Global Challenges最新文献

The cover image is based on the article Tannin: An Insight into its Cosmeceutical Properties and Uses by Mario Pagliaro etal., https://doi.org/10.1002/gch2.202500115

Dye-sensitized solar cells (DSSC) have received significant interest in the photovoltaic technology because of their eco-friendly nature, affordability and flexibility. Here, this work presents a DSSC of the configuration; FTO/WO₃/N719 Dye/GO/C with performance metrics – open-circuit voltage (V_oc) of 1.1055 V, short-circuit current density (J_sc) of 22.23 mA cm⁻², a fill factor (FF) of 84.65%, and a remarkable power conversion efficiency (PCE) of 20.80%. The study utilizes a wide frequency range of 10⁻³ to 10¹⁰ Hz to examine charge transport dynamics and evaluate the electrochemical performance of the model cell. Impedance spectroscopy investigates both complex electrical impedance (Z*) and electric modulus (M*) to provide critical insights into ionic transport, charge recombination, ion migration and diffusion mechanisms within the cell. A model equivalent circuit is developed and theoretically validated by fitting experimental alternating current (AC) data to theoretical predictions, allowing the extraction of characteristic time constants for various processes. The results highlight that efficient ion conduction and rapid electron diffusion are essential for optimizing charge collection and minimizing recombination losses. Further, the study emphasizes the critical role of both series and shunt resistances across low- and high-frequency domains, establishing a strong correlation between time constant behavior and overall device efficiency.

Silver particles (AgPs) are increasingly used across a range of industries, including personal care, household, and food packaging, but conventional synthesis methods involve high production costs and negative environmental impacts. Green synthesis using plant extracts offers a sustainable alternative, though limited comparative data on economic and environmental performance exist. This study evaluates three green methods—BX3 (a patented extract), lemon juice (LJ), and green tea (GT)—against a conventional method using sodium borohydride (NaBH₄). Equal-volume reactions are analyzed via ICP-MS, UV–vis spectroscopy, and dynamic light scattering. Techno-economic analysis and life cycle assessment (LCA) assessed costs and environmental impact. BX3 emerged as the most cost-effective and environmentally friendly option, producing AgPs at $13,000/kg with a 75% yield and a global warming potential of 1,900 kg CO₂-Eq/kg. In contrast, NaBH₄ yielded 7.35% at $195,000/kg, 15x more expensive than the BX3 method, and a global warming potential of 74,000 kg CO₂-Eq/kg. GT, while a green method, has the highest cost $690,000/kg, the lowest yield (1.13%), and the worst environmental impact, including a human toxicity value of 92,000 kg 1,4-DCB-Eq/kg-even surpassing the toxic NaBH₄ process. These findings highlight BX3's promise for scalable, low-impact AgP production and broader industrial use.

Biological methanation is increasingly considered for biogas upgrading. Here, the supplementation of conductive magnetite (Fe₃O₄) nanoparticles is investigated as a strategy to enhance H₂-driven biomethanation in a mixed hydrogenotrophic methanogenic community. An enrichment culture, maintained for over 180 days in a fill-and-draw anaerobic bioreactor under H₂/CO₂ feeding, is used to inoculate batch microcosms containing 0, 1.25, and 2.5 gFe L⁻¹ of magnetite. Magnetite addition resulted in a dose-dependent increase in maximum methane production rates—up to 13-fold compared to controls—and sustained high hydrogen-to-methane conversion yields (78–107%). 16S rRNA gene sequencing reveals that archaeal community composition remained dominated by hydrogenotrophic Methanobrevibacter and Methanobacterium spp., whereas bacterial populations shifted from acetogenic Sporomusa and Acetobacterium spp. toward H₂-oxidizing Paracoccus and Thauera spp. at higher magnetite concentrations. Electron microscopy and energy-dispersive X‑ray spectroscopy show that magnetite nanoparticles formed conductive networks bridging microbial cells, and fluorescence in situ hybridization confirmed co-localization of methanogens and Paracoccus within these aggregates. The findings support a direct interspecies electron transfer (DIET) mechanism facilitated by magnetite, whereby Paracoccus spp. oxidize H₂ and shuttle electrons to methanogens, accelerating biomethanation. These results highlight the potential of magnetite-mediated DIET to improve power-to-methane processes and advance biogas upgrading technologies.

Hydrogen production from renewable energy sources without CO₂ emissions forms a fundamental pillar of the emerging hydrogen-based economy. Hydrogen technologies demonstrate significant potential for energy storage and integration across chemical and materials industries. Direct solar-to-hydrogen (STH) conversion via photoelectrochemical (PEC) water splitting is technologically feasible but has not yet been commercialized. A techno-economic and financial viability assessment is performed on stand-alone PEC reactors operating in Germany. A detailed cost structure of the photoelectrochemical reactor is carried out. The total cost of the PEC reactor with a 500 cm² active area is ≈€94.19 based on experimental data. The levelized cost of hydrogen for an off-grid PEC system in Munich is calculated as €83.71/kg, assuming a 5% STH efficiency. The sensitivity analysis highlights hydrogen production and lifetime as key factors, with hydrogen production determined by STH efficiency and solar irradiance. Upscaling scenarios indicate that achieving a target hydrogen cost of €2/kg is feasible by extending the reactor lifetime to 20 years, reaching 20% STH efficiency, reducing initial capital expenditure by 80%, and securing favorable capital structure with a weighted average cost of capital of 10% or lower. The findings highlight how scaling can support the financial feasibility of PEC hydrogen production.

