Azadirachta indica leaves extract assisted green synthesis of Ag-TiO 2 for degradation of Methylene blue and Rhodamine B dyes in aqueous medium

Green Processing and Synthesis

article

Muhammad Saeed¹  Majid Muneer¹  Muhammad Kaleem Khan Khosa¹  Nadia Akram¹  Sheeba Khalid¹  Muhammad Adeel¹  Asif Nisar¹  Sonia Sherazi² 

[1] Department of Chemistry, Government College University Faisalabad;Department of Chemistry, University of Gujrat

关键词: TiO2;    Ag-TiO2;    Methylene blue;    Rhodamine B;    photo degradation;    Eley-Rideal mechanism;   

DOI  :  10.1515/gps-2019-0036

来源: De Gruyter

【 摘 要 】

Aqueous pollution due to textile industry is an important issue. Photocatalysis is one of the methods used for eradication of dyes from textile industrial effluents. In this study, the synthesis, characterization and evaluation of photo catalytic activity of Ag-TiO 2 is reported. TiO 2 catalysts with 2, 4, 6 and 8% loading of Ag were prepared by green methods using Azadirachta indica leaves extract as reducing agent with titanium dioxide and silver nitrate as precursor materials. Prepared catalyst was characterized by advanced techniques and was used as catalyst for degradation of Methylene blue and Rhodamine B dyes. Deposition of Ag greatly enhanced the catalytic efficiency of TiO 2 towards degradation of dyes. Irradiation of catalyst excites electrons from conduction band of catalyst to valence band yielding an electron-hole pair. This electron-hole pair undergoes secondary reactions and produce OH ∙ radicals. These active radicals take part in degradation of dyes. More than 90% dyes were degraded in 120 min. Photo catalytic degradation of Methylene blue and Rhodamine B followed Eley-Rideal mechanism which states that dye react in fluid phase with adsorbed oxygen.

【 授权许可】

CC BY