2D graphene-coupled ZnS:Mn2+ mechanodetectors for monitoring the pulse rate

• Published in: Ceramics international 2020-07, Vol.46 (10), p.16533-16536
• Main Authors: Zheng, Zhiqin, Zhao, Jun, Jin, Dingfeng, Wang, Xinxing
• Format: Article
• Language: English
• Subjects: 2D graphene; Li; Mechanoluminescence (ML); Pulse rate; ZnS:Mn2
• ISSN: 0272-8842; 1873-3956
• DOI: 10.1016/j.ceramint.2020.03.220

In this work, we prepared a type of traditional mechanoluminescent (ML) material (i.e., ZnS:Mn2+) by using the sol-gel method with addition of K2S to the Zinc Oleate and Mn(NO3)2 water solution. Then, 2D graphene-coupled ZnS:Mn2+ nanocomposites were achieved by coupling the ZnS:Mn2+ with the 2D graphene. All the samples were characterized using powder X-ray diffraction (XRD), transmission electron microscopy (TEM), photoluminescence (PL) and pressure-induced PL spectra, galvanostatic charge-discharge and cyclic voltammetry. The PL results indicated that the ZnS:Mn2+ and 2D graphene-coupled ZnS:Mn2+ samples exhibited a broad Mn2+ emission band at 585 nm. The pressure-induced PL spectra showed that the two samples had pressure-controlled luminescence. The pressure-induced PL positions were the same as the PL positions. Since the ML properties are related to the defects, here we added the Li+ ions into the ZnS:Mn2+ sample in order to study the influence of defects on the ML spectral variation, where the Li+ ions were used as the charge compensator. As a result, a mechanistic profile which could illustrate the ML reason was proposed. When the conductive polyoxometalate (POM) was dispersed into the ZnS:Mn2+ and graphene-coupled ZnS:Mn2+, we found further that the ML intensity and the used pressure value featured a linear relationship and the ML intensity of the two samples could recover after several cycles. Finally, we demonstrated that the graphene-coupled ZnS:Mn2+ could use for monitoring human health problem such as the pulse rate.