Sapovirus is gaining recognition as a significant non-bacterial causative agent of acute gastroenteritis globally, contributing to both sporadic cases and outbreaks across all age groups. In China, it is identified as the second most prevalent pathogen responsible for acute gastroenteritis outbreaks, following norovirus, which underscores its public health importance. Consequently, an extensive systematic review and meta-analysis are undertaken to evaluate the prevalence and genotype distribution of sapovirus among patients presenting with acute gastroenteritis. This analysis incorporated 159 eligible studies spanning 32 provinces in China. The estimated overall prevalence of sapovirus is 1.9% (95% CI: 1.7–2.2), with an asymptomatic prevalence of 0.8% (95% CI: 0–2.5). Notably, in outbreak settings, the respective prevalence rates increase substantially to 16.4% (95% CI: 10.1–23.8) and 14.4% (95% CI: 8.9–20.7). Furthermore, these findings reveal that sapovirus GI genomes predominated in both sporadic and outbreak contexts, with genotypes GI.1, GI.2, and GII.1 being most frequently identified. These insights are crucial for enabling governments to accurately assess disease burden, inform the development of targeted vaccines, and establish evidence-based public health policies and emergency response strategies to mitigate sapovirus outbreaks.

This article investigates the institutional design of scientific advisory bodies (SABs) on climate change across three levels of governance: intergovernmental Intergovernmental Panel on Climate Change (IPCC), national (UK's Climate Change Committee (CCC)), and supranational (European Scientific Advisory Board on Climate Change – ESABCC). Drawing on original empirical data and comparative analysis, the paper examines how institutional features (mandate, composition, autonomy, capacity, and knowledge provision) shape the potential roles and influence of these bodies in climate governance. The ESABCC, established in 2021, represents a novel institutional innovation within the EU's climate policy architecture. As the first supranational advisory body of its kind, it navigates a complex political space, balancing scientific independence with embeddedness in European Union's (EU) policymaking structures. Through a comparative lens, the analysis shows that while all three bodies aim to provide credible scientific input, their design reflects different governance logics and degrees of proximity to policy. The paper argues that institutional design is a critical determinant of how effectively SABs contribute to legitimate, evidence-informed climate policy. By mapping the ESABCC's position within the EU's multi-level governance framework, the study highlights its evolving role and outlines the implications for the broader use of expert knowledge in turbulent policy environments.

This study deals with the reduction reaction of nitroarenes using hydrazine monohydrate as the reducing agent and iron-supported steel slag as a novel green heterogeneous catalyst. Steel slag is a byproduct of the steel industry, which, due to its alkalinity, can act as a reactive support that can trigger the formation of catalytically active iron oxides/hydroxides. A systematic study is conducted to evaluate the catalytic activity of steel slags modified with the following salts (or mixtures): FeSO₄·7H₂O, FeCl₃·6H₂O, and FeCl₂·4H₂O. The modified steel slags are characterized by X-ray powder diffraction, Mössbauer spectroscopy, scanning electron microscopy, scanning transmission electron microscopy, energy dispersive X-ray spectroscopy, nitrogen sorption analysis, and X-ray photoelectron spectroscopy. All iron-supporting steel slags demonstrate active behavior in the hydrogenation of nitrobenzene at 80 °C with the best results, in terms of activity, selectivity, and recyclability achieved with the catalyst prepared from FeCl₃·6H₂O (Fe3). The scalability of the reaction is confirmed by carrying out a test on 12.5 mmol of substrate. The superiority of Fe3 compared with the other studied materials is ascribed to its morphology and the remarkably high surficial area. The iron species active in the Fe3 catalyst are noncrystalline oxo–hydroxo species of Fe(III) (2L-ferrihydrite).

Battery performance and safety heavily depend on battery management systems (BMS), which monitor and control them during operation. Given its crucial role, a BMS should meet several requirements in functionality, performance, robustness, and reliability, often defined in standards and regulations. Considering rapid technological advancements in batteries, updating these requirements is essential to reflect growing system complexity. Therefore, this study reviews current standards and regulations for BMSs in Germany, a key player in the global battery sector. It distinguishes between functional and non-functional, as well as qualitative and quantitative requirements. The review finds that most existing standards focus on qualitative aspects and lack measurable benchmarks, particularly for critical BMS functions like state monitoring and energy management. To address this, this study proposes improvement suggestions and highlights the need for consistent definitions and performance requirements, especially for the state of charge (SoC) and state of health (SoH). It also identifies emerging challenges, such as second-life batteries, BMS, and cloud BMS as important areas for future standards. By mapping standards to BMS functions and identifying gaps, this work offers valuable guidance for improving BMS performance, interoperability, and safety.

Waste wool hydrolysates (WWHs), a by-product originating from the alkaline hydrolysis of waste wool, are recovered and employed as auxiliaries in wool dyeing. In view of an eco-friendly dyeing procedure, a natural dye, Carmine, is selected to dye wool fabrics. Different methodologies for performing the dyeing process are described. In the first procedure, the wool fabrics are pretreated with a water suspension of the WWHs at room temperature, left overnight, and then cured at 180 °C. In the second procedure, the wool fabrics are immersed in the WWH's suspension at 100 °C, dried in an oven, and subsequently dyed through the exhaustion method. In the last procedure, the WWHs are added directly to the dyeing liquor. Dye exhaustion, color coordinates, and K/S are measured to evaluate the dyeing efficiency. The dyed fabrics are also characterized in terms of thermal, chemical, mechanical and morphological properties. The results demonstrate that the WWHs are efficient alternatives to metal-based mordants in assisting wool dyeing with Carmine dye. The evidence of non-significant damages to fabrics as a consequence of the chosen treatment conditions further supports the possibility of WWH valorization in textile industries as a by-product that otherwise would represent a waste to dispose of.