Sustainable Materials and Technologies最新文献

To efficiently and completely remove organic pollutants from water, developing composite catalysts with both adsorption and photocatalytic/Fenton catalytic degradation is a very feasible solution. Herein, a new Cu_xO and g-C₃N₄ codoped bamboo charcoal (BC) composite (Cu-g-C₃N₄/BC) was prepared by the in-situ pyrolysis of Cu²⁺/melamine modified bamboo powders in N₂ atmosphere. Under the catalysis of Cu-g-C₃N₄/BC(600)/H₂O₂ system, the methylene blue (MB) and rhodamine B (RhB) dyes can be completely degraded within 10 min, and the methyl orange (MO) can be degraded within 30 min, indicating a high catalytic efficiency of the catalyst. Electron paramagnetic resonance (EPR) tests and active species trapping experiments suggested that ∙OH was the main active species in the degradation process, while the ·O₂⁻ and h⁺ played a minor role. The synergy of Cu₂O, CuO and g-C₃N₄ active sites in Cu-g-C₃N₄/BC increases the density of photogenerated electrons and promotes the separation of electron-hole pairs via the heterojunctions. The bamboo charcoal matrix plays an important role in the process of adsorbing the dyes and H₂O₂, which greatly promotes the activation of H₂O₂ and the degradation of dyes. In addition, the high conductivity of bamboo charcoal facilitates the charge transfer from the active sites to H₂O₂. The as-prepared Cu-g-C₃N₄/BC catalyst exhibits good reusability due to its structural stability. This work offers a promising bamboo charcoal catalyst with multiple active sites for the rapid elimination of persistent organic pollutants.

Tetracycline (TC) pharmaceutical compound is the third most used antibiotic after penicillin and quinolones, which developed bacterial resistance against them and environmental toxicity due to partially metabolized within humans and animals. At the same time, waste products (WPs) including food, agriculture, and plastic waste significantly increased day-by-day with the growing population. Therefore, there is a pleading requirement to develop a solar active agent that effectively degrades environmental pollution as well as reduces the burden of WPs. In this context, the present works focus on the development of waste-derived bimetallic (Fe/Ca) Oxy-iodide (WD-BMOX) encapsulated with PVDF-based nanosphere (WD-BMOX-P) as a solar active agent for the degradation of TC antibiotics. The band gap values of the synthesized WD-BMOX-P-based nanosphere are easily altered by changing the ratio of Fe/Ca. The lowest band gap values were observed to be ∼1.95 eV of the WD-BMOX-P-1:2, whereas upon increasing the Ca within the nanosphere band gap value significantly increases. The incorporation of PVDF polymer within the WD-BMOX-P aided advantages to formed nanosphere and improved oxygen vacancy, thereby high degradation efficiency. The highest degradation of TC antibiotics ∼96.8% and ∼ 69% was observed using WD-BMOX-P-1:2 nanosphere at 1 mg/L and 10 mg/L, of TC antibiotics within 60 min of solar irradiation, respectively. Moreover, ∼88% and 100% photodegradation of TC antibiotics was observed at pH 10 and the presence of H₂O₂ at 10 mg/L, respectively. The data indicate that the synthesized WD-BMOX-P-based nanosphere might be promising solar active agents, which effectively degrade TC antibiotics from water.

The increase in electronic waste (e-waste) is a significant global concern due to fast technological development in which products rapidly become obsolete. To mitigate this problem in the field of electrochromic devices, four different types of solid polymer electrolytes (SPEs) were developed based on iota-carrageenan, a water-soluble biopolymer, and 40 wt% concentration of different ionic liquids (ILs): 1-butyl-3-methyl-imidazolium thiocyanate ([BMIM][SCN]), 1-ethyl-3-methyl-imidazolium thiocyanate ([EMIM][SCN]), 1-butyl-3-methyl-imidazolium dicyanamide ([BMIM][N(CN)₂)]), and 1-ethyl-3-methyl-imidazolium dicyanamide ([EMIM][N(CN)₂)]). The resulting composites present a uniform and compact morphology, with a good distribution of the ILs within the polymer matrix, thermal stability up to ∼100 °C, and suitable mechanical properties. Their ionic conductivity at room temperature is in the range of ∼10⁻⁴ S.cm⁻¹ in the solid state and around ∼10⁻³ S.cm⁻¹ in the liquid state. Each of the developed electrolytes was integrated on a printed electrochromic device (ECD) fabricated with poly(3,4-ethylenedioxythiophene) polystyrenesulfonate (PEDOT:PSS) as a working electrode and their performance was evaluated using spectroelectrochemical techniques. All four ECDs operate at voltages between -1 V and 1 V, providing coloration efficiencies between 253 and 571 cm².C⁻¹ for the oxidation process and between −435 and − 847 cm².C⁻¹ for the reduction process at 98% full contrast, and presenting switching times between the bleached and colored states around 3.2–4.8 s at 98% full contrast. These low-cost SPEs provide a suitable approach for the development of high-performance sustainable ECDs.

