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FeNbO4 sonocatalysts were successfully synthesized by a simple hydrothermal route at pH conditions of 3, 5, 7, 9 and 11. The catalysts were characterized by XRD, XPS, TEM, SEM, N2 adsorption and DRS to analyse the effect of pH parameters on the physicochemical properties of the materials during hydrothermal synthesis. The sonocatalytic activity of FeNbO4 microspheres was evaluated by using acid orange 7 (AO7) as the simulated contaminant. The experimental results showed that the best sonocatalytic degradation ratio (97.45%) of organic dyes could be obtained when the conditions of initial AO7 concentration of 10 mg/L, ultrasonic power of 200W, catalyst dosage of 1.0g/L, pH=3. Moreover, the sonocatalysts demonstrated consistent durability and stability across multiple test cycles. After active species capture experiments and calculation of the energy band, a possible mechanism was proposed based on the special Fenton-like mechanism and the dissociation of H2O2. The research shows that FeNbO4 microspheres can be used as sonocatalysts for the purification of organic wastewater, which has a promising application prospect.

Polycyclic Aromatic Hydrocarbons (PAHs) have demonstrated potential as active laser materials, showing good Amplified Stimulated Emission (ASE) properties. However, the molecular origin of their ASE properties is still unclear and depends on the particular compound. In this work we study the ASE properties of polystyrene films hosting three different perylene-based PAHs YZ-1, YZ-2 and YZ-3, where only YZ-3 has displayed ASE. Their molecular structure has been systematically changed to establish the connection between their molecular structure and their ASE properties. A complete spectroscopic study, with ground state and time-resolved techniques, show that, even at low yields, triplets play a critical role as a major loss mechanism. Their slow relaxation to ground state completely hinders the required unbalance of the S1 and S0 states for succesful ASE. Quantum chemical calculations suggest that a lower triplet density of states for YZ-3 is responsible for the blockage in triplet formation and, therefore, does not restrict ASE. This work not only presents a new PAH showing ASE, but also unequivocable proves the massive importance of triplet states in the development of organic lasers.

In this work, a detailed comprehensive investigation explores the impact of processing methods and chemical activation parameters on the textural properties of a series of activated carbons (ACs) derived from Argan Nut Shell (ANS) residue using KOH. This study aims to develop and optimize high-quality ACs for use as solid-state supercapacitors with superior performance in a 1 M H2SO4 electrolyte. The two-step process (involving ANS carbonization followed by activation) is found to significantly enhance specific surface area and total pore volume compared to a one-step process, reaching values of 2334 m2·g−1 and 1.21 cm3·g−1 versus 1394 m2·g−1 and 0.83 cm3·g−1, respectively. The superior surface area and pore volume results are achieved at a KOH/char mass ratio of 4:1, carbonization temperature of 500 °C, and an activation temperature of 800 °C, reaching 3091 m2·g−1 and 1.52 m3·g−1, respectively. Evaluation of electrochemical properties in a two-electrode system with 1 M H2SO4 electrolyte demonstrates outstanding capacitance and maximum specific energy at a current density of 125 mA·g−1, reaching up to 416 F·g−1 and 14.5 Wh·kg−1 at a specific power of ~120 Wkg−1. This superior performance is attributed to the ACs' high surface area, well-developed microporosity, and favorable surface chemistry. Additionally, the ACs demonstrate exceptional cycling stability, as they retain 99 % of their specific capacitance even after undergoing 2500 charge and discharge cycles at a rate of 1 A·g−1. This work offers a novel strategy for reclaiming Argan Nutshell, offering a sustainable approach for electrode materials in solid-state supercapacitors.

BaMnO3 (BM) and Ba0.9A0.1MnO3 (BM-A) (A = Ce, La or Mg) perovskite-type mixed oxides were synthesized by the aqueous sol–gel method; thoroughly characterized by ICP-OES, XRD, H2-TPR, BET, and O2-TPD; and tested as catalysts for CO oxidation under simulated automobile exhaust conditions. The characterization results indicate that the main effects of the partial substitution of Ba with A-metal in BM perovskite are the maintenance of the hexagonal structure of the perovskite and the increase in reducibility and oxygen mobility. All samples catalyze the CO to CO2 oxidation reaction in the different reactant mixtures employed, showing the best performance for the mixture with the lowest CO/O2 ratio and in the presence of a dopant in the BM perovskite formulation. BM-La is the most active catalyst for improving CO oxidation, as it is the most reducible, and because is able to evolve oxygen at intermediate temperatures.

This study explores the effects of liquid-phase and gas-phase oxidation treatments on a low-ash activated carbon (RGC30) and its subsequent use as a metal-free catalyst for the hydrogenation of 1-chloro-4-nitrobenzene. Characterisation of the catalysts was accomplished through N2 and CO2 adsorption at −196 °C and 0 °C, respectively, together with techniques like X-ray photoelectron spectroscopy (XPS), Raman spectroscopy, thermogravimetric analysis (TGA) and temperature-programmed desorption (TPD). In particular, it is observed that the catalytic activity depends on the specific oxidation treatment applied, which leads to the generation of different oxygenated groups on the carbon surface. Consequently, through precise control of oxygen groups via thermal treatment under inert conditions, it is found that the most influential groups for the hydrogenation of 1-chloro-4-nitrobenzene are basic groups incorporating Cdouble bondO bonds, such as quinones and carbonyls. Furthermore, certain groups, like phenols, exhibit a detrimental impact on the catalytic activity.

Green hydrogen production via water splitting is vital for decarbonization of hard-to-abate industries. Its integration with renewable energy sources remains to be a challenge, due to the susceptibility to hazardous gas mixture during electrolysis. Here, we report a hybrid membrane-free cell based on earth-abundant materials for decoupled hydrogen production in either acidic or alkaline medium. The design combines the electrocatalytic reactions of an electrolyzer with a capacitive storage mechanism, leading to spatial/temporal separation of hydrogen and oxygen gases. An energy efficiency of 69% lower heating value (48 kWh/kg) at 10 mA/cm2 (5 cm–by–5 cm cell) was achieved using cobalt-iron phosphide bifunctional catalyst with 99% faradaic efficiency at 100 mA/cm2. Stable operation over 20 hours in alkaline medium shows no apparent electrode degradation. Moreover, the cell voltage breakdown reveals that substantial improvements can be achieved by tunning the activity of the bifunctional catalyst and improving the electrodes conductivity. The cell design offers increased flexibility and robustness for hydrogen production.

