Photoelectrochemical Conversion from Graphitic C3N4 Quantum Dot Decorated Semiconductor Nanowires

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• 作者：Tiance An ; Jing Tang ; Yueyu Zhang ; Yingzhou Quan ; Xingao Gong ; Abdullah M. Al-Enizi ; Ahmed A. Elzatahry ; Lijuan Zhang ; Gengfeng Zheng
• 刊名：ACS Applied Materials & Interfaces
• 出版年：2016
• 出版时间：May 25, 2016
• 年：2016
• 卷：8
• 期：20
• 页码：12772-12779
• 全文大小：585K
• 年卷期：0
• ISSN：1944-8252

文摘

Despite the recent progress of developing graphitic carbon nitride (g-C₃N₄) as a metal-free photocatalyst, the synthesis of nanostructured g-C₃N₄ has still remained a complicated and time-consuming approach from its bulk powder, which substantially limits its photoelectrochemical (PEC) applications as well as the potential to form composites with other semiconductors. Different from the labor-intensive methods used before, such as exfoliation or assistant templates, herein, we developed a facile method to synthesize graphitic C₃N₄ quantum dots (g-CNQDs) directly grown on TiO₂ nanowire arrays via a one-step quasi-chemical vapor deposition (CVD) process in a homemade system. The as-synthesized g-CNQDs uniformly covered over the surface of TiO₂ nanowires and exhibited attractive photoluminescence (PL) properties. In addition, compared to pristine TiO₂, the heterojunction of g-CNQD-decorated TiO₂ nanowires showed a substantially enhanced PEC photocurrent density of 3.40 mA/cm² at 0 V of applied potential vs Ag/AgCl under simulated solar light (300 mW/cm²) and excellent stability with ∼82% of the photocurrent retained after over 10 h of continuous testing, attributed to the quantum and sensitization effects of g-CNQDs. Density functional theory calculations were further carried out to illustrate the synergistic effect of TiO₂ and g-CNQD. Our method suggests that a variety of g-CNQD-based composites with other semiconductor nanowires can be synthesized for energy applications.