Chemistry and Materials Science

Abstract: The persistence of pharmaceutical contaminants such as carbamazepine (CBZ) in aquatic environments presents a growing challenge for conventional wastewater treatment processes. In this study, potato peel waste was valorised into carbonaceous adsorbents via hydrothermal carbonization (HTC) and conventional pyrolysis, and their performance for CBZ removal from water was systematically compared. Hydrochars were prepared at 200 °C under varying residence times and biomass-to-water ratios, while biochars were produced at 400 °C using KOH activation under different reaction times and impregnation ratios. The materials were characterised using BET surface area analysis, CHNS elemental analysis, and FTIR spectroscopy. Adsorption experiments revealed that HTC-derived hydrochars achieved outstanding CBZ removal efficiencies (up to ~100%) and high uptake capacities (~50 mg g⁻¹) within one minute of contact, despite relatively low surface areas (< 2 m² g⁻¹). In contrast, pyrolysis biochars exhibited significantly lower removal efficiencies (7–55%) and slower, less stable adsorption behaviour. Correlation analysis demonstrated that CBZ removal was strongly associated with surface chemistry—particularly carbon, hydrogen, and nitrogen content and N/C ratio—rather than BET surface area or pore diameter. FTIR analysis indicated that π–π interactions, hydrogen bonding, and pore filling collectively govern CBZ adsorption, with oxygen- and nitrogen-containing functional groups playing a dominant role in rapid uptake. These findings highlight hydrothermal carbonization as an effective, low-severity route for producing high-performance adsorbents from food waste and demonstrate the potential of potato peel–derived hydrochars for rapid pharmaceutical remediation in water treatment applications.

Abstract: Dry reforming of methane (DRM) is an attractive route for H2 production and simultaneous CO₂ utilization, but its practical implementation is limited by catalyst deactivation. This study experimentally investigates the catalytic performance of Ni/Al₂O₃ and Gd-doped ceria–promoted Ni/GDC–Al₂O₃ catalysts for DRM in a fixed-bed quartz reactor over 400–800 °C at gas residence times of 0.1 s and 0.4 s. Increasing temperature and residence time enhanced CH₄ and CO₂ conversion as well as H₂ and CO yields for both catalysts. The GDC-promoted catalyst exhibited markedly improved activity, achieving conversions and product yields at 0.1 s comparable to those of Ni/Al₂O₃ at 0.4 s and reaching complete CH₄ conversion at about 650 °C, approximately 100 °C lower than the Ni/Al₂O₃. Long-term testing demonstrated high durability of Ni/GDC–Al₂O₃ at 650 °C with no detectable carbon deposition, consistent with thermodynamic equilibrium analysis.

Abstract: This study presents a comprehensive first-principles investigation of the optoelectronic and thermoelectric properties of aluminum antimonide (AlSb) in its cubic (F-43m) and hexagonal (P6₃mc) phases. Structural optimization was performed using the SCAN functional, and all electronic and optical properties were evaluated using the modified Becke-Johnson potential combined with the Hubbard correction (mBJ+U), which best describes the band-edge electronic structure, explicitly accounting for the contribution of the d-states of the Sb half-core, which cannot be adequately accounted for by conventional functionals and may be overestimated by hybrid approaches. Both AlSb phases are found to be quasi-direct bandgap semiconductors, with calculated band gaps of 1.71 eV for the cubic phase and 1.50 eV for the hexagonal phase, in good agreement with available experimental data. The optical response reveals strong absorption in the visible and ultraviolet regions, moderate reflectivity, and high refractive indices, indicating pronounced light-matter interaction characteristic of III-V semiconductors. The hexagonal phase exhibits enhanced low-energy optical absorption due to its reduced symmetry and narrower band gap. Thermoelectric analysis demonstrates large negative Seebeck coefficients, thermally activated carrier generation, and a monotonic increase of the power factor with carrier concentration for both phases. The cubic phase shows higher power factor values due to enhanced carrier mobility, whereas the hexagonal phase benefits from reduced thermal conductivity, which is favorable for thermoelectric performance at elevated temperatures. These results establish AlSb as a multifunctional semiconductor with tunable optoelectronic and thermoelectric properties and highlight the importance of an accurate treatment of Sb d-electron effects for reliable property prediction.