The sol–gel method, adapted to aqueous media, was used for the synthesis of BaMn0.7Cu0.3O3 (BMC) and Ba0.9A0.1Mn0.7Cu0.3O3 (BMC-A, A = Ce, La or Mg) perovskite-type mixed oxides. These samples were fully characterized by ICP-OES, XRD, XPS, H2-TPR, BET, and O2–TPD and, subsequently, they were evaluated as catalysts for CO oxidation under different conditions simulating that found in cars exhaust. The characterization results show that after the partial replacement of Ba by A metal in BMC perovskite: (i) a fraction of the polytype structure was converted to the hexagonal BaMnO3 perovskite structure, (ii) A metal used as dopant was incorporated into the lattice of the perovskite, (iii) oxygen vacancies existed on the surface of samples, and iv) Mn(IV) and Mn(III) coexisted on the surface and in the bulk, with Mn(IV) being the main oxidation state on the surface. In the three reactant atmospheres used, all samples catalysed the CO to CO2 oxidation reaction, showing better performances after the addition of A metal and for reactant mixtures with low CO/O2 ratios. BMC-Ce was the most active catalyst because it combined the highest reducibility and oxygen mobility, the presence of copper and of oxygen vacancies on the surface, the contribution of the Ce(IV)/Ce(III) redox pair, and a high proportion of surface and bulk Mn(IV). At 200 °C and in the 0.1% CO + 10% O2 reactant gas mixture, the CO conversion using BMC-Ce was very similar to the achieved with a 1% Pt/Al2O3 (Pt-Al) reference catalyst.

To enhance their corrosion protection, Guefoams were coated with RGO using both potentiostatic and potentiodynamic methods. The potentiodynamic method produced the thickest RGO coating and the lowest Cl, O, and Al content, as observed using FESEM and EDX. The Guefoams were exposed to a 3.5% NaCl solution and steam. The polarization resistance was examined, electrochemical impedance spectroscopy was performed, and polarization curves were constructed to monitor the corrosion process. After 28 days, the Al concentrations in the solutions were measured, and were found to be 145 mg/L (bare Guefoam), 70 mg/L (RGO-coated, potentiostatic), and 35 mg/L (RGO-coated, potentiodynamic). The potentiodynamic RGO coating also showed the best corrosion protection values.

The present review revisits representative studies addressing the development of efficient Pd-based carbon-supported heterogeneous catalysts for two important reactions, namely, the production of hydrogen from formic acid and the hydrogenation of carbon dioxide into formic acid. The HCOOH-CO2 system is considered a promising couple for a hydrogen storage system involving an ideal carbon-neutral cycle. Significant advancements have been achieved in the catalysts designed to catalyze the dehydrogenation of formic acid under mild reaction conditions, while much effort is still needed to catalyze the challenging CO2 hydrogenation reaction. The design of Pd-based carbon-supported heterogeneous catalysts for these reactions encompasses both the modulation of the properties of the active phase (particle size, composition, and electronic properties) and the modification of the supports by means of the incorporation of nitrogen functional groups. These approaches are herein summarized to provide a compilation of the strategies followed in recent studies and to set the basis for a hydrogen storage system attained using the HCOOH-CO2 couple.

The present work delves into the feasibility of employing a novel structured sorbent referred to as GFAD (Guefoam Adsorption Device) for the determination of volatile organic compounds (VOCs) in liquid samples. The chosen method has been static headspace sorptive extraction-thermal desorption gas chromatography mass spectrometry (HSSE-TD-GC–MS). The GFAD comprises an aluminum cellular material with a distinct replication structure and a solid guest phase consisting of activated carbon particles dispersed within the cavities of the cellular aluminum. The extensive specific surface area, robustness, and exceptional thermal conductivity of this pioneering material offer distinct advantages over commercially available polydimethylsiloxane-based Twister® devices. Therefore, the trapping efficiency for volatile organic compounds is enhanced, and it is possible to perform the analysis of concentrated samples. According to computational simulations, it has been demonstrated that GFAD has a high heat conductivity. As a result, the desorption efficiency is improved, and minimal temperature gradients are generated throughout the GFAD during the heating process. Besides, the energy consumption is significantly lowered, thus aligning with environmentally conscientious and sustainable analytical practices. The experimental results give a proof of the suitability of the GFAD for determining gaseous compounds in liquid samples through HSSE-TD-GC–MS. For volatile species, the new material provides higher peak areas and lower limits of detection than a commercially available Twister® device. Furthermore, the GFAD is reusable, its adsorbing properties remaining unchanged during, at least, 100 consecutive analyses. In addition, unlike to the Twister®, no intense siloxane peaks are observed in the chromatograms obtained with the GFAD. The feasibility of qualitative and semi-quantitative analysis with the new accessory has been demonstrated with both standards and a cereal bioethanol rea

In the present work, multifunctional electrocatalysts formed by palladium nanoparticles (Pd NPs) loaded on Fe or Cu-containing composite supports, based on carbon nitride (C3N4) and super-activated carbon with a high porosity development (SBET 3180 m2/g, VDR 1.57 cm3/g, and VT 1.65 cm3/g), were synthesised. The presence of Fe or Cu sites favoured the formation of Pd NPs with small average particle size and a very narrow size distribution, which agreed with Density Functional Theory (DFT) calculations showing that the interaction of Pd clusters with C3N4 flakes is weaker than with Cu- or Fe-C3N4 sites. The electroactivity was also dependent on the composition and, as suggested by preliminary DFT calculations, the Pd-Cu catalyst showed lower overpotential for hydrogen evolution reaction (HER) while bifunctional oxygen reduction reaction/ oxygen evolution reaction (ORR/OER) behaviour was superior in Pd-Fe sample. The Pd-Fe electrocatalyst was studied in a zinc-air battery (ZAB) for 10 h, showing a performance similar to a commercial Pt/C + RuO2 catalyst with a high content of precious metal. This study demonstrates the synergistic effect between Pd species and transition metals and shows that transition metals anchored on C3N4-based composite materials promote the electroactivity of Pd NPs in HER, ORR and OER due to the interaction between both species.

Metal–organic frameworks have drawn attention as potential catalysts owing to their unique tunable surface chemistry and accessibility. However, their application in thermal catalysis has been limited because of their instability under harsh temperatures and pressures, such as the hydrogenation of CO2 to methanol. Herein, we use a controlled two-step method to synthesize finely dispersed Cu on a zeolitic imidazolate framework-8 (ZIF-8). This catalyst suffers a series of transformations during the CO2 hydrogenation to methanol, leading to ~14 nm Cu nanoparticles encapsulated on the Zn-based MOF that are highly active (2-fold higher methanol productivity than the commercial Cu–Zn–Al catalyst), very selective (>90%), and remarkably stable for over 150 h. In situ spectroscopy, density functional theory calculations, and kinetic results reveal the preferential adsorption sites, the preferential reaction pathways, and the reverse water gas shift reaction suppression over this catalyst. The developed material is robust, easy to synthesize, and active for CO2 utilization.

