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Propane dehydrogenation (PDH) is an on-purpose catalytic technology to produce propylene from propane that operates at high temperatures, 773-973 K. Several key industry players have been active in developing new catalysts and processes with improved carbon footprint and economics, where Pt-based catalysts have played a central role. The optimization of these catalytic systems through computational and atomistic simulations requires large-scale models that account for their reactivity and dynamic properties. To address this challenge, we developed a new reactive ReaxFF force field (2023-Pt/C/H) that enables large-scale simulations of PDH reactions catalyzed on Pt surfaces. The optimization of force-field parameters relies on a large training set of density functional theory (DFT) calculations of Pt-catalyzed PDH mechanism, including geometries, adsorption and relative energies of reaction intermediates, and key C-H and C-C bond-breaking/forming reaction steps on the Pt(111) surface. The internal validation supports the accuracy of the developed 2023-Pt/C/H force-field parameters, resulting in mean absolute errors (MAE) against DFT data of 14 and 12 kJ mol-1 for relative energies of intermediates and energy barriers, respectively. We demonstrated the applicability of the 2023-Pt/C/H force field with reactive molecular dynamics simulations of propane on different Pt surface topologies and temperatures. The simulations successfully model the formation of propene in the gas phase as well as competitive, unproductive reactions such as deep dehydrogenation and C-C bond cleavage that produce H, C1 and C2 adsorbed species responsible of catalytic deactivation of Pt surface. Results show the following reactivity order: Pt(111) < Pt(100) < Pt(211), and that for the stepped Pt(211

Renewable energies can reduce emissions from fossil fuel-based power production by a significant amount, reducing climate change. Among the several options being investigated, hydrogen is now recognized as one of the primary enabling technologies for future large-scale and long-term green storage of renewable energy. However, using clean and renewable energy sources like water and sunlight is the best option. According to recent studies, photoelectrochemical (PEC) water splitting is a potential technology for creating hydrogen using free solar energy since hydrogen and oxygen gases may be easily identified in PEC. This study uses bibliometric and systematic literature review methodologies to examine the scientific understanding of PEC water splitting and hydrogen generation, evaluating 936 articles issued in the Web of Science database from 1970 to 2022. The authors looked at how PEC water splitting research has developed compared to prior research, what criteria make up practical approaches, and what subjects have emerged as new trends in reacting to changing situations. The key findings from the article analysis, future research potential, and practical implications for the field are discussed.

Years of study have shown that creating a commercial photoelectrode to solve particular bottlenecks, such as low charge separation and injection efficiency, short carrier diffusion length and lifespan, and poor stability, requires the employment of a variety of components. Developing photovoltaic-electrolysis, photocatalytic, and photoelectrochemical approaches to accelerate hydrogen production from solar energy has been highly competitive. Photoelectrochemical water splitting utilizing nanoporous materials is one of the promising approaches to produce hydrogen more efficiently, cost-effectively, and on a long-term basis. Nanoporous materials have been highly used in photoelectrochemical water-splitting systems and are crucial in numerous applications. Those materials have a porous structure and excellent conductivity, enabling the deposition of transition metal atoms and electrochemically active chemicals on a large active surface area. However, there remains a dearth of review articles exploring the application of nanoporous materials in photoelectrochemical reactions. Therefore, this review provides bibliometric statistics and various perspectives on a range of nanoporous materials, including indium, nickel, gold, copper, lead, silver, aluminum, silicon, tin, iron, zinc, titanium, bismuth vanadate, cadmium sulfide, and zeolites. Additionally, this review offers a comprehensive assessment of worldwide studies on utilizing nanoporous materials in photoelectrochemical cells. We show how morphological modifications to materials may improve charge transfer and, as a consequence, overall power conversion efficiency.ke The superior catalytic performance of nanostructures with varying levels of complexity has been discovered in photoelectrochemical reactions. Finally, signif

Black phosphorus (BP) has recently emerged as a versatile photocatalyst owing to its unique photophysical properties and tunable bandgap. Nonetheless, the rapid recombination of the photogenerated charges of pristine BP samples has significantly hindered its practical applications in photocatalysis. Herein, we report, for the first time, the effect of transition metal nanoparticles (Ni and Co) as co-catalysts on the photocatalytic activity of BP/tungsten disulfide (WS2) binary heterojunctions (BP/WS2-TM (TM: Ni, Co)) in the hydrogen evolution reaction (HER) under visible light irradiation (& lambda; > 420 nm). Ternary heterojunctions named BP/WS2-TM (TM: Ni, Co) were synthesized via a chemical reduction method, leading to the formation of an S-scheme heterojunction, in which BP acts as a reduction catalyst and WS2 serves as an oxidation catalyst. BP/WS2-Ni and BP/WS2-Co performed substantial amounts of hydrogen generation of 9.53 mmol h(-1)g(-1) and 12.13 mmol h(-1)g(-1), respectively. Moreover, BP/WS2-Co exhibited about 5 and 15 times higher photocatalytic activity compared to the binary BP/WS2 heterojunctions and pristine BP, respectively. The enhanced photocatalytic activity of the heterojunction catalysts is attributed to the extended light absorption ability, enhanced charge separation, and larger active sites. This study is the first example of photocatalytic hydrogen evolution from water by using Ni- and Co-doped binary BP/WS2 heterojunctions., Scientific and Technological Research Council of Turkey (TÜBİTAK); Selcuk University Scientific Research Projects

