Enhanced Charge Separation in Single Atom Cobalt Based Graphitic Carbon Nitride: Time Domain Ab Initio Analysis
Enhanced Charge Separation in Single Atom Cobalt Based Graphitic Carbon Nitride: Time Domain Ab Initio Analysis
复制标题
DOI：
10.1021/acs.jpclett.3c03621
复制
发表时间：
2024-02
期刊：
影响因子：
--
通讯作者：
Sraddha Agrawal;David Casanova;D. Trivedi;O. Prezhdo
中科院分区：
文献类型：
--
作者：
Sraddha Agrawal;David Casanova;D. Trivedi;O. Prezhdo
近年来，单原子催化剂一直是能量转换研究的前沿，特别是在催化领域。氮化碳由于其独特的电子结构，为稳定金属原子提供了巨大的潜力。用从头算非绝热分子动力学方法研究了单原子钴基石墨化碳氮化物的光激发动力学。这些结果阐明了掺杂钴原子对GCN电子结构的正向影响。钴掺杂产生填充的中间能隙状态，作为氧化中心，有利于各种氧化还原反应。中间能隙状态的存在使得能够获得更长波长的光子，从而扩大了太阳光的吸收范围。虽然掺杂总体上加速了电荷弛豫，但电荷复合比电荷分离慢得多，为催化应用创造了有利的条件。模拟揭示了原子缺陷改善掺杂体系性能的详细微观机理，并证明了一种有效的电荷分离策略来构建高效稳定的光催化二维材料。
In recent years, single atom catalysts have been at the forefront of energy conversion research, particularly in the field of catalysis. Carbon nitrides offer great potential as hosts for stabilizing metal atoms due to their unique electronic structure. We use ab initio nonadiabatic molecular dynamics to study photoexcitation dynamics in single atom cobalt based graphitic carbon nitride. The results elucidate the positive effect of the doped cobalt atom on the electronic structure of GCN. Cobalt doping produces filled midgap states that serve as oxidation centers, advantageous for various redox reactions. The presence of midgap states enables the harvesting of longer wavelength photons, thereby extending the absorption range of solar light. Although doping accelerates charge relaxation overall, charge recombination is significantly slower than charge separation, creating beneficial conditions for catalysis applications. The simulations reveal the detailed microscopic mechanism underlying the improved performance of the doped system due to atomic defects and demonstrate an effective charge separation strategy to construct highly efficient and stable photocatalytic two-dimensional materials.