Study of Methylene Blue Degradation by Gold Nanoparticles Synthesized within Natural Zeolites

Abstract EN

We carried out the in situ synthesis of gold nanoparticles inside a natural clinoptilolite-type zeolite matrix, using ascorbic acid as reducing agent.

The microstructure of both zeolite and zeolite-gold nanocomposite was characterized by X-ray diffraction (XRD), Scanning Electron Microscopy (SEM), Scanning Transmission Electron Microscopy (STEM), and Energy-Dispersive X-ray Spectroscopy (EDS) techniques.

Size distribution as assessed by STEM indicated that 60% of gold nanoparticles measured less than 2.5 nm.

Determination of the surface area by the BET method revealed a specific value of 27.35 m2/g.

The catalytic activity of zeolite-gold regarding methylene blue degradation under different light-exposing conditions was evaluated by UV-Vis spectroscopy.

The results indicated that 50% degradation was achieved in only 11 min in presence of sunlight.

This reaction was faster in comparison with those obtained using a white LED light.

A notable aspect of this study is that catalysis was carried out without the addition of any strong reducing agents, such as sodium borohydride (NaBH4).