Development of cost-effective nanomaterials with tailored surfaces and bulk properties play a fundamental role in enhancing efficiency in environmental and energy-related applications. Layered double hydroxides (LDHs) belong to a family of two-dimensional materials, defined by the general formula [M²⁺_1-xM³⁺_x(OH)₂]^x+ (A^n-)_x/n•mH₂O, where M²⁺ and M³⁺ represent divalent and trivalent cations and A^n- is an anion. These compounds exhibit outstanding characteristics such as friendly preparation, tunable composition and anion exchange capacity, being widely used in various fields like drug delivery, energy storage, catalysis, etc. An interesting way to obtain oxide catalysts is through the controlled thermal decomposition of the corresponding LDHs precursors. In this way, mixed-metal oxides with desirable properties including high specific surface area, thermal stability and homogeneous metal dispersion are obtained.

This study investigates the synthesis, characterization and environment-related applications of Zn-Al and Co-Al mixed oxides derived from LDH materials. Both Zn-Al and Co-Al LDH precursors were prepared by a coprecipitation method at a constant pH, starting from the corresponding metal nitrates with a molar ratio of M²⁺/M³⁺ being kept at 3. The precipitating solution was a mixture of NaOH (1 M) and Na₂CO₃ (0.2 M). The slurry was kept under stirring and aged at 75 °C for 12 h. The suspension was then washed with deionized water and dried at 110 °C for 12 h prior to the calcination at 650 °C for 6 h, in air atmosphere. The obtained Zn-Al and Co-Al mixed oxides were characterized by several techniques (e.g., powder X-ray diffraction (XRD), UV-Vis spectra, DRIFT-ATR spectroscopy, specific surface area measurements, etc.), revealing their physicochemical properties. The photocatalytic activity of these catalysts was evaluated for the photodegradation of persistent organic pollutants (e.g., phenol) under simulated solar irradiation, showing good performance.

The rapid spread of nanotechnology calls for a search for alternative processes that can reduce negative impacts, both from an environmental and economical point of view, of the syntheses employed to obtain nanocrystals (NCs). Perovskite NCs are commonly synthesized in 1-octadecene (ODE), a molecule derivate from petroleum with certain drawbacks, such as polymerization during synthesis as well as difficulty in removal from the final NCs.

In our work, we exploited hot-injection methods to obtain perovskite NCs with different morphologies and stoichiometries by substituting the classical solvent with green molecules, i.e., limonene and pinene. Firstly, we demonstrated the possibility to obtain both lead and lead-free halide perovskites in different sizes and morphologies, retaining the optical properties of the same NCs prepared in ODE. Then, exploiting the relative high volatility of the green solvent, we demonstrated the possibility to recover—from the waste of the reactions—the pure molecules that can be reused for subsequent syntheses. Moreover, the NCs can be washed from the solvents using a vacuum pump, avoiding several washing steps.

In conclusion, green solvents can be employed in nanocrystal synthesis both to reduce the environmental impact of the process and to obtain “clean” particles while avoiding several washing steps, thereby preventing their degradation.

To overcome the global energy crisis driven by the depletion of fossil fuels and to address the increasing concerns around a cleaner and sustainable energy future, it is necessary to develop energy storage systems with high electrochemical performance. In this context, two complementary strategies are extensively explored: energy-dense batteries and high-power supercapacitors.

For carbon-based systems, coupling the electrochemical double-layer electrostatic storage with a high-rate redox (faradaic) contribution through the addition of small redox molecules constitutes an attractive approach to increase the charge storage capability of supercapacitors. The introduction of redox-active oxygen-containing functional groups (OFGs) in carbon improves the wettability of their surface and also increases their specific capacitance, and hence stands out as an attractive optimization strategy.

