Due to the expansion of industry, the world's population growth has led to increased air and water contamination. Because they are poisonous and non-biodegradable, organic dyes are a significant source of this contamination. Studies have concentrated on photocatalysts to transform organic dyes into innocuous compounds in order to lessen the harm that organic colours cause. In this study, solution combustion technique was employed to prepare rare-earth metal (terbium (Tb)) doped lanthanum silicate phosphor (La10Si6O27) using lanthanum nitrate and fumed silica were utilized as precursors, oxalyldihydrazide was used as fuel, and terbium nitrate was used as a dopant. The photocatalytic activities for the Direct Green-23 (DG23) dye degradation under UV irradiation were studied and found that 59.05% of dyes degraded at 120 min. These findings shows that, La10Si6O27 is a promising material for industrial dye degradation since 59.05% of the dyes were absorbed by the material in 120 min.