Photochemical synthesis of bimetallic gold/silver nanoparticles in polymer matrix with tunable absorption properties: Superior photocatalytic activity for degradation of methylene blue

Bimetallic nanoparticles are widely used in chemical catalysis. Their practical performance can be better exploited through morphological control by adjusting the synthetic strategy. Herein, a photochemical synthesis route was used to achieve the controlled preparation of bimetallic Au/Ag BNps. Size and shape control is achieved depending on the type of initiating radical therefore synthesized new one-component Type II photoinitiator, namely 2-thioxanthone thioacetic acid-dioxide was employed for the synthesis of Au/Ag BNp both in solution and polymer matrix. The effect of the gold/silver ratio on the nanoparticle size, shape and distribution was investigated, and the characterization of the obtained nanoparticles was performed by UV-Vis spectrophotometry, DLS and SEM techniques. Additionally, photocatalytic oxidative degradation of methylene blue was achieved with the prepared Au/Ag bimetallic nanocomposite films. By evaluating the photocatalytic oxidation degradation of methylene blue under UV-Vis light irradiation, 2:1 ratio of Au/Ag nanoparticles containing nanocomposite film exhibit the best activity compared with other composition of Au/Ag. The size and high SPR absorption band are thought to be responsible for superior photocatalytic activity.