Ferreira Sofia Henriques, Morais Maria, Nunes Daniela, Oliveira Maria João, Rovisco Ana, Pimentel Ana, Águas Hugo, Fortunato Elvira, Martins Rodrigo
i3N/CENIMAT, Department of Materials Science, Faculty of Science and Technology, Universidade NOVA de Lisboa and CEMOP/UNINOVA, Campus de Caparica, 2829-516 Caparica, Portugal.
Materials (Basel). 2021 May 4;14(9):2385. doi: 10.3390/ma14092385.
The degradation of organic pollutants in wastewaters assisted by oxide semiconductor nanostructures has been the focus of many research groups over the last decades, along with the synthesis of these nanomaterials by simple, eco-friendly, fast, and cost-effective processes. In this work, porous zinc oxide (ZnO) nanostructures were successfully synthesized via a microwave hydrothermal process. A layered zinc hydroxide carbonate (LZHC) precursor was obtained after 15 min of synthesis and submitted to different calcination temperatures to convert it into porous ZnO nanostructures. The influence of the calcination temperature (300, 500, and 700 °C) on the morphological, structural, and optical properties of the ZnO nanostructureswas investigated. All ZnO samples were tested as photocatalysts in the degradation of rhodamine B (RhB) under UV irradiation and natural sunlight. All samples showed enhanced photocatalytic activity under both light sources, with RhB being practically degraded within 60 min in both situations. The porous ZnO obtained at 700 °C showed the greatest photocatalytic activity due to its high crystallinity, with a degradation rate of 0.091 and 0.084 min for UV light and sunlight, respectively. These results are a very important step towards the use of oxide semiconductors in the degradation of water pollutants mediated by natural sunlight.
在过去几十年里，氧化物半导体纳米结构辅助降解废水中的有机污染物一直是许多研究团队关注的焦点，同时通过简单、环保、快速且经济高效的工艺合成这些纳米材料也备受关注。在这项工作中，通过微波水热法成功合成了多孔氧化锌（ZnO）纳米结构。合成15分钟后获得了层状氢氧化碳酸锌（LZHC）前驱体，并将其置于不同的煅烧温度下以将其转化为多孔ZnO纳米结构。研究了煅烧温度（300、500和700℃）对ZnO纳米结构的形态、结构和光学性质的影响。所有ZnO样品都作为光催化剂用于在紫外光照射和自然阳光下罗丹明B（RhB）的降解测试。在两种光源下，所有样品均表现出增强的光催化活性，在两种情况下RhB在60分钟内几乎都被降解。在700℃下获得的多孔ZnO由于其高结晶度而表现出最大的光催化活性，在紫外光和阳光下的降解速率分别为0.091和0.084 min⁻¹。这些结果是朝着在自然阳光介导的水污染物降解中使用氧化物半导体迈出的非常重要的一步。
