The Influence of Ag+/Ti4+ Ratio on Structural, Optical and Photocatalytic Properties of MWCNT–TiO2–Ag Nanocomposites

In this paper, we propose a simple procedure to obtain multi-walled carbon nanotubes (MWCNTs) decorated with TiO2–Ag nanoparticles (MWCNT–TiO2–Ag). The MWCNTs were via combined functionalization –OH and –COOH groups polymer-wrapping technique using poly(allylamine)hydrochloride (PAH). TiO2-modified Ag synthesized the Pechini method mixture of acetylacetonate-modified titanium (IV) isopropoxide silver nitrate (with Ag+/Ti4+ atomic ratios 0.5%, 1.0%, 1.5%, 2.0%, 2.5%) L(+)-ascorbic acid as reducing agents. XRD analysis revealed formation nanocomposites containing CNT, anatase TiO2, Ag. presence on MWCNT surfaces was determined TEM. morphology also UV–Vis investigations that an increase in ratio between Ag+ Ti4+ decreased band gap energy samples. characteristic vibrations Ag, C atoms graphite identified Raman spectroscopy. photocatalytic activity MWCNT–TiO2–Ag nanocomposite assessed by examining degradation Allura Red (E129) aqueous solution under UV irradiation. dye photodegradation process followed pseudo-first-order kinetic respect Langmuir–Hinshelwood reaction mechanism. spin-trapping evidenced •O2− main species generated responsible for degradation.