Advanced Sustainable Systems最新文献

The significance of rewetting peatlands, as a key instrument for peatland protection and response to climate change, is increasingly recognized by both experts and the public. Its widespread implementation however still faces numerous challenges. Characteristics of the issue itself as well as the corresponding policies transform the issue into a wicked problem. Showcasing the lack of clarity in funding structures at the German national and federal-state levels highlights the linked obstruction of necessary actions, implementation options, and financial resources for peatland protection. This poses challenges to climate protection, adaptation efforts, and the achievement of related Sustainable Development Goals. In Germany, an update of peatland protection policies highlights the structural challenges in coordinating peatland protection efforts and helps identify gaps and opportunities. A mixed methods approach is used to analyze both strategic documents and the results of a survey on associated funding. The results indicate a multi-level policy structure with several German federal states recognizing the potential and relevance of peatland protection but still facing obstacles regarding the distribution of responsibilities, data availability, and overall structures. Recognizing peatland protection as a wicked problem can highlight research gaps and help in developing individual solutions that can be transferred to an international level.

In converting CO₂ into useful chemical starting materials, the electrochemical CO₂ reduction reaction (CO2RR) promises to be a major carbon-utilization strategy, contributing to a carbon-neutral society. These are proposed using hydrothermal conditions—characterized by high temperature and high pressure—to address the challenges of CO2RR. Technology assessment revealed that the additional energy to create hydrothermal conditions doesnot increase the overall energy demand for chemical production, and the CO₂ emissions from methanol production through hydrothermal electrochemical CO2RR can be negative with the photovoltaic electricity and waste heat supply. Moreover, These experimentally demonstrated promising improvements in the CO2RR process using hydrothermal conditions and elucidated the specific roles of temperature and pressure in promoting CO2RR. An increase in the process temperature to 150 °C, improves the CO₂ diffusion coefficient in water, resulting in the enhancement of current density and the reduction of activation overpotential for CO2RR. On the other hand, the pressurization by CO₂ can prevent the decrease in CO₂ solubility under high-temperature conditions, keeping a high selectivity of CO2RR. These findings indicate a plausible avenue for the efficient recycling of CO₂ and its integration into the carbon cycle, marking a significant stride toward a sustainable, zero-emission society.

Transition metal-based materials explored for energy storage applications viz. batteries, supercapacitors and more recently battery-supercapacitor hybrids (BSHs) abundantly involve Co-based materials. However, the supply chain issues and low electronic conductivity force us to look for alternative options. In this regard, Co-free binary metal phosphide/phosphate consisting of Ni and V metal (NiVP/Pi) microspheres as the positive electrode of BSH which shows a high specific capacity of 502 C g⁻¹ (1004 F g⁻¹) at 2 mV s⁻¹ while retaining a high specific capacity of 214 C g⁻¹ (428 F g⁻¹) at 12 A g⁻¹ is reported. The high electronic conductivity of binary metal phosphide in NiVP/Pi electrode and the rich electrochemical active sites due to Ni and V metal centres results in exciting performance. More interestingly, the hybrid device is successfully developed by employing NiVP/Pi as the positive electrode and carbon nanotubes (CNTs) as the negative electrode. The hybrid device (NiVP/Pi//CNT) is able to achieve a maximum energy density of 22.17 Wh kg⁻¹ and a power density of 5 kW kg⁻¹ with 91.7% capacitance retention after 7500 continuous galvanostatic charge–discharge cycles.

