摘要
Developing a promising step-scheme(S-scheme)heterojunction is an effective strategy to achieve high photocatalytic activity for hydrogen evolution reaction(HER).However,the difference in microstructure and energy level matching between two semiconductors confers limited catalytic activity of traditional S-scheme heterojunctions.In this work,a strong interfacial coupled S-scheme homojunction composed of potassium-doped g-C_(3)N_(4)and nitrogen-doped g-C_(3)N_(4)(K-CN/N-CN)is constructed successfully as an efficient HER catalyst.The engineered K-CN/N-CN not only features well-defined two-dimensional(2D)lamellar morphology with strong interfacial electron interactions but also possesses efficient light utilization and favorable carrier migration dynamics.Subsequent density functional theory(DFT)calculations confirm the optimal hydrogen adsorption Gibbs free energy(ΔG H*)for K-CN/N-CN homojunction,which is extremely close to zero(−0.06 eV).Importantly,the migration of photogenerated electron-hole pairs for the K-CN/N-CN adheres to a typical S-scheme carrier transfer mechanism,which effectively retains the strongly reducing photoexcited electrons.Consequently,the optimal K-CN/N-CN S-scheme homojunction displays a high H_(2)evolution rate of 8.7 mmol g^(−1)h^(−1)under visible light excitation,which is~72 times higher than that of the CN.The S-scheme homojunction developed in this study provides valuable insights for further strategic design and construction of high-performance catalysts.
基金
supported by the National Key R&D Program of China(Grant No.2022YFC3902703)
the Natural Science Foundation of Hubei Province(Grant Nos.2024AFB890,2021CFB133)
the Innovation Project of Hubei Three Gorges Laboratory(Grant No.SC240007).
作者简介
Corresponding author:Haitao WANG,wanghaitao@wit.edu.cn;Corresponding author:Changhui SONG,chsong128@163.com;Corresponding author:Jing ZOU,jingzou@wit.edu.cn。