Graphene oxide (GO) has been electrochemically synthesized by chronoamperometry and using a three-electrode system. Iron, manganese and cobalt phthalocyanines (FePc, MnPc and CoPc, respectively) have been incorporated to GO. These materials were characterized both physicochemically (X-ray Photoelectron Spectroscopy (XPS), UV–Vis, elemental analysis and Raman spectroscopy), morphologically (Transmission Electron Microscopy, TEM) and electrochemically (cyclic voltammetry). Electrochemical studies included the oxygen reduction reaction (ORR) and Zn-air battery performance using the synthesized electrocatalysts. In addition, graphene oxide buckypapers (GOBs) have been fabricated and evaluated as self-supporting electrodes for the Zn-air battery. Both GO/FePc and FePc supported on GOB (GOB/FePc), with a Fe content lower than 0.5 wt%, were subjected to Zn-air battery discharging tests. Both GO/FePc and GOB/FePc show comparable performance to the commercial Pt-based electrocatalyst using a much lower amount of metal.

Multilayer graphene (MLG), obtained by mild sonication of graphite in NMP, was functionalised via 1,3-dipolar cycloaddition with azomethine ylides generated by thermal 1,2-prototropy from various imino esters. The microwave-assisted functionalisation took place in five hours at 100 °C. The resulting MLG, containing substituted proline-based amine functional groups, was characterized using XPS and showed a nitrogen loading three times that obtained for the same transformation performed for five days using convection-assisted heating. The preparation of the imino ester containing a bipyridine unit at the arylidene position allowed for the preparation of the corresponding functionalised MLG, which incorporated the ruthenium atom to achieve a heterogeneous MLG-Ru complex. This supported complex was tested, as a proof of concept, as a photocatalyst of the aerobic oxidative hydroxylation of 4-methoxyphenylboronic acid.

The literature rarely compiles studies devoted to removing pollutants in aqueous media comparing adsorption versus photocatalytic degradation and does not pay enough attention to the analysis of combined adsorption-photocatalytic oxidation processes. In the present manuscript, the removal of malachite green (MG) from aqueous solutions has been investigated in three different cheap and sustainable scenarios: i) adsorption on activated carbon (AC) derived from a residue, luffa cylindrica, ii) photocatalytic oxidation under simulated solar light using titanium dioxide (TP) and iii) combined adsorption-photocatalytic oxidation using TP-AC (70/30 wt/wt.) under simulated solar light. The study has revealed that in the three scenarios and studied conditions, the total removal of this endocrine-disrupting dye from the solution takes place in the assayed time, 2 h, although in some cases just in a few minutes. MG adsorption on the AC is the fastest removal method. MG photocatalytic oxidation with TP also occurs efficiently, although the oxidized MG is not totally mineralized. MG removal using the TP-AC composite under simulated solar light occurs at a rate comparable to that of the MG adsorption on AC, since adsorption is the dominating removal mechanism, more than 90% of the removed MG with TP-AC under simulated solar light is adsorbed in this carbon-containing composite. The obtained results highlight the interest in adsorption, being the selection of the most suitable removal method dependent on several factors (i.e., cost of the AC regeneration, if adsorption, or the toxicity of the intermediate oxidation species, if photooxidation). Paying attention to MG photooxidation with TiO2, comparison of two working photodegradation schemes shows that the direct photodegradation of MG from solution, avoiding any initial dark equilibrium period, is the more efficient option from a time perspective. The use of scavengers has proved that MG photodegradation occurs via an oxidation m

The tandem CO2 hydrogenation to hydrocarbons over mixed metal oxide/zeolite catalysts (OXZEO) is an efficient way of producing value-added hydrocarbons (platform chemicals and fuels) directly from CO2 via methanol intermediate in a single reactor. In this contribution, two MAPO-18 zeotypes (M = Mg, Si) were tested and their performance was compared under methanol-to-olefins (MTO) conditions (350 °C, PCH3OH = 0.04 bar, 6.5 gCH3OH h–1 g–1), methanol/CO/H2 cofeed conditions (350 °C, PCH3OH/PCO/PH2 = 1:7.3:21.7 bar, 2.5 gCH3OH h–1 g–1), and tandem CO2 hydrogenation-to-olefin conditions (350 °C, PCO2/PH2 = 7.5:22.5 bar, 1.4–12.0 gMAPO-18 h molCO2–1). In the latter case, the zeotypes were mixed with a fixed amount of ZnO:ZrO2 catalyst, well-known for the conversion of CO2/H2 to methanol. Focus was set on the methanol conversion activity, product selectivity, and performance stability with time-on-stream. In situ and ex situ Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), solid-state nuclear magnetic resonance (NMR), sorption experiments, and ab initio molecular dynamics (AIMD) calculations were performed to correlate material performance with material characteristics. The catalytic tests demonstrated the better performance of MgAPO-18 versus SAPO-18 at MTO conditions, the much superior performance of MgAPO-18 under methanol/CO/H2 cofeeds, and yet the increasingly similar performance of the two materials under tandem conditions upon increasing the zeotype-to-oxide ratio in the tandem catalyst bed. In situ FT-IR measurements coupled with AIMD calculations revealed differences in the MTO initiation mechanism between the two materials. SAPO-18 promoted initial CO2 formation, indicative of a formaldehyde-based decarboxylation mechanism, while CO and ketene were the main constituents of the initiation pool in MgAPO-18, suggesting a decarbonylation mechanism. Under tandem CO2 hydrogenation conditions, the presence of high water concentrations and low me

Ordinary metals contain electron liquids within well-defined ‘Fermi’ surfaces at which the electrons behave as if they were non-interacting. In the absence of transitions to entirely new phases such as insulators or superconductors, interactions between electrons induce scattering that is quadratic in the deviation of the binding energy from the Fermi level. A long-standing puzzle is that certain materials do not fit this ‘Fermi liquid’ description. A common feature is strong interactions between electrons relative to their kinetic energies. One route to this regime is special lattices to reduce the electron kinetic energies. Twisted bilayer graphene is an example, and trihexagonal tiling lattices (triangular ‘kagome’), with all corner sites removed on a 2 × 2 superlattice, can also host narrow electron bands for which interaction effects would be enhanced. Here we describe spectroscopy revealing non-Fermi-liquid behaviour for the ferromagnetic kagome metal Fe3Sn2 (ref. 6). We discover three C3-symmetric electron pockets at the Brillouin zone centre, two of which are expected from density functional theory. The third and most sharply defined band emerges at low temperatures and binding energies by means of fractionalization of one of the other two, most likely on the account of enhanced electron–electron interactions owing to a flat band predicted to lie just above the Fermi level. Our discovery opens the topic of how such many-body physics involving flat bands could differ depending on whether they arise from lattice geometry or from strongly localized atomic orbitals.

