In the present work, we investigate the structural, microstructural, vibrational, photocatalytic and luminescence properties of the system SmPO₄ thermally treated at 900 °C. Polycrystalline sample was elaborated using a coprecipitation method. The sample was then characterized using different techniques such as X-ray diffraction, Scanning electron microscopy, Infrared spectroscopy, Raman spectroscopy and photoluminescence analysis under UV excitation. X-ray diffraction profile analysis showed that the pure monoclinic phase P2₁/n was observed. The scanning electron microscopy experiments showed a homogeneous distribution of morphologies and indicated that SmPO₄ was in nano-sized particle. Attributions of Raman and FTIR vibrational modes were proposed. For the photocatalytic activity, UV–visible spectrophotometer has been used to analyze the evolution of photodegradation of rhodamine B (RhB). The photocatalytic degradation of rhodamine B in the presence of SmPO₄ photocatalyst has been studied for the first time. Photoluminescence (PL) properties of SmPO₄ nanoparticle under UV excitation has been reported and investigated.