Regulation of the Volume Flow Rate of Aqueous Methyl Blue Solution and the Wettability of CuO/ZnO Nanorods to Improve the Photodegradation Performance of Related Microfluidic Reactors

Abstract

Six CuO/ZnO nanorod (CuO/ZnONR)-based microfluidic reactors were constructed for different UV irradiation durations, with which an aqueous methylene blue (MB) solution was photodegraded at varied volume flow rate Q. Via numerical and experimental routes, the effects of the Q on the kinetic adsorption rate constant K a and the initial rate constant K A of the CuO/ZnONR-based microfluidic reactors were discussed. Moreover, a reverse contacting angle (CA) trend of CuO/ZnONRs to the reaction constant K curve of corresponding CuO/ZnONR-based microfluidic reactor suggested that the CA of CuO/ZnONRs was another key influencing factor that affected greatly the photodegradation performance of the microfluidic reactors. The Q of the aqueous MB solution and the UV irradiation duration for the photodeposition of CuO/ZnONRs were optimized to be 125 μL/min and 1.0 h, the K of the CuO/ZnONR-based microfluidic reactors reached 4.84 min–1, and the related ΔK A/K was less than 6%. Similarly, these methods and results can be employed not only to enhance the mass transport and adsorption of specific species within other nanostructured matrix material-coated microchannels but also to enlarge the actual contacting surface areas between these microchannels and the related solution, which further improve the performance of other nanostructured catalyst-based microfluidic reactors, rGO microfluidic voltage generation, and a GOx/AuNW enzymatic glucose microfluidic sensor.

Improved Photoactivity Of NiO/ZnO Nanorods Heterostructured Films Relying On Scaffold Surface Cleaning And NiO Deposition Time Optimization

“…Compared to a previous study reporting the same type heterostructure [49] as ours, we obtain similar photodegradation efficiencies (70 %) for a pollutant that is much harder to degrade, the RhB. Again, higher efficiencies are reported for ZnO/CuO heterostructured films built on ZNR scaffold [67,68] but also for TiO 2 /In 2 O 3 films built on TiO 2 nanotube scaffold [69] for the standard MB dye. Incredibly high efficiency is reported for the degradation of RhB for physically deposited CuO/TiO 2 flat films but details on the irradiance level are not given [70] .…”

Nanostructure-Based Solution Sensor Fabricated with p-CuOx/n-TiO2 Nanojunctions To Identify Species and Concentrations of Alcohol Molecules

“…12−15 Previously, MOS sensors having p−n junctions formed by combining p-and n-type materials on the sensors' surfaces have been reported. 16−20 For example, the combination of p-CuO NWs with n-ZnO nanoparticles leads to the highly sensitive and fast detection of NO 2 gas, 14 and the combination of n-TiO 2 nanotubes with p-CuO nanoparticles leads to the highly sensitive and minimum detection limit of H 2 S gas. 19 Furthermore, the combination of p-Mn 3 O 4 , n-Fe 2 O 3 , and n-ZnO reportedly enables the identification of NO 2 and NH 3 gases.…”

“…The sensing mechanism of MOS-based sensors mainly originates from the change in resistance caused by interactions between the analyte molecules and the MOS surface. , In addition, MOS materials that function as photocatalysts or chemical catalysts , enhance the adsorption and desorption of molecules on their surfaces. Thus, their sensing performance substantially depends on surface-related factors, such as the geometric structure and surface functionalization. − Previously, MOS sensors having p – n junctions formed by combining p - and n -type materials on the sensors’ surfaces have been reported. − For example, the combination of p -CuO NWs with n -ZnO nanoparticles leads to the highly sensitive and fast detection of NO 2 gas, and the combination of n -TiO 2 nanotubes with p -CuO nanoparticles leads to the highly sensitive and minimum detection limit of H 2 S gas . Furthermore, the combination of p -Mn 3 O 4 , n -Fe 2 O 3 , and n -ZnO reportedly enables the identification of NO 2 and NH 3 gases .…”

Synergistic Effects of Redox Couples and Oxygen Vacancies Improve the Tetracycline Degradation Property of La2NiMnO6

“…Antibiotics that remain in water are harmful to human health and ecosystems. Semiconductor photocatalyst technology has the merit of high efficiency and environmental protection and has become a promising method for water disinfection, , dye degradation, , and antibiotic degradation. , It is important to develop a catalyst that can effectively break down antibiotics.…”