Advanced Sustainable Systems最新文献

Harvesting magnetic noise fields around power cables emerges as an attractive approach due to its potential as a renewable and ubiquitous energy source for powering wireless sensor networks (WSNs) in IoT applications, miniature electronics, and implantable medical devices. Flexible polymer-based magneto-mechano-electric (MME) generators gain attention for their effectiveness in magnetic energy harvesting owing to their durability and flexibility. In this study, a lead-free, flexible MME generator is developed by using Polyvinylidene fluoride (PVDF)-Aluminium nitride (AlN)-nanofiber composites fabricated via electrospinning with different AlN compositions and integrated with a magnetostrictive Metglas layer that offers self-bias characteristics. The MME generator is modeled using COMSOL Multiphysics to analyze the magnetic flux density distribution over the Metglas surface and the piezoelectric effect of the nanofiber composites, with the simulation results aligning well with the experimental data. The optimized, flexible MME generator, incorporating 15 wt.% of AlN in the PVDF/Metglas composite, achieves an open-circuit voltage of 18.5 V and a power density of 0.93 mW-cm⁻³ when exposed to an Alternating Current (AC) magnetic noise field of 6 Oe at a resonance frequency of 50 Hz. The generated power is sufficient to operate LEDs and sensor. This newly developed lead-free, flexible MME generator shows significant promise for advanced applications in self-powered WSNs.

With the advantages of large specific surface area and high porosity of general metal-organic frame materials, russian blue analogs have broad application prospects in catalysis. In this work, a series of ultra-thin N-doped carbon coated Fe-CoP (Fe-CoP@NC) are prepared by phosphating Fe-Co-Co Prussian blue analogs (Fe-Co-Co PBA) in different degrees for the broad-spectrum photocatalytic hydrogen evolution. The results show that Fe-CoP@NC-3 has the highest photocatalytic hydrogen production rate of 16.6 mmol h⁻¹ g⁻¹, which is 83 times greater than that of Fe-Co-Co PBA. The excellent stability of Fe-CoP@NC-3 is proved by cyclic experiments. The outstanding photocatalytic H₂ production activity of Fe-CoP@NC-3 can be ascribed to the strong electron coupling effect between Fe-CoP and N-doped carbon layer. The photogenerated electrons of Fe-CoP are transferred to the N-doped carbon layer, which is electron transport mediator accelerating the electron transfer and synergetic improving the hydrogen evolution efficiency. This work provides an effective strategy for designing an ultra-thin N-doped carbon layer coated phosphide photocatalyst with strong electron coupling effect.

To attain net zero energy-ready building (NZErB) status, various research efforts have focused on identifying potential strategies and creating stringent code compliances for builders. This review presents a comparative assessment of Canadian newly constructed, retrofitted, and potential retrofit buildings from the mid-1900s to 1990, all aiming for NZErB status. 22 case studies from climate zones 5, 6, and 7a are evaluated, including 12 new constructions and 4 retrofitted, and 6 potential retrofit buildings. A life cycle assessment (LCA) analysis is conducted to understand the environmental impacts of different insulation materials. Additionally, this review highlights retrofitted buildings measures toward climate resilience, challenges inretrofitting, andstrategies for achieving high-quality retrofits. The work concluded that 83.3% of new buildings achieved level 5 in thermal energy demand intensity (TEDI), while 70% of completed and potential retrofits reached level 5 in mechanical energy usage intensity (MEUI). Cellulose insulation showed the lowest global warming potential (GWP) at 12.07 kg CO₂-e·m⁻³. By comparing the performance of new constructions with completed and potential retrofits, this review provides valuable insights into the feasibility and effectiveness of retrofitting older buildings to attain net zero energy readiness.

Demand for water- and oil-repellent-coated paper as an alternative to plastics is growing, but the challenge is that coated paper lacks concurrent recyclability and biodegradability. Reported herein is a novel carboxylic acid-functionalized poly(butylene adipate-co-terephthalate) (CPBAT) copolymer investigated for recyclable and repulpable water-borne paper coatings. The CPBAT synthesized here is characterized by spectroscopic methods. Paper coated with waterborne CPBAT exhibited excellent water, oil, moisture, and gas barrier properties suitable for packaging applications. The recyclability and repulpability of the CPBAT-coated paper are successfully validated via certified TAPPI methods. This work demonstrates the first successful preparation of coated paper that is per- and polyfluoroalkyl substances (PFAS)-free, recyclable, and biodegradable, with significant benefits for the environment and human health.

In this work, two major sources of pollution: (1) Water pollution due to heavy metals, and (2) Electromagnetic wave (EMW) pollution, often regarded as the fourth category of pollution (after air, water, and soil pollution) are addressed. A unique bio-based triphasic nanocomposite (Fe₃O₄/α-Fe₂O₃/carbon) is synthesized and its superior properties are demonstrated to address both types of environmental pollution. The nanocomposite, derived from lightweight apple tree roots, is used for Pb (II) ion removal from aqueous solutions via adsorption and magnetic separation. The biomass-derived highly porous biochar decorated with iron-oxide showed adsorption efficiency of nearly 100% and corresponding capacity of 149 mg.g⁻¹ under optimal conditions for initial Pb (II) concentration of 50 mg.L⁻¹. Furthermore, a remarkable adsorption capacity of 731 mg.g⁻¹ is achieved using lower amount of the adsorbent for a slightly lower efficiency (97%). In addition, the mesoporous composite showed excellent EMW absorption efficiency with effective absorption bandwidth of 7.8 GHz and reflection loss of −61.7 dB, arising from very good impedance matching, and high dielectric and magnetic losses. This work establishes the multifunctional properties of the synthesized composite, and addresses the UN Sustainable Development Goal (SDG) 6 (Clean water and sanitation) and SDG 13 (Climate action, including pollution management).