Abstract: The transition from fossil-based resources to renewable feedstocks is a cornerstone of industrial decarbonization. A critical component of this shift lies in deriving intermediates and value-added products from biomass. Among renewable resources, lignin stands out as a promising candidate due to its wide availability, abundance, and non-competitiveness with food production, making it an ideal starting material. The removal and depolymerization of lignin to produce aromatic chemicals can significantly enhance the material usability of all lignocellulose constituents. The removal and depolymerization of lignin to produce aromatic chemicals can significantly enhance the material usability of all lignocellulose constituents. Herein, a process for the polyoxometalate-catalyzed oxidative depolymerization of technical lignins to produce the monoaromatic compounds vanillin (Va), methyl vanillate (MeVa), syringaldehyde (Sy), and methyl syringate (MeSy) is demonstrated, offering the possibility to achive high monoaromatic yields of up to 12wt%.

Abstract: Heating water in outdoor pools is common, particularly in regions with cool or temperate climates. Several factors, including solar radiation, ambient air temperature, wind speed, and humidity, influence the pool water temperature. A key design challenge is to determine the collector surface area required to achieve the desired pool water temperature. In this study, a mathematical model was developed that accounts for the aforementioned factors. Under various operating conditions, thermal performance calculations were carried out. Climatic conditions at three locations across Europe, representing different climate regimes, were analyzed. The model was validated through comparison with results obtained in the POLYSUN simulation software. The calculations demonstrated that wind speed above the water surface has a significant impact on heat losses and, consequently, on water temperature. It causes both convective and evaporative heat losses. Locating the pool in a sheltered area results in a consistent reduction in heat losses. It was determined that, under the climatic conditions of Krakow, the installation of solar collectors with a surface area equal to 50 % of the pool surface enables the maintenance of daytime water temperatures above 21 °C for approximately 100 days. In the absence of solar collectors, achieving such temperatures is not feasible.

Abstract: Pyrolysis of refuse-derived fuel (RDF) is a promising waste-to-energy route, but its use in higher-value applications remains limited by tar carryover, BTEX, heteroatom-containing compounds, and pollutant accumulation in recirculated scrubber water. This study evaluated operating windows for RDF pyrolysis coupled with direct wet scrubbing and closed-loop water reuse, with the aim of identifying regimes suitable for different end-use tiers. An L27 design of experiments was applied to 27 pyrolysis runs by varying pyrolysis temperature, residence time, scrubber liquid-to-gas ratio, scrubber-water temperature, and sequential reuse of the same scrubber-water inventory over 5, 10, and 15 cycles. Cleaned-gas pollutants were quantified by compound-resolved GC–MS after solid-phase adsorption sampling, while phenolics and PAHs in scrubber water were determined by extraction followed by GC–MS. The results showed that stronger scrubbing reduced gas-phase tar and BTEX burdens, whereas extended water reuse caused systematic accumulation of phenolics and PAHs and increased the composite water-loop hazard index. Boiler-grade operation remained feasible across a broad operating range, whereas ICE-CHP feasibility was restricted to a narrow robust regime and no robust microturbine-grade condition was identified. These findings show that operating windows for RDF pyrolysis must be defined jointly by gas-cleanliness and water-loop management constraints.

Abstract: This study presents an innovative approach for the selective extraction of Co(II) and its separation from Ni(II) using ethyl ester glycine-betaine derivatives, specifically tri(n-pentyl)[2-ethoxy-2-oxoethyl]ammonium dicyanamide, as extractants in combi-nation with continuous-mode liquid–liquid contact. Semi-pilot-scale implementation requires non-equilibrium conditions, characterized by short contact times between ef-fluent and extractant phases. To address this, we propose dissolving analog of gly-cine-betaine ionic liquid (AGB-IL) in low-viscosity MIBK solvents to enhance mass transfer while reducing dependence on fossil-based solvents. Liquid–liquid extraction and continuous-flow stripping experiments were designed based on prior batch results and conducted in a saline environment, employing a chaotropic electrolyte for extrac-tion and a kosmotropic electrolyte for stripping. Both open and closed systems were tested to compare extractive performance with batch conditions and with scenarios representative of industrial operations. Results indicate that continuous-flow systems achieve performance comparable to batch systems in terms of extraction efficiency, Co/Ni separation coefficients, and recyclability. These findings provide proof of con-cept for the development of semi-pilot and pilot-scale processes for efficient cobalt re-covery.