OBJECTIVES: Internal medicine clerkship grades are important for residency selection, but inconsistencies between evaluator ratings threaten their ability to accurately represent student performance and perceived fairness. Clerkship grading committees are recommended as best practice, but the mechanisms by which they promote accuracy and fairness are not certain. The ability of a committee to reliably assess and account for grading stringency of individual evaluators has not been previously studied. METHODS: This is a retrospective analysis of evaluations completed by faculty considered to be stringent, lenient, or neutral graders by members of a grading committee of a single medical college. Faculty evaluations were assessed for differences in ratings on individual skills and recommendations for final grade between perceived stringency categories. Logistic regression was used to determine if actual assigned ratings varied based on perceived faculty's grading stringency category. RESULTS: "Easy graders" consistently had the highest probability of awarding an above-average rating, and "hard graders" consistently had the lowest probability of awarding an above-average rating, though this finding only reached statistical significance only for 2 of 8 questions on the evaluation form ( CONCLUSIONS: Perceived differences in faculty grading stringency have basis in reality for clerkship evaluation elements. However, final grades recommended by faculty perceived as "stringent" or "lenient" did not differ. Perceptions of "hawks" and "doves" are not just lore but may not have implications for students' final grades. Continued research to describe the "hawk and dove effect" will be crucial to enable assessment of local grading variation and empower local educational leadership to correct, but not overcorrect, for this effect to maintain fairness in student evaluations.

Undoped V2O5 is characterized by a small surface area and rapid electron-hole recombination, thus rendering it ineffective as a catalytic and antimicrobial agent. In this study, co-precipitation was employed to synthesize vanadium oxide (V2O5) and carbon spheres (CS) followed by doping with specific concentrations (3 and 6 wt%) of graphene oxide (GO) to produce GO/CS-doped V2O5 nanorods (NRs). The enhancement in catalytic and antibacterial activity provided by GO/CS-doped V2O5 was utilized to treat wastewater more efficiently. XRD analysis validated the orthorhombic and tetragonal structure of the synthesized samples. The polycrystalline nature of V2O5 was shown by vibrant circular rings in selected area electron diffraction (SAED) micrographs. TEM analysis endorsed formation of NRs, whereas UV–vis, luminescence (PL) and fourier transform infrared spectroscopy (FTIR), probed the absorption and emission along with stretching and bending vibrations in V-O-V bond. The chemically synthesized NRs exhibited excellent catalytic activity (93.71%) against rhodamine B (RhB) dye in the vicinity of NaBH4. In addition, NRs were used to evaluate in-vitro antimicrobial efficiency of 3.75 mmfor Escherichia coli (E. coli) using inhibition zone measurement. Docking investigations of GO/CS-V2O5 NRs for FabH and FabI of E. coli suggested suppression of above-mentioned enzymes as a possible mechanism. These findings demonstrate that (3 and 6 wt%) GO/CS-V2O5 possessed ample potency for industrial dye degradation and antimicrobial activity.

This study presents an unexplored method to produce formaldehyde-free MDF. Steam exploded Arundo donax L. (STEX-AD) and untreated wood fibers (WF) were mixed at different mixing rates (0/100, 50/50, and 100/0, respectively) and two series of boards were manufactured, with 4 wt% of pMDI, based on dry fibers, and self-bonded. The mechanical and physical performance of the boards was analyzed as a function of the adhesive content and the density. The mechanical performance and dimensional stability were determined by following European standards. The material formulation and the density of the boards had a significant effect on both mechanical and physical properties. The boards made solely of STEX-AD were comparable to those made with pMDI, while the panels made of WF without adhesive were those that performed the worst. The STEX-AD showed the ability to reduce the TS for both pMDI-bonded and self-bonded boards, although leading to a high WA and a higher short-term absorption for the latter. The results presented show the feasibility of using STEX-AD in the manufacturing of self-bonded MDF and the improvement of dimensional stability. Nonetheless, further studies are needed especially to address the enhancement of the internal bond (IB).

