A fast, room temperature excimer laser route for the synthesis of Ag/MWCNT nanocomposite without using reducing agent and investigating its photoresponse behavior to visible illumination

A facile, fast, room temperature excimer laser assisted method was used for the synthesis of multi-walled carbon nanotube (MWCNT)/Ag nanocomposite (NC) without using reducing agent for the formation of Ag Nanoparticles (NPs). We investigated the effect of morphology and size of Ag NPs on photoresponsivity as well as optical absorption of MWCNTs and simply have tuned the wavelength of plasmonic absorption peak in Ag/MWCNT by controlling the size of Ag NPs through excimer laser illumination as well as changing Ag/MWCNT molar ratio. Under 5 V bias and 532 nm laser illumination, an enhancement of similar to 65% in the response current was observed for Ag/MWCNT film as compared to that of pure MWCNT. Chemical structure of Ag/MWCNT NCs was characterized using Fourier transform-infrared (FT-IR), Transmission electron microscopy (TEM), energy dispersive X-ray spectroscopy (EDX), Raman, UV-Vis spectroscopy and X-ray diffraction (XRD). XRD and TEM analyses confirmed the decoration of MWCNTs with Ag NPs and formation of Ag/MWCNT NC. TEM showed the spherical Ag NPs were embedded on the surface of MWCNTs to form a nanohybrid structure. Formation of Ag NPs over the surface of CNTs was led to a tunable plasmonic absorption in UV-Vis spectra of Ag/MWCNTs. Sample with plasmonic absorption peak at similar to 530 nm showed the highest photoresponsivity value among different samples which confirm UV-Vis analysis results.