Synthesis of mica supported tungsten oxide nanoparticles and their photocatalytic, biological and antioxidant activity

Mica-supported tungsten oxide (M/WO₃) and neat WO₃ nanoparticles (NPs) were synthesised through acid precipitation method and then used as photocatalysts for degradation of Methyl Violet (MV) dye in aqueous media. The scanning electron microscopy (SEM) shows that the majority of WO₃ NPs have cubical shape. The SEM micrographs also illustrated that the particles are mostly present in dispersed form, while some are in agglomerated form. The transmission electron microscopy (TEM) presented that the size of the nanoparticles were below 100 nm. The formation of NPs were also confirmed by energy dispersive X-ray (EDX), X-ray diffraction (XRD) and Fourier transform infra-red (FT-IR). The photodegradation study presented that WO₃ and M/WO₃ NPs degraded about 87% and 97% of MV dye within 75 min irradiation time under UV light. The recovered and re-recovered M/WO₃ and WO₃ NPs also significantly degraded MV dye. Both WO₃ and M/WO₃ NPs showed significant bio-activities against two pathogenic bacteria (Citrobacter and Providencia). Further, both types of NPs showed effective antioxidant activity.