The design of stimuli-responsive lignin nanoparticles (LNPs) for advanced applications has hitherto been limited to the preparation of lignin-grafted polymers in which usually the lignin content is low (<25 wt.%) and its role is debatable. Here, the preparation of O2-responsive LNPs exceeding 75 wt.% in lignin content is shown. Softwood Kraft lignin (SKL) is coprecipitated with a modified SKL fluorinated oleic acid ester (SKL-OlF) to form colloidal stable hybrid LNPs (hy-LNPs). The hy-LNPs with a SKL-OlF content ranging from 10 to 50 wt.% demonstrated a reversible swelling behavior upon O2/N2 bubbling, increasing their size – ≈35% by volume – and changing their morphology from spherical to core-shell. Exposition of hy-LNPs to O2 bubbling promotes a polarity change on lignin-fluorinated oleic chains, and consequently their migration from the inner part to the surface of the particle, which not only increases the particle size but also endows hy-LNPs with enhanced stability under harsh conditions (pH < 2.5) by the hydration barrier effect. Furthermore, it is also demonstrated that these new stimuli-responsive particles as gas tunable nanoreactors for the synthesis of gold nanoparticles. Combining a straightforward preparation with their enhanced stability and responsiveness to O2 gas these new LNPs pave the way for the next generation of smart lignin-based nanomaterials.

This study investigates the co-precipitation synthesis of (2 and 4 wt%) Ag and polyacrylic acid-doped SrO nanocomposites for bactericidal activities and catalytic Rhodamine B (RhB) decolorization. The objective of the investigation was to minimize the rate of electron-hole recombination of SrO to enhance charge transfer. The influence of Ag and PAA on the crystal structure, morphology, absorbance wavelength, and exciton recombination rate of SrO was studied using a systematic characterization. The binary dopants were added into SrO to reduce the crystallite size, which produces the new active sites (reduces the recombination rate) and may generate reactive oxygen species (ROS). In a neutral medium with sodium borohydride (NaBH4), the synthesized nanocomposites demonstrated reasonable results for catalytic reduction of RhB dye (74.3 %). The bactericidal efficiency (96.6 %) of prepared samples was measured for Escherichia coli (E. coli) at various concentrations. Molecular docking studies were performed to rationale the antibacterial activity of PAA-SrO and Ag/PAA-SrO nanocomposites against DHFRE. coli, DHPSE. coli, and FabIE.coli suggested their role as inhibitors.

Slow kinetics is one of the capital issues of photocatalytic technology because of its heterogeneous nature, which involves multi-step processes. Herein, we show that the simple modification of the sol-gel-based TiO2-smectite composite by hexadecyltrimethylammonium bromide (HDTMA) significantly boosts adsorption and photocatalytic efficient sol-gel-based light towards the removal of diclofenac from water. Three photocatalysts were prepared, including TiO2, TiO2-smectite, and HDTMA-TiO2-smectite. The materials were characterized to understand the surface interaction and crystal characteristics. In terms of photoactivity, it was found that the addition of HDTMA to TiO2-smectite improved the removal rate by twice. HDTMA changes the functional groups to TiO2-smectite composite allowing enhanced adsorption and photoactivity through the so-called Adsorb and Shuttle process. The recycling tests show that HDTMA-TiO2-smectite can be used up to four times with good performance. This modification approach could intensify the removal of pollutants from water instead of using complicated and costly techniques.

In-situ pyrolysis-catalytic steam reforming reaction of polystyrene waste (PSW) liquefied in phenol can generate hydrogen from phenol and valuable liquid fuel from the PSW and thus has been studied recently. However, due to the complexity of phenol compounds and plastic waste, this reaction suffers from high energy consumption and coking. Herein, Ti, 4Ti3Cu and 3Ti3Cu nano-catalysts were facilitatively prepared using hydrothermal and impregnation methods and the physical and chemical properties of the fresh and used samples were deeply characterized. The experimental results show that almost complete phenol conversion with 97.90% H2 yield was achieved at 800 oC using 3Ti3Cu nano-catalyst. The catalytic pyrolysis products were ethylamine, tert-butyl hydroperoxide (TBHP) and benzene (1,1-dimethylethoxy) (BDE). The correspondence of the preparation, morphology and catalytic activity in this research elucidates the synthesis of anti-coking and stable nano-catalysts for in-situ pyrolysis-catalytic steam reforming reaction.

This work produces a unique microfluidic device that acts as a “lab on a chip,” conducting separation, mixing, and concentration of microparticles similar to that required by cell sorting flow cytometry applications. The passive two-dimensional device shows to be successful at separating polystyrene (PS) beads between 5 and 20 µm in diameter, mixing them with an external media, and concentrating them by 250% continuously with minimal sample preparation, while still being inexpensive, and effective. By implementing the microfluidic device, the processing steps are done within seconds due to its high throughput of 2 mL min−1, wherein different hydrodynamic phenomena such as Dean's forces, inertial lift forces, and enhanced diffusion are taken advantage of.