This study evaluates the removal of several dyes with different charge properties, i.e., anionic (Acid Red 88), cationic (Basic Red 13), and neutral (Basic Red 5) using transition metal-doped TiO2 supported on a high-surface-area activated carbon. Experimental results confirm the successful deposition of TiO2 and the derivatives (Zr-, Cu-, and Ce-doped samples) on the surface of the activated carbon material and the development of extended heterojunctions with improved electronic properties. Incorporating a small percentage of dopants significantly improves the adsorption properties of the composites towards the three dyes evaluated, preferentially for sample AC/TiO2_Zr. Similarly, the photodegradation efficiency highly depends on the nature of the composite evaluated and the characteristics of the dye. Sample AC/TiO2_Zr demonstrates the best overall removal efficiency for Acid Red 88 and Basic Red 5—83% and 63%, respectively. This promising performance must simultaneously be attributed to a dual mechanism, i.e., adsorption and photodegradation. Notably, the AC/TiO2_Ce outperformed the other catalysts in eliminating Basic Red 13 (74%/6 h). A possible Acid Red 88 degradation mechanism using AC/TiO2_Zr was proposed. This study shows that the removal efficiency of AC/TiO2 composites strongly depends on both the material and pollutant.

Oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) are key electrochemical reactions for the development of rechargeable Zn-air batteries. However, due to the high cost of commercial noble metal-based catalysts and their limited bifunctionality, it is necessary the design of new electrocatalysts. In this study, stable electrocatalysts have been synthesized through a hydrothermal method and further low-temperature thermal treatment. The materials consist of La stabilized low crystallinity Mn and Co metal (hydro-)oxides. The electrocatalytic performance of these materials has been compared with counterparts calcined at higher temperatures. The findings demonstrate that materials synthesized at lower temperatures and with low crystallinity exhibit superior electrocatalytic activity for both ORR and OER. Moreover, the research highlights the favorable influence of the lanthanum cation, which enhances changes of surface morphology and oxidation states of other cations (Mn and Co). Additionally, the positive contribution of the carbon component to electrochemical activity and electrical conductivity has been elucidated. The best electrocatalyst was studied in a rechargeable Zn-air battery with a durability of up to 120 hours. They exhibited better stability and performance than the commercial Pt/C + RuO2 catalyst currently used.

Hydrogen storage by cryoadsorption on porous materials has the advantages of low material cost, safety, fast kinetics, and high cyclic stability. The further development of this technology requires reliable data on the H2 uptake of the adsorbents, however, even for activated carbons the values between different laboratories show sometimes large discrepancies. So far no reference material for hydrogen cryoadsorption is available. The metal-organic framework ZIF-8 is an ideal material possessing high thermal, chemical, and mechanical stability that reduces degradation during handling and activation. Here, we distributed ZIF-8 pellets synthesized by extrusion to 9 laboratories equipped with 15 different experimental setups including gravimetric and volumetric analyzers. The gravimetric H2 uptake of the pellets was measured at 77 K and up to 100 bar showing a high reproducibility between the different laboratories, with a small relative standard deviation of 3–4 % between pressures of 10–100 bar. The effect of operating variables like the amount of sample or analysis temperature was evaluated, remarking the calibration of devices and other correction procedures as the most significant deviation sources. Overall, the reproducible hydrogen cryoadsorption measurements indicate the robustness of the ZIF-8 pellets, which we want to propose as a reference material.

Electrofluorochromism (EFC) is a phenomenon widely employed for the development of optoelectronic devices. In this work, we applied EFC as a powerful tool in sensing applications. The ability to tune the photoluminescence emission by controlling the applied potential may help maximize the response to target molecules. We have explored the EFC of the conjugated copolymer poly[9,9-dioctylfluorene-alt-benzothiadiazole] (F8BT) to design an electrofluorochromic sensor able to detect emerging pollutants with a significant impact in the marine ecosystems. In particular, a sulfonic acid-based chemical sunscreen (Ecamsule) was used as a model molecule. The photoluminescence emission modulation is affected by the presence of Ecamsule, which is attributed to the enhanced quenching process of F8BT during the p-doping process. The quenching is due to the formation of exciplex-like within the conjugated film upon the insertion of the organic anionic molecule in the polymer chain. The developed F8BT-based electrofluorochromic sensor displays a low limit of detection and good selectivity in the presence of interfering anions that are common in seawater.

Graphene-like molecules with multiple zigzag edges are emerging as promising gain materials for organic lasers. Their emission wavelengths can vary widely, ranging from visible to near-infrared (NIR), as molecular size increases. Specifically, rhombus-shaped molecular graphenes with two pairs of parallel zigzag edges, known as [n]rhombenes, are excellent candidates for NIR lasers due to their small energy gaps. However, synthesizing large-size rhombenes with emission beyond 800 nm in solution remains a significant challenge. In this study, we present a straightforward synthesis of an aryl-substituted [4]rhombene derivative, [4]RB-Ar, using a method that combines intramolecular radical-radical coupling with Bi(OTf)3-mediated cyclization of vinyl ethers. The structure of [4]RB-Ar was confirmed through X-ray crystallographic analysis. Bond length analysis and theoretical calculations indicate that aromatic sextets are predominantly localized along the molecule's long axis. Significantly, [4]RB-Ar demonstrates narrow amplified spontaneous emission at around 834 nm when dispersed in polystyrene thin films. Moreover, solution-processed distributed feedback lasers employing [4]RB-Ar as the active gain material display tunable narrow emissions in the range of 830 to 844 nm.

The present contribution describes an electrochemical system for the detection of alkaline phosphatase (ALP) enzyme inhibitors in seawater medium. Fluorescence spectroscopy and thermal unfolding results suggest that the state of free ALP is affected in this medium, yet the protein remains active. The enzyme activity can be evaluated using hydroquinone diphosphate as the substrate, with hydroquinone as the electrochemically monitored product. It has been demonstrated that encapsulation in conventional and organic modified silica matrices maintains ALP integrity, although diffusion across the formed monoliths hinders the electrochemical response. ALP@Phenyl-modified silica exhibits the best performance due to higher affinity between substrate molecules and aromatic moieties and, probably, to larger pore size. This electrochemical system can detect and quantify calyculin A in seawater at sub-nanomolar concentrations and it can also be employed for the development of electrochemical biosensors tailored for the marine environment.

Water parks often use chlorine for water disinfection despite its ineffectiveness and health risks. This research explored the efficacy of combining electromagnetic treatment (EMT) with chlorination in disinfecting swimming pool water. Water samples, with different organic loads, were subjected to EMT-chlorination tests. EMT significantly affected the physicochemical parameters of the water, notably reducing turbidity by 50 % and decreasing COD levels compared to systems without EMT. The system with EMT reported lower chlorine consumption, suggesting a lower formation of chlorogenic by-products. Therefore, it is evident that the combined method can decrease the levels of organic contamination in the water, reduce the presence of algae, and minimize the consumption of conventional chemical disinfectants, thus reflecting an interesting synergy between EMT and chlorination, which could be advantageous from a health, environmental and economic perspective.

