Mono-lithium salt of adipic acid exfoliated molybdenum sulphide incorporated poly(vinylidene fluoride) nanocomposites with enhanced piezoelectric properties for energy harvesting and dye degradation
Ananya Aishwarya, Abhishek Naskar, Titas Dasgupta, Arup R. Bhattacharyya
Abstract
The current investigation has reported the enhancement of piezoelectric properties in poly(vinylidene fluoride) (PVDF) nanocomposites through the incorporation of mono lithium salt of adipic acid (Li-AA) modified molybdenum sulphide (MoS 2 ). The Li-salt was utilized to non-covalently modify MoS 2 , facilitating its exfoliation into few-layered structures. Raman spectroscopy, X-ray photoelectron spectroscopy (XPS) and transmission electron microscopy (TEM) were performed to confirm the successful exfoliation and structural integrity of the Li-AA modified MoS 2 nanofiller with varying ratios of MoS 2 and Li-AA. The nanofiller was then incorporated into PVDF matrix via melt-mixing, followed by solution-casting to form nanocomposites (PML) films. From Fourier transform infrared (FTIR) spectroscopic analysis, it was observed that the PML (1:6) nanocomposite contained the highest amount of polar phase of ∼ 96 %. The enhancement of polar phase content was attributed to the Li-AA modification of MoS 2 , promoting better dipole alignment within the PVDF matrix. The energy harvesting capabilities of these nanocomposites were validated through device testing, where the device made from PML (1:6) nanocomposite film generated an output voltage of ∼ 96 ± 0.3 V, which can be attributed to the presence of highest amount of electroactive phases among all the other PML nanocomposites. Additionally, the piezo-catalytic properties observed in these materials facilitated effective dye degradation of Rhodamine B, with removal efficiency of ∼ 80.9 % under mechanical ultra-sonication. This research highlighted the significant impact of Li-AA exfoliated MoS 2 nanomaterials on the piezoelectric properties of PVDF nanocomposites. These findings have paved the way for innovative applications in sustainable energy solutions and environmental remediation technologies.