Henan Key Laboratory of Rare Earth Functional Materials; International Joint Research Laboratory for Biomedical Nanomaterials of Henan; The Key Laboratory of Rare Earth Functional Materials and Applications, Zhoukou Normal University, Zhoukou 466001, China.
Phys Chem Chem Phys. 2019 Jan 21;21(3):1514-1520. doi: 10.1039/c8cp06956e. Epub 2019 Jan 7.
Graphitic carbon nitride (g-CN) is a promising photocatalyst for the reduction of CO into fuels. However, the reduction mechanism of CO using g-CN is not clear in the literature. In the present study, the fixation of CO and the formation of carbamate on the nitrogen atom at the edge of g-CN were investigated using first-principles density functional theory. The calculated results shows that two adjacent bare nitrogen atoms at the edge of g-CN could be the activation sites for the proton and CO molecule respectively, which are crucial to the formation of carbamate. The calculated energy barrier of carbamate formation is 0.95 eV for a preferential pathway. From studies on these micro processes, we propose a mechanism with proton assistance for the g-CN-catalyzed photoreduction of CO to CO.
石墨相氮化碳 (g-CN) 是一种很有前途的用于将 CO 还原为燃料的光催化剂。然而，文献中对于 g-CN 还原 CO 的还原机制并不清楚。在本研究中，使用第一性原理密度泛函理论研究了 CO 在 g-CN 边缘氮原子上的固定和氨基甲酸酯的形成。计算结果表明，g-CN 边缘两个相邻的裸露氮原子可能分别是质子和 CO 分子的活性位点，这对于氨基甲酸酯的形成至关重要。形成氨基甲酸酯的计算能垒对于一个优势路径是 0.95 eV。通过对这些微观过程的研究，我们提出了一种在质子辅助作用下 g-CN 光催化 CO 还原为 CO 的机制。