The decomposition of hydrogen peroxide (H2O2) is the main undesired side reaction in catalytic oxidationprocessesof industrial interest that make use of H2O2 as a terminal oxidant, such as the epoxidation of alkenes. However,the mechanism responsible for this reaction is still poorly understood,thus hindering the development of design rules to maximize the efficiencyof catalytic oxidations in terms of product selectivity and oxidantutilization efficiency. Here, we thoroughly investigated the H2O2 decomposition mechanism using a Zr-monosubstituteddimeric Lindqvist tungstate, (Bu4N)(6)[{W5O18Zr(& mu;-OH)}(2)] ({ZrW ( 5 ) } ( 2 )),which revealed high activity for this reaction in acetonitrile. Themechanism of the {ZrW ( 5 ) } ( 2 )-catalyzed H2O2 degradationin the absence of an organic substrate was investigated using kinetic,spectroscopic, and computational tools. The reaction is first orderin the Zr catalyst and shows saturation behavior with increasingH(2)O(2) concentration. The apparent activationenergy is 11.5 kcal & BULL;mol(-1), which is significantlylower than the values previously found for Ti- and Nb-substitutedLindqvist tungstates (14.6 and 16.7 kcal & BULL;mol(-1), respectively). EPR spectroscopic studies indicated the formationof superoxide radicals, while EPR with a specific singlet oxygen trap,2,2,6,6-tetramethyl-piperidone (4-oxo-TEMP), revealed the generationof O-1(2). The interaction of test substrates,& alpha;-terpinene and tetramethylethylene, with H2O2 in the presence of {ZrW ( 5 ) } ( 2 ) corroborated the formationof products typical of the oxidation processes that engage O-1(2) (endoperoxide ascaridole and 2,3-dimethyl-3-butene-2-hydroperoxide,respectively). While radical scavengers (BuOH)-Bu- t and p-benzoquinone produced no effect on theperoxide p

The enantioselective reaction of 1,6-enynes with O-, N-, and C-nucleophiles has been developed by matched ion pair gold(I) catalysis in which the chiral gold(I) cation and anion are H-bonded through a urea group. Very high levels of enantiocontrol are achieved (up to >99:1 er) for a broad scope of substrates. DFT studies demonstrate the importance of the H-bond donor group in anchoring the matched chiral cation- and anion-favoring additional noncovalent interactions.

The Ir-MaxPHOX-type catalysts demonstrated high catalytic performance in the hydrogenation of a wide range of nonchelating olefins with different geometries, substitution patterns, and degrees of functionalization. These air-stable and readily available catalysts have been successfully applied in the asymmetric hydrogenation of di-, tri-, and tetrasubstituted olefins (ee ' s up to 9996). The combination of theoretical calculations and deuterium labeling experiments led to the uncovering of the factors responsible for the enantioselectivity observed in the reaction, allowing the rationalization of the most suitable substrates for these Ircatalysts.

The present computational work analyzes singlet fission(SF) asa pathway for multiplication of photogenerated excitons in crystallinepolyacenes. Our study explores the well-known crystalline pentacene(C22H14) and the prospective and potentiallyinteresting doped B,N-pentacene (BC20NH14).At the molecular level, the singlet fission process involves a pairof neighboring molecules and is based on the coupling between an excitedsinglet state (S1S0) and two singlet-coupledtriplets ((T1T1)-T-1), which, typically,is influenced by an intermolecular charge transfer state. Taking datafrom periodic density functional theory and ab initio wave functioncalculations, we applied the non-orthogonal configuration interactionmethod to determine electronic coupling parameters. The comparisonof the results for both equilibrium structures reveal smaller SF couplingfor pentacene than for B,N-pentacene by a factor of & SIM;5. Introductionof the dynamic behavior to the crystals (vibrations, thermal motion)provides a more realistic picture of the effect of the disorder atthe molecular level on the SF efficiency. The coupling values associatedto out-of-equilibrium structures show that most of the S1S0/(T1T1)-T-1 couplings remainvirtually constant or slightly increase for pentacene when moleculardisorder is introduced. Homologous calculations on B,N-pentacene showa generalized decrease in the coupling values, notably if large phonondisplacements are considered. A few of the structures analyzed featuremuch larger SF coupling if some distortion results in (nearly) degeneratecharge transfer and excited singlet and triplet states. For theseparticular situations, an acceleration of the SF process could occuralthough in competition with electron-hole separation as analternative pathway.

