Investigation of sunlight driven SPR assisted photocatalytic activity of Ag doped SnO2 nanoparticles

Abstract

Photocatalysis triggered by visible light has emerged as a viable method for addressing environmental pollution and the energy crisis in our society. Numerous metal oxide semiconductors are transformed into visible light active photocatalysts by adopting some straightforward methods. One such efficient way of creating a visible light active photocatalyst is doping a pure semiconductor with plasmonic metal nanoparticles. Our work thoroughly investigates the photocatalytic properties of pure SnO2 nanoparticles (NP) and SnO2 doped with 1%, 3%, and 5% ‘Ag’ under sunlight. These samples are prepared using a straightforward sol–gel approach, followed by a hydrothermal procedure. To examine the different properties and morphology of the synthesized samples, several analytical tools, including UV–visible spectrometer, XRD, XPS, TEM, PL spectrometer and FTIR are used. Analysis of UV-visible absorbance spectra shows a noticeable narrowing of the band gap with increased ‘Ag’ doping. XRD analysis confirms the tetragonal structure of all samples. Methyl orange (MO) dye is used as an imitation of an organic pollutant to examine the photocatalytic activity under sunlight. When compared to pure SnO2 NP, every ‘Ag’ doped SnO2 NP sample exhibits a considerable improvement in the photodegradation of methyl orange. Analysis of PL spectra of SnO2 NPs doped with ‘Ag’ suggests that the major causes of this enhancement in photocatalysis are surface defects and the surface plasmon resonance (SPR) effect caused by ‘Ag’ doping. The scavenging test claims that the holes are the primary and the superoxide radicals are the secondary reactive species which are responsible for MO degradation under sunlight.