In the search of versatile electrocatalysts for the electrochemical reduction of carbon dioxide (CO2RR), different transition metal phthalocyanines (MPc, where M=Fe, Co, Ni and Cu) have been immobilized by an easy and scalable wet impregnation on carbon nanotubes (CNTs) in the form of buckypaper (BP). Both the nature of the metal and the surface chemistry of the carbon support were found to play a pivotal role in determining their CO2RR efficiency and selectivity. We disclose here a potentiodynamic strategy for the controlled surface modification of BP with N- and P-containing polymeric species as a simple heterogenization strategy for molecular catalysts, enabling to easily tune their electrocatalytic performance. Syngas (mixture of H2 and CO) was obtained as the main product from CO2RR using FePc, CoPc and NiPc as electrocatalysts on functionalized (BPf) or non-modified BP. In contrast, CuPc was found to mainly catalyze the hydrogen evolution reaction (HER), with small amounts of formate as the only CO2RR product. It is possible to modulate the H2/CO ratio in the final product through the appropriate selection of the metal in MPc, the modification of the coordination environment by the controlled functionalization of the carbon support and the adjustment of the operating conditions. In particular, H2/CO ratios in a range between 0.17 and 1.28 have been obtained with good stability during electrolysis. Among all the MPc studied, CoPc surfaced as the most promising candidate for the reduction of CO2 to CO and H2 production, a finding substantiated by computational studies highlighting the positive impact of phosphate ligands on CoPc. This strategy outlines the starting line of a potential route toward the controlled generation of CO2RR-related products.

The present research describes one of the processes outlined in the literature, known as Chemical Looping Dry Reforming of Methane, which is currently to gain attraction to produce clean fuels from natural gas using a metal oxide support as a catalyst. This two-step method offers distinct advantages by physically separating the reaction steps. This spatial separation effectively eliminates undesirable side reactions, leading to highly efficient syngas production with minimal carbon deposition. Crucial to optimizing this process is a deep understanding of the oxygen storage capacity (OSC) of the support (oxygen carrier) that will work in synergy with the supported active phase. Among the candidates, praseodymium stands out due to its favourable redox properties and exceptional OSC characteristics, making it a promising option for cleaner fuel technologies. In particular, this study emphasizes the significant influence of the nature of the active phases (Ni, Co or their bimetallic combinations), with bimetallic phases being the most promising (even without reduction, they can exhibit activity that equals or improves that of the Ru as benchmark), underscoring the fundamental role of catalyst design in achieving optimal performance. The results indicate that these compositions have high activities to generate the products, remaining close to the activity of ruthenium and generating minimal coke deposits in one reaction cycle.

This review shows the endeavors performed to prepare immobilized formulations of bromelain extract, usually from pineapple, and their use in diverse applications. This extract has a potent proteolytic component that is based on thiol proteases, which differ depending on the location on the fruit. Stem and fruit are the areas where higher activity is found. The edible origin of this enzyme is one of the features that determines the applications of the immobilized bromelain to a more significant degree. The enzyme has been immobilized on a wide diversity of supports via different strategies (covalent bonds, ion exchange), and also forming ex novo solids (nanoflowers, CLEAs, trapping in alginate beads, etc.). The use of preexisting nanoparticles as immobilization supports is relevant, as this facilitates one of the main applications of the immobilized enzyme, in therapeutic applications (as wound dressing and healing components, antibacterial or anticancer, mucus mobility control, etc.). A curiosity is the immobilization of this enzyme on spores of probiotic microorganisms via adsorption, in order to have a perfect in vivo compatibility. Other outstanding applications of the immobilized enzyme are in the stabilization of wine versus haze during storage, mainly when immobilized on chitosan. Curiously, the immobilized bromelain has been scarcely applied in the production of bioactive peptides.

Currently, the production of complex SiC and SiC/SiC parts through reactive infiltration is one of the most widely used technologies, due to its versatility and cost-effectiveness compared to more conventional technologies such as Hot Isostatic Pressing (HIP). This technology, while widely adopted, still faces some debate regarding the mechanisms of infiltration. Questions persist about what determines how infiltration occurs and whether the process is governed by physics (flow dynamics) or chemistry (reactions at the triple line (LT: (contact line between the solid, liquid and gas phases)). The present work provides new strong/consistent proof that reactive infiltration is mainly controlled by chemical reaction.

Current methods for producing open-pore graphite foams with heat dissipation potential involve costly graphitization processes, limiting their widespread use. This study presents a sustainable approach to fabricate high-performance graphite/carbon composite foams with porosities in the range of 49–82 %. The method involves the densification and carbonization of solid mixtures comprising natural graphite flakes, sucrose, and NaCl particles. The dissolution of NaCl creates coarse pores, while carbonized sucrose contributes fine porosity and serves as a binder to impart mechanical stability, ensuring the maintenance of thermally conductive percolative contacts between flakes. The composite foams exhibit thermal conductivities of up to 91 Wm−1K−1, permeability values in the range of 10−11–10−10 m2, and excellent mechanical properties. Experimental and computational findings demonstrate that the developed materials surpass the heat dissipation capabilities of conventional heat sinks based on graphite and aluminum foams by about 3 and 1.5 times, respectively, making them excellent candidates for thermal management applications.

The particulate and soluble matter present in aerosols from combustible cigarettes (CCs) and Heated Tobacco Products (HTPs) was collected in liquid water. These liquids, yellowish in the experiments with cigarettes and colourless after using HTPs, were analysed by Laser Diffraction (LD) and by Transmission Electron Microscopy coupled to Energy Dispersive X-ray spectroscopy (TEM-EDX) to study the amount, size, composition, and other features of the particulate matter (PM) present in the collected aerosols. The particulate matter concentration in HTPs samples is below the limit of quantification for LD, and only samples from cigarettes show a particulate matter concentration above such limit. TEM analysis has revealed that the liquid samples (from both, cigarettes and HTPs experiments) contain particulate matter, mainly composed of carbon (C) and oxygen (O), but also of traces of inorganic elements. The TEM electron beam results in the evaporation of the particulate matter derived from HTPs, but not of that derived from cigarettes, highlighting the different nature of the particulate matter in both systems, i.e. liquid particulate matter present in the HTPs aerosols and solid particulate matter in the cigarettes smoke. A protocol for the quantitative comparison of the particulate matter present in aerosols has been applied over sixteen TEM images for each sample, confirming important differences from the point of view of the amount of particulate matter and particle size ranges. Thus, the amount of particulate matter for HTPs aerosol samples is more than one order of magnitude lower than for cigarettes smoke.

