Abstract
The morphology of zinc oxide (ZnO) powders synthesised via a modified microwave assisted method under varying heating parameters, as well as by chemical bath deposition, was investigated. Image analysis revealed clear correlations between synthesis parameters and structural features. Increasing the microwave heating time at constant power led to a consistent transformation from loose nanoparticles to dense, well-faceted microstructures. In contrast, reducing heating power slowed crystallisation and agglomeration, preserving a finer, more porous structure. Scanning electron microscopy also demonstrated significant morphological differences in samples grown by chemical bath deposition, which were strongly influenced by the initial molar concentration of zinc acetate while keeping the concentrations of other solution components constant. These findings confirm that low-cost, environmentally friendly synthesis approaches can be used to control ZnO particle morphology through careful adjustment of precursor concentrations, heating time, and microwave power. Photocatalytic degradation tests of rhodamine B demonstrated a strong link between particle morphology and degradation rate. The highest rate (~0.5 h– ¹) was recorded for a chemically precipitated sample, whereas the lowest (~0.1 h–¹) corresponded to a microwavesynthesised sample.