摘要
光生电子-空穴对的快速复合是导致半导体光催化剂性能不佳的重要因素之一,构建异质结是分离光生电子-空穴对的有效方法。结合热缩合和两步水热反应构建了g-C3N4-CdS-NiS2复合纳米管,并进一步研究了在可见光照射下不同CdS含量的g-C3N4-CdS-NiS2分解水制氢的光催化性能。结果表明,当CdS含量为10%(质量)时,三元复合物的产氢速率最高(50.9μmol·h−1),是纯g-C3N4纳米管的25倍,是g-C3N4-CdS和g-C3N4-NiS2二元复合物的11倍。而且,经过五次循环光催化反应后,产氢速率保持不变。光催化制氢性能的提高主要源于g-C3N4、CdS与NiS2形成的异质结促进光生电子和空穴的迁移及电子-空穴对的分离。
Rapid recombination of photogenerated electron-hole pairs is one of important factors leading to poor performance of semiconductor photocatalysts.Constructing a heterojunction is an effective method for separation of photogenerated electron-hole pairs.In the present work,g-C3N4-CdS-NiS2 composite nanotube was synthesized via thermal condensation using urea and thiourea as precursors,and subsequent two-step hydrothermal reactions.The photocatalytic activity of g-C3N4-CdS-NiS2 composite was investigated for H2 generation from water using triethanolamine as sacrificial agent under visible light irradiation.The optimal g-C3N4-CdS-NiS2 composite with the content of CdS 10%(mass)produced H2 at a rate of 50.9μmol·h−1,which is 25 times and 11 times of that of pure g-C3N4 nanotube and g-C3N4-CdS(NiS2)binary composite,respectively.Moreover,cyclic photocatalytic experiments demonstrated the high stability of g-C3N4-CdS-NiS2 composite.The improvement in the photocatalytic performance for H2 production can be mainly attributed to the formation of heterojunction between CdS,NiS2 and g-C3N4 nanotubes,which is beneficial to the separation of photogenerated electron-hole pairs.
作者
陈克龙
黄建花
CHEN Kelong;HUANG Jianhua(Department of Chemistry,Zhejiang Sci-Tech University,Hangzhou 310018,Zhejiang,China)
出处
《化工学报》
EI
CAS
CSCD
北大核心
2020年第1期397-408,共12页
CIESC Journal
基金
国家自然科学基金项目(21574117)
关键词
制氢
催化
光化学
异质结
硫化镉
硫化镍
纳米管
可见光催化
g-C3N4
hydrogen production
catalysis
photochemistry
heterojunction
cadmium sulfide
nickel sulfide
nanotube
visible light catalysis
g-C3N4