In this article we demonstrate that contrary to general belief, the standard Einstein-Helfand (EH) formulas are valid for the evaluation of transport coefficients of systems containing dissipative and random forces provided that for these mesoscopic systems: (i) the corresponding conservation laws are satisfied, and (ii) the transition probabilities satisfy detailed balance. Dissipative particle dynamics (DPD) and energy-conserving DPD methods (DPDE), for instance, are archetypical of such mesoscopic approaches satisfying these properties. To verify this statement, we have derived a mesoscopic heat flux form for the DPDE method, suitable for the calculation of the thermal conductivity from an EH expression. We have compared EH measurements against non-equilibrium simulation values for different scenarios, including many-body potentials, and have found excellent agreement in all cases. The expressions are valid notably for systems with density- and temperature-dependent potentials, such as the recently developed generalised DPDE method (GenDPDE) [Avalos et al., Phys. Chem. Chem. Phys., 2019, 21, 24891]. We thus demonstrate that traditional EH formulas in equilibrium simulations can be widely used to obtain transport coefficients, provided that the appropriate expression for the associated flux is used.

Electronic couplings in intermolecular electron and energy transfer processes calculated by six different existing computational techniques are compared to nonorthogonal configuration interaction for fragments (NOCI-F) results. The paper addresses the calculation of the electronic coupling in diketopyrrolopyrol, tetracene, 5,5'-difluoroindigo, and benzene-Cl for hole and electron transport, as well as the local exciton and singlet fission coupling. NOCI-F provides a rigorous computational scheme to calculate these couplings, but its computational cost is rather elevated. The here-considered ab initio Frenkel-Davydov (AIFD), Dimer projection (DIPRO), transition dipole moment coupling, Michl-Smith, effective Hamiltonian, and Mulliken-Hush approaches are computationally less demanding, and the comparison with the NOCI-F results shows that the NOCI-F results in the couplings for hole and electron transport are rather accurately predicted by the more approximate schemes but that the NOCI-F exciton transfer and singlet fission couplings are more difficult to reproduce.

Nano/micromotors (NMs) are tiny structures capable of converting various forms of energy into mechanical motion at the micro and nanoscale. These motors operate in environments characterized by low inertia and low Reynolds numbers. The potential applications of NMs are vast, particularly in the fields of biomedicine and environmental science. One of the most intriguing developments in this field is the integration of NMs with surface-enhanced Raman scattering (SERS) spectroscopy. SERS is a powerful analytical technique that enhances the Raman intensity of molecules, allowing for highly sensitive detection and analysis of trace amounts of substances. This integration offers highly precise and localized ultrasensing capabilities. The combination of NMs with SERS can also facilitate real-time imaging inside living organisms. This has immense potential in chemical and cell biology and medical diagnostics and prognosis. Herein this review describes the types of NMs and their fabrication, the incorporation of plasmonic nanostructures, capable of creating strong electromagnetic fields when illuminated by light, which in turn enhances the Raman signals significantly, their applications, and their future prospects in areas such as precision medicine, environmental monitoring, and possibly even in new realms like microscale robotics and targeted therapeutics.This review investigates the synergistic integration of SERS and nano/micromotors, showcasing their combined applications in bioanalytical sensing, environmental monitoring, and nanoscale imaging. Furthermore, future prospects and challenges are discussed, emphasizing the crucial role of ongoing research in fully realizing the potential of SERS and nano/micromotors.image

Mixed zinc-zirconium oxides, ZnZrOx, are highly selective and stable catalysts for CO2 hydrogenation to methanol, a pivotal energy vector. However, their activity remains moderate, and descriptors to design improved systems are lacking. This work applies flame spray pyrolysis (FSP), a one-step and scalable method, to synthesize a series of ZnZrOx catalysts, and systematically compares them to coprecipitated (CP) analogs to establish deeper synthesis-structure-performance relationships. FSP systems (up to 5 mol%) generally display a threefold higher methanol productivity compared to their CP counterparts. In-depth characterization and theoretical simulations show that, unlike CP, FSP maximizes the surface area and formation of atomically dispersed Zn2+ sites incorporated in lattice positions within the ZrO2 surface, which is key to improving performance. Analysis by in situ electron paramagnetic resonance (EPR) spectroscopy reveals that the specific architecture of the flame-made catalyst markedly fosters the generation of oxygen vacancies. Together with surrounding Zn and Zr-O atoms, the oxygen vacancies create active ensembles that favor methanol formation through the formate path while suppressing undesired CO production, as confirmed by kinetic modeling. This study elucidates the nature of active sites and their working mechanism, pushing forward ZnZrOx-catalyzed methanol synthesis by providing a new benchmark for this cost-effective and earth-abundant catalyst family.

