Controlled construction of NaNbO3@g-C3N4 composites and their piezo-photocatalytic properties
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摘要: 促进光催化过程中载流子的高效分离一直是困扰科研人员的难题。最近,利用压电效应抑制光生电子-空穴对复合从而提升光催化效率的策略引起了人们的广泛关注。在此,以制备的由g-C3N4包覆的一维NaNbO3纳米棒异质结材料作为研究对象,通过施加超声场引入压电效应,研究其在压电光催化过程中的性能增强机制。通过SEM及XPS等表征手段对材料的微观形貌和键合情况进行了考察。性能实验结果表明:在利用超声波引入压电效应后,NaNbO3@g-C3N4在压电光催化过程中(1.02 mmol·g−1·h−1)表现出比单一的光催化过程(0.49 mmol·g−1·h−1)更高的产氢速率,表明压电效应可极大促进NaNbO3@g-C3N4异质结材料在光催化过程中的载流子分离效率,抑制光生电子与空穴复合,提高其光催化性能。此外,在数据分析的基础上,本文提出了压电-光催化协同作用的机制,为高效压电光催化剂的设计和开发提供了参考。
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关键词:
- NaNbO3@g-C3N4 /
- 异质结 /
- 压电光催化 /
- 载流子分离 /
- 协同作用
Abstract: Facilitating the efficient separation of carriers in photocatalytic processes has always been a problem for researchers. Recently, the use of piezoelectric effect as an effective strategy to enhance photocatalytic process from inhibitting the recombination of electrons and holes has attracted great interest. Here, we prepared 1D NaNbO3 nanorods coated with g-C3N4 heterojunction materials as the object to investigate the performance enhancement mechanism in the piezo-photocatalytic process by applying an ultrasonic field to introduce the piezoelectric effect. The microscopic morphology and bonding of the materials were investigated through SEM and XPS characterization. The results show that after the introduction of the piezoelectric effect using ultrasonic, NaNbO3@g-C3N4 exhibites a higher H2 evolution rate in the piezo-photocatalytic process (1.02 mmol·g−1·h−1) than in the single photocatalytic process (0.49 mmol·g−1·h−1), indicating that the constructed NaNbO3@g-C3N4 heterojunction materials with the support of piezoelectric effect greatly promote the separation of carriers in the photocatalytic process, inhibite their complexation and improve the photocatalytic performance. In addition, based on the data analysis, the mechanism of piezo-photocatalytic coupling effects is proposed for the design and development of highly efficient piezoelectric photocatalysts.-
Key words:
- NaNbO3@g-C3N4 /
- heterojunction /
- piezo-photocatalytic /
- charge separation /
- coupling effects
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图 6 NaNbO3@g-C3N4与NaNbO3在纯光条件下 (a) 和压电光催化条件下 (b) 的产氢实验;NaNbO3 (c) 与NaNbO3@g-C3N4 (d)分别在纯光与压电光催化条件下的产氢速率图
Figure 6. H2 evolution experiments of NaNbO3@g-C3N4 and NaNbO3 under light conditions (a) and piezo-photocatalytic conditions (b); H2 evolution rates of NaNbO3 (c) and NaNbO3@g-C3N4 (d) under light and piezo-photocatalytic conditions, respectively
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