A microfluidic device with integrated ZnO nanowires for photodegradation studies of methylene blue under different conditions

Anodized titania nanotube array microfluidic device for photocatalytic application: Experiment and simulation

“…The Navier-Stokes equations for conservation of momentum (2) and the continuity equation for conservation of mass (3) are used to model the laminar flow of a single phase Newtonian fluid in the micro-channel.…”

“…Although all of the studies mentioned in Table 1 use methylene blue, it is difficult to compare the performance of TNA photocatalyst with these systems due to the different channel geometries, flow-rates, pollutant concentration and photocatalyst surface area involved. The degradation performance in these systems is reported as a function of irradiation time [2] or the effective residence time [6]. In the case of microfluidic surface reactors, the Péclet number determines whether diffusion or advection is the dominating means of pollutant mass transport to the photocatalyst surface.…”

“…Many studies involve conventional macroscale reactors with limited mass transport and poor photon transport. This can potentially limit the degradation performance of the system [2][3][4]. The use of microfluidic system has the potential to reduce such aforementioned reactor limitations.…”

“…This is especially critical when a large-scale array of microfluidic channels is required [4]. For example, previous reports on microfluidic photocatalytic devices used clean-room techniques to fabricate the mold for the microfluidic device [14,3,6] or to pattern the photocatalyst substrate [2] or CNC milling to pattern the substrate [19]. In contrast, in this study the microreactor mold was fabricated using laser patterned polymethyl methacrylate (PMMA) sheets [20,21] and polydimethylsiloxane (PDMS) was used to fabricate the device.…”

“…The degradation kinetics of a model pollutant (methylene blue) in a microfluidic channel with TNA vs. P25 TiO 2 particles as catalyst under solar irradiation (AM 1.5, ∼100 mW/cm 2 ) was used in this study. Most of the existing work on microfluidic photocatalytic system, however, have been done under UV light [2,6,17], limiting the practical application.…”