Impedance spectroscopy (IS) is an effective characterization technique used to probe and distinguish charge dynamics occurring at different timescales in optoelectronic and electric devices. With the rapid rise of research being conducted on perovskite solar cells (PSCs), IS has significantly contributed to the understanding of their device performance and degradation mechanisms, including metastable effects such as current–voltage hysteresis. The ionic–electronic behavior of PSCs and the presence of a wide variety of perovskite compositions and cell architectures add complexity to the accurate interpretation of the physical processes occurring in these devices. In this review, the most common IS protocols are explained to help perform accurate impedance measurements on PSC devices. It critically reviews the most commonly used equivalent circuits alongside drift-diffusion modeling as a complementary technique to analyze the impedance response of PSCs. As an emerging method for characterizing the interfacial recombination between the perovskite layer and selective contacts, light intensity modulated impedance spectroscopy technique is further discussed. Lastly, important works on the application of IS measurement protocols for PSCs are summarized followed by a detailed discussion, providing a critical perspective and outlook on the growing topic of IS on PSCs.

In this work, the morphology, surface composition, and electronic properties of porous GaN films containing hexagonal V-shaped pits were studied. The V-pits are orientated along the [0001] direction of GaN, and we observed a clear relation between the growth time with the surface composition, film thickness, and pit morphology, which in turn had a significant impact on the band gap, valence band maximum, and the work function. The effect on the position of the valence band maximum and work function is explained by the formation of superficial oxygen-rich phases such as Ga2O3 and nonstoichiometric GaNxOy as supported by X-ray photoelectron spectroscopy and density functional theory (DFT). We further show a change in the optical band gap with the thickness of the porous films explained by a change in the tensile strain caused by open-core screw dislocations that gives rise to the formation of V-pits. The correlation between strain and the band gap is supported by DFT calculations. Our study provides insights into the intricate relation between surface states and electronic properties of semiconducting materials and offers directions for designing GaN heterojunctions with specific optical and electronic properties.

Acetylene gas isan important feedstock for chemical production,although it is underutilized in organic synthesis. We have developedan intermolecular gold(I)-catalyzed alkyne/alkene reaction of o-allylphenols with acetylene gas that gives rise to chromanesby a stereospecific aryloxycyclization through the nucleophilic regioselectiveopening of cyclopropyl gold(I)-carbene intermediates. The syntheticapplication of this method was demonstrated in the late-stage functionalizationof the natural product lapachol.

Perylenediimide molecules constitute a family of chromophores that undergo singlet fission, a process in which an excited singlet state converts into lower energy triplets on two neighboring molecules, potentially increasing the efficiency of organic solar cells. Here, the nonorthogonal configuration interaction method is applied to study the effect of the different crystal packing of various perylenediimide derivatives on the relative energies of the singlet and triplet states, the intermolecular electronic couplings, and the relative rates for singlet fission. The analysis of the wave functions and electronic couplings reveals that charge transfer states play an important role in the singlet fission mechanism. Dimer conformations where the PDI molecules are at large displacements along the long axis and short on the short axis are posed as the most favorable for singlet fission. The role of the substituent at the imide group has been inspected concluding that, although it has no effect in the energies, for some conformations it significantly influences the electronic couplings, and therefore, replacing this substituent with hydrogen may introduce artifacts in the computational modeling of the PDI molecules.

Organic solar cells (OSCs) have reached an efficiency near 20%; however, their low long-term stability is the main limitation to their industrialization. In this work, we investigated the degradation of bulk heterojunction non-fullerene solar cells (NFA-OSCs) based on PM6:Y7 with an efficiency of 17.5%. The degradation analysis was carried out following the established ISOS-D-1 protocol under different degradation conditions: N-2 atmosphere (H2O < 0.1 ppm and O-2 < 0.1 ppm) and encapsulated devices and non-encapsulated devices exposed to ambient conditions (60 & PLUSMN; 5% relative humidity). The evolution of the current density-voltage (J-V) and impedance spectroscopy (IS) measurements were used to analyse the degradation process during 1000 h and its relationship with physical mechanisms. The degradation of encapsulated and non-encapsulated devices is mainly caused by the drop in the open circuit voltage (V-OC). For devices exposed to the N-2 atmosphere, the fill factor (FF) was the most affected parameter. The dependence of short circuit current density (J(SC)) versus light intensity study reveals that the efficiency of non-encapsulated devices decreases faster due to a higher bimolecular recombination degree. The devices under a N-2 atmosphere and those encapsulated showed T-80 lifetimes of 1000 h and 336 h, respectively, whereas the non-encapsulated devices have a short T-80 lifetime of less than 24 h. The analysis of the efficiency decay was used to identify the different degradation mechanisms (by diffused environmental water or oxygen or by intrinsic polymer chemical reactions) under different conditions. The degradation origin of the active layer and interlayers was investigated through impedance spectroscopy measurements.

