Silk nanofibrils-MOF composite membranes for pollutant removal from water

Onion peel derived carbon nanoparticles incorporated polysulfone membranes: enhanced dye removal from water

The ongoing discharge of hazardous dyes from industrial processes has intensified global water pollution, posing serious threats to aquatic ecosystems and human health. Addressing this challenge, our study explores the potential of bio-based carbon nanomaterials (CNM), synthesized from onion peel biowaste and designated as ON11, as effective agents in dye removal. These CNMs were incorporated into a mixed matrix membrane (MMM), using polysulfone (PSU) as the membrane substrate, to enhance dye adsorption. The CNM synthesis was achieved through a simple, eco-friendly process. We examined their impact on adsorption efficiency by introducing ON11 nanoparticles at varying concentrations into the PSU membrane (ON11@PSU). This CNM-embedded membrane structure offers a solution to challenges associated with the large-scale application of nanomaterials, particularly by minimizing leaching into water and improving durability. The ON11 and ON11@PSU membranes were characterized using various techniques, including SEM, Raman spectroscopy, XRD, optical profilometer, and FTIR, to confirm their behavior, morphology, and structural integrity. The surface area of ON11 was 423.26 m2 g-1, with BJH average pore diameter of 4.5 nm and BET pore volume of 0.26 cm3 g-1. ON11 nanoparticles were adsorptive in nature, and their utility in membrane adsorption is explored. The influence of parameters, including contact time, dye concentration, membrane thickness, pH, and adsorbent dosage, was systematically evaluated to optimize the dye adsorption efficiency of the ON11@PSU membrane pad. It was observed that the thickness of the 60 μm membrane (S a = 2.170 μm and S q = 2.75 μm) showed higher removal efficiency for all the selected dyes than the other thicknesses at the native pH itself. The MMM demonstrated its effectiveness as an adsorbent membrane, achieving maximum removal efficiencies of approximately 98% for MG dye, 92% for RhB dye, and 67% for MB dye. The negative zeta potential of adsorptive membranes enabled the electrostatic attraction of positively charged dyes, enhancing adsorption capacity. The findings contribute to developing sustainable and effective membrane utility as adsorbents, opening avenues for the effective use of agricultural waste products in environmental remediation applications.

Green, Low-carbon Silk-based Materials in Water Treatment: Current State and Future Trends

The improper and inadequate treatment of industrial, agricultural, and household wastewater exerts substantial pressure on the existing ecosystem and poses a serious threat to the health of both humans and animals. To address these issues, different types of materials have been employed to eradicate detrimental pollutants from wastewater and facilitate the reuse of water resources. Nevertheless, owing to the challenges associated with the degradation of these traditional materials post-use and their incompatibility with the environment, natural biopolymers have garnered considerable interest. Silk protein, as a biomacromolecule, exhibits advantageous characteristics including environmental friendliness, low carbon emissions, biodegradability, sustainability, and biocompatibility. Considering recent research findings, this comprehensive review outlines the structure and properties of silk proteins and offers a detailed overview of the manufacturing techniques employed in the production of silk-based materials (SBMs) spanning different forms. Furthermore, it conducts an in-depth analysis of the state-of-the-art SBMs for water treatment purposes, encompassing adsorption, catalysis, water disinfection, desalination, and biosensing. The review highlights the potential of SBMs in addressing the challenges of wastewater treatment and provides valuable insights into prospective avenues for further research.

Satisfactory degradation of tetracycline by a pH-universal CoFe-LDH/MoS2 heterojunction catalyst in Fenton process

Fenton or Fenton-like reactions have been widely used in various fields, including solar energy conversion to generate hydroxyl radicals, environmental remediation, biology, and life science. However, the slow Fe3+/Fe2+ cycle and narrow applicable pH range still present significant challenges. Here, a heterostructured CoFe-layered double hydroxide/MoS2 nanocomposite (CoFe-LDH/MoS2) was prepared via simple electrostatic interactions. The heterostructure establishes a robust interfacial contact, leading to an abundance of exposed Mo6+ sites. Consequently, the developed CoFe-LDH/MoS2+H2O2 system exhibited superior performance in the degradation of tetracycline (>85%) within 60 min across a wide pH range from acidic to basic. Moreover, the CoFe-LDH/MoS2 heterojunction catalysts exhibited exceptional resistance to common anions and efficiently degraded various organic pollutants. The mechanism study verified that the CoFe-LDH/MoS2 had high efficiency in producing 1O2 and ‧OH to degrade various organic pollutants. The present study will serve as a foundation for creating efficient catalyst systems for related environmental remediation.

A Simplified Method for the Preparation of Highly Conductive and Flexible Silk Nanofibrils/MXene Membrane

Silk nanofibers (SNF) have great applications in high-performance functional nanocomposites due to their excellent mechanical properties, biocompatibility, and degradability. However, the preparation of SNF by traditional methods often requires the use of some environmentally harmful or toxic reagents, limiting its application in green chemistry. In this paper, we successfully prepared SNF using natural silk as raw material and solvent stripping technology by adjusting the solvent concentration and solution ratio (the diameter of about 120 nm). Using the above SNFs as raw materials, SNF membranes were prepared by vacuum filtration technology. In addition, we prepared an SNF/MXene nanocomposite material with excellent humidity sensitivity by simply coating MXene nanosheets with silk fibers. The conductivity of the material can approach 1400.6 S m-1 with excellent mechanical strength (51.34 MPa). The SNF/MXene nanocomposite material with high mechanical properties, high conductivity, and green degradability can be potentially applied in the field of electromagnetic interference (EMI) shielding, providing a feasible approach for the development of functional nanocomposite materials.