Preparation and characterization of Vanadium pentoxide (V2O5) for photocatalytic degradation of monoazo and diazo dyes

Inadequacy of visible radiation response and reduced quantum yield confine the practical application of V2O5 as a high-performance photocatalyst. We have developed template-free growth of pure vanadium pentoxide nanoparticles (V2O5NPs) by two different but facile and economical production methods: (i) Hydrothermal (HT) and (ii) Sol-gel (SG) method. A detailed comparison of the HT and SG methods for preparation V2O5NPs and its photocatalytic activity is discussed. The photocatalyst prepared by HT-method demonstrated superior visible light absorption response, which proceeds to improved oxidation of both azo dyes by photocatalytic degradation. The V2O5NPs prepared by HT-method also show higher photoelectrochemical (PEC) performance. The V2O5NPs is prepared using the NH4VO3 as a major precursor in de-ionized water without any template, under controlled pH conditions. The nanocomposites were characterized using XRD, SEM, EDX, FTIR, BET, UV–Vis, EIS, EPR and PL techniques. The HT prepared V2O5NPs shows higher crystallinity in comparison to others. The particle sizes from the Scherrer's formula were calculated as 242 nm (HT-method) and 290 nm (SG-method). The enhanced photocatalytic response of V2O5NPs prepared by HT-method owed to large surface area 238.45 cm2g̵1. Our work demonstrates, through HT synthesis, one can attain nanostructures which are suitable for practical applications to enhance and optimize photocatalytic degradation of organic pollutants .