Morphologically engineered metal oxides for the enhanced removal of multiple pollutants from water with degradation mechanism

Abstract

The efficient removal of organic effluent from the water has attracted greater attention globally and continue to be major challenge for the environmental welfare. In the present study, we synthesized nanosized particles of Co3O4, TiO2 and ZnO via a facile sol-gel reaction and explored for the photocatalysis application. The obtained nanosized particles were characterized by the aid of XRD, FESEM, BET Raman and XPS spectroscopy. The influence of the surface modification of nanosized particles on photocatalytic degradation of multiple organic dyes such as methyl blue (MB) and rhodamine B (RB) have been examined. More than 95% of MB and RB degradation dyes with ZnO nanosized particles were noticed after subjecting to the UV illuminations for 40 m and 35 min, respectively. Nanosized ZnO particles exhibited the significantly higher photocatalytic performance than that of the TiO2 and Co3O4 nanosized particles due to the larger surface area (⁓36 m2/g) and smaller particle size (⁓8.9 nm). Additionally, the higher photocatalytic activity of the ZnO NPs might be attributed to the lower e–/h+ pair recombination (narrow bandgap; 3.01 eV) as well as greater photon absorption and dyes were degraded through the photocatalytic oxidation reaction (verified by the trapping active species experiment). Our study demonstrates the ZnO as attractive photocatalyst due to its remarkable stability, cost-effectiveness and eco-friendly reusable property to replace other metal oxides for certain catalytic applications.