In-situ hydrothermal synthesized γ-Al₂O₃/O-g-C₃N₄ heterojunctions with enhanced visible-light photocatalytic activity in water splitting for hydrogen

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• 作者：Yu Wang ; Yaping Zeng ; Boqiao Li ; Anqi Li ; Ping Yang ; Liu Yang ; Gang Wang ; Jinwei Chen ; Ruilin Wang ; ^{rl.wang@scu.edu.cn" class="auth_mail" title="E-mail the corresponding author}
• 关键词：O doped g-C3N4 ; γ-Al2O3 ; Visible-light photocatalysis ; In-situ hydrothermal ; Hydrogen
• 刊名：Journal of Energy Chemistry
• 出版年：2016
• 出版时间：July 2016
• 年：2016
• 卷：25
• 期：4
• 页码：594-600
• 全文大小：1739 K

文摘

In this work, γ-Al₂O₃ and hydrogen peroxide treated g-C₃N₄ (O-g-C₃N₄) were combined through a novel in-situ hydrothermal method to form heterojunction structured photocatalysts. These photocatalysts were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS), UV–vis diffuse reflectance spectroscopy and photoluminescence spectroscopy (PL). FT-IR results indicate that oxygen functional groups can be grafted on the surface of O-g-C₃N₄ by hydrogen peroxide treatment. The visible light photocatalytic hydrogen evolution rate was investigated in 10 vol% TEOA aqueous solution. The optimal Al₂O₃ mass content is set to be 20 wt% and the corresponding hydrogen evolution rate is 1288 µmol/h/g which is approximately 6, 3 folds that of pristine g-C₃N₄ and O-g-C₃N₄ respectively and 1.6 folds that of mechanical mixed composite with the same Al₂O₃ mass content. The photocurrent density–time curves were carried out under visible light illumination for four on–off cycles. The electrochemical impedance spectroscopy (EIS) measurements verified the enhanced separation efficiency of electron–hole pairs. This work raised a new method to form the heterojunction structured photocatalysts and achieved a remarkable improvement of the photocatalytic activity in water splitting for hydrogen under visible light irradiation.