In current work, silver sulfide nanoparticles (Ag2S NPs) were prepared in presence of 0.0, 0.1, 0.25.0.5 and 1.0 g of sodium dodecyl sulfate surfactant (named as S1, S2, S3, S4 and S5) though a microwave assisted route within 10 min of irradiation at 700 W power. XRD established decent crystalline nature of the prepared Ag2S NPs of crystallite size in range from 44 to 49 nm. Scanning electron microscopy showed that the synthesized particles have three-dimensional irregular shape, very close to fused-spheres or worm-like structure. More importantly; the size of the particles is decreased with the amount of the applied SDS surfactant. Kubelka-Munk relation was used to evaluate energy gap and noticed ~1.014 for S1, 1.017 eV for S2, 1.021 eV for S3, 1.023 eV for S4, and 1.026 eV for S5 samples, i.e. the energy gap is slightly increase with the amount of the applied SDS surfactant. The estimated refractive index values are noted in 1.51–2.2 range. Dielectric constant (ε1), loss tangent (tanδ) and dielectric loss (ε2) were calculated and shows high values of ε1 and low values of tanδ. The photocatalytic performance was examined in methyl green dye photocatalytic decolourization under illumination of UV/visible light. Ag2S samples exhibited excellent photocatalytic behavior, hence can be used in water treatment applications.