Ahmad Naveed, Kuo Chung-Feng Jeffrey, Mustaqeem Mujahid
Department of Materials Science and Engineering, National Taiwan University of Science and Technology, Taipei, 10607, Taiwan, ROC.
Department of Materials Science and Engineering, National Taiwan University of Science and Technology, Taipei, 10607, Taiwan, ROC.
Chemosphere. 2022 Jul;298:134153. doi: 10.1016/j.chemosphere.2022.134153. Epub 2022 Mar 10.
The further development of an efficient and sustainable water treatment requires the development of a very active and controllable photocatalyst. The heterojunction is a promising site where the activity of such a photocatalyst can be enhanced. Organic dyes have become a severe concern in recent years owing to their significant presence in wastewater. Hexavalent Chromium (Cr (VI)) is a potential carcinogen also exhibiting great persistence in wastewater. So, a low-waste, high-performance materials is required to eliminate organic dyes and Cr (VI) from wastewater. In this study, CNO/g-CN (CuNbO/g-CN) photocatalyst synthesized via co-precipitation, followed by calcination which were characterized using physiochemical and photo-electrochemical approaches to identify their structural, photochemical and optical traits. The uniqueness of the synthesized photocatalyst is due to both its efficient photo-reduction of Cr (VI) and photo-degradation of Rhodamine B (RhB), Methylene Blue (MB) and Methyl Orange (MO) under visible light. The CNO/g-CN composite with 30% CNO heterojunctions exhibited the highest photocatalytic activity with Cr (VI) 92.80% photoreduction and efficiency degradation for RhB, MB, MO of 99.6%, 98.50%, 99.0%, respectively, with constant rate (k). This efficient photocatalytic activity is attributed to the lower recombination rate of electron-hole pairs. Free radical trapping experiments showed that O and h play an important role in the photodegradation. The study, therefore, opens an alternative route in the synthesis of very efficient binary photocatalysts for application in environmental remediation.
高效且可持续的水处理技术的进一步发展需要开发一种非常活跃且可控的光催化剂。异质结是一个有前景的位点，在该位点这种光催化剂的活性可以得到增强。近年来，有机染料因其在废水中的大量存在而成为一个严重问题。六价铬（Cr(VI)）是一种潜在致癌物，在废水中也具有很强的持久性。因此，需要一种低废弃物、高性能的材料来去除废水中的有机染料和Cr(VI)。在本研究中，通过共沉淀法合成CNO/g-CN（CuNbO/g-CN）光催化剂，随后进行煅烧，并采用物理化学和光电化学方法对其进行表征，以确定其结构、光化学和光学特性。合成的光催化剂的独特之处在于其在可见光下对Cr(VI)的高效光还原以及对罗丹明B（RhB）、亚甲基蓝（MB）和甲基橙（MO）的光降解。具有30% CNO异质结的CNO/g-CN复合材料表现出最高的光催化活性，Cr(VI)的光还原率为92.80%，RhB、MB、MO的降解效率分别为99.6%、98.50%、99.0%，具有恒定速率（k）。这种高效的光催化活性归因于较低的电子-空穴对复合率。自由基捕获实验表明，O和h在光降解中起重要作用。因此，该研究为合成用于环境修复的高效二元光催化剂开辟了一条替代途径。