In this paper, we offer new porous activated carbons (PACs) made from waste Argan pulp for use in solid-state supercapacitors. The synthesis is a two-step process of carbonization and KOH activation, with temperatures ranging from 700 to 850 °C and ratios ranging from 1:3 to 1:4. The carbon material obtained exhibits a significant surface area ranging from 2757 to 3235 m2 g−1. The evaluation of electrochemical characteristics in a two-electrode system using a 1 M H2SO4 electrolyte reveals exceptional capacitance and specific energy when subjected to a current density of 125 mAg-1. The AP-800-3 has outstanding performance, with a specific capacitance of 460 F g−1 and a specific energy of 15.98 Wh kg−1. Significantly, this particular PAC has exceptional durability in cycling, as it maintains its full specific capacitance even after undergoing 2500 charge and discharge cycles at a rate of 1 A.g−1. When testing with 6 M KOH and 1 M Na2SO4 electrolytes, the capacitance is found to be lower compared to 1 M H2SO4 (239 F g−1 and 258 F g−1, respectively). The superior performance in 1 M H2SO4 emphasizes the interplay between electrolyte composition, porosity, and appropriate microstructure of the PACs. This study proposes eco-friendly method for selecting supercapacitor electrode materials.

In response to the environmental impacts of conventional polyurethane adhesives derived from fossil fuels, this study introduces a sustainable alternative utilizing lignin-based polyols extracted from rice straw through a process developed at INESCOP. This research explores the partial substitution of traditional polyols with lignin-based equivalents in the synthesis of reactive hot melt polyurethane adhesives (HMPUR) for the footwear industry. The performance of these eco-friendly adhesives was rigorously assessed through Thermogravimetric Analysis (TGA), Differential Scanning Calorimetry (DSC), rheological analysis, and T-peel tests to ensure their compliance with relevant industry standards. Preliminary results demonstrate that lignin-based polyols can effectively replace a significant portion of fossil-derived polyols, maintaining essential adhesive properties and marking a significant step towards more sustainable adhesive solutions. This study not only highlights the potential of lignin in the realm of sustainable adhesive production but also emphasises the valorisation of agricultural by-products, thus aligning with the principles of green chemistry and sustainability objectives in the polymer industry.

Environmentally friendly polymers such as cellulose acetate (CA) and chitosan (CS) were used to obtain electrospun fibers for Cu2+, Pb2+, and Mo6+ capture. The solvents dichloromethane (DCM) and dimethylformamide (DMF) allowed the development of a surface area of 148 m2 g−1 for CA fibers and 113 m2 g−1 for cellulose acetate/chitosan (CA/CS) fibers. The fibers were characterized by IR-DRIFT, SEM, TEM, CO2 sorption isotherms at 273 K, Hg porosimetry, TGA, stress-strain tests, and XPS. The CA/CS fibers had a higher adsorption capacity than CA fibers without affecting their physicochemical properties. The capture capacity reached 102 mg g−1 for Cu2+, 49.3 mg g−1 for Pb2+, and 13.1 mg g−1 for Mo6+. Furthermore, optimal pH, adsorption times qt, and C0 were studied for the evaluation of kinetic models and adsorption isotherms. Finally, a proposal for adsorbate-adsorbent interactions is presented as a possible capture mechanism where, in the case of Mo6+, a computational study is presented. The results demonstrate the potential to evaluate the fibers in tailings wastewater from copper mining.

Addressing contemporary environmental and health concerns requires reducing pollutant emissions and converting them into less harmful or valuable compounds within the framework of the circular economy. Guefoam materials offer a promising solution by enabling the capture and pre-concentration of volatile organic compounds (VOCs), while facilitating the structuring of active phases for heterogeneous catalytic conversions. This study demonstrates the benefits of merging two newly designed electromagnetic induction-assisted ceramic matrix Guefoams into a portable integrated unit, synergizing the pre-concentration and chemical transformation of n-hexane, a VOC with special challenges. One Guefoam serves as an adsorbent, whereas the other plays a catalytic role. These Guefoams host guest phases, which consist of composite materials combining a steel core with magneto-inductive properties encased in a highly porous carbonaceous layer. This carbonaceous material undertakes a dual mission: adsorbing n-hexane from a nitrogen stream within the adsorptive Guefoam and, upon phosphorus doping in the catalytic Guefoam, orchestrating the metal-free selective dehydroaromatization of n-hexane into benzene. The design and integration of these novel Guefoam materials into a unified functional entity prove highly effective in pre-concentrating (enrichment factors up to 275) and catalyzing n-hexane with up to 84 % conversion and 94 % benzene selectivity while remaining energy-efficient and environmentally sustainable.

Carbon materials have emerged as a new generation of catalysts for the crucial industrial hydrogenation of nitroarenes. Activated carbon, known for its cost-effectiveness and facile modifiability, stands out among various carbon materials. This study focuses on the preparation of N and P co-doped carbons for catalysing the hydrogenation of 1-chloro-4-nitrobenzene. Comprehensive characterisation using thermal analysis (TGA-MS), X-ray photoelectron spectroscopy (XPS), Raman spectroscopy, N2 adsorption at -196 ºC, and ICP-MS was performed. The synergistic effect of N and P was evident, with co-doped carbons outperforming their mono-doped counterparts, underscoring the significance of nitrogen. N,P-codoped activated carbon emerges as a promising, active, stable, and selective metal-free catalyst for the hydrogenation of 1-chloro-4-nitrobenzene, leading to 4-chloroaniline.

A method to fabricate gold nanoparticles in gelatin films and pattern them into gratings with periods down to 200 nm is reported. The procedure, based on holographic lithography, dry etching and temperature annealing, enables tuning the size and particle distribution. These materials offer potential for wearable and bio-compatible plasmonic-based applications.

In the present work, a series of supports with varying compositions (ranging from pure CeO2 to pure PrO2-y) was designed to investigate their ability to release oxygen (with the concomitant formation of oxygen vacancies) under diverse reducing atmospheres: hydrogen (H2), helium (He), and in the presence of a carbonaceous substance that mimics eventual carbon deposits formed under practical reaction conditions (DRM). Oxygen vacancies were generated effectively in all three atmospheres (following the order He < H2 < carbon material). With regard to the influence of the composition, the capability to generate oxygen vacancies clearly increased with the Pr content, for whatever the conditions tested. Notably, the non-stoichiometry obtained with the support of pure praseodymia in both inert and reducing atmospheres is very remarkable, as it approaches the maximum non-stoichiometry value of the well-established theoretical Bevan cluster. This leads to consider this formulation as a very promising support for applications in catalysis and other fields where oxygen vacancies play a crucial role. Dry Reforming of Methane requires catalytic supports that possess highly mobile oxygen, enabling it to actively participate in the reactions step involved or potentially gasify undesirable carbon deposits generated during parallel reactions. Consequently, designing and elucidating the behavior of ceria-praseodymium-based supports with high reducibility and generation of oxygen vacancies (oxygen storage and release capacity) holds particular relevance in this context. Actually, the very preliminary results comparing two counterpart formulations (5%Ni/PrO2-y versus 5%Ni/Al2O3) already confirm the suitability of the choice of pure praseodymia in terms of activity, stability and very high selectivity towards H2 and CO, reaching a very close value to the ideal H2/CO ratio of 1.

