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We explore the thermal oxidation of hyper-cross-linked polymers to enhance their hydrophilicity and efficacy in atmospheric water harvesting. Comprehensive chemical and physical characterizations are used to confirm the successful incorporation of polar oxygen moieties and the preservation of porosity upon thermal treatment. Newly introduced oxygen-based functional groups significantly improve water sorption properties, increasing total water uptake capacities by up to 400% and shifting water uptake onsets to significantly lower relative humidity. We also investigate the regeneration of oxidized hyper-cross-linked polymers after water sorption to probe their potential for multiple water harvesting cycles and reuse. Our findings outline a simple and cost-effective postsynthetic modification route for optimizing porous organic polymers for more sustainable and efficient atmospheric water harvesting.

The legislature determines the recycled and waste contents in fabrication processes to ensure more sustainable production. PLA's mechanical recycling and reuse are limited due to the performance decrease caused by thermal or hydrolytic instability. Our concept introduces an upcycling route involving PLA depolymerization using propylene glycol as a reactant, followed by the methacrylation, assuring the liquid systems' curability provided by radical polymerization. PLA-containing curable systems were studied from a rheological and thermomechanical viewpoint. The viscosity levels varied from 33 to 3911 mPa·s at 30 °C, giving a wide capability potential. The best system reached 2240 MPa storage modulus, 164.1 °C glass-transition temperature, and 145.6 °C heat-resistant index, competitive values to commercial systems. The printability was verified for all of the systems. Eventually, our concept led to SLA resin production containing PLA waste content up to 51 wt %.

Determining the local coordination of the active site is a prerequisite for the reliable modeling of single-atom catalysts (SACs). Obtaining such information is difficult on powder-based systems and much emphasis is placed on density functional theory computations based on idealized low-index surfaces of the support. In this work, we investigate how Pt atoms bind to the (11̅02) facet of α-Fe 2 O 3 ; a common support material in SACs. Using a combination of scanning tunneling microscopy, X-ray photoelectron spectroscopy, and an extensive computational evolutionary search, we find that Pt atoms significantly reconfigure the support lattice to facilitate a pseudolinear coordination to surface oxygen atoms. Despite breaking three surface Fe-O bonds, this geometry is favored by 0.84 eV over the best configuration involving an unperturbed support. We suggest that the linear O-Pt-O configuration is common in reactive Pt-based SAC systems because it balances thermal stability with the ability to adsorb reactants from the gas phase. Moreover, we conclude that extensive structural searches are necessary to determine realistic active site geometries in single-atom catalysis.

Agricultural practices introduce pharmaceutical (PhAC) residues into the terrestrial environment, potentially endangering agricultural crops and human health. This study aimed to evaluate various aspects related to the presence of pharmaceuticals in the lettuce-soil system, including bioconcentration factors (BCFs), translocation factors (TFs), ecotoxicological effects, the influence of biochar on the PhAC bioavailability, persistence in soil, and associated environmental and health risks. Lettuce ( Lactuca sativa L.) was exposed to a mixture of 25 PhACs in two scenarios: initially contaminated soil (ranging from 0 to 10,000 ng·g -1 ) and soil irrigated with contaminated water (ranging from 0 to 1000 μg·L -1 ) over a 28-day period. The findings revealed a diverse range of BCFs (0.068-3.7) and TFs (0.032-0.58), indicating the uptake and translocation potential of pharmaceuticals by lettuce. Significant ecotoxicological effects on L. sativa , including weight change and increased mortality, were observed ( p < 0.05). Interestingly, biochar did not significantly affect PhAC uptake by L. sativa ( p > 0.05), while it significantly influenced the soil degradation kinetics of 12 PhACs ( p < 0.05). Additionally, the estimated daily intake of PhACs through the consumption of L. sativa suggested negligible health risks, although concerns arose regarding the potential health risks if other vegetable sources were similarly contaminated with trace residues. Furthermore, this study evaluated the environmental risk associated with the emergence of antimicrobial resistance (AMR) in soil, as medium to high. In conclusion, these findings highlight the multifaceted challenges posed by pharmaceutical contamination in agricultural environments and emphasize the importance of proactive measures to mitigate the associated risks to both environmental and human health., Competing Interests: The authors declare no competing financial interest., (© 2024 The Authors. Published by American Chemical Society.)

Machine learning potentials have become an essential tool for atomistic simulations, yielding results close to ab initio simulations at a fraction of computational cost. With recent improvements on the achievable accuracies, the focus has now shifted on the data set composition itself. The reliable identification of erroneously predicted configurations to extend a given data set is therefore of high priority. Yet, uncertainty estimation techniques have achieved mixed results for machine learning potentials. Consequently, a general and versatile method to correlate energy or atomic force uncertainties with the model error has remained elusive to date. In the current work, we show that epistemic uncertainty cannot correlate with model error by definition but can be aggregated over groups of atoms to yield a strong correlation. We demonstrate that our method correctly estimates prediction errors both globally per structure and locally resolved per atom. The direct correlation of local uncertainty and local error is used to design an active learning framework based on identifying local subregions of a large simulation cell and performing ab initio calculations only for the subregion subsequently. We successfully utilized this method to perform active learning in the low-data regime for liquid water.

We present the first observation of vibrational transitions in the [H 3 O] - anion, an intermediate in the anion-molecule reaction of water, H 2 O, and hydride, H - , using a laser-induced isotopic H/D exchange reaction action spectroscopy scheme applied to anions. The observed bands are assigned as the fundamental and first overtone of the H 2 O-H - vibrational stretching mode, based on anharmonic calculations within the vibrational perturbation theory and vibrational configuration interaction. Although the D 2 O·D - species has the lowest energy, our experiments confirm the D 2 O·H - isotope to be a sink of the H/D exchange reaction. Ab initio calculations corroborate that the formation of D 2 O·H - is favored, as the zero-point-energy difference is larger between D 2 and H 2 than between D 2 O·H - and D 2 O·D - .

Femtosecond laser ablation of Cu 0.70 Zn 0.30 targets in ethanol led to the formation of periodic surface nanostructures and crystalline CuZn alloy nanoparticles with defects, low-coordinated surface sites, and, controlled by the applied laser fluence, different sizes and elemental composition. The Cu/Zn ratio of the nanoparticles was determined by energy dispersive X-ray spectroscopy, X-ray photoelectron spectroscopy, and selected area electron diffraction. The CuZn nanoparticles were about 2-3 nm in size, and Cu-rich, varying between 70 and 95%. Increasing the laser fluence from 1.6 to 3.2 J cm -2 yielded larger particles, more stacking fault defects, and repeated nanotwinning, as evident from high-resolution transmission electron microscopy, aided by (inverse) fast Fourier transform analysis. This is due to the higher plasma temperature, leading to increased random collisions/diffusion of primary nanoparticles and their incomplete ordering due to immediate solidification typical of ultrashort pulses. The femtosecond laser-synthesized often nanotwinned CuZn nanoparticles were supported on highly oriented pyrolytic graphite and applied for ethylene hydrogenation, demonstrating their promising potential as model catalysts. Nanoparticles produced at 3.2 J cm -2 exhibited lower catalytic activity than those made at 2.7 J cm -2 . Presumably, agglomeration/aggregation of especially 2-3 nm sized nanoparticles, as observed by postreaction analysis, resulted in a decrease in the surface area to volume ratio and thus in the number of low-coordinated active sites.

Polymer coating to substrates alters surface chemistry and imparts bulk material functionalities with a minute thickness, even in nanoscale. Specific surface modification of a substate usually requires an active substrate that, e.g., undergoes a chemical reaction with the modifying species. Here, we present a generic method for surface modification, namely, solid-state adsorption, occurring purely by entropic strive. Formed by heating above the melting point or glass transition and subsequent rinsing of the excess polymer, the emerging ultrathin (<10 nm) layers are known in fundamental polymer physics but have never been utilized as building blocks for materials and they have never been explored on soft matter substrates. We show with model surfaces as well as bulk substrates, how solid-state adsorption of common polymers, such as polystyrene and poly(lactic acid), can be applied on soft, cellulose-based substrates. Our study showcases the versatility of solid-state adsorption across various polymer/substrate systems. Specifically, we achieve proof-of-concept hydrophobization on flexible cellulosic substrates, maintaining irreversible and miniscule adsorption yet with nearly 100% coverage without compromising the bulk material properties. The method can be considered generic for all polymers whose T g are below those of the to-be-coated adsorbed layer, and whose integrity can withstand the solvent leaching conditions. Its full potential has broad implications for diverse materials systems where surface coatings play an important role, such as packaging, foldable electronics, or membrane technology.T m are below those of the to-be-coated adsorbed layer, and whose integrity can withstand the solvent leaching conditions. Its full potential has broad implications for diverse materials systems where surface coatings play an important role, such as packaging, foldable electronics, or membrane technology.

