Separation and Purification Technology ( IF 8.6 ) Pub Date : 2017-12-27 , DOI: 10.1016/j.seppur.2017.12.048 Sung-Min Kang , Cheol Hwan Kwak , Muruganantham Rethinasabapathy , Sung-Chan Jang , Sang-Rak Choe , Changhyun Roh , Young-Kyu Han , Yun Suk Huh
We describe a facile, economic, and environment friendly green method for simultaneous detection of palladium ions (Pd2+) and recovery Pd nanoparticles (Pd NPs) from wastewater through a non-toxic gamma-irradiation based reduction reaction. Basic orange 2 (BO), an azo dye, is used as a sensing probe in Pd2+ detection and acts as a stabilizing agent in the recovery of monodispersed small Pd NPs. The presence of Pd2+ in waste water was easily observed by naked eye through the color change from yellow to red upon adding the Basic orange 2. More importantly, Pd forms a square-planar structured complex with Pd2+ which aids the development of smaller and monodispersed Pd NPs during radiolytic reduction. The size control mechanism during the recovery of Pd NPs was ascertained by varying the intensity of gamma-ray (from 10 to 50 kGy) and initial concentrations of Pd2+ (from 20 to 100 ppm). We are able to control the size of Pd NPs from 5 to 400 nm by irradiating gamma-ray doses from 1 and 50 kGy, as evident from UV-vis absorption spectra (UV-vis) and transmission electron microscopy (TEM) images. About 15 nm colloidal Pd NPs were formed at 10 kGy gamma-irradiation, and various sizes of aggregates, which may be attributed to Ostwald ripening crystal growth, were observed in the irradiation condition of 20 to 50 kGy. Further, the size of the recovered Pd NPs increases as the Pd2+ concentration increased, due to the increase in the ion association rate. Our proposed green method is a promising strategy that can easily detect Pd2+ from waste water and recover Pd NPs in desired size and morphology.
中文翻译:
γ辐射介导的绿色技术可回收废水中的Pd纳米颗粒
我们描述了一种简便,经济和环保的绿色方法,用于通过基于无毒γ射线的还原反应同时检测废水中的钯离子(Pd 2+)和回收钯纳米颗粒(Pd NPs)。碱性橙2(BO),一种偶氮染料,在Pd 2+检测中用作传感探针,并在回收单分散的小Pd NP中用作稳定剂。添加碱性橙2时,从黄色到红色的颜色变化,用肉眼可以很容易地观察到废水中Pd 2+的存在。更重要的是,Pd与Pd 2+形成了正方形平面结构的复合物。这有助于在辐射还原过程中开发较小且单分散的Pd NP。通过改变伽马射线的强度(从10到50 kGy)和Pd 2+的初始浓度(从20到100 ppm)来确定Pd NP回收过程中的尺寸控制机制。我们可以通过照射1kky和50kGy的伽马射线剂量来将Pd NP的尺寸控制在5至400 nm之间,这从UV-vis吸收光谱(UV-vis)和透射电子显微镜(TEM)图像中可以明显看出。在10 kGyγ射线辐照下形成了约15 nm的胶体Pd NP,在20至50 kGy的辐照条件下观察到各种尺寸的聚集体,这可能归因于奥斯特瓦尔德熟化晶体的生长。此外,回收的Pd NPs的尺寸随着Pd 2+的增加而增加。由于离子缔合速率的增加,浓度增加。我们提出的绿色方法是一种有前途的策略,可以轻松地从废水中检测Pd 2+并回收所需大小和形态的Pd NP。