Zinc selenide (ZnSe) microspheres and nanonetwork microspheres were synthesised via the modified composite hydroxide-mediated approach at 200°C for 24 and 48 h, respectively. These microspheres were characterised by X-ray diffraction, scanning electron microscope, energy dispersive X-ray spectroscopy, and UV-visible absorption spectrum. Photocatalytic activity of the as-prepared ZnSe products for the degradation of methylene blue and methyl orange under the irradiation of the simulated sunlight (100 mW/cm2) was studied and the results indicated that ZnSe nanonetwork microspheres exhibited higher photocatalytic activity than that of ZnSe microspheres, owing to its larger specific surface area.