Electrocatalytic Membrane Containing CuFeO2/Nanoporous Carbon for Organic Dye Removal Application

Synthesis of UiO-66-NH2@PSF Hollow Fiber Membrane with Enhanced Simultaneous Adsorption of Pb2+ and Phosphate for Hydrogen Peroxide Purification

Electronic grade hydrogen peroxide plays a crucial role in the fabrication of large-scale integrated circuits. However, hydrogen peroxide prepared by the anthraquinone method contains impurities such as lead ions (Pb2+) and phosphate, which can seriously affect the yield of the circuit. Traditional adsorbent materials have difficulty in solving the problem of simultaneous adsorption of trace anions and cations in hydrogen peroxide due to the single adsorption site and poor adsorption kinetics. In this study, UiO-66-NH2 was prepared by introducing a -NH2 group on the terephthalic acid ligand, and a series of hybrid matrix hollow fiber membranes with different UiO-66-NH2 contents were prepared by loading it on polysulfone (PSF). This initiative not only improved the pore size and water flux of hollow fiber membranes but also enhanced the removal efficiency of ions from hydrogen peroxide solution, thereby facilitating practical application. Among them, UiO-66-NH2@PSF-1.5 showed the best adsorption of phosphate and lead ions with adsorption capacities of 3.099 and 2.160 mg g-1 and reached the removal efficiency of 67.1 and 60.1%, which fully confirms the practicability in the purification of electronic chemicals. This work innovatively proposes that UiO-66-NH2@PSF hybrid matrix hollow fiber membranes have great potential as simultaneous adsorbents for cations and anions in the efficient purification of electronic grade solvents.

The synergistic effect and mechanism of in-site algae inactivation in simulated ballast water by dimension-stable anode electrocatalysis

The spread of harmful algae through ballast water poses serious threats to marine ecosystems, so the development of effective methods to inactivate the algae and to treat the harmful pollution in ballast water was important. Electrocatalysis technology is safe and reliable and has been widely used in water treatment. In this paper, a dimensionally stable anode (DSA) electrocatalysis system was studied to investigate the efficiency of in-site algae inactivation in simulated ballast water. The studies showed that the DSA electrocatalysis system showed good efficiency for algae inactivation in ballast water, and the inactivation rate varied depending on the algae and could be optimized by adjusting hydraulic retention time (HTR), current density, and electrode surface area. Furthermore, the DSA electrocatalysis provided a significantly sustained inactivation effect on algae in the holding time after electrolytic operation. The inactivation rate for Platymonas helgolandica and Heterosigma akashiwo reached 99.27% and 99.09%, respectively, in short treatment time (HRT of 60 s), and the energy consumption was 0.350 kWh/L and 2.654 kWh/L. Besides the direct oxidation and reduction of electric field, the reactive oxides generated in the DSA electrocatalysis process were the primary factors which caused algae inactivation. The total residual oxides (TRO) damaged algae cells and led to algae inactivation. The DSA electrocatalysis led to lipid peroxidation in algal cell membranes, causing structural damage and metabolic failure. The DSA electrocatalysis was an effective and clean technology for the in-site algae removal in ballast water.

Cu3(hexaamino triphenylhexane)2/reduced graphene oxide composites with boosting electron-transfer properties for acetaminophen electrocatalytic degradation

Electron-transfer properties, as great contributors for electrocatalytic oxidation on the anode, are crucial to pollution degradation. The strong relationship between electron-transfer properties and active species (such as radicals) generation of anode catalysts suggests a new strategy for pollution-degradation efficiency improvement. In this study, a novel composite of Cu3(hexaamino triphenylhexane)2 [Cu3(HITP)2] and reduced graphene oxide (RGO) was synthesized to construct electron-transfer pathways between the two layers. Benefiting from the connection formed through RGO-O-N-Cu, the electron transfer from RGO to Cu3(HITP)2 was accelerated. The resettled charge distribution led the C atoms in the RGO layer, and the Cu and C atoms in Cu3(HITP)2 layer acted as the main surface active sites. O2•-, 1O2, and reactive chlorine were then triggered to boost the degradation of acetaminophen. The source of O2•- and 1O2 was more likely from surface oxygen groups rather than dissolved O2. Overall, this research provided a perspective proof of conductive Cu3(HITP)2/RGO composite construction with 2D/2D structure for electrocatalytic-oxidation improvement.

Catalyst regulated interfacial synthesis of self-standing covalent organic framework membranes at room temperature for molecular separation

Covalent organic framework (COF) membranes have shown enormous potential for molecular separation due to their large surface areas and pre-designable structures. However, the mild and convenient preparation of COF membranes with high crystallinity has remained a significant challenge. In this work, we reported on a facile liquid-liquid interfacial polymerization method to fabricate self-standing imine-based COF membranes with excellent crystallinity and a tunable thickness at room temperature. Polymerization was confined at the immiscible organic solvent-water interface when the monomers in the dichloromethane met the catalyst aqueous solution. This unique design concept exploited the rapid formation of COF monolayers at the liquid-liquid interface to control catalyst diffusion and structural rearrangement, achieving high crystallinity of the COF membrane. Moreover, the thickness of the self-standing COF membranes could be regulated from 50 nm to 1 μm through the flexible regulation of the growth process. Benefiting from the large surface area of the COF membranes (378 m2/g) and the intensive π-π conjugate effect between the COFs and organic dyes, the obtained COF membranes exhibited high adsorption capacities toward Chrome Black T and Rose Bengal. This work may open a viable avenue to easily and mildly prepare COF membranes for water treatment.