Facile Synthesis and Integration of Poly(vinyl alcohol) Sponge-Supported Metal Nanocatalysts on a Microfluidic Chip Enable a New Continuous Flow Multireactor Nanocatalysis Platform for High Efficiency and Reusability Catalysis

Abstract

A new poly­(vinyl alcohol) (PVA) sponge-supported nanocatalysis platform on a continuous-flow microfluidic multireactor device was constructed for high-efficiency and high-reusability catalytic degradation of environmental pollutants. PVA sponge-supported metal nanoparticle catalysts (MNPs/PVA) were prepared by a simple improved impregnation self-assembly method, without any complicated surface modification. The MNPs/PVA catalysts were further integrated on a multireactor microfluidic device to form a continuous flow (CF) reactor platform (MNPs/PVA/chip) for simultaneous catalytic degradation of pollutants with two different nanocatalysts. After condition and catalyst optimizations, the catalytic activities of AuNPs/PVA and CoNPs/PVA were evaluated on this continuous flow microfluidic multireactor platform, by using p-nitrophenol (4-NP) as a model organic pollutant. Both catalysts exhibited outstanding catalytic efficiency (e.g., 100% for fresh catalysts), and the strong interactions between MNPs and PVA ensured high reusability (e.g., >20 cycles). After 20 cycles of catalysis, the optimal catalyst AuNPs/PVA still maintained a high catalytic efficiency of 97.6%. Compared to AuNPs/PVA-5, the cost-effective CoNPs/PVA catalyst exhibited similar catalytic performance within the first 10 cycles, while AuNPs/PVA showed better stability for long-term use. Hence, this continuous flow catalytic platform that combines the advantages of porous material-supported nanocatalysts with microfluidic devices has tremendous potential for various cost-effective environmental research and practical applications.

Portable in situ temperature‐dependent spectroscopy on a low‐cost microfluidic platform integrated with a battery‐powered thermofoil heater

“…Compared to the conventional spectrophotometric system, the proposed system owns various merits, including portability, simplicity, low‐cost, integrated battery‐powered heating elements instead of external AC power, and low‐reagent consumption (only 10.6 µl of analyte volume needed for the spectroscopic analysis). All these features allow the system ideal for wide applications such as precious chemical reaction characterization, kinetic studies of chemical reactions, and on‐site spectroscopic measurement, especially when handling expensive chemicals as well as in low‐resource settings 36 …”

“…All these features allow the system ideal for wide applications such as precious chemical reaction characterization, kinetic studies of chemical reactions, and on-site spectroscopic measurement, especially when handling expensive chemicals as well as in low-resource settings. 36 …”

Direct Electron Transfer of Glucose Oxidase on Pre-Anodized Paper/Carbon Electrodes Modified through Zero-Length Cross-Linkers for Glucose Biosensors

“…The specific surface area of the sample was calculated by the Brunauer-Emmett-Teller (BET) [41] surface adsorption method through the accelerated surface area and porosimetry system (ASAP) 2020 Sorptometer from Micromeritics by measuring the N 2 adsorption on the surface of the sample. The sample was degassed at 150 • C for 70 min at 10 mm Hg to remove any remaining solvent and ensure complete dryness and emptiness of the pores.…”

Low-cost microfluidics: Towards affordable environmental monitoring and assessment

“…In addition, other low-cost materials have also been reported. For example, sponge was used for thedetection of heavy metal ions in environmental samples (Ding and Lisak, 2019), leveraging the strength of sponge structure and the coupling with other materials for better mechanical properties (Hu et al, 2022;Silva et al, 2022). A few examples of the applications of low-cost porous materials are shown in Figure 3.…”