption, Exciton Dissociation, and Charge Transfer of a Polymeric Carbon Nitride with Ultrahigh Solar Hydrogen Production Activity.

• DOI: 10.1002/anie.201706870
• 发表时间: 2017-10
• 期刊: Angewandte Chemie
• 作者: Guigang Zhang;Guosheng Li;Zhi‐An Lan;Lihua Lin;Aleksandr Savateev;T. Heil;S. Zafeiratos;Xinchen Wang