The development of advanced oxidation processes (AOPs) for environmental remediation has spurred a growing interest in catalysts that selectively generate non-radical species such as singlet oxygen (O). However, the precise engineering of catalytic sites to enhance targeted O production remains a formidable challenge. This study reports a B-doped graphitic carbon nitride-supported Cu single-atom catalyst (CuBCN) that significantly enhances HO activation for efficient O production.
View Article and Find Full Text PDFMetal-organic frameworks (MOFs) hold considerable promise for environmental remediation owing to their exceptional performance and distinctive structure. Nonetheless, the practical implementation of MOFs encounters persistent technical hurdles, notably susceptibility to loss, challenging recovery, and potential environmental toxicity arising from the fragility, insolubility, and poor processability of MOFs. MOF-based three-dimensional macrostructures (3DMs) inherit the advantageous attributes of the original MOFs, such as ultra-high specific surface area, tunable pore size, and customizable structure, while also incorporating the intriguing characteristics of bulk materials, including hierarchical structure, facile manipulation, and structural flexibility.
View Article and Find Full Text PDFDue to the neighborhood explosion phenomenon, scaling up graph neural networks to large graphs remains a huge challenge. Various sampling-based mini-batch approaches, such as node-wise, layer-wise, and subgraph sampling, have been proposed to alleviate this issue. However, intensive random sampling incurs additional overhead during training and often fails to deliver good performance consistently.
View Article and Find Full Text PDFIn recent years, photothermal-assisted Fenton-like degradation of organic pollutants has become a prominent green method in environmental pollution control. Nevertheless, the design of suitable catalysts remains a significant challenge for this approach. Herein, zeolite-imidazolate framework-derived CoMn bimetallic nanoparticles embedded in hollow carbon nanofibers (CoMnHCF) have been developed as a photothermal nano-confinement reactor with multiple active sites to enhance reaction performance and promote peroxymonosulfate (PMS) activation.
View Article and Find Full Text PDFTetracycline (TC), a commonly used antibiotic in wastewater, poses environmental and health risks, thus demanding advanced catalysts for its effective removal. In this work, for the first time, we integrated cobalt ferrite (CoFeO) and MXene quantum dots (MQDs) to form magnetic heterojunctions for rapid degradation of TC in the presence of peroxymonosulfate (PMS). Anchoring MQDs on the CoFeO nanoparticles remarkably promoted the overall degradation rate of TC to 98.
View Article and Find Full Text PDFEfficient oil-water separation has always been a research hotspot in the field of environmental studies. Employing a one-step hydrothermal approach, NiFe-layered double hydroxides (LDH) nanosheets were synthesized on nickel foam substrates. The resulting NiFe-LDH/NF membrane exhibited rejection rates exceeding 99% across six diverse oil-water mixtures, concurrently demonstrating a remarkable ultra-high flux of 1.
View Article and Find Full Text PDFHydrogen-bonded organic frameworks (HOFs) are a new class of crystalline porous materials that are formed through the interconnection of organic or metal-organic building units intermolecular hydrogen bonds. The remarkable flexibility and reversibility of hydrogen bonds, coupled with the customizable nature of organic units, endow HOFs with mild synthesis conditions, high crystallinity, solvent processability, and facile self-healing and regeneration properties. Consequently, these features have garnered significant attention across various fields, particularly in the realm of membrane separation.
View Article and Find Full Text PDFIn the evolving landscape of water treatment, membrane technology has ascended to an instrumental role, underscored by its unmatched efficacy and ubiquity. Diverse synthesis and modification techniques are employed to fabricate state-of-the-art liquid separation membranes. Click reactions, distinguished by their rapid kinetics, minimal byproduct generation, and simple reaction condition, emerge as a potent paradigm for devising eco-functional materials.
View Article and Find Full Text PDFTo address current energy crises and environmental concerns, it is imperative to develop and design versatile porous materials ideal for water purification and energy storage. The advent of covalent organic frameworks (COFs), a revolutionary terrain of porous materials, is underscored by their superlative features such as divinable structure, adjustable aperture, and high specific surface area. However, issues like inferior electric conductivity, inaccessible active sites impede mass transfer and poor processability of bulky COFs restrict their wider application.
View Article and Find Full Text PDFSingle-atom catalysts, characterized by individual metal atoms as active centers, have emerged as promising candidates owing to their remarkable catalytic efficiency, maximum atomic utilization efficiency, and robust stability. However, the limitation of single-atom catalysts lies in their inability to cater to multistep reactions using a solitary active site. Introducing an additional metal atom can amplify the number of active sites, modulate the electronic structure, bolster adsorption ability, and enable a gamut of core reactions, thus augmenting their catalytic prowess.