Recent research has shed light on the critical role of pH in determining the charge storage mechanism and overall electrochemical performance of carbon-based supercapacitors. In this work, the surface functional groups on the synthesized carbon material were analyzed using EQCM (Electrochemical Quartz Crystal Microbalance) to give an insight into the influence of pH on the charge storage mechanisms of the carbon in aqueous electrolytes. Comparative studies performed on the non-oxidized and oxidized carbon further support the significant improvement in electrochemical performance observed in the latter. This study lays the foundation for future modifications in carbon materials and optimizing the electrolyte pH to improve supercapacitor performance.

The textile industry is the second largest global polluter, mainly due to the intensive use of non-biodegradable synthetic fibers, which account for about 35% of the microplastics contaminating the marine environment annually. Chicken feathers, an abundant byproduct of poultry farming, represent approximately 10% of the bird’s weight and contain about 90% β-keratin, a biodegradable and biocompatible protein. This study investigated the potential of keratin extracted from these feathers, combined with cellulose acetate as a biodegradable, naturally derived auxiliary polymer, for the production of electrospun nonwoven fabrics, offering a sustainable alternative to synthetic polymers.

The obtained samples were characterized by thermal analysis (TGA and DSC), Fourier-transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM).

The DSC curves indicated that nanofibers with a 10% concentration presented a higher amount of adsorbed moisture, thus requiring a higher temperature for the endothermic dehydration event. Regarding the endothermic degradation event, no significant differences were observed among the samples.

The FTIR spectra revealed some characteristic functional groups, within the ranges of 1700 cm⁻¹ (C=O), 1200 cm⁻¹ (C–O stretching), and 1000 cm⁻¹ (C–O stretching).

SEM analysis showed that nanofibers with 5% keratin concentration had the smallest diameters; however, these samples also exhibited a greater amount of beads/fine agglomerates.

It is worth noting that, in the electrospinning process, the increase in keratin content affected conductivity and surface tension, requiring higher voltage during electrospinning. Lower deposition of nanofibers on the metallic collector, a cloudier coloration, and reduced viscosity of the polymer solution were also observed.

This work demonstrated innovation by proving the feasibility of producing sustainable nonwoven fabrics through electrospinning of cellulose acetate incorporated with chicken feather keratin. In addition to adding value to an abundant waste and reducing environmental impacts, it integrates innovation and circular economy principles.

The conversion of biomass waste into porous carbon for supercapacitor electrode applications represents a highly promising and sustainable approach due to its low cost, abundance of raw materials, and environmental benefits. In this work, activated carbon (AC) was synthesized from Lapsi (Choerospondias axillaris) seed biomass through a chemical activation process using zinc chloride (ZnCl₂) as an activating agent, followed by carbonization in a tubular furnace at 850 °C under a continuous nitrogen flow of 100 cc/min for 4 hours. The resulting activated carbon, with its porous structure, was then explored as a potential electrode material for supercapacitors. Electrochemical performance was systematically examined in a three-electrode setup using a potentiostat, employing cyclic voltammetry (CV), galvanostatic charge–discharge (GCD), and electrochemical impedance spectroscopy (EIS) to obtain a comprehensive understanding of its behavior. Key parameters such as specific capacitance, charge–discharge stability, and impedance were carefully evaluated. The electrode achieved a specific capacitance of 71.95 F/g at a current density of 1 A/g and demonstrated remarkable cycling stability, retaining 95.71% of its capacitance even after 5000 consecutive charge–discharge cycles. These findings clearly underline the potential of Lapsi seed-derived activated carbon as a low-cost, environmentally friendly, and durable electrode material, offering a sustainable pathway toward the development of next-generation supercapacitor technologies.

Emissions of carbon dioxide are considered to be the major factors leading to climate change. Reducing CO₂ influence on global warming requires its capture and utilization. Current technologies of CO₂ capture include chemical and physical absorption, membrane separation, and cryogenic distillation. Particularly, solid adsorbents demonstrate a high efficiency for CO₂ capture and storage tasks. Porous liquids, containing a solid adsorbent dispersed on a compatible liquid, represent another promising approach for CO₂ capture.

