Optofluidic Microreactors with TiO₂-Coated Fiberglass

Abstract

Optofluidic microreactors are promising prospects for photocatalytic reactions. However, because the flow type in conventional designs is typically laminar, the mass transport mainly relies on diffusion, and thus the rate of mass transport is limited. Accordingly, poor mass transport reduces the photocatalytic reaction rate. To alleviate the limitation of mass transport, in this work, we proposed a novel optofluidic microreactor with TiO2-coated fiberglasses immersed in the microreaction chamber. Such a design enables enhanced mass transport by shortening the transport length and inducing the perturbation to liquid flow so as to improve the performance. We demonstrated the feasibility of the optofluidic microreactor with the TiO2-coated fiberglass by the photocatalytic water treatment of methylene blue under UV irradiation. Results showed that the proposed optofluidic microreactor yielded much higher degradation efficiency than did the conventional optofluidic microreactor as a result of enhanced mass transport. The microreactor with the TiO2-coated fiberglass showed a 2-3-fold improvement in the reaction rate constant as opposed to conventional ones. The maximal increment of the degradation efficiency can reach more than 40%.

Prototyping of meso- and microfluidic devices with embedded TiO2photocatalyst for photodegradation of an organic dye

“…• ads and O 2 − responsible for the degradation of organic compounds [6,43,44] and consequently increase the photocatalytic efficiency of the microfluidic device in respect with the mesoreactor. Fixing the flow rate at 50 μL/min, the micro and meso flow cell present two different resident times (R Time = volume cell/flow rate): 0.2 min and 16 min, respectively.…”

“…where k represents the reaction rate constant, C x /C 0 is the degradation of rhodamine B, and t is the effective reaction time [44]. For both photocatalytic reactors, the linearized Eq.…”

“…There are several techniques for prototyping photocatalytic meso-and microfluidic devices [22,25] and various methods to integrate TiO 2 into flow reactors systems, such as chemical vapor deposition on pyrex [41], drop casting on PDMS [40], electrospun nanofibrous TiO 2 on glass [42], calcination [43] on glass, coating on fiber glass [44], and adhesive substrate [45]. These techniques should be rapid, simple, avoiding the use of a clean room with expensive photolithography techniques, and should have a low cost from the design stage to the final test.…”

Microfluidic reactors for visible-light photocatalytic water purification assisted with thermolysis

“…1932-1058/2014/8(5)/054122/10/$30.00 V C 2014 AIP Publishing LLC 8, 054122-1 transfer, [21][22][23][24][25][26][27][28][29][30][31][32][33][34] efficient photon transfer, 6,7,33,34 short reaction time, 6,7,[21][22][23][24][25][26]34 and self-refreshing of reaction surface by running flow (and thus long photocatalyst durability). 7,34 Based on these understandings, a number of reactors have been developed using microfluidic structures.…”

“…Nevertheless, most of the demonstrated microfluidic reactors are designed to use UV light from external UV sources. 6,[21][22][23][24][25][26][27][28][29][30][31][32][33][34] Due to the small receiving area of microreactors (typically < 10 cm 2 ), only a small portion of light from the UV source is utilized for photocatalytic reaction.…”