Sustainable Materials and Technologies最新文献

Energy consumption associated with the catalysts contributes partly to the high ohmic resistance arising from the low conductivity of the catalyst and poor charge transfer between nanoparticles, which has been difficult to study due to the complicated nanostructured framework of the catalysts. We constructed a novel heterostructure electrocatalyst (MoS₂/MoP@NC) composed of nanosized MoS₂/MoP heterostructures anchoring on hierarchical N-doped carbon for smoothing electron transfer in boosting hydrogen evolution reaction (HER). With the merits of large surface area, rapid charge transfer, and optimized electronic structure induced by charge transfer across the sufficient interface, the optimal MoS₂/MoP@NC (MoSP) catalyst shows a competitive overpotential of 140 (0.5 M H₂SO₄), 76 (1.0 M KOH), and 103 mV (0.5 M NaCl &1.0 M KOH) at 10 mA cm⁻², respectively. Raman experiment and Density functional theory (DFT) calculations reveal the formation of Mo-S-Mo bonds between MoS₂ and MoP, which favor enhancing the Femi level to facilitate the electron transfer, therefore regulating the electronic structure for the optimization of adsorption energy of hydrogen intermediate. Based on the experimental results, we constructed an energy consumption model of catalysts, where energy consumption comes from three aspects. The heterostructure design decreases the energy consumption of the catalysts greatly compared to the single-phase Mo-based catalyst of MoS₂ (78.0%) and MoP (45.2%) in alkaline electrolytes.

MXene-based composites are relatively easy to prepare, inexpensive, and well-suited to the integration of guest materials, which are some of the interesting features that have made them some of the most technically requirable functional materials. In this paper, we presented examples of the synthesis of MXene composites along with examples of their excellent properties as photocatalysts. We also reviewed recent examples as well as the decomposition/removal mechanisms for an antibiotic derived from pharmaceuticals with the ultimate aim of demonstrating the roles they play during such procedures. This review systematically summarizes the performance of removing pollutants that cause constraints using MXene-based materials along with their mechanisms for oxidant activation. An important target is the target milestone of next-generation adsorbents and catalysts based on MXene-combining materials while taking certain considerations into account. One of the several factors for these is that the increase in the number of chemically active reaction sites is high because the specific surface area is increased. The high catalytic activities are directly related to the high amount of hydrogen produced due to superior optical properties. The present work aims to contribute to the design of a future promising catalyst by comprehensively summarizing and discussing the current state of antibiotics decomposition reactions based on the use of various kinds of MXene combined photocatalysts for the active characteristics of electrons. Finally, we propose existing problems and future research directions for pharmaceutical antibiotic-induced contaminants caused by MXene and MXene-based composites.

A large amount of waste eggshells raises environmental issues. This study uses eggshells as recycled calcium source to synthesize fly ash and eggshell geopolymer (FAEG). The effects of eggshell content, liquid-solid ratio, NaOH/Na₂SiO₃ ratio, and NaOH solution concentration on the strength of the FAEG were evaluated by unconfined compressive strength (UCS) test. The geopolymerization products and microstructure characteristics of the FAEG were analyzed by XRD, FTIR, TGA, and SEM test. The results show that eggshells acted as recycled calcium sources are capable of significantly enhancing the UCS of the FAEG. The optimal content of eggshells is 15%. The NaOH/Na₂SiO₃ ratio has a significant effect on the UCS of the FAEG, while the influence of liquid-solid ratio and NaOH concentration is slight. The optimal NaOH/Na₂SiO₃ ratio is 50:50 and the liquid-solid ratio is recommended to be 0.55. Eggshells take part in the geopolymerization by acting as a precipitating and seeding element in the reaction and favoring the generation of the geopolymeric gels in the FAEG.

This paper presents a comprehensive investigation into the sustainable development of nano-enabled multifunctional materials (NMMs) for metal additive manufacturing (MAM), based on the principles of the Safe and Sustainable-by-Design (SSbD) framework. The work focuses on both environmental impacts and health risks potentially associated with these materials, offering a groundwork for a more complete SSbD assessment that includes socio-economic considerations.

The Life Cycle Assessment (LCA) identified significant environmental advantages of using Titanium Nitride (TiN) and Chromium Nitride (CrN) in wire coating processes over Titanium Carbide (TiC), with a 77% reduction in environmental impacts. However, despite the emphasis on environmental aspects during materials selection, the primary environmental hotspot is the heat treatment stage used during the process to shape NMMs into pellets. Eco-toxicity assessments performed on both nano- and microparticles from the studied NMMs for MAM, identified specific thresholds to ensure over 80% cell viability, labelling MoCu and CCuCr as particularly cytotoxic. Additionally, a task-based risk assessment in laboratory environments, evaluating the potential release of engineered nanoparticles (ENPs), identified minimal inhalation exposure risk for workers due to effective control measures implemented.