Cobalt-based spinel oxides, such as Co₃O₄, have emerged as promising electrocatalysts for chlorine and bromine evolution reactions (CER and BrER) in recent years. However, the role of Co valence in determining the exceptional performance of Co₃O₄ for both CER and BrER remains ambiguous due to the coexistence of both octahedrally coordinated Co³⁺ (Co³⁺_Oh) and tetrahedrally coordinated Co²⁺ (Co²⁺_Td) sites, despite their high catalytic activity and stability. Herein, combining experiment results and electrochemical data analysis, the Co³⁺_Oh site functions as the primary active site for CER is demonstrated. In contrast, for BrER, both Co³⁺_Oh and Co²⁺_Td sites exhibit good catalytic activity, with Co³⁺_Oh sites displaying better BrER catalytic performance than Co²⁺_Td sites. To further enhance the CER catalytic activity of the Co³⁺_Oh site, inert Co²⁺_Td is replaced with Cu²⁺ cations. As expected, CuCo₂O₄ featuring an optimized Co³⁺_Oh site demonstrates an overpotential of 24 mV at a current density of 10 mA cm⁻² while exhibiting exceptional stability for ≈60 h, surpassing the performance of the majority of non-noble and even noble metal-based electrocatalysts reported to date. Therefore, the study elucidates the significance of geometric configuration-dependent activity in electrocatalytic halogen evolution reactions.

Ferrate (Fe(VI)) is of great interest in energy storage solutions, organic synthesis, and wastewater treatment due to its decent oxidation potential and non-toxic end-product formation, making it a green oxidizer. The electrochemical generation of ferrate in NaOH at current densities of j ≥ 100 mA cm⁻² is presented using low-cost sacrificial iron anodes, mild steel, and spheroidal graphite cast iron (ductile iron). Under optimized reaction parameters with 40 wt.% (14 m) NaOH and a ZrO₂-based diaphragm, spheroidal graphite cast iron shows no signs of passivation in 5 h experiments even at j = 150 mA cm⁻². The results are used in a novel electrolysis cell with a combined geometric anode surface area of 230 cm², incorporated in a mini-plant suitable for continuous synthesis. This setup produces a peak ferrate concentration of 10.1 g L⁻¹ (84 mm) after 5 h in 1.6 L anolyte volume, resulting in a total ferrate mass of 16.2 g. Optimal electrolysis temperatures are between 35 and 50 °C. The highest current efficiency is 63.0%, and the lowest specific energy consumption is 9.2 kWh kg⁻¹ ferrate. The presented work is an essential step toward the continuous electrochemical synthesis of ferrate using sacrificial anodes under basic conditions.

Photocatalytic water splitting is capable of converting abundant solar energy into environmentally friendly and renewable chemical energy, presenting a promising solution to alleviate the energy crisis and combat environmental pollution. The development of high-performance photocatalysts is crucial for significantly improving the efficiency of the hydrogen evolution reaction (HER) involved. Polyoxometalate (POM)-derived materials, known for their tunable compositions, diverse structures, electron storage/release capabilities, as well as quasi-semiconductor photochemical properties, serve as highly efficient catalysts in sustainable photosynthesis. This comprehensive review navigates the latest advancements in the assembly strategies and HER performance of POM-based crystalline materials. It also discusses the composite materials formed by infiltrating POM into metal-organic frameworks (MOF) and examines the roles of transition metal compounds derived from polyoxometalates, such as sulfides and carbides, in photocatalytic HER. Emphasis is placed on the prospects for the future development of POM-based compounds as photocatalysts, along with several strategies and outlooks that could facilitate their progress. POM-derived materials are believed to have significant potential to enhance hydrogen production efficiency while maintaining thermal stability in HER processes.

Thermoelectric materials are potential energy harvesting technologies that enable direct, clean conversion between thermal and electrical energy. The efficacy of thermoelectric energy conversion is influenced by the electrical conductivity, thermal conductivity, and Seebeck coefficient. Flexibility, manufacturability, and cost-effectiveness are also important factors. Polymeric nanocomposites offer advantages in these respects. However, the development of conductive-polymer thermoelectric materials is limited to an in-plane architecture, which does not resemble common real-world scenarios. Moreover, existing works have low thermoelectric properties or rely on additives for performance improvement. In this work, a free-standing thermoelectric nanocomposite foam is fabricated via the integration of thermally activated microspheres. Due to the microstructure, a thermal conductivity as low as 0.03 W m−1 K−1 is achieved, which is lower than reported for aerogels fabricated via freeze-drying methods. Additionally, the nanocomposite foam can reach a maximum electrical conductivity of 1.13 S cm−1, power factor of 0.12 µW m−1 K−2, and thermoelectric figure of merit of 3.0 × 10−4. The study also evaluated the compressive stiffness and demonstrated the potential for sound absorption. With the unique combination of the thermoelectric, sound absorption, and mechanical behavior, these nanocomposite foams would offer versatile solutions to address the next generation energy harvesting and acoustic absorption applications.

