Photocatalytic activity of visible-light-driven ternary Ag/Ag2S/ZnO nanocomposites for phenol degradation in water

Abstract

Silver sulphide (Ag2S) and zinc oxide (ZnO) nanoparticles were synthesized through a sol-gel method. The Ag constituent of the ternary was achieved by photodesposition of the binary Ag2S/ZnO resulting in a color change from brownish grey to purple indicating its formation. The synthesised particles were characterised using Scanning electron microscopy (SEM), Transmission electron microscopy (TEM) and Energy-dispersive X-ray spectroscopy (EDX) to confirm its elemental presence and morphology. The crystallinity of the nanoparticles was determined using the X-ray diffractometer (XRD), and Brunauer–Emmett–Teller (BET) analysis surface area was 4.95 m2 g-1. The progressive degradation of phenol was analysed and results showed that under visible light, the ternary composite Ag/Ag2S/ZnO, exhibited the highest phenol degradation efficiency (95 %) compared to the constituent compounds, ZnO (37 %) and Ag2S/ZnO (83 %) after 6 h of visible light irradiation respectively. However, investigations have revealed that extrinsic factors such as pH of the solution, the initial concentration of phenol and photocatalyst dosage could significantly affect the overall system performance.