Ling Chongyi, Niu Xianghong, Li Qiang, Du Aijun, Wang Jinlan
School of Physics , Southeast University , Nanjing 211189 , People's Republic of China.
School of Chemistry, Physics and Mechanical Engineering, Science and Engineering Faculty , Queensland University of Technology , Gardens Point Campus, Brisbane , Queensland 4001 , Australia.
J Am Chem Soc. 2018 Oct 31;140(43):14161-14168. doi: 10.1021/jacs.8b07472. Epub 2018 Oct 17.
Solar nitrogen (N) fixation is the most attractive way for the sustainable production of ammonia (NH), but the development of a highly active, long-term stable and low-cost catalyst remains a great challenge. Current research efforts for N reduction mainly focus on the metal-based catalysts using the electrochemical approach, while metal-free or solar-driven catalysts have been rarely explored. Herein, on the basis of a concept of electron "acceptance-donation", a metal-free photocatalyst, namely, boron (B) atom, decorated on the optically active graphitic-carbon nitride (B/g-CN), for the reduction of N is proposed by using extensive first-principles calculations. Our results reveal that gas phase N can be efficiently reduced into NH on B/g-CN through the enzymatic mechanism with a record low onset potential (0.20 V). Moreover, the B-decorated g-CN can significantly enhance the visible light absorption, rendering them ideal for solar-driven reduction of N. Importantly, the as-designed catalyst is further demonstrated to hold great promise for synthesis due to its extremely high stability. Our work is the first report of metal-free single atom photocatalyst for N reduction, offering cost-effective opportunities for advancing sustainable NH production.
太阳能固氮是实现氨（NH₃）可持续生产最具吸引力的途径，但开发高活性、长期稳定且低成本的催化剂仍然是一个巨大挑战。当前氮还原的研究工作主要集中在采用电化学方法的金属基催化剂上，而无金属或太阳能驱动的催化剂很少被探索。在此，基于电子“接受-给予”的概念，通过广泛的第一性原理计算，提出了一种用于氮还原的无金属光催化剂，即在光学活性石墨相氮化碳（B/g-C₃N₄）上修饰硼（B）原子。我们的结果表明，气相氮可以通过酶促机制在B/g-C₃N₄上高效还原为NH₃，起始电位低至创纪录的0.20 V。此外，硼修饰的g-C₃N₄可以显著增强可见光吸收，使其成为太阳能驱动氮还原的理想材料。重要的是，所设计的催化剂因其极高的稳定性，在合成方面展现出巨大潜力。我们的工作是关于无金属单原子光催化剂用于氮还原的首次报道，为推进可持续氨生产提供了具有成本效益的机会。