As an electrochemical energy storage device with high power density, supercapacitors are favored by researchers. Transition metal-based oxide materials have attracted extensive attention from researchers due to their high theoretical pseudocapacitance characteristics and are used to design and construct high-performance composite electrode materials for supercapacitors. In this miniature review, the application and existing problems of several typical transition metal-based oxide composites in the field of supercapacitors in recent years are summarized. Finally, the development trend of transition metal-based oxide composites in the field of supercapacitors is prospected. The aim is to provide some timely and effective new ideas for the research work of researchers in related fields.

Atmospheric pollution has been recognized as a primary global emergency, especially in large cities and industrial areas. Among the most common harmful pollutants, nitrogen oxides (NO_x) are responsible for a plethora of adverse effects, and their effective elimination from air has become an imperative task. In this regard, photocatalysis stands as an attractive technology for NO_x degradation, provided that low-cost and efficient visible -light photocatalysts are developed. In this regard, the construction of heterojunctions between energy band-matched semiconductors is an effective strategy to boost the ultimate material photoactivity. In the present study, green heterocomposites based on MgAlTi layered double hydroxides (LDHs) and graphitic carbon nitride (gCN) are prepared using an amenable and cost-effective route. A proper modulation of the system characteristics, as demonstrated by a comprehensive investigation, enabled to obtain very attractive DeNO_x performances thanks to the efficient construction of MgAlTi/gCN heterojunctions with tailored features. The formation of the target heterocomposites significantly enhances the visible light photoactivity of the pristine LDH, boosting nitrogen monoxide transformation to nitrites/nitrates with a remarkable recycling stability. Overall, the presently reported results open the door to a profitable system exploitation for air purification under real-world conditions, with considerable impact on both human wellbeing and environmental protection.

V/S co-doped SnO₂ bimetal sulfur-oxides catalysts labeled as (Sn,V)_1-x(S,O)_2-y or (SnVSO) with heterovalent state and oxygen vacancy defect are prepared via a green and facile method. The presence of SnVSO in the heterovalent states of Sn⁴⁺/Sn²⁺ and V⁵⁺/V⁴⁺ facilitates the rapid transfer of the electrons. It improves the electronic charge lifetime, accelerating the efficiency of the catalytic reduction of pollutants. The V/S co-doped SnO₂ regulates the bandgap energy structure. The hydrazine adjusts the heterovalent metal states to reduce Sn⁴⁺ to Sn²⁺ and V⁵⁺ to V⁴⁺. Also, it introduces oxygen vacancies to SnVSO to maintain the charge equilibrium and increase the active surface reactive sites, which enhance the catalytic activity. The SnVSO-3 prepared with 0.4 mL hydrazine exhibits excellent catalytic activity, which wholly reduces 20 ppm of 100 mL methyl orange (MO), rhodamine B (RhB), methylene blue (MB), hexavalent chromium (Cr⁶⁺), and 4-nitrophenol (4-NP) within 6 min. In addition, the SnVSO-3 also has good stability after repeated 6 runs with a reduction efficiency of 96.8%. Therefore, the V/S co-doped SnO₂ sulfur oxide catalysts have a promising potential for reducing Cr⁶⁺ and organic pollutants.

The potential of a biodegradable polylactic acid (PLA)-TiO₂ membrane for air purification is investigated, utilizing the environmentally friendly solvent Cyrene. Through the integration of TiO₂ nanoparticles within a PLA matrix, the membrane is used to degrade ethanol as a model volatile organic compound (VOC) under UV light. Scanning Electron Microscopy (SEM), Energy Dispersive X-ray Analysis (EDX), and UV–vis spectrophotometry confirm the porous structure of the membrane, the even distribution of TiO_2, and its effective band gap of 3.06 eV, respectively. Ethanol adsorption is best described by the Langmuir isotherm model, suggesting monolayer coverage on a homogeneous surface. Photocatalytic tests demonstrate that the membrane decomposes ethanol (6800 ppm) within 14 min under UV light, generating acetaldehyde, acetic acid, formaldehyde, and formic acid as intermediates, and ultimately producing CO₂ and water. Reusability tests indicate a decrease in decomposition time over successive cycles due to increased TiO₂ exposure from the gradual degradation of PLA. However, this degradation poses challenges for continuous use, compromising the membrane's long-term durability.

Lithium-oxygen (Li-O₂) battery is considered a high-energy alternative to Li-ion one due its characteristic electrochemical conversion process, with the additional advantage of lower cost and environmental impact. However, this emerging battery still requires an enhancement of stability and lifespan to allow its use as a practical energy storage system. In this work we investigate an electrode material benefitting of multiwalled carbon nanotubes (MWCNTs), few layer graphene (FLG), and gold nano-powder catalyst to improve the Li-O₂ battery performances in terms of energy efficiency, cycle life and stability. Morphological, structural, and electrochemical tests indicate that the composite electrode can actually boost the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER), and enhance the Li-O₂ process reversibility, with a capacity of 1000 mAh g⁻¹ over 70 cycles. On the other hand, the tests reveal the role of the gold in decreasing the polarization and increasing the cell life. Therefore, the results suggest the combination of carbons with various morphologies as a suitable architecture for hosting the Li-O₂ reaction products and allowing their reversible reaction. On the other hand, the results highlight the necessity for a better tuning the noble metal characteristics to further enhance the cell performances.