羧基表面修饰与钾离子层间调控双重优化的氮化碳用于增强CO_(2)光还原性能

Dual-facet engineering of surface carboxyl functionalization and interlayer potassium ions regulation in carbon nitride for enhanced CO_(2)photoreduction

对石墨相氮化碳(g-C_(3)N_(4))的表面和层间结构进行同时优化,可以显著提高其光生载流子分离效率.然而,将具有特定优势的改性策略有效整合,从而构建由体相到表面的电荷传输通道仍存在巨大挑战.在此,我们提出了一种利用羧基和钾离子共修饰g-C_(3)N_(4)的新方法,用于引导其动态电荷转移过程.具体而言,我们将羧基官能团修饰在表面,通过其吸电子效应产生的驱动力改善表面的载流子动力学.同时,我们将钾离子插入g-C_(3)N_(4)层间,通过连接相邻层间促进载流子的跨层传输.该双功能光催化剂在无需助催化剂或牺牲剂的气固体系中实现了高达17.93μmol g^(-1)h^(-1)的CO产出速率,比未改性的g-C_(3)N_(4)高出8.68倍.这项工作有望进一步加深我们对光催化剂材料体相和层间区域载流子定向迁移机制的理解.

Simultaneous optimization of surface and interlayer characteristics of graphite-phase carbon nitride(g-C_(3)N_(4))is crucial for enhanced photogenerated-carrier separation efficiency.Integration of distinct strategies with specific merits for constructing efficacious charge carrier transport pathways from bulk to surface faces challenges.Herein,we proposed a novel carboxyl functional group and potassium(K)ions co-modified g-C_(3)N_(4)for steering dynamic charge transfer processes.Specifically,carboxyl functional groups were grafted to the surface to substantially improve charge carrier dynamics through the driving force induced by its electron-withdrawing effects.Concurrently,K ions were inserted into the interlayers of g-C_(3)N_(4)to facilitate interlayer carrier transport by bridging adjacent layers.Such a bi-functional photocatalyst achieves 8.68-fold increase in CO yield compared wtih the pristine g-C_(3)N_(4)without any cocatalyst or sacrificial agent.This work provides a profound discernment into the directional transport of charge carriers within the surface and interlayers,and presents a promising approach for rational design of photocatalysts with remarkably efficient solar energy conversion.