The emergence of paper-based electronic devices marks a significant leap forward in the design of flexible, lightweight, and eco-friendly electronics. Paper-based electronic sensors represent a transformative approach to creating flexible, lightweight, and environmentally friendly electronics. This review will discuss recent applications of paper-based electronics, mainly in exploring emergent technologies employed in developing innovative sensors for chemical analysis. Furthermore, the role of paper-based electronics in electrochemical, and physical sensing, specifically addressing relative humidity, temperature, pressure, and strain sensors will be commented. In addition, the integration of paper electronics in energy harvesting and storage is discussed, covering solar cells, tribogenerators, antennas, and supercapacitors. These advancements underscore the versatility and potential of paper-based electronics in diverse applications, from wearable health monitors to sustainable energy solutions, paving the way for the future of recyclable and biodegradable electronic devices.

Materials prepared from biomass residues are potential candidates to substitute the Pt-based commercial electrocatalysts in oxygen reduction reaction (ORR). Although some investigations have reported activity and durability comparable to Pt/C using biomass-derived catalysts based on Fe─N─C sites, it remains a challenge to decrease the environmental impact of the production of these materials. A straightforward procedure is developed to obtain excellentORR electrocatalysts from biomass residues which requires a single high-temperature treatment. The final washing step is avoided by optimizing the initial amount of Fe precursor (FeC₂O₄). Besides the formation of iron oxide nanoparticles, a highly dispersed Fe phase is detected by High Angle Annular Dark Field Scanning Transmission Electron Microscopy and Energy Dispersive X-Ray Spectroscopy (HAADF-STEM-XEDS) analysis as well as graphitic carbon structures. The best performance for almond shell-based electrocatalysts is achieved for the sample containing 4.6 wt. % of Fe. The procedure developed is also applied to oceanic posidonia and eucalyptus residues, also showing excellent ORR behavior. The best sample is studied in a primary Zn-air battery (ZAB) obtaining a maximum power density of 59 mW cm⁻² and 755 mAh gZn⁻¹ capacity.

Seawater, being the most plentiful natural water source worldwide, is a highly abundant and cost-efficient medium for producing hydrogen by alkaline water electrolysis. However, the advancement of seawater electrolysis is hindered by notable impediments caused by chloride corrosion at the anode and the simultaneous chlorine evolution process. Only a limited number of non-noble electrocatalysts demonstrate noteworthy bifunctional catalytic efficacy and long-term durability. In this regard, Nickel Nitride tailored V₂CT_X Mxene nanostructures is reported as a bifunctional catalyst for overall water/seawater applications. The optimized sample Ni₃N@3000-V₂CT_x exhibits low overpotential values of 90 and 300 mV in acidic and alkaline + seawater solutions respectively at 10 mA cm⁻² for hydrogen evolution reaction. Similarly, this catalyst shows 70 and 240 mV overpotential values in alkaline water and alkaline + seawater solutions respectively at the same current density for oxygen evolution reaction. Synergetic effects of Multiple Vanadium and Nickel valency along with compelling nitrogen bonds creates elevated density of exposed functional sites for electrocatalytic activity. Furthermore, the notable electrochemical active surface area and mass activity suggest an enhanced and significant presence of abundant active sites. Additionally, the high stability and significantly decreased charge transfer resistance expedited the overall water/seawater-splitting reaction rate.