Hydraulic fracturing for oil and gas production generates a substantial amount of wastewater, and photocatalysis is a potential method for treating fracture flowback fluids due to its low cost and efficiency. This study utilized the hydrothermal method to synthesize layered α-Ni(OH)₂ with a controllable microstructure by substituting various nickel sources, including Cl⁻, SO₄²⁻, OAc⁻, and NO₃⁻ interlayer ions, to focus on the photocatalytic degradation of hydroxypropyl guanidine gum, the primary constituent of fracturing fluid. The results indicate that α-Ni(OH)₂/OAc⁻ exhibits the most effective photocatalytic activity under optimal experimental conditions. The stability of the catalyst was confirmed through cycling studies. Possible degradation mechanisms were hypothesized based on DFT adsorption energy calculations and capture tests. The field performance of the application demonstrates that this work offers novel perspectives on the photocatalytic degradation of fracturing fluids.

Laser-induced breakdown spectroscopy (LIBS) is a commonly employed technique in commercial plastic recycling for purposes including classification, sorting, identification, and elemental analysis. However, understanding the molecular-level kinetics, thermodynamic interactions, bonding cleavage, and process parameter impacts is crucial for identifying necessary modifications to enhance plastic recycling. A review of the literature revealed that LIBS can also facilitate plastic pyrolysis, a significant research area that remains largely unexplored. Based on theoretical hypotheses, it can be concluded that laser-induced pyrolysis may offer advantages over traditional pyrolysis, which requires understanding the chemistry of plastic bond-breaking during degradation, identifying resistant bonds, and uncovering the root causes of these challenges. This approach is described in detail in sections 9 and 10, focusing on high-density polyethylene (HDPE) under controlled conditions. The identified research gaps could be further investigated, and advancements could be made toward establishing efficient plastic recycling and designing laser-induced pyrolysis reactors.

In recent years, the demand for energy storage devices with high-performance has propelled intense research efforts toward the development of promising supercapacitors. Among various electrode material, vanadium pentoxide (V₂O₅) has gained significant interest due to its excellent electrochemical properties. For the application of energy storage, V₂O₅ has intrinsic low electrical conductivity and limited cycle stability, makes its practical application limited. To overcome these challenges, the integration of V₂O₅ with metal-organic framework (MOF) nanocomposites has emerged as a promising strategy. This study focuses on the synthesis, characterization, and electrochemical analysis of V₂O₅ with zeolitic imidazolate framework-67 (ZIF-67) nanocomposites for supercapacitor applications. The V₂O₅@ZIF-67 hybrid material has been prepared by a simple in-situ chemical method. The XRD pattern of V₂O₅@ZIF 67 nanocomposites illustrate the combination of V₂O₅ with ZIF 67, as well as the subsequent growth of two phases without any modification to the parent. Within a potential window of 0 to 0.45 V, the synthesised V₂O₅@ZIF-67 in the three-electrode system exhibits a high specific capacitance of 913.06 F g⁻¹ at a current density of 6 A g⁻¹. The fabricated asymmetric supercapacitor (ASC) device delivers a superior energy density of 9.69 Wh kg⁻¹ and power density of 2187.5 W kg⁻¹.

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This study addresses the challenge of pathogen regulation in confined spaces by introducing the T-robot, an innovative air filtration robot featuring the F-MAX multilayer composite plate. Designed to capture a wide range of pollutants, including harmful viruses and bacteria, the T-robot significantly enhances air quality. The experimental setup used magnesium phosphate cement, electrostatically charged melt-blown fabric, and eco-friendly materials such as lithium brine by-product magnesia. Key results include a virus removal rate of 99.99% and an antibacterial rate of 98%.

The F-MAX system combines multiple layers, each targeting specific particles, with features like the self-healing Desert Rose (DR) coating and high-speed air circulation. The T-robot's high filtration efficiency and sustainable design make it superior to traditional methods, suitable for both commercial and residential use. Its durability and advanced filtration capabilities help reduce airborne contaminants, creating healthier living spaces and demonstrating a commitment to a sustainable future.