Abstract: Wheat straw is an abundant agricultural residue with high potential for carbohydrate-based bioconversion, yet its efficient utilization is limited by lignocellulosic recalcitrance. This study systematically investigated Organosolv extraction of German wheat straw with the goal of achieving near-complete enzymatic hydrolysis at minimized process severity and energy demand. Process severity was evaluated using the P-Factor concept. In preliminary screening, acid catalysts and liquor ratios were assessed. Strong acids clearly outperformed weak acids: at comparable severity, 5% (w/w, DM) H2SO4 or p-toluenesulfonic acid (PTSA) yielded glucose yields of 83 ± 2.4% and 81 ± 6.2%, respectively, whereas weak acids (phosphoric, lactic, acetic) and a catalyst-free control resulted in only ~20–41% glucose yield. Liquor ratio strongly affected extraction performance; a ratio of 1:19 provided the highest glucose yield (85 ± 1.4%) and robust mixing compared to 1:12–1:15 (67–68%). Two novel pretreatment strategies applied prior to Organosolv extraction, namely hot-water pretreatment (HWP) and water pretreatment (WP), significantly increased hydrolysability compared to untreated straw (58 ± 3%), reaching 79 ± 2% for HWP and 86 ± 5% for WP. DOE-based experiments (135–170 °C; P-Factor 3.0–4.0) showed that increasing temperature from 135 to 150 °C markedly improved hydrolysability (e.g., WP: 74 ± 3% to 96 ± 3%), while further increase to 170 °C provided no additional benefit. Response-surface modeling predicted a maximum hydrolysability of approximately 88% for HWP but complete hydrolysis for WP within 152–170 °C, indicating a broad operational window. Overall, combining simple pretreatment with severity-optimized Organosolv extraction enables energy-efficient, near-complete enzymatic hydrolysis of wheat straw.

Abstract: The catalytically supported upgrading of green ethanol and green methanol mixtures can produce higher alcohols, such as iso-butanol, in a sustainable manner. Iso-butanol can be used as a feedstock to defossilize the chemical and transportation sectors. MgO-Al₂O₃ hydrotalcite-based catalysts are a promising option for this purpose. In this study, samples were synthesized using co-precipitation and urea methods with different Mg/Al molar ratios, with Ni acting as the active catalytic component. ICP-OES analysis revealed that Ni impregnation onto the hydrotalcite structure had been successful. However, in the case of the urea method, the pH value for the precipitation of Mg(OH)₂ was too low, resulting in insufficient Mg being incorporated into the hydrotalcite structure. XRD analysis revealed the presence of NiO, MgO and the spinels Al₂NiO₄ and Al₂MgO₄ in both synthesis variants, as well as elemental Ni in one sample from the urea synthesis. CO₂-TPD and NH₃-TPD experiments showed the dominance of strong basic and strong acidic catalyst centers in both synthesis pathways. The catalysts synthesized using the urea method exhibited the greatest activity, producing iso-butanol concentrations of up to 170 mmol l^-1 at 185 °C, with a maximum space-time yield of 8.2 mmol g^-1 h^-1.

