Synthesis and enhancement of photocatalytic activities of ZnO by silver nanoparticles

• Synthesis of Ag–ZnO composite in ethanol–water mixture is reported.
• Method is simple, novel, non-toxic and cost effective without use of surfactant.
• The composite showed high photocatalytic activity than bare ZnO towards Rh. B.
• The results of XRD, DRS, PL, TEM and PSD are good agreement.

Herein, we reports synthesis, characterization and photocatalytic degradation of Rhodamine B under natural sunlight using zinc oxide and Ag–ZnO composite. Zinc oxide nanoparticles were prepared by simple wet chemical method using ethanol–water mixture. Ag–ZnO composite was prepared in two steps by dispersing synthesized ZnO in silver nitrate solution and subsequently reducing it with Ocimum tenuiflorum leaves extract as bioreducing agent. The synthesized bare zinc oxide and Ag–ZnO composite was characterized by various techniques like XRD, DRS, FE-SEM, TEM, SAED, PSD, Zeta potentials, etc. Zinc oxide being wide band gap material can absorbs UV light from solar spectrum which is only 5% so is not efficient material for dye degradation under sunlight. The absorption of visible light was increased by preparing the Ag–ZnO composite. The enhancement in photocatalytic activities of Ag–ZnO composite was observed than bare ZnO. This enhancement is due to shift of absorption edge of ZnO in visible region and decrease in band gap.

Mechanism elaborating photocatalytic activity.Figure optionsDownload as PowerPoint slide