原位光沉积制备Z型α-Fe2O3/g-C3N4异质结及其可见光驱动光解水产氢性能 |
Preparation of Z-Scheme α-Fe2O3/g-C3N4 Heterojunction Based on In-Situ Photodeposition and Photocatalytic Activity for Hydrogen Production under Visible Light |
|
摘要: 采用原位光沉积-煅烧法制得了Z型α-Fe2O3/g-C3N4异质结复合光催化剂。分别采用透射电子显微镜、X射线衍射、X射线光电子能谱、紫外可见漫反射光谱、荧光光谱以及电化学测试对样品进行了表征,并考察了可见光下光解水产氢活性。结果表明:当α-Fe2O3的负载量为2.9%时,α-Fe2O3/g-C3N4复合光催化剂具有最优的产氢催化活性,产氢速率高达1 841.9 μmol·g-1·h-1,约为g-C3N4的3.3倍。光催化性能的提高主要归因于3方面:(1) 高温煅烧过程中α-Fe2O3的形成,有效促进了氮化碳片层的热剥离,增大了比表面积,从而为光催化反应提供了更多反应活性位;(2) 超细α-Fe2O3颗粒(5~8 nm)高度均匀地分散在g-C3N4表面,并且与其紧密结合,形成了高质量的Z型异质结;(3) Z型异质结不仅有效抑制地了光生载流子的复合,同时极大地保留了g-C3N4导带电子的强还原性和α-Fe2O3价带空穴的强氧化性。 |
关键词: 氮化碳 Z型异质结 三氧化二铁 光催化产氢 |
基金项目: 国家自然科学基金(No.21878254)和广东石油化工学院人才引进项目(No.2018rc49)资助 |
Abstract: A Z-scheme α-Fe2O3/g-C3N4 photocatalyst was successfully prepared by the method of in-situ photodeposition-calcination. The as-prepared samples were characterized by transmission electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, UV-Vis diffuse reflectance spectroscopy, photoluminescence spectroscopy, and electrochemical test. The photocatalytic activity was evaluated by visible-light-driven water-splitting hydrogen production. The results showed that when the loading amount of α-Fe2O3 was 2.9%, the photocatalyst exhibited remarkably high photocatalytic activity toward H2 evolution with a rate of 1 841.9 μmol·g-1·h-1, 3.3 times higher than that of pure g-C3N4. The enhanced performance is attributed to the following reasons: (1) α-Fe2O3 promotes exfoliation of g-C3N4 during high-temperature calcination, enlarging specific surface area and providing more active sites; (2) ultrafine α-Fe2O3 particles (5-8 nm) are highly uniformly dispersed on the surface of g-C3N4 and tightly combined to it, forming high-quality Z-scheme heterojunctions; (3) the Z-scheme structure not only effectively suppresses the photocarriers recombination, but also greatly retains the strong reduction originated from g-C3N4 conduction band and the strong oxidation originated from α-Fe2O3 valence band. |
Keywords: g-C3N4 Z-scheme heterojunction α-Fe2O3 photocatalytic hydrogen evolution |
投稿时间:2021-09-25 修订日期:2021-12-14 |
摘要点击次数: 1445 |
全文下载次数: 946 |
陈烽,张成花,金培岳,赵才贤.原位光沉积制备Z型α-Fe2O3/g-C3N4异质结及其可见光驱动光解水产氢性能[J].无机化学学报,2022,38(3):469-478. |
查看全文 查看/发表评论 下载PDF阅读器 |
Support information: 相关附件: file支持信息 |
|
|
|