View Article and Find Full Text PDFTransition metal carbides/nitrides/carbonitrides, commonly referred to as MXenes, have gained widespread attention since their discovery in 2011 as a promising family of two-dimensional (2D) materials. Their impressive chemical, electrical, thermal, mechanical, and biological properties have fueled a surge in research focused on the synthesis and application of MXenes in various fields, including membrane-based separation. By engineering the materials and membrane structures, MXene-based membranes have demonstrated remarkable separation performance and added functionalities, such as antifouling and photocatalytic properties.
View Article and Find Full Text PDFAssembling metal-organic frameworks (MOFs) into high-performance macroscopic membranes is crucial but still challenging. MOF-containing hybrid membranes can effectively integrate the advantages of flexible guest materials and MOFs. Nevertheless, the inherent limitations in fully harnessing the distinct characteristics of MOFs persist due to the substantial guest material content necessitated in membrane fabrication.
View Article and Find Full Text PDFThe photothermal process has attracted considerable attention in water treatment due to its advantages of low energy consumption and high efficiency. In this respect, photothermal materials play a crucial role in the photothermal process. Particularly, carbonaceous materials have emerged as promising candidates for this process because of exceptional photothermal performance.
View Article and Find Full Text PDFPhotocatalytic membranes can effectively integrate membrane separation and photocatalytic degradation processes to provide an eco-friendly solution for efficient water purification. It is of great significance to develop highly efficient photocatalytic membranes driven by visible light to ensure the long-term stability of membrane separation systems and the maximum utilization of solar energy. Metal-organic framework (MOF) is an emerging photocatalyst with a well-defined structure and tunable chemical properties, showing a broad application prospect in the construction of high-performance photocatalytic membranes.
View Article and Find Full Text PDFThe integration of catalytic degradation and membrane separation processes not only enables continuous degradation of contaminants but also effectively alleviates inevitable membrane fouling, demonstrating fascinating practical value for efficient water purification. Such membrane-catalysis integrated system (MCIS) has attracted tremendous research interest from scientists in chemical engineering and environmental science recently. In this review, the advantages of MCIS are discussed, including the membrane structure regulation, stable catalyst loading, nano-confinement effect, and efficient natural organic matter (NOM) exclusion, highlighting the synergistic effect between membrane separation and catalytic process.
View Article and Find Full Text PDFSingle-atom catalysts (SACs) for photocatalytic hydrogen peroxide (H O ) generation are researched but it is still challenging to obtain high H O yields. Herein, graphite carbon nitride (Fe /CN) confined single Fe atoms with N/O coordination is prepared, and Fe /CN shows high H O production via oxalic acid and O activation. Under visible light illumination, the concentration of H O generated by Fe /CN can achieve 40.
View Article and Find Full Text PDFOver the last decades, advanced oxidation processes (AOPs) have been widely used in surface and ground water pollution control. The heterogeneous electro-Fenton (EF) process has gained much attention due to its properties of high catalytic performance, no generation of iron sludge, and good recyclability of catalyst. As of October 2022, the cited papers and publications of EF are around 1.
View Article and Find Full Text PDFMembrane-based carbon dioxide (CO ) capture and separation technologies have aroused great interest in industry and academia due to their great potential to combat current global warming, reduce energy consumption in chemical separation of raw materials, and achieve carbon neutrality. The emerging covalent organic frameworks (COFs) composed of organic linkers via reversible covalent bonds are a class of porous crystalline polymers with regular and extended structures. The inherent structure and customizable organic linkers give COFs high and permanent porosity, short transport channel, tunable functionality, and excellent stability, thereby enabling them rising-star alternatives for developing advanced CO separation membranes.
View Article and Find Full Text PDFThe oily water treatment is becoming one of the hottest topics due to that increase of offshore oil transportation and the various accident oil leakages. In this study, a functional TiO-ABS composite membrane was generated through the three-dimensional (3D) printing strategy for the first time and was conducted to simulated oily water treatment. The TiO-ABS composite membrane demonstrated a significant promotion in hydrophilicity and oleophobicity which were evidenced by the water contact angle of 14.
View Article and Find Full Text PDFThe greatest environmental issue of the twenty-first century is climate change. Human-caused greenhouse gas emissions are increasing the frequency of extreme weather. Carbon dioxide (CO) accounts for 80% of human greenhouse gas emissions.
View Article and Find Full Text PDFThe increasingly serious pollution of antibiotics brings an enormous threat to the ecological environment and human health. Graphite phase carbon nitride (g-CN), as a popular photocatalytic material, is widely used in photocatalytic degradation of antibiotics in water. In order to make up for the shortage of g-CN monomer, CeO/N-doped g-CN (CeNCN) composite photocatalysts co-modified with nitrogen doping and CeO loading were designed and synthesized with the idea of expanding visible light absorption and promoting photogenerated carrier separation.
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