Photoelectrochemical carbon dioxide reduction (CO2) at ambient temperature and pressure was performed using molecular chromophores and catalyst assemblies on CuGaO2-based electrodes in an ionic liquid (IL) organic solution, acting as a CO2 absorbent and electrolyte. A simple and versatile methodology based on the silanization of the CuGaO2 electrode followed by electropolymerization provided a series of molecular and supramolecular hybrid photocathodes for solar driven CO2 reduction. Focusing on the cathodic half reactions, the most promising conditions for the formation of CO2 reduction products were determined. The results revealed a beneficial effect of the ionic liquid on the conversion of CO2 to formic acid and suppression of the production of hydrogen. The potentiality of anchoring supramolecular complexes on semiconductor photoelectrocatalysts was demonstrated to boost both carrier transport and catalytic activity with a FEred of up to 81% compared with the obtained FEred of 52% using bare CuGaO2 with formate as the major product.

The synthesis of two series of catalysts based on ligand-capped supported Pd nanoparticles was carried out using a simple procedure and the resulting materials were tested in the formate synthesis. Within these series, PPh3 revealed the most appropriate stabilizing ligand while TiO2 was the most efficient support for these catalysts. The hydrogenation of CO2 was carried out under mild reaction conditions (1.8 MPa CO2, 1.8 MPa H2, 60 °C) using water as solvent and in the presence of a base, providing excellent selectivity towards formates with a TON of 1032 (TOF of 69 h−1, [HCOOK]=1.1 mol/l).

Zinc(II) complexes [Zn(L1-L5)Cl2] with tetra-aza donor ligands bearing phenanthroline and bipyridine bis(aniline) skeleton L1-L5 have been prepared and characterised. These ligands were selected to analyse the influence on the catalytic activity for the CO2-cycloaddition to epoxides of three parameters: the steric hindrance of the orto substituent of the aniline ring, the central skeleton and the nature of the non-aromatic amine. X-ray diffraction characterisation of [Zn(L1)Cl2] and [Zn(L2)Cl2] showed that the geometry is pentacoordinate while in the case of [Zn(L5)Cl2] a four-coordinate tetrahedral complex was formed. Computational calculations using density functional theory methods (DFT) agreed with these results. These complexes combined with tetrabutylammonium bromide (TBAB) are very selective for the CO2/terminal epoxides coupling to form cyclic carbonates providing activity up to TOF 565 h−1.

Mealworm, TM (Tenebrio molitor), and black soldier fly, BSF (Hermetia illucens) are of special interest for food and feed applications due to their environmental benefits such as low water and land requirements, low greenhouse gas emissions, and high feed-conversion efficiency. This study assesses the use of ultrafiltration (UF) to fractionate protein concentrates from TM and BSF (TMPC, BSFPC) in order to enhance emulsifying and foaming properties. A 30 kDa regenerated cellulose acetate membrane enabled the separation of concentrate and permeate fractions for both insect proteins from two different initial feed concentrations (10 and 7.5 g/L). Permeate flux and protein transmission behave differently depending on the insect type and the initial concentration; while for TMPC permeate flux increases with a decrease in the initial protein concentration, it is not affected for BSFPC. The existing membrane cleaning protocols are suitable for recovering water flux after UF of insect proteins, enabling membrane re-use. Emulsifying activity is maintained for all the TMPC fractions, but it is significantly lower for the permeate fractions of BSFPC. Foaming properties are maintained for all the UF fractions of BSFPC and the ones from 7.5 g/L TMPC. Acidic solubilization leads to a fraction with enhanced emulsifying capacity and one with higher foaming capacity than the original for BSFPC. This study opens the door to membrane technology for insect protein fractionation, which has not been studied so far and has already provided useful solutions for other animal and plant proteins.

H2 production can be used as a clean and renewable energy source for various applications, including fuel cells, internal combustion engines, and chemical production. Using nickel-based catalysts for steam reforming biomass tar presents challenges related to catalyst deactivation, poisoning, heterogeneous composition, high process temperatures, and gas impurities. To overcome these challenges, adopting a nickel-based catalyst with selected oxide support and MgO and CaO promoter is a promising approach for improving the efficiency and sustainability of steam reforming for hydrogen production. The majority of studies conducted to date have focused on the steam reforming of particular tar compounds, most commonly benzene, phenol, toluene, or naphthalene, over a range of support catalysts. However, the actual biomass tar composition is complex, and each component impacts how well steam reforming works. In this research, a multi-compound biomass tar model including phenol, toluene, naphthalene, and pyrene underwent a steam reforming process. Various types with 10 wt.% of nickel-based catalysts were generated by the co-impregnation technique, which included 90 wt.% different oxide supports (Al2O3, La2O3, and ZrO2) and 10 wt.% of combination alkaline oxide earth promoters (MgO and CaO). Thermogravimetric analysis, Brunauer–Emmett–Teller (BET) method, N2 physisorption, temperature-programmed reduction (H2-TPR), temperature-programmed desorption (CO2-TPD), and X-ray diffraction (XRD) of ni-based catalyst characterized physiochemical properties of the prepared catalyst. The reaction temperature used for steam reforming was 800 °C, an S/C ratio of 1, and a GHSV of 13,500 h−1. Ni/La2O3/MgO/CaO (NiLaMgCa) produced the most carbon to-gas conversion (86.27 mol%) and H2 yield (51.58 mo

