Continuous Flow Reactor for the Controlled Synthesis and Inline Photocatalysis of Antibacterial Ag₂S Nanoparticles

Abstract

The present study is focused on the integration of microreactors to synthesize visible light active nanophotocatalysts for inline photocatalytic degradation of organic dye and antibacterial activity. A wire‐assisted and a rapid laser micromachining technique has been employed for the fabrication of polydimethylsiloxane (PDMS) and poly(methyl methacrylate) (PMMA)‐based microreactors, respectively. By varying the design and chemical reagents involved, different sizes of visible light active Ag2S nanoparticles were prepared via a continuous microfluidics approach using fabricated microreactors. When polyvinylpyrrolidone (PVP) was utilized as the capping agent during the reaction, smaller particles of the size of ~ 15 nm were observed. The photocatalytic performance of these nanoparticles has been evaluated inline by employing the single‐inlet planar microreactor as a function of flow rate and channel length. The photocatalyst durability test and a comparative photocatalytic efficiency study between the microreactor and the conventional beaker reactor have also been carried out. Under visible light, these nanoparticles exhibit a remarkable enhancement of ~ 94.5% in the inline microreactor‐based photocatalytic degradation of methylene blue dye. The slower the flow rate and longer the channel length, gradual enhancement in the performance has been observed. Also, these nanoparticles express an antibacterial effect with very high efficacy even at very low (2 mg mL−1) concentration toward the inhibition of Escherichia Coli.

AgBr nanoparticle surface modified SnO2 enhanced visible light catalytic performance: characterization, mechanism and kinetics study

“…The stability of the SnO 2 –AgBr (1 : 1) composite is related to its practicability and is also an important factor to measure its photocatalytic performance. 71,72 After four cycles of experiment, the degradation rates of MO and MG decreased to 66.42% and 70.86%, respectively (Fig. 11a and b).…”

Ultrasonic enhancement of microdroplet-based interfacial reaction for improving the synthesis of Ag2S QDs

“…Some attempts also have been made to utilize microreactor in the synthesis of Ag 2 S QDs [14] . Bhanu Prakash et al synthesized QDs in milliliter-scale microchannels [15] . Whereas, the slower mass transfer in the laminar-flow dominated microchannel resulted in less new nucleation of crystals, and larger the average size of QDs (about 15 nm) which severely exceeded the natural filtration threshold in living organisms (5 nm) [16] .…”

Continuous Preparation of Fe3O4 Nanoparticles with Narrow Size Distribution by Partial Oxidation Coprecipitation of Fe2+ Ions in Microchannels

“…In recent years, microfluidic technology has attracted increasing attention across various fields due to its precise control and high operational efficiency. Enhanced mass transfer within the microchannel enables the continuous execution of certain synthetic processes, thus ameliorating the productivity of products traditionally inefficient in complex batch operations. − Segmented flow, one of the most studied flow patterns in microfluidics, features a vortex in each segment, facilitating robust internal recirculation and superior mass and heat transfer. − Owing to this attribute, segmented flow has been utilized not only in chemical reactions but also in extraction and crystallization procedures. − In our previous study, we effectively regulated the length of the gas–liquid segment in a 1.59 mm perfluoroalkoxy (PFA) tube without varying the fluid flow rates . We further demonstrated that mass transfer at the segment interface is significantly enhanced relative to that at the bubble surface, and the rate of mass transfer can be modulated by altering the segment length, a topic to be elaborated upon in our upcoming publication.…”