In this study, commercial and synthetic porous carbon nanomaterials and frameworks were obtained. Structure, amorphous domain, and thermal stability of samples were checked by Fourier-transform infrared spectroscopy, thermogravimetric analysis, and X-ray diffraction. Synthesized nanomaterials were dispersed in the water solutions of different surfactants and further compared on the efficiency of CO₂ uptake. The characterization of samples confirmed successful synthesis and modification of nanomaterials in different conditions and provided the necessary data for further optimization of synthesis parameters for targeted applications.

Synthetic porous carbon nanomaterials and frameworks were compared for their efficiency as porous fillers in the fluids. The efficiency of porous fluids was estimated and compared with blank measurements for water and water with surfactants. Adding surfactants enhanced the dissolution of CO₂, leading to a double increase in CO₂ uptake for the water–surfactant solution, compared with pure water. Dispersion with commercial materials as porous fillers demonstrated a slight enhancement in CO₂ uptake, compared with the water–surfactant solution. Synthesized carbon nanomaterials resulted in higher CO₂ adsorption, exhibiting two times higher CO₂ uptake in comparison with water–surfactant.

The modification of carbon nanomaterials led to an enhancement in CO₂ adsorption capacity. Porous liquids containing adsorbents with a greater number of polar groups demonstrated higher CO₂ uptake. Particularly, nitrogen-doped carbon nanomaterials were more efficient, while surface-modified materials without nitrogen in their composition demonstrated less CO₂ uptake.

NH₃ electrosynthesis is gaining interest as this molecule, essential for fertilizer production, may be exploited as a carbon-free fuel. However, NH₃ production relies almost exclusively on the Haber–Bosch process, which operates under extreme conditions, resulting in a global average ratio of about 2.5 tons of CO₂ emitted per ton of NH₃ produced.^[1] Moreover, the Haber–Bosch plants are usually centralized to maximize the efficiency. Many challenges slowed down the decarbonization of NH₃ synthesis.
A fully electrified N₂-to-NH₃ pathway is hindered by particularly low selectivity, leading to a limited production and Faradaic efficiency (FE). Recently, the lithium-mediated strategy in aprotic media has opened up to remarkable results, as it leverages the lithium singular ability to both activate N₂ and stabilize the intermediate, enabling simultaneous protonation at ambient conditions.^[2] After 300 h of continuous operation, an FE of 64% has been achieved.^[3] However, scalability and long-term stability remain unresolved, as a deep understanding of this dynamic system evolution.
The effect of different process parameters will be detailed, towards an efficient lithium electrodeposition, passing through the electrolyte engineering.^[4] In particular, the electrolyte composition and the electrochemical protocol were studied by means of different analytical and statistical tools. The main limitations encountered in studying this strategy will also be exposed. The findings underscore the potential of NH₃ electrosynthesis towards a more sustainable process, while identifying critical areas for future research.

References

[1] M. Wang, et al., Energy Environ. Sci. 2021, 14, 2535–2548.

[2] A. Mangini, et al., Adv. Energy Mater. 2024, 14 (25), 2400076.

[3] S. Li, et al., Nature 2024, 629.

[4] A. Mangini, et al., Angew. Chem. Int. Ed. 2025, 64 (8), e202416027.

This project has received funding from the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme (grant agreement No. 948769, project title: SuN₂rise).

Introduction

Although lithium-ion batteries are nowadays found in everyday life, such as in portable devices and vehicles, there is a high demand for a better technology to overcome the current conceivable maximum power and storage capacity, and also to address some issues regarding the environmental challenges. Stable organic compounds with unpaired electrons (open-shell molecules) are known as free radicals, and usually they possess fascinating and unique properties—the most important being their redox behavior. Therefore, organic radical batteries offer promising improvements on all characteristics of classical batteries, including freedom from rare metals, faster charging time, environmental friendliness, and so on. Stable hydrazyl free radicals are ideal redox species for such new batteries. Therefore, the well-known DPPH free radical (2,2-diphenyl-1-picrylhydrazyl) was tested as a redox mediator in a lithium–graphene battery.

