Efficient reduction of dyes to leuco form over silver nanoparticles on functionalised SBA-15 and aminoclay

In this work, a simple chemical method for synthesis of Ag nanoparticles (NPs) incorporated on amine-functionalised mesoporous silica SBA-15 support (Ag/NH2-SBA-15) is reported for various dye degradation as the first time. The synthesised sample was characterised by powder XRD, BET surface area and pore size analyser, ICP-OES, XPS HRTEM, and HRSEM techniques. About 5 nm-sized Ag nanoparticles are dispersed over the support. The Ag/NH2-SBA-15 catalytic efficiency was investigated on various dyes degradation such as Malachite green (MG), Phenol red (PR), Bromophenol blue (BPB), Rose Bengal (RB), Methylene Blue (MB), Rhodamine derivatives (Rh 6 G, Rh B), Congo red (CR) and 4-Nitrophenol (4-NP) in the presence of NaBH4. About 90% degradation efficiency resulted in 6 min of reaction time in the presence of a catalyst. Besides, the Ag/NH2-SBA-15 catalyst activity has been compared with homogeneous Ag/aminoclay and shown higher catalytic activity. All the reactions were monitored by UV-Visible spectrometer. The reaction kinetics of Ag nanoparticle catalysed reduction illustrates pseudo-first-order kinetics with the rate constant for the reduction is in the order Ag/NH2-SBA-15 (3.34 x 10(-1)s(-1)) and Ag/aminoclay (1.80 x 10(-2)s(-1)).

Automated summary

This work presents a simple chemical method to synthesize Ag nanoparticles incorporated on amine-functionalized mesoporous silica SBA-15 support. The synthesized sample shows efficient catalytic activity for various dye degradation and outperforms other catalysts. The reaction kinetics indicate pseudo-first-order kinetics with higher rate constant for the Ag/NH2-SBA-15 catalyst compared to Ag/aminoclay.