Abstract: Direct air capture (DAC) of CO2 via temperature-swing adsorption (TSA) can support sustainable carbon dioxide removal, but only if sorbents regenerate with low energy demand and maintain performance under humid ambient air. Here, we evaluate three commercial molecular sieves (JLPM3, 13X and 4A) in packed-bed tests using humid ambient air. We compared 40 g samples as received with 200 g samples conditioned for 12 days at 100 °C to emulate prolonged exposure to regeneration temperature (the cumulative effect of many heating/desorption cycles); all cycle-stabilized uptake values are reported from the conditioned materials. JLPM3 delivered the highest stabilized CO2 uptake (0.24 ± 0.01 mmol·g-1), consistent with a combined physisorption/chemisorption mechanism. Its higher total porosity and smaller mesopores promoted rapid mass transfer and site accessibility, while slightly greater micropore area and volume than 13X supported its marginally higher capacity. Evidence of partial structural degradation under mechanical and thermal stress indicates that minimizing strain during cycling will be important for scale-up and for reducing sorbent replacement. Conditioning at 100 °C activated additional chemisorption sites across all sieves but reduced physisorption capacity. Importantly, a ~100 °C desorption step fully regenerated physisorbed CO2 while purging moisture from zeolite pores, indicating that low-temperature TSA (compatible with low-grade or waste heat) can replace harsher 300 °C regeneration and lower energy demand. CO2–H2O competition experiments confirmed substantial site occupancy by water vapor, which limits capture under humid conditions and motivates water-management strategies. Overall, maximizing DAC performance requires tailoring pore structure and operating conditions while preserving sorbent integrity; JLPM3 emerges as a promising candidate for more energy- and resource-efficient DAC.

Abstract:

The critical role of lithium in powering the new energy economy necessitates prioritizing efficient extraction methods. This study investigates a novel zeolitic imidazolate framework (ZIF-8)-coated manganese-based lithium ion sieve (LIS) for enhanced lithium recovery. The precursor of LIS, Li1.6Mn1.6O4, was synthesized via the hydrothermal method, followed by acid pickling to obtain the spinel lithium ion sieve H_1.6Mn_1.6O₄. The material was then immersed in a 2-methylimidazole/Zn(NO₃)₂ solution, undergoing ultrasonic-assisted hydrothermal growth to form ZIF@H_1.6Mn_1.6O₄ composites. Under optimized conditions (30 °C, pH=11, 24 h), the composite demonstrated superior lithium extraction performance compared to single-phase adsorbents, reaching 26.44 mg/g at the solution with 250 mg/L Li⁺. The adsorption capacity of the composite increased with Li⁺ concentration and reaction time. The adsorption kinetics followed a pseudo-second-order kinetic model and is dominated by chemisorption.

Abstract: Per- and polyfluoroalkyl substances (PFAS) are persistent and mobile contaminants of global concern, and while granular activated carbon (GAC) is widely used for their removal, it is limited by high regeneration and disposal costs. This study investigates surface-modified clinoptilolite zeolites as low-cost and thermally regenerable alternatives to GAC for PFAS removal from water. Natural clinoptilolite was modified through acid washing, ion exchange with Fe³⁺ or La³⁺, grafting with aminosilane (APTES) or hydrophobic silane (DTMS), dual APTES–DTMS grafting, and graphene oxide coating. Adsorption performance was evaluated for perfluorooctanoic acid (PFOA, C8) and perfluorobutanoic acid (PFBA, C4) at 100 µg L⁻¹ in single and mixed-solute systems, with an additional high-concentration PFOA test (1 mg L⁻¹). Raw zeolite showed limited PFOA removal (4%), whereas dual-functionalised APTES+DTMS zeolites achieved up to 93% removal, comparable to GAC (97%) and superior to single-silane or metal-exchanged variants. At lower concentrations, modified zeolites effectively removed PFOA but showed limited PFBA removal (< 25%), highlighting ongoing challenges for short-chain PFAS. Overall, the results demonstrate that dual-functionalised clinoptilolite zeolites represent a promising and scalable platform for PFAS remediation, particularly for mid- to long-chain compounds, provided that strategies for enhancing short-chain PFAS binding are further developed.

Abstract: The textile industries mostly rely on synthetic dyes, which contains nonbiodegradable components and high toxicity make its use environmentally hazardous. The present research delves into the unique application of proteins extracted Black Soldier Fly (BSF), as a natural dyes for wool fabrics. The hydrolyzed proteins extracted from each insect material (larvae, cocoons and flies) using superheated water at 170 °C for 1 h were used as natural dyes for dyeing wool fabrics with and without mordant (ferrous sulfate, 5% o.w.f.). Fabrics treated with mordant-free protein hydrolysate derived from cocoons showed best results with an increase in color strength (K/S value) from 0.43 to 2.78 with an increasing dye concentration from 2% to 50% o.w.f. . Color fastness to washing shows that dyed fabrics undergo variable color changes (from grade 4 to grade 1) but release little dye onto other fabrics, especially wool and synthetic fibers. Dry and wet rubbing color fastness tests showed overall variable color fastness, with little color loss on the abraded reference fabric. Overall, this work highlights the potential of protein hydrolysate from BSF as a natural and environmentally friendly dye, which may represent a promising alternative to synthetic dyes in the textile industry.