We explore the phonon transport properties of defect-laden bilayer PtSTe using equilibrium molecular dynamics simulations based on a neural-network force field. Defects prove very efficient at depressing the thermal conductivity of the structure, and flower defects have a particularly powerful effect, comparable to that of double vacancies. Furthermore, the conductivity of the structure with flower defects exhibits an unusual temperature dependence due to structural instability at high temperatures. We look into the distortion to normal modes around the defect by means of the projected phonon density of states and find diverse phenomena including localized modes and blue shifts., Competing Interests: The authors declare no competing financial interest., (© 2024 The Authors. Published by American Chemical Society.)

The discharge of toxic dye effluents from industry is a major concern for environmental pollution and toxicity. These toxic dyes can be efficiently removed from waste streams using a photocatalysis process involving visible light. Due to its simple synthesis procedure, inexpensive precursor, and robust stability, graphitic carbon nitride (g-C 3 N 4 , or CN) has been used as a visible light responsive catalyst for the degradation of dyes with mediocre performance because it is limited by its low visible light harvesting capability due to its wide bandgap and fast carrier recombination rate. To overcome these limitations and enhance the performance of g-C 3 N 4 , it was coupled with a narrow bandgap copper tin sulfide (CTS) semiconductor to form a p-n heterojunction. CTS and g-C 3 N 4 were selected due to their good stability, low toxicity, ease of synthesis, layered sheet/plate-like morphology, and relatively abundant precursors. Accordingly, a series of copper tin sulfide/graphitic carbon nitride nanocomposites (CTS/g-C 3 N 4 ) with varying CTS contents were successfully synthesized via a simple two-step process involving thermal pyrolysis and coprecipitation for visible-light-induced photocatalytic degradation of methyl orange (MO) dye. The photocatalytic activity results showed that the 50%(wt/wt) CTS/g-C 3 N 4 composite displayed a remarkable degradation efficiency of 95.6% for MO dye under visible light illumination for 120 min, which is higher than that of either pristine CTS or g-C 3 N 4 . The improved performance is attributed to the extended light absorption range (due to the optimized bandgap), effective suppression of photoinduced electron-hole recombination, and improved charge transfer that arose from the formation of a p-n heterojunction, as evidenced by electrochemical impedance spectroscopy (EIS), photocurrent, and photoluminescence results. Moreover, the results of the reusability study showed that the composite has excellent stability, indicating its potential for the degradation of MO and other toxic organic dyes from waste streams., Competing Interests: The authors declare no competing financial interest., (© 2024 The Authors. Published by American Chemical Society.)

The improved production of a polar curable monomer, isosorbide monomethacrylate (MISD), with methacrylic anhydride (MAAH) as an acyl donor, was performed. A sustainable and cheap catalyst, potassium acetate (CH 3 COOK), was used for a solvent-free synthesis, requiring only the equimolar amount of reagents (no excess). The production included the quantitative separation of the secondary product, methacrylic acid (MAA), preventing the reaction batch from the purification process (neutralization of MAA), and gaining a usable reagent. The synthesis resulted in a sufficient yield of MISD (61.8%) obtained by the liquid-liquid extraction process (LLE), which is a significant improvement in the process, avoiding the flash chromatography step in the isolation of MISD. The purity of synthesized and isolated MISD via the LLE was confirmed by 1 H NMR, MS, and FTIR analyses. The thermal analyses, namely, DSC and TGA, were used to characterize the curability and thermal stability of MISD. The activation energy of MISD's curing was calculated ( E a = 136.8). The polar character of isosorbide monomethacrylate was investigated in a mixture with epoxidized acrylated soybean oil (EASO). It was found that MISD is entirely soluble in EASO and can modify the rheological behavior and surface energy of EASO-based resins. The apparent viscosity of EASO at 30 °C (η T = 3413 mPa·s) decreased with the 50% content of MISD significantly (η s = 500 mPa·s), and the free surface energy value of EASO (γ app = 3413 mPa·s) decreased with the 50% content of MISD significantly (η app ) also increased with the 50% content of MISD (γ S = 42.2 mJ/m 2 ). The produced MISD can be successfully used as a diluent and the polarity modifier of curable oil-based resins.S = 48.7 mJ/m 2 ). The produced MISD can be successfully used as a diluent and the polarity modifier of curable oil-based resins., Competing Interests: The authors declare no competing financial interest., (© 2024 The Authors. Published by American Chemical Society.)

The nickel-rich region of the system Ce-Ni-Si has been reinvestigated utilizing X-ray single-crystal, powder, and electron diffraction as well as electron microprobe and thermal analyses. Two novel hexagonal compounds, τ-Ce 20+ x Ni 36+ y Si 30- z and τ'-Ce 30+ x Ni 50+ y Si 42- were identified. The crystal structure of τ-Ce z , were identified. The crystal structure of τ-Ce 20+ x Ni 36+ y Si 30- z was derived from single-crystal X-ray diffraction and found to be isotypic with the Sm 10 Ni 20.8 P 15 -type structure (S.G. P 6 3 / m, x = 1.8, y = 3.0, z = 1.8, a = 0.048). Rietveld refinement of τ'-Ce c = 0.39990(1) nm, R F = 0.048). Rietveld refinement of τ'-Ce 30+ x Ni 50+ y Si 42- z revealed isotypism with Tb 15 Ni 28 P 21 (S.G. P 6 3 / m , a = 2.46926(13) nm, c = 0.40019(3) nm, R F = 0.058). The compound Ce 3 Ni 4 Si 2 from X-ray single-crystal analysis was found to crystallize in a novel structure type with monoclinic unit cells (S.G. C 2/ c = 0.017). This compound belongs to a new homologue series in the RE-Ni-Si system (RE = La and Ce) with general formula of RE a = 1.54708(3) nm, b = 0.58677(1) nm, c = 0.74331(1) nm, β = 102.985(1)°, R = 0,1, ..., ∞. The crystal structure of this series is characterized by alternating numbers (2 F ) of corner-sharing Si-polyhedral blocks sandwiched between zigzag nickel chains. Higher-order members of this series are produced by the formation of more corner-sharing Si-polyhedral blocks due to removal of nickel chains.(3×2 n ) Ni (3×2 n  + 1) Si (2 n +1 ) ; n = 0,1, ..., ∞. The crystal structure of this series is characterized by alternating numbers (2 n ) of corner-sharing Si-polyhedral blocks sandwiched between zigzag nickel chains. Higher-order members of this series are produced by the formation of more corner-sharing Si-polyhedral blocks due to removal of nickel chains.

Proteins are highly labile molecules, thus requiring the presence of appropriate solvents and excipients in their liquid milieu to keep their stability and biological activity. In this field, ionic liquids (ILs) have gained momentum in the past years, with a relevant number of works reporting their successful use to dissolve, stabilize, extract, and purify proteins. Different approaches in protein-IL systems have been reported, namely, proteins dissolved in ( i ) neat ILs, ( ii ) ILs as co-solvents, ( iii ) ILs as adjuvants, ( iv ) ILs as surfactants, ( v ) ILs as phase-forming components of aqueous biphasic systems, and ( vi ) IL-polymer-protein/peptide conjugates. Herein, we critically analyze the works published to date and provide a comprehensive understanding of the IL-protein interactions affecting the stability, conformational alteration, unfolding, misfolding, and refolding of proteins while providing directions for future studies in view of imminent applications. Overall, it has been found that the stability or purification of proteins by ILs is bispecific and depends on the structure of both the IL and the protein. The most promising IL-protein systems are identified, which is valuable when foreseeing market applications of ILs, e.g., in "protein packaging" and "detergent applications". Future directions and other possibilities of IL-protein systems in light-harvesting and biotechnology/biomedical applications are discussed.

