Luo Jin, Chen Jiayi, Chen Xiaoting, Ning Xiaomei, Zhan Liang, Zhou Xiaosong
School of Chemistry and Chemical Engineering, Research Center for Clean Energy Materials Chemical Engineering Technology of Guangdong, Key Laboratory of Clean Energy Materials Chemistry of Guangdong Higher Education Institutes, Lingnan Normal University, Zhanjiang 524048, China.
School of Chemistry and Chemical Engineering, Research Center for Clean Energy Materials Chemical Engineering Technology of Guangdong, Key Laboratory of Clean Energy Materials Chemistry of Guangdong Higher Education Institutes, Lingnan Normal University, Zhanjiang 524048, China.
J Colloid Interface Sci. 2021 Apr;587:831-844. doi: 10.1016/j.jcis.2020.11.044. Epub 2020 Nov 13.
Construction of Z-scheme heterojunction has been deemed to be an effective and promising approach to boost the photocatalytic activity on account of accelerating the separation efficiency of the photogenerated carriers and maintaining the strong redox ability. Herein, an attractive CeO/ZnVO Z-scheme heterojunction photocatalyst was rationally constructed by zero-dimensional (0D) CeO nanoparticles immobilized on the surface of three-dimensional (3D) ZnVO nanoflowers using a simple mixing method, and applied to the photocatalytic degradation of tetracycline (TC) under visible light irradiation. As expected, it was observed that the prepared CeO/ZnVO hybrid illustrated significantly boosted the photocatalytic activity for the elimination of TC compared to pure ZnVO. More importantly, the optimized CeO(40 wt%)/ZnVO hybrid owned the largest elimination rate of TC with 1.13 × 10 min, which was around 8.1 and 3.8 times as high as single CeO (0.14 × 10 min) and ZnVO (0.30 × 10 min), respectively. The appreciable performance improvement was mainly ascribed to the formation of Z-scheme heterojunction between CeO and ZnVO, facilitating the transfer rate of photogenerated carriers and remaining the high reducibility of photoexcited electrons in CeO and strong oxidizability of photoinduced holes in ZnVO. Active species capture experiments and electron spin resonance spectra showed that superoxide radicals and holes were the main active species for TC degradation. Besides, the possible degradation pathways of TC were speculated by identifying degradation intermediates, and the reasonable degradation mechanism including migration and transport behaviors of charge carriers and generation processes of reactive species were revealed in depth. This investigation enriches ZnVO-based Z-scheme heterojunction photocatalytic system and offers a new inspiration for the construction and fabrication of high-efficiency Z-scheme heterojunction photocatalysts to remove the antibiotics from wastewater.
由于能够提高光生载流子的分离效率并保持较强的氧化还原能力，Z 型异质结的构建被认为是提高光催化活性的一种有效且有前景的方法。在此，通过一种简单的混合方法，将零维（0D）CeO 纳米颗粒固定在三维（3D）ZnVO 纳米花表面，合理构建了一种具有吸引力的 CeO/ZnVO Z 型异质结光催化剂，并将其应用于可见光照射下四环素（TC）的光催化降解。正如预期的那样，观察到制备的 CeO/ZnVO 复合材料与纯 ZnVO 相比，对 TC 的光催化消除活性显著提高。更重要的是，优化后的 CeO(40 wt%)/ZnVO 复合材料对 TC 的最大消除速率为 1.13×10⁻³ min⁻¹，分别约为单一 CeO（0.14×10⁻³ min⁻¹）和 ZnVO（0.30×10⁻³ min⁻¹）的 8.1 倍和 3.8 倍。性能的显著提升主要归因于 CeO 和 ZnVO 之间形成了 Z 型异质结，促进了光生载流子的转移速率，并保持了 CeO 中光激发电子的高还原性以及 ZnVO 中光生空穴的强氧化性。活性物种捕获实验和电子自旋共振光谱表明，超氧自由基和空穴是 TC 降解的主要活性物种。此外，通过鉴定降解中间体推测了 TC 可能的降解途径，并深入揭示了包括电荷载流子的迁移和传输行为以及活性物种的生成过程在内的合理降解机制。这项研究丰富了基于 ZnVO 的 Z 型异质结光催化体系，并为构建和制备高效 Z 型异质结光催化剂以去除废水中的抗生素提供了新的思路。
