Photoluminescence studies in HCl-doped polyaniline nanofibers

Abstract

In the present work polyaniline (PAni) nanofibers have been synthesized by interfacial polymerization technique. Pellets are made from PAni nanofibers and characterized by XRD, TEM, UV-Vis spectroscopy, Photoluminescence spectroscopy and Four-probe conductivity measurements. XRD results show the increase in the degree of crystallinity with the increase of concentration of dopant acid. It also shows peak broadening, which indicates reduction of fiber diameter with increasing dopant concentration. TEM micrograph confirms the formation of PAni nanofibers of diameter around 20-30 nanometer. The UV-Visible spectra show three prominent peaks at 320nm, 430nm and 800nm, which confirm the formation of a single broad polaronic band in the band-gap of the PAni nanofibers. Four-probe measurements show that the electrical conductivity of PAni nanofibers increases with doping. PL spectra show a broad peak in violet region ( = 405nm) and indicate a decrease of fiber diameter with the increase in HCl concentration.

Electrical conductivity, optical property and ammonia sensing studies on HCl Doped Au@polyaniline nanocomposites

“…This can be attributed to the parallel and perpendicular periodicity of the polymer chain. [13] The XRD pattern of Au in Au@Pani nanocomposite fibers was consistent with previously published work, [14] indicating the successful incorporation of gold nanoparticles into the polymer Pani. On the other hand, in case of Au, all the reflection peaks at ~38°, 42°, 64°, and 78° 2θ, showed broader peaks, which can be interpreted based on Pani being amorphous and having a significant effect on the crystallinity of Au in terms of beige formation, resulting in a decrease in peak intensity.…”

Effects of solvent interactions on the structure and properties of prepared PAni nanofibers

“…The XRD patterns of different PAni nanofibers (Fig. 5) display broad reflections at around 2θ = 19.2° and 26°, typical of HCl‐doped PAni 30. The peaks at 19.2° and 26° due to the (100) and (110) reflections are assigned to the regular spacing between phenyl rings of adjacent chains of PAni in a parallel orientation and perpendicular orientation, respectively.…”

“…The PL spectra of different PAni samples are shown in Figure 7. The nanofibers were excited at 220 nm, and they showed luminescence in the blue region of the spectrum around 390 nm 30. It was observed that PL intensity was quenched with the increase of interaction between the solvent and aniline.…”

Hybrid TiO2–Polyaniline Photocatalysts and their Application in Building Gypsum Plasters

“…Therefore, the visible luminescence band for TiO2 originates from the oxygen vacancies associated with Ti 3+ in the TiO2 structure. The polyaniline PL spectrum is corresponding to the PL spectra presented in the literature [47,48]. Emission from the UV region, with the maximum at 395 nm, could be attributed to the π*-π transition of the benzoic units in the The UV-Vis absorption spectrum of pure TiO 2 , PANI, and the PANI-TiO 2 nanocomposite is presented in Figure 3a.…”