Perylenediimides (PDIs) are the focus of a huge number of research lines for their awesome properties which can be modulated over a wide range by chemical modification of their structure. However, industrial applications require reduced costs in materials preparation and transformation. In this contribution we explore the ability of sulfur-substituted PDIs to vary their electronic character from strong electron-donating to strong electron-accepting in just one reaction.

The selectivity of the sodium channel has been the subject of numerous experimental and theoretical studies. In this work, this problem is approached from a theoretical point of view based on a model built from the Selective Filter (SF) of the open structure of the voltage-activated channel of the bacterium Magnetococcus marinus. This approach has allowed us to calculate the interaction energies of the system (cation-water-SF-fragment), both for the sodium cation and the potassium cation. The results have highlighted the importance of differential dehydration of cations, as well as the environment where it occurs. Semi-empirical and ab initio methods have been applied to analyze and quantify the interaction energies when the cations are in the SF of the sodium channel, with the DFT (ab initio) methods giving us the key to the distribution of the interaction energies and therefore how dehydration occurs.

Due to the need for decarbonization in energy generation, it is necessary to develop electrocatalysts for the oxygen reduction reaction (ORR), a key process in energy generation systems such as fuel cells and metal–air batteries. Perovskite–carbon material composites have emerged as active and stable electrocatalysts for the ORR, and the interaction between both components is a crucial aspect for electrocatalytic activity. This work explores different mixing methods for composite preparation, including mortar mixing, ball milling, and hydrothermal and thermal treatments. Hydrothermal treatment combined with ball milling resulted in the most favorable electrocatalytic performance, promoting intimate and extensive contact between the perovskite and carbon material and improving electrocatalytic activity. Employing X-ray photoelectron spectroscopy (XPS), an increase in the number of M-O-C species was observed, indicating enhanced interaction between the perovskite and the carbon material due to the adopted mixing methods. This finding was further corroborated by temperature-programmed reduction (TPR) and temperature-programmed desorption (TPD) techniques. Interestingly, the ball milling method results in similar performance to the hydrothermal method in the zinc–air battery and, thus, is preferable because of the ease and straightforward scalability of the preparation process.

The present manuscript focuses on important aspects regarding TiO2, which is typically used in many applications. On one hand, a thorough review of methods for synthesizing nanostructured TiO2 is presented. Using these methods, and different post-synthesis heat-treatment conditions, close to thirty TiO2 materials have been prepared, and their porous texture and crystalline and amorphous structure have been characterized. In this large number of samples, the porous texture characterization has revealed a high contribution of mesoporosity in a large number of the synthesized materials, being in many materials around 60–70 %. Moreover, different percentages of crystalline phases, anatase, brookite, rutile, and amorphous titania are developed depending on the TiO2 preparation conditions. These fractions have been determined from X-ray diffraction data using the “simple” characterization method reported by Cano-Casanova et al., inspired by Jensen et al., and Bellardita et al., also exploring its limitations. This analysis has allowed assessing a linear relationship between porosity, particularly between the surface area, and the amorphous phase content in titanium dioxide. A relationship had been previously suggested in the literature, but never correlated in such a way. In summary, the present study constitutes a tool to help other researchers select the most suitable method for synthesizing nanostructured TiO2 materials with target properties and, also, to characterize them, and have a very easy and straightforward estimation of TiO2 amorphous phase content after the determination of their surface areas.

This study addresses the critical need to reduce energy penalties in CO2 capture processes by exploring the potential of activated carbons derived from argan paste cake for post-combustion CO2 capture applications. Leveraging their cost-effectiveness, stability in humid conditions, and microporous structure, a series of activated carbons with diverse textural characteristics were synthesized through a two-step chemical activation process employing a KOH: biochar ratio of 1:1. Activation temperatures ranged from 700 to 850 °C. Characterization techniques such as Raman spectroscopy, X-ray spectroscopy, scanning electron microscopy, transmission electron microscopy, elemental analysis, and Fourier-transform infrared spectroscopy were employed to analyze the structural and chemical properties of the synthesized activated carbons. Remarkably, all synthesized samples exhibited excellent CO2 adsorption properties. Notably, the activated carbon sample prepared at 700 °C (APC-500–700) demonstrated the highest CO2 adsorption capacity, reaching up to 4.89 mmol/g at 0 °C and 2.98 mmol/g at 25 °C. Additional samples, including APC-500–800 and APC-500–850, exhibited CO2 adsorption capacities of 4.89 mmol/g and 4.83 mmol/g, respectively, at 0 °C, with corresponding values of 2.74 mmol/g and 2.60 mmol/g observed at 25 °C. Selectivity and stability tests were conducted to evaluate the adsorption performance under varied conditions, further highlighting the potential of activated carbon derived from argan paste cake in contributing to efficient CO2 capture processes. These findings underscore the significance of synthesis conditions in tailoring adsorption performance and pave the way for the sustainable utilization of waste biomass for environmental applications.

Ba1−xCexMnO3 (BM-Cex) and Ba1−xLaxMn0.7Cu0.3O3 (BMC-Lax) perovskite-type mixed oxides were synthesized using the sol–gel method adapted for aqueous media with different values of x (0, 0.1, 0.3, 0.6) to estimate the effect of the degree of the partial substitution of Ba by Ce or La on the structure and properties that are relevant for their use as catalysts for gasoline direct injection (GDI) soot oxidation. The samples were deeply characterized by ICP-OES, XRD, XPS, N2 adsorption, H2-TPR, and O2-TPD, and their potential as catalysts for soot oxidation has been analyzed in various scenarios that replicate the exhaust conditions of a GDI engine. By comparing the catalytic performance for soot oxidation of the two tested series (BM-Cex and BMC-Lax) and in the two conditions used (100% He and 1% O2 in He), it could be concluded that (i) in the absence of oxygen in the reaction atmosphere (100% He), BMC-La0.1 is the best catalyst, as copper is also able to catalyze the soot oxidation; and (ii) if oxygen is present in the reaction atmosphere (1% O2/He), BM-Ce0.1 is the most-active catalyst as it presents a higher proportion of Mn(IV) than BMC-La0.1. Thus, it seems that the addition of an amount of Ce or La higher than that corresponding to x = 0.1 in Ba1−xCexMnO3 and Ba1−xLaxCu0.3Mn0.7O3 does not allow us to improve the catalytic performance of BM-Ce0.1 and BMC-La0.1 for soot oxidation in the tested conditions.

