Salt-melt synthesis of poly(heptazine imide)in binary alkali metal bromides for enhanced visible-light photocatalytic hydrogen production  

作　　者：Yaxuan Jin Dandan Zheng Zhongpu Fang Zhiming Pan Sibo Wang Yidong Hou Oleksandr Savateev Yongfan Zhang Guigang Zhang 

机构地区：[1]State Key Laboratory of Photocatalysis on Energy and Environment College of Chemistry,Fuzhou University,Fuzhou,China [2]College of Environment and Safety Engineering,Fuzhou University,Fuzhou,China [3]Department of Chemistry,The Chinese University of Hong Kong,Shatin,New Territories,Hong Kong,China

出　　处：《Interdisciplinary Materials》2024年第3期389-399,共11页交叉学科材料（英文）

基　　金：National Key R&D Program of China,Grant/Award Number:2021YFA1502100;National Natural Science Foundation of China,Grant/Award Number:22172029;Science Foundation of the Fujian Province,Grant/Award Number:2022L3084。

摘　　要：Poly(heptazine imide)(PHI),a semicrystalline version of carbon nitride photocatalyst based on heptazine units,has gained significant attention for solar H_(2)production benefiting from its advantages including molecular synthetic versatility,excellent physicochemical stability and suitable energy band structure to capture visible photons.Typically,PHI is obtained in saltmelt synthesis in the presence of alkali metal chlorides.Herein,we examined the role of binary alkali metal bromides(LiBr/NaBr)with diverse compositions and melting points to rationally modulate the polymerization process,structure,and properties of PHI.Solid characterizations revealed that semicrystalline PHI with a condensedπ-conjugated system and rapid charge separation rates were obtained in the presence of LiBr/NaBr.Accordingly,the apparent quantum yield of hydrogen using the optimized PHI reaches up to 62.3%at 420 nm.The density functional theory calculation shows that the dehydrogenation of the ethylene glycol has a lower energy barrier than the dehydrogenation of the other alcohols from the thermodynamic point of view.This study holds great promise for rational modulation of the structure and properties of conjugated polymeric materials.

关 键 词：crystallinity hydrogen evolution photocatalysis poly(heptazine imide) salt-melt synthesis 

分 类 号：O62[理学—有机化学]