Overall, by integrating findings on eco-toxicity, worker safety, and environmental hotspots in production processes, this study offers an approach for advancing sustainable practices during the production of NMMs for MAM in laboratory settings. These findings can be valuable for future research and development in the field, ensuring that sustainability and safety are integral to the advancement of nanotechnology.

Nowadays, electromagnetic wave radiation is one of the sources of environmental pollution, which seriously affects human health and and the environment. Fiber paper made from high-performance fibers has shown potential for use in the electromagnetic interference (EMI) shielding due to adapting different complex working environments. However, achieving lightweight, high-efficiency, and flexible electromagnetic shielding remains challenging. To address this issue, we design a lightweight polysulfonamide/polyurethane-CNTs@Ag (PSA/PU-CNTs@Ag) fiber paper with double-layered structure and high electromagnetic shielding efficiency (EMI SE) via vacuum-assisted filtration and heat treatment. The results show the content of Ag nanoparticles 0.3 g in PSA/PU-CNTs@Ag fiber paper, the resistance is less than 1 Ω, the electrical conductivity reaches 883.57 S/m. At the same time, the thickness of Ag film increases, the EMI SE value reaches 90.537 dB. The EMI SE value of PSA/PU-CNTs@Ag fiber paper after folding one thousand times has decreased, but still maintains 95% of the original shielding performance. Moreover, its EMI SE values still maintain above 60 dB in various extreme environments (hot 150 °C, cold −70 °C). In summary, this work shows PSA based EMI shielding materials own excellent overall performance and hold broad different working extreme environments.

Bacterial infections pose a serious worldwide public health concern and play an important role in slowing or dramatically delaying wound healing. However, traditional antibiotics are faced with obstacles such as bacterial resistance and unsatisfactory biocompatibility, which has impeded further clinical translation. In recent years, antimicrobial nanomaterials have emerged as viable alternatives for combating bacterial infections, and carbon dots (CDs) have received particularly widespread attention due to their superior characteristics. In this work, a simple and eco-friendly one-step hydrothermal method was employed using the natural herbal medicine Eucommia ulmoides as a biomass carbon source to synthesize an Fe-doped CDs nanozyme (Fe-CDs) with good peroxidase-like (POD-like) activity, high biocompatibility, and strong antimicrobial activity for safe and effective antimicrobial therapy and the promotion of wound healing. L929 cells co-cultured with Fe-CDs did not show significant cytotoxicity and favored cell proliferation at appropriate concentrations. In addition, Fe-CDs catalyzed the decomposition of low-concentration H₂O₂ to ·OH, leading to enhanced antimicrobial activity. Both in vitro and in vivo experiments demonstrated that Fe-CDs exhibit potent antibacterial properties, the ability to promote cell migration and angiogenesis, and significant potential for promoting the healing of infected wounds. In summary, a green and safe antimicrobial nanozyme based on a biomass herbal medicine was developed in this work, offering promising insight into the development of novel antimicrobial materials and tissue regeneration engineering.

A facile pathway of upcycling waste/discarded polysulfone (WPSF) membranes has been proposed using deep eutectic solvent (DES) system composed of choline chloride and ethylene glycol (CC:EG) in 1:1 ratio as a green template. This approach offers a viable solution for addressing polymer membrane waste management challenges while simultaneously promoting feasible method, resource efficiency and economic viability. The WPSF was doped with Mn ions prior to the solvothermal conversion at 200 °C and pyrolysis at 900 °C. The obtained functional porous carbon showed superior adsorption capacity towards Malachite green (MG) (423.72 mg/g), Eriochrome black-T (EBT) (326.79 mg/g), Diclofenac (DCF) (195.31 mg/g), and Ofloxacin (OFX) (121.8 mg/g). The adsorption followed pseudo second order kinetics and well agreed with Langmuir isotherm. Further, the optimised carbon material i.e., Mn-WPSF-01 was used as an adsorptive-based membrane water filtration system, in which a remarkable water flux about 965 L.m⁻².h⁻¹ for different feed streams with outstanding rejection of >90% even after ten cycles of regeneration was obtained. Therefore, Mn-doped carbon materials integrate the advantages of easy preparation, robustness, and effective adsorption performances, as well as good recyclability. Furthermore, the utilized or secondary carbon materials were used as electrode system in supercapacitors after the pyrolysis, where they displayed a specific capacitance of 110.88 F/g at 0.1 A/g of current density with capacity retention 90.85% for about 20,000 cycles with a current density increased to 5 A/g. Therefore, this approach promises to recycle the WPSF via potential applications in water treatment and energy applications through greener way.

