Synthesis and visible light photocatalytic activity of nanocrystalline PrFeO 3 perovskite for hydrogen generation in ethanol–water system

Abstract

Nanocrystalline PrFeO3 perovskite type orthoferrite was synthesized at 700°C by using three different synthesis methods, namely sol–gel, template and combustion method. The synthesized materials were characterized by XRD, BET-SA, SEM, HRTEM, XPS, FTIR and UV-DRS techniques to understand their physico-chemical properties. Characterization data reveal the formation of nanocrystalline PrFeO3 perovskite composition with improved physical properties, possibly due to lower synthesis temperature used. PrFeO3 synthesized by sol–gel method consists of crystallite size of about 20 nm with absorption maxima at 595 nm wavelength in visible light range. This photocatalyst shows hydrogen generation of about 2847 μmol.g−1.h−1, under visible light irradiation in ethanol–water system. The photocatalyst was further investigated for various operational parameters such as photocatalyst dose variation, illumination intensity, time, etc. in a view to optimize the hydrogen generation as well as to understand mechanistic aspects. This material appears to follow a semiconductor type mechanism for ethanol-assisted visible light photocatalyic water-splitting and can also be an interesting candidate to develop hetero-junction type photocatalysts. PrFeO3–type perovskite was synthesized by sol–gel, template and combustion methods. PrFeO3 synthesized by sol–gel method consists of crystallite size of about 20 nm with absorption maxima at 595 nm wavelength in visible light range. This photocatalyst shows hydrogen generation of about 2847 µmol.g-1.h-1, under visible light irradiation in ethanol-water system, and follows semiconductor type mechanism with alcohol acting as sacrificial donor.