On islands distant from the mainland, obtaining raw materials for concrete production is often more challenging. To achieve sustainable development in island reef engineering, using discarded marine concrete and coral waste generated during island construction as recycled aggregates are of considerable significance. The preparation of Recycled Coral Aggregate Concrete (RCAC) for island reef engineering thus holds substantial importance. In this study, RCAC and Natural Aggregate Concrete (NAC), both designed with a compressive strength of C60, were prepared. Initially, the fundamental physical properties of the recycled coarse aggregate, such as apparent density, water absorption, and crushing index, were determined. Subsequently, a comparative analysis of the quasi-static mechanical properties of RCAC with varying proportions of recycled coral coarse aggregate (RCCA) was conducted. Furthermore, the impact compression mechanical properties of different RCAC specimens under various strain rates were examined using the Ф100mm Split Hopkinson Pressure Bar (SHPB) apparatus. The microstructure and long-term drying shrinkage performance of RCAC were also analyzed using Scanning Electron Microscopy (SEM) and a drying shrinkage apparatus. The finding indicated that the 28-day compressive strength of RCAC specimens with 100% coarse aggregate replacement reached a maximum of 62.4 MPa. The quasi-static compressive strength of RCAC specimens with 50% and 100% RCCA replacement was only 11.5% and 14.2% lower than that of NAC, respectively. Under impact loading, the dynamic compressive strength of RCAC specimens increased with the strain rate, with peak stress exhibiting an approximately linear relationship with the strain rate. The energy dissipation of RCAC specimens generally occurred in three stages, with the reflected and absorbed energies of the specimens increasing linearly with strain rate. At the same strain rate, the transmitted energy of RCAC specimens was higher than that of NAC specimens. Microstructural analysis revealed that the morphology of recycled coral aggregate is characterized by its porous and rough surface. The interfacial transition zone between the recycled coral aggregate and the cement mortar was relatively dense. Incorporating recycled coarse aggregate significantly affected the drying shrinkage properties of the concrete, with higher contents of RCCA leading to greater drying shrinkage rates.

The white pollution caused by non-degradable plastics poses a serious threat to human society and the environment, thus developing biodegradable material is urgent. In this work, a novel phosphonitrile hybrid metal-polyphenol network was constructed and used for the preparation of flame retardant, UV resistant and antibacterial multifunctional polyvinyl alcohol composite (PVA@HCPD-Ag). The limiting oxygen index (LOI) value of PVA@HCPD-Ag was improved to 33.5%, while the peak heat release rate (PHRR) and total heat release (THR) decreased by 35.62% and 47.76%. Besides, the ultraviolet protection factor (UPF) value of PVA@HCPD-Ag was significantly improved from 4.63 of the original PVA to 482.79, while the tensile strength was increased by 10.23%. Furthermore, the inhibition efficacy of PVA@HCPD-Ag for E. coli and S. aureus was up to 98.12% and 99.99%. This work explored the synergistic flame retardant effect of in-situ reduced Ag⁰ and phosphonitrile crosslinked polyphenol network and proposed an advanced strategy for developing high value-added functionalized PVA materials.

Amid increasing concerns over microplastic pollution and the persistence of nonbiodegradable polymers in the ocean, this study evaluates the biodegradability of polybutylene succinate (PBS)-based fishing gear under different conditions: pristine PBS fibers, PBS fibers utilized in fishing (PBS_used), and PBS fibers blended with 10% polyhydroxyalkanoate (PHA). By simulating compost and marine–sediment interface environments with reference to ISO 14855 and ISO 19679 standards, respectively, we aimed not only to assess the degradation performance of these fibers but also to examine the physical and chemical property changes pre and postdegradation. PBS, PBS_used, and PBS/PHA (9:1) fibers exhibited degradation rates of 31.9%, 35.5%, and 39.5% in compost environments, and 20.3%, 22.1%, and 25.9% at the seawater–sediment interface, respectively. Through comprehensive physicochemical analyses involving molecular weight measurement, field emission–scanning electron microscope, Fourier transform infrared spectroscopy, tensile property evaluation, and thermogravimetric analysis, the degradation behavior of PBS-based fibers depending on the degradation environment was compared. This study suggests that PBS-based fishing gear can biodegrade under various conditions encountered in the actual fishing sector, thereby preventing ghost fishing and mitigating the issue of abandoned, lost, or otherwise discarded fishing gear.