The functionalization of polyacrylamide with MoS2 nanoflakes for use in transient photodetectors

Abstract

Herein, we report solvent-free frontal polymerization of acrylamide monomers with transition metal dichalcogenides (TMDs), i.e. MoS₂ nanoflakes. Scanning electron microscopic (SEM) images confirm the formation of nanoflakes of MoS₂ and the interface between nanoflakes and polyacrylamide. The band structure was observed from the Raman spectra, which shows the E¹_2g peak at 384.802 cm⁻¹ and 410.039 cm⁻¹ in MoS₂–polyacrylamide. X-ray diffraction (XRD) pattern revealed the crystallinity of the as-prepared metallopolymer, and Fourier-transform infrared (FTIR) spectroscopy confirmed the presence of surface functional groups attached to the metallopolymer. UV-visible spectra of the metallopolymer nanomaterial exhibited the broad range absorption of the spectrum by the metallopolymer. The thermal properties of functionalized metallopolymers were investigated using thermogravimetric (TG) analysis – and differential thermal analysis (DTA). Photodetection was successfully performed via the development of metallopolymer photodetectors. Current–voltage (I–V) and time-dependent photoresponse characteristics of MoS₂–polyacrylamide were studied under constant exposure to UV light. The as-prepared metallopolymeric nanomaterial shows enhanced photodetection performance under ambient conditions. The responsivity and detectivity were found to be 60.092 mA W⁻¹ and 4.963 × 10¹¹ Jones. The rise and the decay time were 0.773 s and 0.386 s with an LDR of 60.092 dB at a very low power of 40 μW cm⁻².