Visible light driven photocatalysis of azo dyes using indium sulphide quantum dot – Ag metal nanoparticles embedded in nafion membrane

We report on the visible light driven photocatalytic activity of β-Indium sulfide and β-Indium sulfide/Ag nanohybrid structures embedded in nafion film. The β-Indium sulfide quantum dots with In/S ratio 1:1 were embedded on Nafion film by ion exchange mechanism. The structural and optical properties of the samples were analysed using X-Ray Diffraction, FESEM, TEM, Raman spectroscopy and UV-Vis absorption spectroscopy studies. These structures were reported to possess cubic crystalline structure with size ∼8nm and band gap of 2.4 eV. The Ag nanoparticles with surface plasmon resonance ∼460 nm and size ∼30 nm were grown over β - In2S3 by ion exchange mechanism. The coupling of the Ag nanoparticles lead to a blue shift of ∼200 meV in the band gap. The β - In2S3 embedded in nafion matrix showed 100% photodegration for 120 minutes and whereas β - In2S3 / Ag in nafion matrix shows complete degradation for 90 minutes. The Ag coupled quantum dots shows enhanced photocatalytic activity with lesser photodegradation time (60 minutes). The structural integrity of the β - In2S3 and β - In2S3 / Ag were maintained as it was embedded in the nafion.