Nitrogen-doped carbons were obtained by the pyrolysis of polyaniline (PANI), which had been previously synthesized by chemical oxidative polymerization of aniline at two different temperatures (0 and 25 °C). A series of activation treatments with steam under different experimental conditions were carried out in order to develop carbon porosity. It has been shown that the experimental polymerization conditions greatly affect the properties of the N-doped carbons and their reactivity to the steam activation treatment. Carbons were characterized by N2 adsorption at −196 °C, CHNS Elemental Analysis and XPS and their hydrophilicity/hydrophobicity were assessed by water adsorption measurements. The carbons prepared from PANI synthesized at 0 °C showed a more developed porosity and specific surface area than those obtained from PANI synthesized at 25 °C. The increase in the activation temperature produces the loss of the nitrogen heteroatom. Adsorption of water and toluene depends on the amount of surface nitrogen atoms as well as on the pore structure developed in the carbon.

The use of sacrificial agents in photocatalysis is a powerful resource to enhance the performance of photoactive materials. Despite its importance, the effect of the amount of sacrificial agent is not properly described in the literature. In this paper, we have focused on the role of EtOH in the photoreduction of CO2 to CH4 using Cu-P25 photocatalysts in a flow reactor. We found that the production of CH4 increased with the concentration of EtOH, achieving an outstanding CH4 production yield of 235 µmol/(g·h) for a flow of 0.25 µmol/min of EtOH in the gas stream, hinting at the important role of the sacrificial agent in the reaction. The catalytic results together with the characterization of the materials highlight the need to achieve a minimum surface coverage of EtOH on the surface of the catalyst to control the reaction pathway. The adsorption of EtOH is a key factor in boosting the catalytic activity of the best-performing catalyst and producing CH4 from CO2 photoreduction and C2H4O from the photooxidation of EtOH, obtaining two easily separable interesting products for industrial applications in one reaction.

Activated carbon (AC) is a common material of choice in catalysis, as it is a suitable support material for many catalytic reactions. In this work, the effect of cobalt nanoparticles on activated carbon derived from a biomass waste, peach stone, is reported. The presence of cobalt during heat treatments at 900 °C under reductive (H2) and inert (He) atmospheres resulted in the appearance of an intense 2D band in the Raman spectra, indicating a high degree of graphitization. Temperature-programmed reduction and desorption experiments were conducted to evaluate the activation reactions. Quenched solid density functional theory (QSDFT) analysis using N2 adsorption data revealed that cobalt increased pore development in the samples, regardless of the atmosphere (reductive or inert) used.

The optical and mechanical properties of 2D semiconductors make them excellent candidates for the active components of plastic optoelectronic devices. Here, the integration of single-layer WSe2 (1L-WSe2) into a polystyrene (PS) film containing dispersed perylene orange (PDI-O) molecules is investigated. The findings reveal a notable enhancement in the light emission of 1L-WSe2, which occurs exclusively upon PDI-O excitation and scales with the concentration of molecules in the PS film. Moreover, the increase in 1L-WSe2 photoluminescence coincides with a quenching of the PDI-O light emission intensity and a decrease in its lifetime. These results point to efficient long-range interactions, such as Förster energy transfer, between PDI-O (acting as the donor) and 1L-WSe2 (acting as the acceptor), as the mechanism responsible for the enhanced light emission in the latter. These findings are of great interest for the development of flexible optoelectronic devices integrating active 2D materials; the polymeric matrix plays a dual role, serving as both physical support and host for organic dopants that can optimize the light emission properties of the active 2D material.

Metal promotion could unlock high performance in zinc-zirconium catalysts, ZnZrOx, for CO2 hydrogenation to methanol. Still, with most efforts devoted to costly palladium, the optimal metal choice and necessary atomic-level architecture remain unclear. Herein, we investigate the promotion of ZnZrOx catalysts with small amounts (0.5 mol%) of diverse hydrogenation metals (Re, Co, Au, Ni, Rh, Ag, Ir, Ru, Pt, Pd, and Cu) prepared via a standardized flame spray pyrolysis approach. Cu emerges as the most effective promoter, doubling methanol productivity. Operando X-ray absorption, infrared, and electron paramagnetic resonance spectroscopic analyses and density functional theory simulations reveal that Cu0 species form Zn-rich low-nuclearity CuZn clusters on the ZrO2 surface during reaction, which correlates with the generation of oxygen vacancies in their vicinity. Mechanistic studies demonstrate that this catalytic ensemble promotes the rapid hydrogenation of intermediate formate into methanol while effectively suppressing CO production, showcasing the potential of low-nuclearity metal ensembles in CO2-based methanol synthesis.

In this work, we study the quantum transition taking place when titanium phthalocyanine molecules are adsorbed on a copper’s surface. Submitted to thermal annealing, depending on the way in which the molecule is adsorbed, this system can be characterized by a Kondo ground state, giving rise to a zero bias peak in the differential conductance. To clarify this new property, derived from the annealing process, we propose a model Hamiltonian that describes the essential physics involved. We show that the Kondo ground state appears as a consequence of the broken symmetry introduced by the annealing. It is not due to an increase of the molecule–substrate interactions but to the modification of the intermolecular lobe orbital matrix elements. This rearrangement rules the entrance of charge into the molecule and provides the conditions for the establishment of the Kondo state. Our results for the differential conductance, corresponding to the electronic current between a STM tip and one of the molecular lobes, agree with the experimental differential conductance measurements. It presents an Abrikosov–Suhl–Kondo resonance at the Fermi level for the configuration where the molecule is distorted. The results obtained within the model we propose, when compared with the experiments, give quantitative support to our interpretation.

A mesoporous material was synthesized using silica extracts from fly ash and its properties were studied. Subsequently, it was functionalized with carbamoylmethylphosphine oxide (CMPO) to capture La3+ and Ce3+. The developed mesoporous material was obtained by the sol-gel method and was called Si-MMS (siliceous mesoporous materials), subsequently functionalized with APTMS (1-(2-aminoethyl)-3-aminopropyl trimethoxysilane) in a reflux system, which led to the synthesis of Si-MMS-APTMS. This derivative was modified with carbonyldiimidazole (CDI) and diethylphosphonoacetic acid, which finally resulted in the synthesis of Si-MMS-CMPO as the final product. The materials were characterized by DRIFT, XRD, SEM-EDS, TEM, XPS, elemental analysis and nitrogen isotherms at −196 °C, confirming that the synthesis and subsequent modification of the mesoporous structure was successful. Adsorption studies in batch systems indicated that the optimal pH for La3+ was 6, the Langmuir isotherm model and the non-linear Sips models were perfectly fitted and the best fitting kinetics is the Elovich model. For Ce3+ the optimal pH was 7.5, the non-linear Sips isotherm fit the best and the non-linear Pseudo-second order kinetics was the mechanism that best represents the adsorption. The maximum experimental adsorption capacity qe of La3+ was 17.00 mg g−1 and for Ce3+ was 30.09 mg g−1. In both cases, the rapid adsorption suggests an open porous matrix that facilitates the formation of chelates between the adsorbates and the phosphoryl group -PO32-.