Improved photo-catalytic activity of novel nano-dimension Ce/Zn composite oxides deposited on flat-glass surface for removal of Acid Black 4BN dye pollution

Abstract

In this research, we studied an easy method to prepare pure cerium oxide nano particle (CeONP), pure zinc oxide nano particle (ZnONP) and Ce/Zn nano composite (Ce/ZnONP) coupled oxide by one pot reaction of cerium and zinc nitrate as precursors in aqueous solution using a Teflon-lined stainless autoclave at 120 °C for 12 h. Model water pollutant Acid Black 4BN as a di-azo textile dye was used to compare the photo-catalytic activity of (CeONP), (ZnONP) and (CeZnONP) deposited on flat-glass surface to overcome the problem of nano catalyst separation from suspension. Thermal, structural and spectral characterization of nano-structures were studied by thermo-gravimetric analysis, X-ray diffraction method, field emission scanning electron microscopy, Fourier transform infrared spectroscopy, energy dispersive X-ray spectroscopy. The elemental analysis using energy dispersive X-ray spectroscopy proved the existence of cerium and zinc in immobilized nano-structures Ce/Zn oxides. The X-ray diffraction result of the composite showed high crystalline cubic cerium oxide and hexagonal wurtzite zinc oxide. The photo-catalytic activity of Ce/Zn nano composite oxide coated on flat-glass surface for degradation dia-azo dye was enhanced compared to their single oxide counterparts. This heterogeneous photo-catalytic degradation of dia-azo dye can be applied as an alternative to suspended oxide powders and over-come drawbacks of filtration of photo-catalysts. This study for the first time showed the potential application of Ce/Zn nano composite for removal of organic pollutant from water.