Adding photocatalytically active TiO 2 nanoparticles (NPs) to polymeric paints is a feasible route toward self-cleaning coatings. While paint modification by TiO 2 -NPs may improve photoactivity, it may also cause polymer degradation and release of toxic volatile organic compounds. To counterbalance adverse effects, a synthesis method for nonmetal (P, N, and C)-doped TiO 2 -NPs is introduced, based purely on waste valorization. PNC-doped TiO 2 -NP characterization by vibrational and photoelectron spectroscopy, electron microscopy, diffraction, and thermal analysis suggests that TiO 2 -NPs were modified with phosphate (P=O), imine species (R=N-R), and carbon, which also hindered the anatase/rutile phase transformation, even upon 700 °C calcination. When added to water-based paints, PNC-doped TiO 2 -NPs achieved 96% removal of surface-adsorbed pollutants under natural sunlight or UV, paralleled by stability of the paint formulation, as confirmed by micro-Fourier transform infrared (FTIR) surface analysis. The origin of the photoinduced self-cleaning properties was rationalized by three-dimensional (3D) and synchronous photoluminescence spectroscopy, indicating that the dopants led to 7.3 times stronger inhibition of photoinduced e - /h + recombination when compared to a benchmark P25 photocatalyst., Competing Interests: The authors declare no competing financial interest., (© 2024 The Authors. Published by American Chemical Society.)

Liquid-like surfaces featuring slippery, omniphobic, covalently attached liquids (SOCALs) reduce unwanted adhesion by providing a molecularly smooth and slippery surface arising from the high mobility of the liquid chains. Such SOCALs are commonly prepared on hard substrates, such as glass, wafers, or metal oxides, despite the importance of nonpolar elastomeric substrates, such as polydimethylsiloxane ( PDMS ) in anti-fouling or nonstick applications. Compared to polar elastomers, hydrophobic PDMS elastomer activation and covalent functionalization are significantly more challenging, as PDMS tends to display fast hydrophobic recovery upon activation as well as superficial cracking. Through the extraction of excess PDMS oligomers and fine-tuning of plasma activation parameters, homogeneously functionalized PDMS with fluorinated polysiloxane brushes could be obtained while at the same time reducing crack formation. Polymer brush mobility was increased through the addition of a smaller molecular silane linker to exhibit enhanced dewetting properties and reduced substrate swelling compared to functionalizations featuring hydrocarbon functionalities. Linear polymer brushes were verified by thermogravimetric analysis. The optical properties of PDMS remained unaffected by the activation in high-frequency plasma but were impacted by low-frequency plasma. Drastic decreases in solid adhesion of not just complex contaminants but even ice could be shown in horizontal push tests, demonstrating the potential of SOCAL-functionalized PDMS surfaces for improved nonstick applications.

Despite having favorable energetics and tunable optoelectronic properties, utilization of BaTiO 3 (BTO) for photocatalytic reactions is limited by its absorption only in the ultraviolet region. To address this challenge, BTO is doped with iridium (Ir) to induce visible light absorption. The visible light-induced photocatalytic H 2 generation efficiency is enhanced by 2 orders of magnitude on selective conversion of the Ir valence state from Ir 4+ to Ir 3+ . To understand such intriguing behavior, valence state-dependent changes in the optoelectronic, structural, and surface properties and electronic band structure are comprehensively investigated. The effect of electron occupancy change between Ir 4+ (t 2g 5 e g 0 ) and Ir 3+ (t 2g 6 e g 0 production in these emerging BTO-based photocatalysts. Collectively, the observations made in this work highlight the promising application of Ir 2 generation. Besides this, converting Ir 4+ to Ir 3+ enhanced the photocathodic current and lowered the onset potential. Results aid in designing photocatalysts to efficiently use low-energy photons for enhancing solar H 2 production in these emerging BTO-based photocatalysts. Collectively, the observations made in this work highlight the promising application of Ir 3+ :BTO in z-scheme photocatalysis.

Copper tin sulfide, Cu 4 SnS 4 (CTS), a ternary transition-metal chalcogenide with unique properties, including superior electrical conductivity, distinct crystal structure, and high theoretical capacity, is a potential candidate for supercapacitor (SC) electrode materials. However, there are few studies reporting the application of Cu 4 SnS 4 or its composites as electrode materials for SCs. The reported performance of the Cu 4 SnS 4 electrode is insufficient regarding cycle stability, rate capability, and specific capacity; probably resulting from poor electrical conductivity, restacking, and agglomeration of the active material during continued charge-discharge cycles. Such limitations can be overcome by incorporating graphene as a support material and employing a binder-free, facile, electrodeposition technique. This work reports the fabrication of a copper tin sulfide-reduced graphene oxide/nickel foam composite electrode (CTS-rGO/NF) through stepwise, facile electrodeposition of rGO and CTS on a NF substrate. Electrochemical evaluations confirmed the enhanced supercapacitive performance of the CTS-rGO/NF electrode compared to that of CTS/NF. A remarkably improved specific capacitance of 820.83 F g -1 was achieved for the CTS-rGO/NF composite electrode at a current density of 5 mA cm -2 , which is higher than that of CTS/NF (516.67 F g -1 ). The CTS-rGO/NF composite electrode also exhibited a high-rate capability of 73.1% for galvanostatic charge-discharge (GCD) current densities, ranging from 5 to 12 mA cm -2 , and improved cycling stability with over a 92% capacitance retention after 1000 continuous GCD cycles; demonstrating its excellent performance as an electrode material for energy storage applications, encompassing SCs. The enhanced performance of the CTS-rGO/NF electrode could be attributed to the synergetic effect of the enhanced conductivity and surface area introduced by the inclusion of rGO in the composite., Competing Interests: The authors declare no competing financial interest., (© 2024 The Authors. Published by American Chemical Society.)

Olefin metathesis is one of the most significant transformations in organic chemistry and is an excellent example for efficient homogeneous catalysis. Although most currently used catalysts are primarily based on 4d and 5d metals, cycloaddition and cycloreversion reactions can also be attributed to first-row transition metals, such as Fe. Surprisingly, the potential of Mn(I)-based catalysts for olefin metathesis has been unexplored despite their prominence in homogeneous catalysis and their diagonal relationship to Ru(II). In the present study, we have investigated the prospective capabilities of Mn complexes for cycloaddition and reversion reactions using density functional theory. Therefore, we have initially compared the literature known iron model systems and their isoelectronic Mn counterparts regarding their reactivity and electronic structure. Next, we constructed potential Mn complexes derived from synthetically accessible species, including carbonyl ligands and obeying octahedral geometry. Based on thermodynamic parameters and the calculation of electronic descriptors, we were able to validate the isodiagonal relationship. Our study serves as guidance for the experimental chemist., Competing Interests: The authors declare no competing financial interest., (© 2024 The Authors. Published by American Chemical Society.)

Ethylene, a plant hormone, is a gas that plays a crucial role in fruit ripening and senescence. In this work, a novel ethylene scavenger was prepared from amorphous silica-alumina derived from sugar cane bagasse ash (SC-ASA) and used to prolong the shelf life of mango fruits during storage. KMnO 4 at 2, 4, or 6 wt %/w was loaded on SC-ASA using an impregnation method. The results showed that 4% w/w KMnO 4 loaded on SC-ASA (4KM/SC-ASA) was superior for ethylene removal at an initial ethylene concentration of 400 μL L -1 for 120 min under ambient conditions (25-27 °C and 70-75% relative humidity), resulting in 100% ethylene removal. The kinetic study of ethylene removal showed that the adsorption data were best fitted with a pseudo-first-order kinetic model. The effects of 4KM/SC-ASA as sachets on the quality changes of the mango fruits were investigated, with the results showing that mango fruits packed in cardboard boxes with 4KM/SC-ASA had significantly delayed ripening, low levels of ethylene production, respiration, and weight loss, high fruit firmness, low total soluble solids, and high acidity compared to those of the control treatment. These findings should contribute to developing an ethylene scavenger to extend the shelf life of fruits, reduce the waste of the sugar and ethanol industries, and make it a valuable material., Competing Interests: The authors declare no competing financial interest., (© 2024 The Authors. Published by American Chemical Society.)

