Gomes Bárbara R, Lopes Joana L, Coelho Lorena, Ligonzo Mattia, Rigoletto Monica, Magnacca Giuliana, Deganello Francesca
CeNTItvc-Centre for Nanotechnology and Smart Materials, Vila Nova de Famalicão 4760-034, Portugal.
Dipartimento di Chimica, Università degli Studi di Torino (UNITO), Via Pietro Giuria 7, 10124 Torino, Italy.
Nanomaterials (Basel). 2023 Aug 8;13(16):2276. doi: 10.3390/nano13162276.
SiO@TiO core-shell nanoparticles were successfully synthesized via a simple, reproducible, and low-cost method and tested for methylene blue adsorption and UV photodegradation, with a view to their application in wastewater treatment. The monodisperse SiO core was obtained by the classical Stöber method and then coated with a thin layer of TiO, followed by calcination or hydrothermal treatments. The properties of SiO@TiO core-shell NPs resulted from the synergy between the photocatalytic properties of TiO and the adsorptive properties of SiO. The synthesized NPs were characterized using FT-IR spectroscopy, HR-TEM, FE-SEM, and EDS. Zeta potential, specific surface area, and porosity were also determined. The results show that the synthesized SiO@TiO NPs that are hydrothermally treated have similar behaviors and properties regardless of the hydrothermal treatment type and synthesis scale and better performance compared to the SiO@TiO calcined and TiO reference samples. The generation of reactive species was determined by EPR, and the photocatalytic activity was evaluated by the methylene blue (MB) removal in aqueous solution under UV light. Hydrothermally treated SiO@TiO showed the highest adsorption capacity and photocatalytic removal of almost 100% of MB after 15 min in UV light, 55 and 89% higher compared to SiO and TiO reference samples, respectively, while the SiO@TiO calcined sample showed 80%. It was also observed that the SiO-containing samples showed a considerable adsorption capacity compared to the TiO reference sample, which improved the MB removal. These results demonstrate the efficient synergy effect between SiO and TiO, which enhances both the adsorption and photocatalytic properties of the nanomaterial. A possible photocatalytic mechanism was also proposed. Also noteworthy is that the performance of the upscaled HT1 sample was similar to one of the lab-scale synthesized samples, demonstrating the potentiality of this synthesis methodology in producing candidate nanomaterials for the removal of contaminants from wastewater.
通过一种简单、可重复且低成本的方法成功合成了SiO@TiO核壳纳米颗粒，并对其进行了亚甲基蓝吸附和紫外光降解测试，以期用于废水处理。通过经典的Stöber方法获得单分散的SiO核，然后用TiO薄层包覆，接着进行煅烧或水热处理。SiO@TiO核壳纳米颗粒的性能源于TiO的光催化性能与SiO的吸附性能之间的协同作用。使用傅里叶变换红外光谱（FT-IR）、高分辨率透射电子显微镜（HR-TEM）、场发射扫描电子显微镜（FE-SEM）和能谱仪（EDS）对合成的纳米颗粒进行了表征。还测定了zeta电位、比表面积和孔隙率。结果表明，无论水热处理类型和合成规模如何，水热法处理的合成SiO@TiO纳米颗粒具有相似的行为和性能，并且与煅烧的SiO@TiO和TiO参考样品相比具有更好的性能。通过电子顺磁共振（EPR）测定了活性物种的产生，并通过紫外光下亚甲基蓝（MB）在水溶液中的去除率来评估光催化活性。水热法处理的SiO@TiO在紫外光下15分钟后显示出最高的吸附容量和光催化去除率，几乎能去除100%的MB，分别比SiO和TiO参考样品高55%和89%，而煅烧的SiO@TiO样品显示的去除率为80%。还观察到，与TiO参考样品相比，含SiO的样品显示出相当大的吸附容量，这提高了MB的去除率。这些结果证明了SiO和TiO之间有效的协同效应，增强了纳米材料的吸附和光催化性能。还提出了一种可能的光催化机理。同样值得注意的是，放大后的HT1样品的性能与实验室规模合成的样品之一相似，这表明这种合成方法在生产用于去除废水中污染物的候选纳米材料方面具有潜力。
