Microfluidic Chip for the Photocatalytic Production of Active Chlorine

Abstract

Active chlorine is the most powerful microbicidal reagent in swimming pools, potable water, hospitals, and medical surgeries. Its production mainly relies on reactive inorganic intermediates and electrochemical methods that involve undesired waste products and high energy as well as material costs. In this study, we fabricated a low-cost chip based on sputter-coated thin films of silver (Ag) that acted as recyclable and effective photoelectrode for the photocatalytic production of active chlorine (HOCl) from aqueous media and artificial sunlight. The photoelectrode was electrochemically activated to AgCl at low overpotentials between 0.2 and 0.4 V vs Ag|AgCl (3 M KCl) and photocatalytically reduced to Ag(0) for 15 consecutive cycles, showing the electrode still being active. However, because of poor adhesion properties on the selected substrates, degradation effects were observed over time. Furthermore, the Ag@AgCl photoelectrode was integrated into a microfluidic chip, and we showed for the first time a light-driven microfluidic chip generating a constant stream of active chlorine.

Evaluation of the BET Theory for the Characterization of Meso and Microporous MOFs

“…The BET method can be used for the characterization of various types of microporous materials including zeolites, photocatalysts, polymers, and photoelectrodes . Since MOFs can contain different sizes of micropores, from “ultramicropores” (below 7 Å) to bigger “super‐micropores” (between 7 and 20 Å) or even mesopores (above 20 Å), the obtained BET surface areas can potentially be inaccurate.…”

“…The BET method can be used for the characterization of various types of microporous materials including zeolites, [91][92][93] photocatalysts, [94][95][96][97][98][99] polymers, [100][101][102] and photoelectrodes. [103][104][105][106][107][108] Since MOFs can contain different sizes of micropores, from "ultramicropores" (below 7 Å) to bigger "super-micropores" (between 7 and 20 Å) or even mesopores (above 20 Å), the Small Methods 2018, 2, 1800173 Figure 3. Crystal structures of IRMOF-9, IRMOF-11, and IRMOF-13.…”

Porous PEI Coating for Copper Ion Storage and Its Controlled Electrochemical Release

“…The recorded end potentials at high current densities are likely to be well above the water splitting potential at the carbon‐based electrode (Figure S3, Supporting Information), which bears the risk of generating molecular chlorine in artificial seawater . The in situ generated chlorine gas forms active chlorine, a common disinfectant in swimming pool sanitation, potable water and health care facilities and, is well known to react with organic matter …”

“…[30,38] The in situ generated chlorine gas forms active chlorine, a common disinfectant in swimming pool sanitation, potable water and health care facilities and, is well known to react with organic matter. [39][40][41][42][43] In order to investigate if the generated active chlorine will have major impact on the storage capacity of the PEI@CC for copper, in a separate experiment, the PEI@CC electrode was subjected to electrochemical water splitting in artificial seawater prior to the copper uptake. The PEI@CC was subjected Adv.…”

Alignment System and Application for a Micro/Nanofluidic Chip

“…Nevertheless, the chip’s small size has many advantages such as a rapid reaction rate [6,7], low cost, and high efficiency. It has not been promoted widely owing to the associated complicated processes of photolithography, development, micro-manufacturing, nano-manufacturing, and micro/nano integration [8,9,10]. Notably, micro/nano integration manufacturing is the bottleneck of the micro/nanofluidic chip’s development because of the high-accuracy requirement and the time needed to process the chips.…”