The organic semiconductor 3,4,9,10-perylenetetracarboxylic diimide (PTCDI), a widely used industrial pigment, has been identified as a diffusion-less Na-ion storage material, allowing for exceptionally fast charging/discharging rates. The elimination of diffusion effects in electrochemical measurements enables the assessment of interaction energies from simple cyclic voltammetry experiments through the theoretical work of Laviron and Tokuda. In this work, the two N-substituted perylenes, N , N '-dimethyl-3,4,9,10-perylenetetracarboxylic diimide (Me 2 PTCDI) and N , N '-diphenyl-3,4,9,10-perylenetetracarboxylic diimide (Ph 2 PTCDI), as well as the parent molecule 3,4,9,10-perylenetetracarboxylic diimide (H 2 PTCDI) are investigated as thin-film composite electrodes on carbon fibers for sodium-ion batteries. The composite electrodes are analyzed with Raman spectroscopy. Interaction parameters are extracted from cyclic voltammetry measurements. The stability and rate capability of the three PTCDI derivatives are examined through galvanostatic measurements in sodium-ion half-cell batteries and the influence of the interactions on those parameters is evaluated. In addition, self-consistent charge density function tight binding calculations of the different PTCDI systems interacting with graphite have been carried out. The results show that the binding motif displays notable deviations from an ideal ABA stacking, especially for the neutral state. In addition, data obtained for the electron-transfer integrals show that the difference in performance between different PTCDI thin-film batteries cannot be solely explained by the electron-transfer properties and other factors such as H-bonding have to be considered., Competing Interests: The authors declare no competing financial interest., (© 2024 The Authors. Published by American Chemical Society.)

Transformations of oxygenates (CO 2 , CO, H 2 O, etc.) via Mo 2 C-based catalysts are facilitated by the high oxophilicity of the material; however, this can lead to the formation of oxycarbides and complicate the identification of the (most) active catalyst state and active sites. In this context, the two-dimensional (2D) MXene molybdenum carbide Mo 2 C T x are passivating surface groups) contains only surface Mo sites and is therefore a highly suitable model catalyst for structure-activity studies. Here, we report that the catalytic activity of Mo T x in Fischer-Tropsch (FT) synthesis increases with a decreasing coverage of surface passivating groups (mostly O*). The 2 removal of T species and its consequence on CO conversion is highlighted by the observation of a very pronounced activation of Mo x in Fischer-Tropsch (FT) synthesis increases with a decreasing coverage of surface passivating groups (mostly O*). The in situ removal of T x reductive defunctionalization of 2 C T x (pretreated in H 2 alkanes) with 55% selectivity. Alkanes up to the kerosine range form, with value of α = 0.87, which is ca. twice higher than the α value reported for 3D-Mo in situ C catalysts. The steady-state productivity of 2D-Mo T x hydrocarbons is ca. 2 orders of magnitude higher relative to a reference β-Μo 2 C (i.e., a material containing no passivating surface groups). Under steady-state FT conditions, 2D-Mo 2 C yields higher hydrocarbons (C 5+ groups of Mo 2 C catalysts. The steady-state productivity of 2D-Mo 2 C to C 5+ pretreatment temperature of 500 °C. Yet, this approach leads to a removal of carbidic carbon (as methane), resulting in a 2D-Mo 2 C catalyst that shows no in situ activation under identical FT conditions. The passivating T x hydrocarbons that are formed with only 2% selectivity. Density functional theory (DFT) results attribute the observed selectivity of 2D-Mo 2 C T alkanes to a higher energy barrier for the hydrogenation of surface alkyl species relative to the energy barriers for C-C coupling. The removal of O* is the rate-determining step in the FT reaction over 2D-Mo x C, and O* is favorably removed in the form of CO 2 pretreatment temperature of 500 °C. Yet, this approach leads to a removal of carbidic carbon (as methane), resulting in a 2D-Mo 2 O, consistent with the observation of a high CO 1- x selectivity (ca. 50%). The absence of other carbon oxygenates is explained by the energetic favoring of the direct over the hydrogen-assisted dissociative adsorption of CO.4 with 61% selectivity in preference to C 5+ hydrocarbons that are formed with only 2% selectivity. Density functional theory (DFT) results attribute the observed selectivity of 2D-Mo 2 C to C 5+ alkanes to a higher energy barrier for the hydrogenation of surface alkyl species relative to the energy barriers for C-C coupling. The removal of O* is the rate-determining step in the FT reaction over 2D-Mo 2 C, and O* is favorably removed in the form of CO 2 relative to H 2 O, consistent with the observation of a high CO 2 selectivity (ca. 50%). The absence of other carbon oxygenates is explained by the energetic favoring of the direct over the hydrogen-assisted dissociative adsorption of CO., Competing Interests: The authors declare no competing financial interest., (© 2024 The Authors. Published by American Chemical Society.)

Silicon oxycarbides (SiOCs) impregnated with tetrabutylammonium halides (TBAX) were investigated as an alternative to silica-based supported ionic liquid phases for the production of bio-based cyclic carbonates derived from limonene and linseed oil. The support materials and the supported ionic liquid phases (SILPs) were characterized via Fourier transform infrared spectroscopy, thermogravimetric analysis, nitrogen adsorption, X-ray photoelectron spectroscopy, microscopy, and solvent adsorption. The silicon oxycarbide supports were pyrolyzed at 300-900 °C prior to being coated with different tetrabutylammonium halides and further used as heterogeneous catalysts for the formation of cyclic carbonates in batch mode. Excellent selectivities of 97-100% and yields of 53-62% were obtained with tetrabutylammonium chloride supported on the silicon oxycarbides. For comparison, the catalytic performance of commonly employed silica-supported ionic liquids was investigated under the same conditions. The silica-supported species triggered the formation of a diol as a byproduct, leading to a lower selectivity of 87% and a lower yield of 48%. Ultimately, macroporous monolithic SiOC-SILPs with suitable permeability characteristics ( k 1 = 10 -11 ) were produced via photopolymerization-assisted solidification templating and applied for the selective and continuous production of limonene carbonate with supercritical carbon dioxide as the reagent and sole solvent. Constant product output over 48 h without concurrent catalyst leaching was achieved.2 ) were produced via photopolymerization-assisted solidification templating and applied for the selective and continuous production of limonene carbonate with supercritical carbon dioxide as the reagent and sole solvent. Constant product output over 48 h without concurrent catalyst leaching was achieved., Competing Interests: The authors declare no competing financial interest., (© 2024 The Authors. Published by American Chemical Society.)

Transition metal dichalcogenides are investigated for various applications at the nanoscale because of their unique combination of properties and dimensionality. For many of the anticipated applications, heat conduction plays an important role. At the same time, these materials often contain relatively large amounts of point defects. Here, we provide a systematic analysis of the impact of intrinsic and selected extrinsic defects on the lattice thermal conductivity of MoS 2 and WS 2 monolayers. We combine Boltzmann transport theory and Green's function-based T -matrix approach for the calculation of scattering rates. The force constants for the defect configurations are obtained from density functional theory calculations via a regression approach, which allows us to sample a rather large number of defects at a moderate computational cost and to systematically enforce both the translational and rotational acoustic sum rules. The calculated lattice thermal conductivity is in quantitative agreement with the experimental data for heat transport and defect concentrations for both MoS 2 and WS 2 . Crucially, this demonstrates that the strong deviation from a 1/ T temperature dependence of the lattice thermal conductivity observed experimentally can be fully explained by the presence of point defects. We furthermore predict the scattering strengths of the intrinsic defects to decrease in the sequence V Mo ≈ V 2S = > V 2S ⊥ in both materials, while the scattering rates for the extrinsic (adatom) defects decrease with increasing mass such that Li S > S ad in both materials, while the scattering rates for the extrinsic (adatom) defects decrease with increasing mass such that Li ad . Compared with earlier work, we find that both intrinsic and extrinsic adatoms are relatively weak scatterers. We attribute this difference to the treatment of the translational and rotational acoustic sum rules, which, if not enforced, can lead to spurious contributions in the zero-frequency limit.ad > K ad . Compared with earlier work, we find that both intrinsic and extrinsic adatoms are relatively weak scatterers. We attribute this difference to the treatment of the translational and rotational acoustic sum rules, which, if not enforced, can lead to spurious contributions in the zero-frequency limit., Competing Interests: The authors declare no competing financial interest., (© 2024 The Authors. Published by American Chemical Society.)

