DOI: https://doi.org/10.55373/mjchem.v27i5.121

Keywords: Co-precipitation; methylene blue dye; photocatalytic; urea; ZnO

Abstract

Synthetic dyes such as methylene blue (MB) pose significant environmental challenges due to their toxicity and persistence in aquatic ecosystems. In this study, pure and urea-derived carbon-doped ZnO photocatalysts were synthesized via the co-precipitation method to evaluate their efficiency in degrading MB under UV light irradiation. Urea was incorporated as a carbon source in varying weight percentages (1, 3, and 5 wt.%) to enhance the photocatalytic properties of ZnO. The morphological and structural characteristics of the prepared samples were analyzed using Scanning Electron Microscopy (SEM), Mapping-Energy Dispersive X-ray Spectroscopy (EDX), and Fourier Transform Infrared Spectroscopy (FTIR). SEM images revealed agglomerated spherical grains densely distributed across the samples, while EDX mapping confirmed the presence of carbon in the urea-doped ZnO. FTIR analysis revealed the incorporation of carbon species from urea into the ZnO lattice, resulting in lattice distortions and alteration to vibrational properties, as indicated by shifts in Zn–O peaks and the emergence of C=O vibrations, suggesting surface modifications that enhance photocatalytic performance. The photocatalytic activity of urea-derived carbon-doped ZnO demonstrated significant enhancement compared to pure ZnO, with the 5 wt.% urea-derived carbon-doped ZnO, achieving a 66.71% degradation of MB within one hour of UV exposure. These findings suggest that urea-derived carbon-doped ZnO is a promising photocatalyst for dye removal in wastewater treatment applications.