Abstract

Polymers have attracted attention for their use in enabling biodegradable electronics. However, many polymers suitable as substrates either have no adhesion or suffer from weak and unstable adhesion. Addressing this challenge, we report a simple method to achieve tunable adhesion on various surfaces for wide applications. We achieve this by combining poly(vinyl alcohol) (P), dopamine (DA) and citric acid (CA) to produce modified poly(vinyl alcohol) adhesive films. These films are derived from bio-based constituents through an environmentally benign, easily reproducible and scalable fabrication process. They offer strong adhesion to various surfaces, such as stainless steel (138–191 kPa) and Polytetrafluoroethylene (PTFE) (67–93 kPa) and facilitate easy detachment with water. Notably, the modified films showed a better degradation compared to pristine P films under anaerobic conditions. The extent of degradation was characterized both quantitatively and qualitatively. The biokinetic parameters of anaerobic digestion process were estimated using three different kinetic models. It is anticipated that DA and CA molecules penetrate the interplanar distance of P chains as supported by powder X-ray diffraction (XRD) studies, thus, accelerating the degradation process. Additionally, the inclusion of CA enhanced the stability of DA molecules against oxidation, increased the extent of H-bonding and acted as a plasticizer. The addition of DA and CA bestowed the films with self-healing property due to the presence of multiple H-bonds. Tensile experiments revealed that the strength of self-healed samples approached that of pristine samples. The findings of this study hold promise for the development of innovative, biodegradable poly(vinyl alcohol)-based self-healing adhesive films with potential applications across various domains like smart packaging, soft robotics, on-skin electronic tattoos and self-healing electronics.

Starting from spent coffee grounds, the use of coffee-derived biochar (CB) as a flame retardant (FR) additive was explored following a waste-to-wealth approach. CB was employed alone and in combination with ammonium polyphosphate (APP) and a ternary (Si-Ti-Mg) mixed oxide to enhance the thermal, fire, and mechanical performances of a bisphenol A diglycidyl ether (DGEBA)-based epoxy resin modified with (3-aminopropyl)-triethoxysilane (APTES) and cured with a cycloaliphatic amine hardener. The presence of silicon-modified epoxy chains guaranteed the uniform distribution of CB throughout the resin. The combined FR action of fillers (CB, APP, and Si-Ti-Mg oxide) and the acidic characteristics of hybrid epoxy moieties enabled the achievement of a no dripping UL 94-V-0 classification for epoxy resin containing 20 wt% CB and 1 wt% of phosphorus loading, significantly increasing the flexural modulus (by ∼15%). Although it is not self-extinguishing, compared to pristine resin, the silicon-modified epoxy nanocomposite filled only with CB exhibited a remarkable decrease in the peak of heat release rate (pHRR) (by ∼65%) and a beneficial smoke suppressant effect with a notable decrease (∼11%) in the total smoke production. Cone calorimetry tests, pyrolysis combustion flow calorimetry analysis, and microscopy measurements helped to outline the combined mode of action of CB, APP, and Si-Ti-Mg oxide in the flame retardation of the hybrid epoxy resin, highlighting a strong FR action in the condensed phase, with the formation of a stable aromatic ceramic char, as well as the smoke suppressant character due to the basic nature of the ternary metal oxide and the ability of porous biochar to adsorb the generated gases.

Lignocellulosic materials, despite their abundance and attractiveness, have long been marred with challenges in optimising the cost-functionality-quality trade-off. This comprehensive authoritative review paper explores how various lignocellulosic feedstock have been utilised to prepare marketable and sustainable bioplastics, as potential substitutes to conventional petroleum-based packaging. Dependence on hydrocarbon-derived plastics is increasingly being supplanted by both consumer-driven and sustainability-oriented materials design. This comprehensive paper encompasses a broad review relating to recent research (2013−2023) on the innovations and heuristic approaches to modify lignocellulose for the production of packaging films. The review paper holds extensive focus across various lignocellulosic materials such as - but not limited to - cellulose nanomaterials, cellulose esters and grafted cellulose. Advances in processes reported to date such as mechanochemical, chemical, thermochemical, biochemical and other novel methods have been studied. The materials design and process implications in terms of its cost, energy input and sustainability in its true sense, for all known techniques have been extensively investigated in this review paper. The review paper has further provided an elaborate process-structure-property-performance framework that characterises how material properties could be fine-tuned via different process considerations. A techno-economic feasibility overview for said processes and materials' use is also described herein.