Deep learning has become a powerful and frequently employed tool for the prediction of molecular properties, thus creating a need for open-source and versatile software solutions that can be operated by nonexperts. Among the current approaches, directed message-passing neural networks (D-MPNNs) have proven to perform well on a variety of property prediction tasks. The software package Chemprop implements the D-MPNN architecture and offers simple, easy, and fast access to machine-learned molecular properties. Compared to its initial version, we present a multitude of new Chemprop functionalities such as the support of multimolecule properties, reactions, atom/bond-level properties, and spectra. Further, we incorporate various uncertainty quantification and calibration methods along with related metrics as well as pretraining and transfer learning workflows, improved hyperparameter optimization, and other customization options concerning loss functions or atom/bond features. We benchmark D-MPNN models trained using Chemprop with the new reaction, atom-level, and spectra functionality on a variety of property prediction data sets, including MoleculeNet and SAMPL, and observe state-of-the-art performance on the prediction of water-octanol partition coefficients, reaction barrier heights, atomic partial charges, and absorption spectra. Chemprop enables out-of-the-box training of D-MPNN models for a variety of problem settings in fast, user-friendly, and open-source software.

The photodegradation of organic pollutants using metal oxide-based catalysts has drawn great attention as an effective method for wastewater treatment. In this study, zinc oxide nanoparticles (ZnO NPs) and zinc oxide/copper oxide nanocomposites (ZnO/CuO NCs) were fabricated using the leaf extract of Croton macrostachyus as a nontoxic, natural reducing and stabilizing agent. The synthesized samples were characterized by employing X-ray diffraction, microscopic, spectroscopic, and electrochemical methods. The results confirmed the successful synthesis of ZnO NPs and ZnO/CuO NCs with well-defined crystalline structures and morphologies. The prepared samples were tested for the photodegradation of methylene blue (MB) dye under visible light irradiation. Compared to ZnO NPs, ZnO/CuO NCs showed greatly improved photocatalytic performances, particularly with the sample prepared with the 20 mol % Cu precursor (97.02%). The enhancement could be related to the formed p-n heterojunction, which can suppress the recombination of charge carriers and extend the photoresponsive range. A theoretical study of the photocatalytic activity of ZnO/CuO NCs against MB dye degradation was also conducted by using COMSOL Multiphysics software. The results of the simulation are in reasonable agreement with those of the experiment. This study contributes to the development of sustainable and effective photocatalytic materials that are suitable for application in environmental remediation, particularly in the treatment of wastewater., Competing Interests: The authors declare no competing financial interest., (© 2023 The Authors. Published by American Chemical Society.)

Two new ternary platinum borides, YPt x B 6-2 x and YbPt x B 6-2 x , were obtained by argon-arc melting of the elements followed by annealing at 780 °C (750 °C). The structures of these compounds combine the fragments of CaB 6 - and AuCu 3 -type structures [space group Pm 3̅ m ; x = 1.15, a = 4.0550(4) Å and x = 1.34, a = 4.0449(2) Å for YPt x B 6-2 x and YbPt x B 6-2 x , respectively; single-crystal X-ray diffraction]. Two possible variants of B/Pt ordering (space group P 4/ mmm ) were created via a group-subgroup approach targeting the derived stoichiometry. The architecture of the type- I YPt x B 6-2 x structure model ( a ' = a , b ' = b , c ' = c ) combines the 4.8 2 boron nets alternating with the layers of Y and Pt; the type- II YPt x B 6-2 x structure model ( a ' = 2 a , b ' = 2 b , c ' = c ) exhibits columns of linked [B 24 ] truncated cubes filled with Y running along the c axis. The striking features of both structural models are [B 4 Pt 2 ] octahedra. The structural similarities with hitherto reported structures (YB 2 C 2 , M 2 Ni 21 B 20 , MNi 21 B 20 , and ErNiB 4 ) were drawn supporting the verity of these models. A chemical bonding analysis for type- I and type- II YPt x B 6-2 x based on electron localization function distribution revealed a two-center interaction forming the 4.8 2 boron nets for type- I YPt x B 6-2 x and a covalent bonding within [B 4 Pt 2 ] octahedra as well as a two-center interaction for B-B intraoctahedral bonds for type- II YPt x B 6-2 x . Analysis of Bader charges revealed the cationic character of the yttrium atoms. The interactions for nondistorted areas of the structures agree well with the bonding picture calculated for constituent building structures, YB 6 and YPt 3 . Electronic structure calculations predict YPt x B 6-2 x to be a metal with the density of states of around N ( E F ) = 1 states eV -1 . The exploration of the Y-Pt-B system in the relevant concentration range elucidated the homogeneity field of YPt -1 . The exploration of the Y-Pt-B system in the relevant concentration range elucidated the homogeneity field of YPt x B 6-2 x ≤ 1.40) and revealed the existence of three more ternary phases at 780 °C: YPt x ≤ 1.40) and revealed the existence of three more ternary phases at 780 °C: YPt 2 B (space group P 6 2 22), YPt 3 B (space group P 4 mm ), and YPt 5 B 2 (space group C 2/ m ).

Chiral gold nanoclusters offer significant potential for exploring chirality at a fundamental level and for exploiting their applications in sensing and catalysis. However, their widespread use is impeded by low yields in synthesis, tedious separation procedures of their enantiomeric forms, and limited thermal stability. In this study, we investigated the direct synthesis of enantiopure chiral nanoclusters using the chiral ligand 2-MeBuSH in the fabrication of Au 25 , Au 38 , and Au 144 nanoclusters. Notably, this approach leads to the unexpected formation of intrinsically chiral clusters with high yields for chiral Au 38 and Au 144 nanoclusters. Experimental evaluation of chiral activity by circular dichroism (CD) spectroscopy corroborates previous theoretical calculations, highlighting the stronger CD signal exhibited by Au 144 compared to Au 38 or Au 25 . Furthermore, the formation of a single enantiomeric form is experimentally confirmed by comparing it with intrinsically chiral Au 38 (2-PET) 24 (2-PET: 2-phenylethanethiol) and is supported theoretically for both Au 38 and Au 144 . Moreover, the prepared chiral clusters show stability against diastereoisomerization, up to temperatures of 80 °C. Thus, our findings not only demonstrate the selective preparation of enantiopure, intrinsically chiral, and highly stable thiolate-protected Au nanoclusters through careful ligand design but also support the predicted "super" chirality in the Au 144 cluster, encompassing hierarchical chirality in ligands, staple configuration, and core structure.

Direct air capture (DAC) using solid adsorbents has gained significant attention as a carbon dioxide removal (CDR) technology to help limit global temperature rise to below 2 °C. One large area of focus is the development of new adsorbent materials for DAC. However, the necessary data needed to employ these materials in process models for adsorbent screening are rarely available. Here, we showcase Purolite A110, a commercially available amine-functionalized polymeric resin, as a new candidate adsorbent for DAC and compare its properties to a current benchmark, Lewatit VP OC 1065. For both materials, we report their chemical features and composition, skeletal, particle, and bed density, total pore volume, particle porosity, BET area, thermal stability, and specific heat capacity. We determine their equilibrium sorption properties by measuring the volumetric CO 2 isotherms at 288, 298, 308, 333, 343, 353, and 393 K, N 2 and H 2 O isotherms at 288, 298, and 308 K, and Ar and O 2 isotherms at 298 K. For CO 2 , N 2 , and H 2 O, we also present the corresponding isotherm model fitting parameters and heats of adsorption. These data can help facilitate process modeling and optimization studies to properly assess these adsorbents at scale., Competing Interests: The authors declare no competing financial interest., (© 2023 The Authors. Published by American Chemical Society.)

The greenhouse gas reduction as well as the utilization of more renewable and clean energy via a dry reforming reaction is of interest. The impact of a CeMgZnAl oxide quad-blend-supported Ni catalyst on performance and anticoking during dry reforming reactions at 700 °C was studied. A high Ce-Mg/Zn ratio, as seen in the CeMg0.5ZnAl-supported nickel catalyst, enhances lattice oxygen, and the presence of strong basic sites, along with the creation of the carbonate intermediate species, is accompanied by the production of gaseous CO through a gasification reaction between the carbon species and Ni-CO ads-lin site. The phenomena caused the outstanding performance of the Ni/CeMg0.5ZnAl catalyst-CH 4 (84%),CO 2 (83%) conversions, and the H 2 /CO (0.80) ratio; moreover, its activity was also stable throughout 30 h., Competing Interests: The authors declare no competing financial interest., (© 2023 The Authors. Published by American Chemical Society.)