Abstract: The paper studied the effect of high-voltage short-pulse electrohydraulic discharge (HVSPED) on the processes of catalytic cracking of oil sludge in order to increase the yield of light hydrocarbon fractions. A set of laboratory experiments was carried out with varying the key parameters of HVSPED - voltage, pulse frequency and exposure time. A nanocomposite bentonite catalyst impregnated with nickel was used. The optimal electrophysical parameters of oil-sludge treatment by HVSPED were determined, providing the maximum yield of gasoline and kerosene fractions. The effectiveness of HVSPED treatment of oil sludge in the presence of a catalyst was confirmed by DTA–thermogravimetric analysis and chromatographic-mass spectral analysis of the light and middle fractions of the hydrogenate. The proposed approach made it possible to enhance the resource and energy efficiency of oil-sludge processing using HVSPED, demonstrating high potential for further industrial application.

Abstract:

This article presents the design, synthesis and application of novel C₈/PW₁₂O₄₀³⁻–IL Janus nanopaticles for highly efficient, recyclable catalytic degradation of methyl orange (MO) in wastewater. The catalyst's innovative asymmetric architecture comprises a hydrophobic C₈ hemisphere that selectively adsorbs and pre-concentrates MO molecules, and a catalytic phosphotungstate-ionic liquid hemisphere that activates oxidants to generate hydroxyl radicals for rapid dye degradation. A magnetic Fe₃O₄ core facilitates instantaneous catalyst recovery. This "collect, degrade, and separate" mechanism synergistically results in exceptional performance, surpassing that of many conventional homogeneous and heterogeneous systems, as validated through comparative analysis. This work establishes a strategic paradigm for designing smart, multifunctional materials that combine targeted interfacial engineering with practical recyclability for advanced environmental remediation.

Abstract: The study investigates the kinetics of redistribution of oils, resins, and asphaltenes in high-viscosity oil from the Karazhanbas field during ultrasonic treatment (22 kHz, 50 W) in the presence of a zeolite catalyst (1.0% by mass). The parameters of the technological process - temperature range from 30 to 70°C, exposure time from 3 to 11 min - were established, which lead to an increase in oil content (by 14.8%), and a decrease in the concentration of resins (by 12.2%) and asphaltenes (by 2.6%). An increase in the conversion rate between oil components is observed until the 7th minute of treatment. Group analysis of light and medium oil fractions showed an increase in the content of paraffinic, naphthenic, benzene and olefinic hydrocarbons while reducing the proportion of naphthalenes and heteroatom compounds. The results obtained confirm the effectiveness of ultrasonic-catalytic treatment for the structural destruction of high-viscosity oil and the formation of lighter hydrocarbon fractions.

Abstract: Electrochemical mechanical polishing (ECMP) has emerged as a promising alternative to conventional chemical mechanical polishing (CMP), particularly for addressing challenges in planarizing ruthenium (Ru)—a critical barrier-layer material in advanced copper interconnects. This study systematically investigates the triboelectrochemical behavior and underlying mechanisms of ruthenium during ECMP, with a focus on the effects of mechanical power (induced by load and rotational speed) and applied potential. Through open-circuit potential measurements, potentiodynamic polarization, and electrochemical impedance spectroscopy (EIS), we demonstrate that mechanical energy input significantly enhances electrochemical reactions, with rotational speed exerting a more pronounced influence than applied load. Notably, the corrosion potential increases with load at constant speed, while the friction coefficient rises as rotational speed decreases. EIS analyses further reveal that higher rotational speeds promote the formation and growth of a thicker passive oxide film on ruthenium surfaces. These insights provide a theoretical foundation for optimizing ECMP processes toward high-efficiency, high-selectivity, and low-damage planarization of Ru-based interconnect structures.