We present an agile, hardware independent analysis methodology based on the spectral windows technique to detect and quantify the environmental activity concentration of artificial isotopes of interest. The method removes counts from Compton scattering, peak overlapping, intrinsic background and other unconsidered contributions to the spectral region where photopeaks from artificial elements are expected. Taking into account the varying concentration of 214Bi, 214Pb, and 212Pb, we compute the activity concentration of the artificial isotopes (when detectable), or a variable Minimum Detectable Activity Concentration (MDAC). This allows to set statistically robust early-warning levels. In the scenario with the lowest concentration of natural occurring isotopes, and for 10-min integration time, we achieve a MDAC of 5.4/4.1/3.9 (Bq/m³) for 131I/137Cs/60Co using a LaBr3(Ce) detector; and 4.2/2.8/2.7 (Bq/m³) for 131I/137Cs/60Co with a SrI2(Eu) detector.

Nowadays, CO2 electroreduction is gaining special interest as achieving net zero CO2 emissions is not going to be enough to avoid or mitigate the negative effects of climate change. However, the cost of CO2 electroreduction is still very high because of the low efficiency of conversion (around 20%). Therefore, it is necessary to optimize the reaction conditions. Thus, a miniaturized novel membrane reactor was designed and manufactured in this study, with a shorter distance between the electrodes and a reduced volume, compared with CNC-manufactured reactors, using novel stereolithography-based 3D printing. The reduced distance between the two electrodes reduced the electrical resistance and therefore lowered the overpotential necessary to trigger the reaction from −1.6 V to −1.2 V, increasing the efficiency. In addition, the reduction in the volume of the reactor increased the catalyst area/volume ratio, which also boosted the concentration of the products (from FE 18% to FE 21%), allowing their better identification. Furthermore, the smaller volume and reduced complexity of the reactor also improved the testing capacity and decreased the cost of experimentation. The novel miniaturized reactor can help researchers to perform more experiments in a cost/time-effective way, facilitating the optimization of the reaction conditions.

Even though lignin is very rich in aromatic compounds, it remains the least exploited fraction of biomass due to its recalcitrant nature. Consequently, prevailing efforts to fully unlock its potential are still far from reaching due to the use of harsh conditions and energy-intensive processes which are not environmentally friendly. Herein, a facile approach for coupling acid-catalyzed mechanocatalysis (MC) via ball milling with TiO2 photocatalysis (PC)/Fenton for depolymerization of alkaline lignin was investigated. Mechanocatalysis (MC) involved prior acid impregnation (AI) followed by ball milling. A direct comparison of pretreatments (AI, BM, MC) coupled with oxidation processes was preliminarily undertaken. The untreated lignin (UL) served as the control. MC/PC showed the highest yield of major aromatic products. Vanillin, homovanillic acid, acetovanillone, guaiacol, and vanillic acid were major aromatic building blocks identified and quantified. Further optimization revealed a total monomer yield of 22.77 wt%. SEM and FTIR analysis were done with the latter revealing the existence of pre-oxidation reaction in the BM and MC lignin prior to PC. The proposed synergetic process could offer an advantage over prevailing robust systems used for lignin depolymerization.

This paper reports a straightforward and inexpensive method for the fabrication of gas sensing devices based on graphene oxide (GO) synthesized by a modified Hummer's method and decorated with strontium titanate perovskite (SrTiO3). The active layers developed were employed for the detection of hazardous gases such as NO2, CO2, and NH3. The physical and chemical properties were also analyzed using various experimental techniques including field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), X-ray powder diffraction (XRD), and Raman spectroscopy. Repeated response and recovery cycles were applied in the detection of nitrogen dioxide (NO2), carbon dioxide (CO2), and ammonia (NH3). Accordingly, the gas sensing study reveals that decorated GO exhibits a high response towards NO2 at an operating temperature of 100 °C with good sensitivity (up to 4-fold higher than that of pristine GO) and highly improved selectivity. Additionally, the effect of ambient humidity was tested for NO2, demonstrating that GO/SrTiO3 sensors show a good immunity to humidity cross-sensitivity. Lastly, a gas sensing mechanism was schematically proposed and discussed. These findings prove that the functionalization of GO with SrTiO3 can overcome the limitations of GO-based sensors by enhancing their adsorption capability of gas molecules and their sensitivity towards target gases.