We introduce PyConSolv, a freely available Python package that automates the generation of conformers of metal- and nonmetal-containing complexes in explicit solvent, through classical molecular dynamics simulations. Using a streamlined workflow and interfacing with widely used computational chemistry software, PyConSolv is an all-in-one tool for the generation of conformers in any solvent. Input requirements are minimal; only the geometry of the structure and the desired solvent in xyz (XMOL) format are needed. The package can also account for charged systems, by including arbitrary counterions in the simulation. A bonded model parametrization is performed automatically, utilizing AmberTools, ORCA, and Multiwfn software packages. PyConSolv provides a selection of preparametrized solvents and counterions for use in classical molecular dynamics simulations. We show the applicability of our package on a number of (transition-metal-containing) systems. The software is provided open source and free of charge.

Hubbard U -corrected density functional theory within the periodic boundary condition model in the WIEN2k code is used to simulate the actinide L III and O K edge X-ray absorption near-edge structure (XANES) for UO 2 . Spin-orbit coupling effects are included, as are possible excitonic effects using supercells with a core hole on one of the atoms. Our calculations yield spectra in excellent agreement with previous experiments and superior to previous simulations. Density of states analysis reveals the mechanism behind the XANES peaks: the main contribution to the U/Pu 2 . Spin-orbit coupling effects are included, as are possible excitonic effects using supercells with a core hole on one of the atoms. Our calculations yield spectra in excellent agreement with previous experiments and superior to previous simulations. Density of states analysis reveals the mechanism behind the XANES peaks: the main contribution to the U/Pu L III edges comes from the U/Pu d edges of both UO p states primarily determine the O K edges of both UO 2 and PuO 2 . The O K edges also feature O p hybridizing with U/Pu d and f states in the low-energy region and with U/Pu s and p states for the higher-energy peaks., Competing Interests: The authors declare no competing financial interest., (© 2023 The Authors. Published by American Chemical Society.)

The rational synthesis and tailoring of metal-organic frameworks (MOFs) with multifunctional micro/nanoarchitectures have emerged as a subject of significant academic interest owing to their promising potential for utilization in advanced energy storage devices. Herein, we explored a category of three-dimensional (3D) NiCo 2 S 4 nanospikes that have been integrated into a 1D Fe 3 C microarchitecture using a chemical surface transformation process. The resulting electrode materials, i.e. , Fe 3 C@NiCo 2 S 4 nanospikes, exhibit immense potential for utilization in high-performance hybrid supercapacitors. The nanospikes exhibit an elevated specific capacity (1894.2 F g -1 at 1 A g -1 ), enhanced rate capability (59%), and exceptional cycling stability (92.5% with 98.7% Coulombic efficiency) via a charge storage mechanism reminiscent of a battery. The augmented charge storage characteristics are attributed to the collaborative features of the active constituents, amplified availability of active sites inherent in the nanospikes, and the proficient redox chemical reactions of multi-metallic guest species. When using nitrogen-doped carbon nanofibers as the anode to fabricate hybrid supercapacitors, the device exhibits high energy and power densities of 62.98 Wh kg -1 and 6834 W kg -1 , respectively, and shows excellent long-term cycling stability (95.4% after 5000 cycles), which affirms the significant potential of the proposed design for applications in hybrid supercapacitors. The DFT study showed the strong coupling of the oxygen from the electrolyte OH - with the metal atom of the nanostructures, resulting in high adsorption properties that facilitate the redox reaction kinetics.

Characterizing uncertainty in machine learning models has recently gained interest in the context of machine learning reliability, robustness, safety, and active learning. Here, we separate the total uncertainty into contributions from noise in the data (aleatoric) and shortcomings of the model (epistemic), further dividing epistemic uncertainty into model bias and variance contributions. We systematically address the influence of noise, model bias, and model variance in the context of chemical property predictions, where the diverse nature of target properties and the vast chemical chemical space give rise to many different distinct sources of prediction error. We demonstrate that different sources of error can each be significant in different contexts and must be individually addressed during model development. Through controlled experiments on data sets of molecular properties, we show important trends in model performance associated with the level of noise in the data set, size of the data set, model architecture, molecule representation, ensemble size, and data set splitting. In particular, we show that 1) noise in the test set can limit a model's observed performance when the actual performance is much better, 2) using size-extensive model aggregation structures is crucial for extensive property prediction, and 3) ensembling is a reliable tool for uncertainty quantification and improvement specifically for the contribution of model variance. We develop general guidelines on how to improve an underperforming model when falling into different uncertainty contexts.

The catalytic behavior of Rh particles supported by three different materials (Rh, Au, and ZrO 2 ) in H 2 oxidation has been studied in situ by correlative photoemission electron microscopy (PEEM) and scanning photoemission electron microscopy (SPEM). Kinetic transitions between the inactive and active steady states were monitored, and self-sustaining oscillations on supported Rh particles were observed. Catalytic performance differed depending on the support and Rh particle size. Oscillations varied from particle size-independent (Rh/Rh) via size-dependent (Rh/ZrO 2 ) to fully inhibited (Rh/Au). For Rh/Au, the formation of a surface alloy induced such effects, whereas for Rh/ZrO 2 , the formation of substoichiometric Zr oxides on the Rh surface, enhanced oxygen bonding, Rh-oxidation, and hydrogen spillover onto the ZrO 2 support were held responsible. The experimental observations were complemented by micro-kinetic simulations, based on variations of hydrogen adsorption and oxygen binding. The results demonstrate how correlative in situ surface microscopy enables linking of the local structure, composition, and catalytic performance., Competing Interests: The authors declare no competing financial interest., (© 2023 The Authors. Published by American Chemical Society.)

Regenerated cellulose (RC) produced from waste pineapple leaves was used to develop a colorimetric sensor as a Cu-PAN sheet (RCS). Microcrystalline cellulose derived from dried pineapple leaves was combined with Cu-PAN, dissolved in NaOH and urea, and made into an RC sheet using Na 2 SO 4 as a coagulant. The RCS was used as an H 2 S indicator at various H 2 S concentrations (0-50 ppm) and temperatures (5-25 °C). The RCS color changed from purple to New York pink when exposed to H 2 S. A colorimeter method was used to develop prediction curves with values of R 2 S concentrations at 5-25 °C. The physicochemical properties of fresh and spent RCS were characterized using various techniques (Fourier transform infrared spectroscopy, X-ray diffraction, scanning electron microscopy/energy-dispersive X-ray spectroscopy, and thermogravimetric analysis). In addition, when stored at 5 and 25 °C for 90 days, the RCS had outstanding stability. The developed RCS could be applied to food packaging as an intelligent indicator of meat spoilage.2 S concentrations at 5-25 °C. The physicochemical properties of fresh and spent RCS were characterized using various techniques (Fourier transform infrared spectroscopy, X-ray diffraction, scanning electron microscopy/energy-dispersive X-ray spectroscopy, and thermogravimetric analysis). In addition, when stored at 5 and 25 °C for 90 days, the RCS had outstanding stability. The developed RCS could be applied to food packaging as an intelligent indicator of meat spoilage., Competing Interests: The authors declare no competing financial interest., (© 2023 The Authors. Published by American Chemical Society.)

Using multipulse linearly polarized femtosecond laser processing of a Au-coated Ni surface in various liquid media created subwavelength self-organized nanoripples. The thin gold film improved the laser absorptivity, decreasing the ripple generation threshold in liquids. High spatial frequency ripples exhibited lower angular deviation than low spatial frequency ones, but in water the deviation was comparable for both types of ripples. The initiation of nanoripples may precede nanoparticle generation, which is why in hexane several cuboid Au particles were trapped between the ripples. Fast cooling processes freeze ejected molten droplets during the phase explosion and surface reorganization. Grazing incidence X-ray diffraction of samples processed in butanol showed a small shift toward smaller angles for the Ni phase, indicating a lattice expansion due to higher tensile stress. Confocal micro-Raman spectroscopy detected surface graphitization and amorphization in areas laser-treated in ethanol, butanol, and hexane, with the highest carbonization observed in butanol. Presumably, femtosecond laser-induced photolysis triggers the formation of graphite nanocrystallites, and consecutive pulses cause amorphization. Static contact angle measurements showed a general tendency toward hydrophobicity with highest contact angles for rippled areas created in butanol., Competing Interests: The authors declare no competing financial interest., (© 2023 The Authors. Published by American Chemical Society.)