Abstract: In the Yucatán Peninsula, Citrus aurantium L. has a strong cultural and culinary relevance where local industries already process its juice and essential oils, producing large amounts of by-products. In this context, green chemistry strategies have accelerated the valorization of agro-industrial residues, where natural deep eutectic solvents (NADES) stand out due to their low cost, ease of preparation, and high extraction efficiency. This study focuses on evaluating different NADES combinations for the extraction of bioactive compounds from C. aurantium by-products, followed by essential oil (cold pressing) and juice (mechanical pressing) extraction. A 3×2×2 factorial design was implemented to evaluate the effect of hydrogen bond donor (HBD: fructose, glucose and glycerol), molar ratio (MR: 1:1 and 1:2 mol/mol choline chloride (ChCl) :HBD and added water (AW: 50 and 70%) on the polyphenolic profile, total phenolic content, total flavonoid content, ascorbic acid content and antioxidant capacity. HBD was the most critical factor in the extraction of bioactive compounds, the extract obtained with glycerol and 70% AW exhibited the highest hesperidin content (2186.08 mg/100 g dry mass), while the same HBD with 50% added water exhibited the highest quercetin + luteolin extraction (721.32 mg/100 g dry mass), both at same MR (1:1 mol/mol). Glycerol also achieved the highest recovery of total flavonoids (1829.7 ± 17.85 mg quercetin equivalent/100g dry mass) with a MR of 1:2 mol/mol and 70% AW. Finally, all other maximum values were obtained with fructose-based NADES: the highest total phenolic content (3603. 7 ± 52.9 mg gallic acid equivalent/100 g dry mass) was achieved at MR of 1:1 mol/mol and 50% AW, while for both, vitamin C (1964.8 ± 33.7 mg ascorbic acid equivalent/100g dry mass) and antioxidant capacity (84.31% inhibition) the maximum was reached at MR of 1:2 mol/mol and 50% AW.

Abstract:

Tropical fruit waste composed of peels, pulp, and discards, presents a growing disposal challenge in high and rising fruit production regions. This review explores transforming this waste into bioethanol which can also be defined as a clean-burning biofuel. It examines pre-treatment techniques like enzymatic and acidic hydrolysis that explains how complex carbohydrates is broken down into fermentable sugar efficiently. These techniques are very much required for a complete and efficient production of bioethanol. Additionally, the study focuses on optimizing fermentation conditions, including temperature, yeast strain selection, and nutrient supplementation, to maximize bioethanol yield. The impact of fruit ripeness on bioethanol yield is discussed, noting how sugar content changes during ripening affecting the ethanol output. Saccharomyces cerevisiae , a robust fermenting agent, is highlighted for its potential in bioethanol production. The feasibility of bioethanol production from various fruit substrates using a simulation model is highlighted. The model incorporates key factors such as substrate concentration of glucose, yeast cell density where various parameters of Saccharomyces cerevisiae is considered, and ethanol production. While the simulation results exhibit similar trends for different fruits, factors like model simplifications and parameter sensitivity can influence the outcomes. By integrating findings from various studies and other sources, this review aims to develop a cost-effective and sustainable bioethanol production process using tropical fruit waste.

Abstract: Biofuels offer potential to mitigate climate change, increase energy security, and economically support farmers around world. Licuri (Syagrus coronata) could be an important biofuel feedstock because its kernel (edible seed) has high energy content. This research investigates optimal reaction conditions to convert fatty acids (FA) and fatty acid methyl esters (FAME) (including licuri biodiesel) to hydrocarbons via deoxygenation in a trickle-bed reactor over granular Pd/C catalysts. Our results indicate that a 20 wt.% palmitic acid (PA) feed is optimum for continuous deoxygenation at 300 °C and 15 bar in 5% H2/He because of decarboxylation inhibition at higher concentrations. Deoxygenation rates are higher for PA than for methyl palmitate (MP) because of the slow initial hydrogenolysis of the methoxy bond over Pd/C. The hydrocarbon product distributions from deoxygenation of licuri biodiesel were fully consistent with FA decarboxylation and decarbonylation. A lab-prepared 5 wt.% Pd/C catalyst with higher metal dispersion provided modestly higher hydrocarbon yields from licuri biodiesel than a commercial 1 wt.% Pd/C catalyst.