State Key Laboratory of Fine Chemicals and Key Laboratory of Industrial Ecology and Environmental Engineering, School of Environmental Science & Technology, Dalian University of Technology, Dalian 116024, China.
State Key Laboratory of Fine Chemicals and Key Laboratory of Industrial Ecology and Environmental Engineering, School of Environmental Science & Technology, Dalian University of Technology, Dalian 116024, China; Department of Chemical Engineering, Curtin University, GPO Box U1987, Perth, WA 6845, Australia.
J Colloid Interface Sci. 2019 Oct 15;554:91-102. doi: 10.1016/j.jcis.2019.07.001. Epub 2019 Jul 2.
In this work, carbon and nitrogen co-doped yolk-shell ZnFeO nanostructures (CN-ZnFeO) were successfully synthesized through a facile self-templated method with in situ doping strategy. A series of characterizations were processed to present a comprehensive properties of the as-prepared photocatalyst samples. Doping amount could be moderated by the addition mass of dopamine, which was regarded as both the carbon and nitrogen source. And the void space between yolk and shell could be adjusted by heating rates in the calcination process of precursors. With an excellent separation efficiency of photogenerated electron-hole pairs and transfer efficiency of photogenerated electrons, the obtained CN-ZnFeO sample exhibited an enhanced visible light response than ZnFeO. And their photocatalytic performances towards gaseous 1, 2-dichlorobenzene (o-DCB) was also systematically studied. The results demonstrated that the CN-ZnFeO sample with 100 mg dopamine addition and 20 °C/min calcination heating rate exhibited the best o-DCB degradation efficiency. In situ Fourier Transform infrared (FTIR) spectroscopy was also recorded to give a detailed information of intermediate products and reveal the mechanism of photocatalytic degradation towards o-DCB. Particularly, density functional theory (DFT) calculation was used to further study the electronic structure of prepared samples to support the experimental results and especially explain the mechanism of enhanced photocatalytic activity through a proposed lattice junction. Additionally, electron paramagnetic resonance (EPR) technique was carried out to prove the reactive oxygen species involved in the photodegradation process. This work not only presents a promising strategy in photocatalyst fabrication but also provides a new sight of enhanced photocatalysis mechanism.
在这项工作中，通过一种简便的自模板法和原位掺杂策略，成功合成了碳氮共掺杂蛋黄壳 ZnFeO 纳米结构（CN-ZnFeO）。对一系列的样品进行了一系列的表征，以呈现出所制备的光催化剂样品的综合性能。通过添加多巴胺的质量可以调节掺杂量，多巴胺既可以作为碳源又可以作为氮源。并且可以通过在煅烧前体的过程中改变升温速率来调节蛋黄壳之间的空隙空间。通过光生电子-空穴对的有效分离和光生电子的转移效率，所获得的 CN-ZnFeO 样品表现出比 ZnFeO 更好的可见光响应。并对其气态 1,2-二氯苯（邻二氯苯，o-DCB）的光催化性能进行了系统的研究。结果表明，添加 100mg 多巴胺和以 20°C/min 的升温速率进行煅烧的 CN-ZnFeO 样品具有最好的 o-DCB 降解效率。还记录了原位傅里叶变换红外（FTIR）光谱，以提供中间产物的详细信息，并揭示 o-DCB 光催化降解的机理。特别地，使用密度泛函理论（DFT）计算进一步研究了所制备样品的电子结构，以支持实验结果，特别是通过提出的晶格结解释增强光催化活性的机理。此外，还进行了电子顺磁共振（EPR）技术以证明光降解过程中涉及的活性氧物种。这项工作不仅提出了一种有前途的光催化剂制备策略，而且为增强光催化机制提供了新的视角。
