Simultaneous Hydrogen Formation and Pollutant Degradation over Pt-modified Morphology Controlled ZnSe Photocatalyst

Abstract

In this tentative work, various ZnSe photocatalysts were synthesized employing hydrothermal route. Different parameters like reaction temperature, reaction time and concentration of KOH were optimized to observe the effect of these factors on morphology of photocatalysts. The optical and morphological properties of as synthesized nanostructures were studied using X-ray Diffraction Spectroscopy (XRD), Scanning Electron Microscopy (SEM), UV-Vis spectroscopy, Transmission Electron Microscopy (TEM) and Energy Dispersive X-ray Spectroscopy (EDS) for elemental analysis. Spherical morphology for ZnSe nanoparticles was seen in SEM studies, the size of particle was affected significantly by change in reaction temperature and KOH conc. Whereas, change in reaction time showed no significant effect on morphology or size of nanoparticles. Average particle size was around 28 nm confirmed by SEM and TEM analysis. This ZnSe photocatalyst was then investigated simultaneously for H2 formation and for degradation of organic pollutants such as CH3OH and Na2S under illumination of different lights. Low hydrogen production (3 μmol/h) was observed in case of bare ZnSe. In order to enhance the photocatalyst efficiency and to reduce the e-/h+ recombination, 1% by wt. Pt was introduced via in situ photoreduction due. This metallized ZnSe/Pt photocatalyst was exposed to Na2S and CH3OH solutions under UV and visible light. A maximum of hydrogen formation rate of about 30 μmol/h and 17 μmol/h was observed in case of methanol and sodium sulphide, respectively.