Methods

Our work is primarily focused on the synthesis and characterization of a large number of such stable hydrazyl (di)radicals, tailoring their redox properties based on chemical design. After synthesis, structural characterization was performed by NMR, IR, UV-Vis, MS, (para)magnetic measurements (ESR, SQUID), and cyclic voltammetry, which allow for the evaluation of the redox properties.

Results

Structures of the DPPH free radical derivatives were confirmed by different means. Electrochemistry was performed for both stable and persistent free (di)radicals. As expected, stable radicals showed a full reversible redox process. The oxidation potential usually ranges in the domain range of 0.5–1.5 V, with higher values recorded for poly-nitrated radicals and diradicals. The bond dissociation energy of the -NH- group (hydrazine-hydrazyl) is around 70-90 kcal/mol. Further experiments are underway.

Conclusions

The use of stable hydrazyl radicals in organic batteries as redox active materials can potentially be an important step towards a new technology for the generation and storage of electrical energy.

Energy storage plays a key role in distinct fields such as smart grid systems, portable electronics, space technology, telecommunication industry and so on. However, in order to meet the rising requirements of next-generation technologies and ensure sustainable development, the limitations of energy storage devices such as—low lifespan, insufficient efficiency and limited energy density—must be overcome. For this purpose, BT/PVDF nanocomposites are considered very suitable and promising materials, with high dielectric constant and electrical breakdown strength and reduced loss tangent leading to advanced energy storage potential. BT/PVDF nanocomposites can be synthesized with various methods such as solvent-casting, electrospinning, and spin coating. The structural, morphological, and functional properties of BT/PVDF nanocomposites are defined with XRD, SEM, and FTIR techniques.

It has been demonstrated that various factors influence the dielectric properties of BT/PVDF nanocomposites, thereby increasing energy density. Previous studies have been reported that the consolidation of BT nanoparticles into polymer matrix can significantly enhance the dielectric permittivity and power density of the nanocomposite because of increased interface areas. On the other hand, it has been shown that the thermal treatment advances the dielectric and energy storage properties of BT/PVDF nanocomposite by enhancing compatibility of BT and PVDF. At the same time, thermal treatment results in the limitations of movements of the molecular chains of PVDF and BT nanoparticles, which further increase the energy storage performances. Thus, BT/PVDF nanocomposites with substantial dielectric properties and energy density, high power density, and good processing performance have promising potential in energy storage applications as capacitors and electronic devices.

Eco-friendly, biodegradable, and recyclable materials for food packaging are a priority worldwide. Among packaging materials, the use of plastics accounts for about 38-40%, and this trend of using plastics for packaging is expected to remain unchanged. Thus, the main challenge is minimising the negative effect of plastic packaging on the environment is the creation of plastic packaging consisting of biobased materials with a high content.

Birch wood (Betula pendula) is utilised in the production of pulp, plywood, and furniture. During this process, sawdust and bark are generated as by-products, which are often used as fuel. However, sawdust and bark can be utilised more effectively in the formulation of recycled polypropylene/polylactic acid (rPP/PLA) composite packaging, specifically designed for creating food containers through extrusion and injection moulding. The birch outer bark is rich in extractives, which can be isolated in good yields with organic solvents. After the extraction, birch outer bark contains suberin and, by its depolymerisation, suberinic acids are obtained. Thus, the remaining biomass can be used as a valuable ingredient for composite packaging.

The research conducted showed that the alkali-treated sawdust and microparticles from the residue obtained after extracting betulin (a non-aromatic diol) from the outer bark were used as a lignocellulosic filler in the developed composite packaging. Additionally, suberinic acids obtained from the outer bark were used as a lubricant, enhancing the processing parameters of the composite packaging by reducing energy consumption. The obtained composite packaging samples, filled with the lignocellulosic fillers and containing the biolubricant, exhibited good mechanical properties, decreased water uptake and dimensional swelling, as well as lower energy consumption compared to the formulation without suberinic acids.