Cobaltocenium carbaldehyde (formylcobaltocenium) hexafluoridophosphate, a long sought-after functionalized cobaltocenium salt, is accessible from cobaltocenium carboxylic acid by a three-step synthetic sequence involving (i) chlorination to the acid chloride, (ii) copper-borohydride reduction to the hydroxymethyl derivative, and (iii) Dess-Martin oxidation to the title compound. Due to the strongly electron-withdrawing cationic cobaltocenium moiety, no standard aldehyde reactivity is observed. Instead, nucleophilic addition followed by haloform-type cleavage prevails, thereby ruling out common useful aldehyde derivatization. One-electron reduction of cobaltocenium carbaldehyde hexafluoridophosphate affords the deep-blue, isolable cobaltocene carbaldehyde 19-valence-electron radical whose spin density is located fully at cobalt and not at the formyl carbon atom. 1 H/ 13 C NMR, IR, EPR spectroscopy, high-resolution mass spectrometry, cyclic voltammetry, single crystal structure analysis (XRD), and density functional theory are applied to characterize these unusual formyl-cobaltocenium/cobaltocene compounds., Competing Interests: The authors declare no competing financial interest., (© 2023 The Authors. Published by American Chemical Society.)

Co-doping represents a valid approach to maximize the performance of photocatalytic and photoelectrocatalytic semiconductors. Albeit theoretical predictions in hematite suggesting a bulk n-type doping and a surface p-type doping would deliver best results, hematite co-doping with coupled cations possessing low and high oxidation states has shown promising results. Herein, we report, for the first time, Sb and Li co-doping of hematite photoanodes. Particularly, this is also a seminal work for the introduction of the highly reactive Sb 5+ directly into the hematite thin films. Upon co-doping, we have a synergistic effect on the current densities with a 67-fold improvement over the standard. Via a combined investigation with profuse photoelectrochemical measurements, X-ray diffraction, X-ray photoelectron spectroscopy, and Raman analyses, we confirm the two doping roles of Sb 5+ and Li + as the substitutional and interstitial dopant, respectively. The improvements are attributed to a higher charge carrier concentration along with a lower charge transfer resistance at the surface., Competing Interests: The authors declare no competing financial interest., (© 2023 The Authors. Published by American Chemical Society.)

Driving metal-cluster-catalyzed high-temperature chemical reactions by sunlight holds promise for the development of negative-carbon-footprint industrial catalysis, which has yet often been hindered by the poor ability of metal clusters to harvest and utilize the full spectrum of solar energy. Here, we report the preparation of Mo 2 TiC 2 MXene-supported Ru clusters (Ru/Mo 2 TiC 2 ) with pronounced broadband sunlight absorption ability and high sintering resistance. Under illumination of focused sunlight, Ru/Mo 2 TiC 2 can catalyze the reverse water-gas shift (RWGS) reaction to produce carbon monoxide from the greenhouse gas carbon dioxide and renewable hydrogen with enhanced activity, selectivity, and stability compared to their nanoparticle counterparts. Notably, the CO production rate of MXene-supported Ru clusters reached 4.0 mol·g Ru -1 , which is among the best reported so far for photothermal RWGS catalysts. Detailed studies suggest that the production of methane is kinetically inhibited by the rapid desorption of CO from the surface of the Ru clusters.-1 , which is among the best reported so far for photothermal RWGS catalysts. Detailed studies suggest that the production of methane is kinetically inhibited by the rapid desorption of CO from the surface of the Ru clusters.

The molecular structures synthesizable by organic chemists dictate the molecular functions they can create. The invention and development of chemical reactions are thus critical for chemists to access new and desirable functional molecules in all disciplines of organic chemistry. This work seeks to expedite the exploration of emerging areas of organic chemistry by devising a machine-learning-guided workflow for reaction discovery. Specifically, this study uses machine learning to predict competent electrochemical reactions. To this end, we first develop a molecular representation that enables the production of general models with limited training data. Next, we employ automated experimentation to test a large number of electrochemical reactions. These reactions are categorized as competent or incompetent mixtures, and a classification model was trained to predict reaction competency. This model is used to screen 38,865 potential reactions in silico, and the predictions are used to identify a number of reactions of synthetic or mechanistic interest, 80% of which are found to be competent. Additionally, we provide the predictions for the 38,865-member set in the hope of accelerating the development of this field. We envision that adopting a workflow such as this could enable the rapid development of many fields of chemistry.

Hydrophobically modified associating polymers could be effective drag-reducing agents containing weak "links" which after degradation can reform, protecting the polymer backbone from fast scission. Previous studies using hydrophobically modified polymers in drag reduction applications used polymers with M ≥ 1000 kg/mol. Homopolymers of this high w already show significant drag reduction (DR), and the contribution of macromolecular associations on DR remained unclear. We synthesized associating poly(acrylamide- M w already show significant drag reduction (DR), and the contribution of macromolecular associations on DR remained unclear. We synthesized associating poly(acrylamide- co ≈ 1000 kg/mol increase DR in pipe flow by a factor of ∼2 compared to the unmodified polyacrylamide of similar M w ≤ 1000 kg/mol and various hydrophobic moiety content. Their DR effectiveness in turbulent flow was studied using a pilot-scale pipe flow facility and a rotating "disc" apparatus. We show that hydrophobically modified copolymers with M w ≈ 1000 kg/mol increase DR in pipe flow by a factor of ∼2 compared to the unmodified polyacrylamide of similar M w albeit at low DR level. Moreover, we discuss challenges encountered when using hydrophobically modified polymers synthesized via micellar polymerization., Competing Interests: The authors declare no competing financial interest., (© 2022 The Authors. Published by American Chemical Society.)

The kinetic behavior of individual Rh( hkl ) nanofacets coupled in a common reaction system was studied using the apex of a curved rhodium microcrystal (radius of 0.65 μm) as a model of a single catalytic particle and field electron microscopy for in situ imaging of catalytic hydrogen oxidation. Depending on the extent of interfacet coupling via hydrogen diffusion, different oscillating reaction modes were observed including highly unusual multifrequential oscillations: differently oriented nanofacets oscillated with differing frequencies despite their immediate neighborhood. The transitions between different modes were induced by variations in the particle temperature, causing local surface reconstructions, which create locally protruding atomic rows. These atomic rows modified the coupling strength between individual nanofacets and caused the transitions between different oscillating modes. Effects such as entrainment, frequency locking, and reconstruction-induced collapse of spatial coupling were observed. To reveal the origin of the different experimentally observed effects, microkinetic simulations were performed for a network of 105 coupled oscillators, modeling the individual nanofacets communicating via hydrogen surface diffusion. The calculated behavior of the oscillators, the local frequencies, and the varying degree of spatial synchronization describe the experimental observations well., Competing Interests: The authors declare no competing financial interest., (© 2022 The Authors. Published by American Chemical Society.)

We present a continuous flow method for the conversion of bioderived limonene oxide and limonene dioxide to limonene carbonates using carbon dioxide in its supercritical state as a reagent and sole solvent. Various ammonium- and imidazolium-based ionic liquids were initially investigated in batch mode. For applying the best-performing and selective catalyst tetrabutylammonium chloride in continuous flow, the ionic liquid was physisorbed on mesoporous silica. In addition to the analysis of surface area and pore size distribution of the best-performing supported ionic liquid phase (SILP) catalysts via nitrogen physisorption, SILPs were characterized by diffuse reflectance infrared Fourier transform spectroscopy and thermogravimetric analysis and served as heterogeneous catalysts in continuous flow. Initially, the continuous flow conversion was optimized in short-term experiments resulting in the desired constant product outputs. Under these conditions, the long-term behavior of the SILP system was studied for a period of 48 h; no leaching of catalyst from the supporting material was observed in the case of limonene oxide and resulted in a yield of 16%. For limonene dioxide, just traces of leached catalysts were detected after reducing the catalyst loading from 30 to 15 wt %, thus enabling a constant product output in 17% yield over time., Competing Interests: The authors declare no competing financial interest., (© 2022 The Authors. Published by American Chemical Society.)

Numerous hyper-cross-linked polymers (HCPs) have been developed as CO 2 adsorbents and photocatalysts. Yet, little is known of the CO 2 and H 2 O adsorption mechanisms on amorphous porous polymers. Gaining a better understanding of these mechanisms and determining the adsorption sites are key to the rational design of improved adsorbents and photocatalysts. Herein, we present a unique approach that combines density functional theory (DFT), in situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS), and multivariate spectral analysis to investigate CO 2 and H 2 O adsorption sites on a triazine-biphenyl HCP. We found that CO 2 and H 2 O adsorb on the same HCP sites albeit with different adsorption strengths. The primary amines of the triazines were identified as favoring strong CO 2 binding interactions. Given the potential use of HCPs for CO 2 photoreduction, we also investigated CO 2 and H 2 O adsorption under transient light irradiation. Under irradiation, we observed partial CO 2 and H 2 O desorption and a redistribution of interactions between the H 2 O and CO 2 molecules that remain adsorbed at HCP adsorption sites.

Spatio-temporal nonuniformities in H 2 oxidation on individual Rh( h   k   l ) domains of a polycrystalline Rh foil were studied in the 10 -6 mbar pressure range by photoemission electron microscopy (PEEM), X-ray photoemission electron microscopy (XPEEM), and low-energy electron microscopy (LEEM). The latter two were used for in situ correlative microscopy to zoom in with significantly higher lateral resolution, allowing detection of an unusual island-mediated oxygen front propagation during kinetic transitions. The origin of the island-mediated front propagation was rationalized by model calculations based on a hybrid approach of microkinetic modeling and Monte Carlo simulations., Competing Interests: The authors declare no competing financial interest., (© 2022 The Authors. Published by American Chemical Society.)

CuO-ZnO nanocomposites (NCs) were synthesized using an aqueous extract of Verbascum sinaiticum Benth. (GH) plant. X-ray diffraction (XRD), spectroscopic, and microscopic methods were used to explore the crystallinity, optical properties, morphology, and other features of the CuO-ZnO samples. Furthermore, catalytic performances were investigated for methylene blue (MB) degradation and 4-nitrophenol (4-NP) reduction. According to the results, CuO-ZnO NCs with 20 wt % CuO showed enhanced photocatalytic activity against MB dye with a 0.017 min -1 rate constant compared to 0.0027 min -1 for ZnO nanoparticles (NPs). Similarly, a ratio constant of 5.925 min -1 g -1 4-NP reductions was achieved with CuO-ZnO NCs. The results signified enhanced performance of CuO-ZnO NCs relative to ZnO NPs. The enhancement could be due to the synergy between ZnO and CuO, resulting in improved absorption of visible light and reduced electron-hole (e - /h + ) recombination rate. In addition, variations in the CuO content affected the performance of the CuO-ZnO NCs. Thus, the CuO-ZnO NCs prepared using V. sinaiticum Benth. extract could make the material a desirable catalyst for the elimination of organic pollutants., Competing Interests: The authors declare no competing financial interest., (© 2022 The Authors. Published by American Chemical Society.)

The purification of value-added compounds by three-phase partitioning (TPP) is a promising alternative to conventional processes since the target compound can be easily recovered from the liquid-liquid interphase. Although this technique has been successfully applied to the recovery of proteins, the minimization of the use of salts and solvents must be pursued to improve the overall process sustainability. Accordingly, we have here investigated the use of biobased glycine-betaine ionic liquids (IL) directly with honey, a carbohydrate-rich matrix, as phase-forming components of TPP systems. These ILTPP systems were applied in the purification of major royal jelly proteins (MRJPs) from honey. The results obtained show that MRJPs mostly precipitate in the ILTPP interphase, with a recovery yield ranging between 82.8% and 97.3%. In particular, MRJP1 can be obtained with a purity level up to 90.1%. Furthermore, these systems allow the simultaneous separation of antioxidants and carbohydrates to different liquid phases. The proposed approach allows the separation of proteins, antioxidants, and carbohydrates from honey in a single step, while using only ILs and a real carbohydrate-rich matrix, thus being sustainable TPP processes., Competing Interests: The authors declare no competing financial interest., (© 2022 American Chemical Society.)

Porous core-shell nanoparticles (NPs) have emerged as a promising material for broad ranges of applications in catalysts, material chemistry, biology, and optical sensors. Using a typical Ag core-Fe 3 O 4 shell NP, a.k.a., magnetoplasmonic (MagPlas) NP, two porous shell models were prepared: i.e. , Ag@Fe 3 O 4 NPs and its SiO 2 -covered NPs (Ag@Fe 3 O 4 @SiO 2 ). We suggested using cyclic voltammetry (CV) to provide unprecedented insight into the porosity of the core-shell NPs caused by the applied potential, resulting in the selective redox activities of the core and porous shell components of Ag@Fe 3 O 4 NPs and Ag@Fe 3 O 4 @SiO 2 NPs at different cycles of CV. The porous and nonporous core-shell nanostructures were qualitatively and quantitatively determined by the electrochemical method. The ratio of the oxidation current peak (μA) of Ag to Ag + in the porous shell to that in the SiO 2 coated (nonporous) shell was 400:3.2. The suggested approach and theoretical background could be extended to other types of multicomponent NP complexes.

Achieving light-driven splitting of water with high efficiency remains a challenging task on the way to solar fuel exploration. In this work, to combine the advantages of heterogeneous and homogeneous photosystems, we covalently anchor noble-metal- and carbon-free thiomolybdate [Mo 3 S 13 ] 2- clusters onto photoactive metal oxide supports to act as molecular co-catalysts for photocatalytic water splitting. We demonstrate that strong and surface-limited binding of the [Mo 3 S 13 ] 2- to the oxide surfaces takes place. The attachment involves the loss of the majority of the terminal S 2 2- groups, upon which Mo-O-Ti bonds with the hydroxylated TiO 2 surface are established. The heterogenized [Mo 3 S 13 clusters are active and stable co-catalysts for the light-driven hydrogen evolution reaction (HER) with performance close to the level of the benchmark Pt. Optimal HER rates are achieved for 2 wt % cluster loadings, which we relate to the accessibility of the TiO 2- clusters are active and stable co-catalysts for the light-driven hydrogen evolution reaction (HER) with performance close to the level of the benchmark Pt. Optimal HER rates are achieved for 2 wt % cluster loadings, which we relate to the accessibility of the TiO 2 . Our data demonstrate the importance of the trinuclear core of the [Mo 2 . Our data demonstrate the importance of the trinuclear core of the [Mo 3 S 13 ] 2- and vacant coordination sites at the Mo centers as likely HER active sites. This work provides a prime example for the successful heterogenization of an inorganic molecular cluster as a co-catalyst for light-driven HER and gives the incentive to explore other thio(oxo)metalates.2 2- and vacant coordination sites at the Mo centers as likely HER active sites. This work provides a prime example for the successful heterogenization of an inorganic molecular cluster as a co-catalyst for light-driven HER and gives the incentive to explore other thio(oxo)metalates., Competing Interests: The authors declare no competing financial interest., (© 2022 The Authors. Published by American Chemical Society.)

We performed matrix-isolation infrared (MI-IR) spectroscopy of carbon dioxide monomers, CO 2 , and dimers, (CO 2 ) 2 , trapped in neon and in air. On the basis of vibration configuration interaction (VCI) calculations accounting for mode coupling and anharmonicity, we identify additional infrared-active bands in the MI-IR spectra due to the (CO 2 ) 2 dimer. These bands are satellite bands next to the established CO 2 monomer bands, which appear in the infrared window of Earth's atmosphere at around 4 and 15 μm. In a systematic carbon dioxide mixing ratio study using neon matrixes, we observe a significant fraction of the dimer at mixing ratios above 300 ppm, with a steep increase up to 1000 ppm. In neon matrix, the dimer increases the IR absorbance by about 15% at 400 ppm compared to the monomer absorbance alone. This suggests a high fraction of the (CO 2 ) 2 dimer in our matrix experiments. In atmospheric conditions, such increased absorbance would significantly amplify radiative forcings and, thus, the greenhouse warming. To enable a comparison of our laboratory experiment with various atmospheric conditions (Earth, Mars, Venus), we compute the thermodynamics of the dimerization accordingly. The dimerization is favored at low temperatures and/or high carbon dioxide partial pressures. Thus, we argue that matrix isolation does not trap the gas composition "as is". Instead, the gas is precooled to 40 K, where CO 2 dimerizes before being trapped in the matrix, already at very low carbon dioxide partial pressures. In the context of planetary atmospheres, our results improve understanding of the greenhouse effect for planets of rather thick CO 2 atmospheres such as Venus, where a significant fraction of the (CO 2 ) 2 dimer can be expected. There, the necessity of including the mid-IR absorption by stable (CO 2 ) 2 dimers in databases used for modeling radiative forcing, such as HITRAN, arises.