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This study proposes a simple method for preparing highly dispersed ultrafine 3 mol% yttrium-stabilized zirconia nanopowders (3YSZ NPs), which provide high-quality powders for use in high-performance ceramics. First, 3YSZ NPs were prepared using a reverse precipitation method with different precipitants: NaOH, NH 3 ·H 2 O and (NH 3) 2 CO 3. The thermal decomposition, phase evolution, morphology and chemical composition of the precursor particles and 3YSZ NPs were analysed. The effects of precipitant and reaction conditions on 3YSZ NPs were systematically studied. The results show that there are differences in the mechanism of powder synthesis using the co-precipitation method among the three precipitants. In addition, ultrafine 3YSZ NPs with minimum agglomeration and high sphericity can be prepared using NaOH. Y3+ and ZrO2+ cannot coprecipitate in solution according to the designed molar ratio in the NH 3 ·H 2 O and (NH 4) 2 CO 3 methods. Considering agglomeration, crystallinity and elemental distribution, NaOH is the best precipitant. The prepared zirconia powder exhibits high crystallinity, good dispersion, a narrow particle size distribution and a tetragonal phase structure. By investigating the effects of calcination temperature, titration end point pH and NaOH concentration, 3YSZ NPs with an average particle size of 22.29–38.94 nm are obtained. [ABSTRACT FROM AUTHOR]

• An effective recovery of antioxidants was obtained from breweŕs spent grain. • A comparison among chemical, enzymatic and hydrothermal hydrolysis was conducted. • The highest ferulic acid yield was 7.2 g FA/kg BSG for the hydrothermal treatment. • Alkaline hydrolysis showed the lowest operating costs: €34.5/kg FA at 100 kgBSG/m3. Brewers' spent grain (BSG) is the main byproduct from the brewing industry, which accounts for 85 % of the total waste generated during beer production. This lignocellulosic material is traditionally used as livestock feed and sold at a low price. However, BSG can be used as a low-cost feedstock for the production of bioactive molecules and chemicals precursors, upgrading the value of this byproduct. In this context, BSG is a promising feedstock for the extraction of antioxidants like ferulic acid (FA) and p-coumaric acid (p -Cu). The effectiveness of three hydrolysis treatments were evaluated for the extraction of FA and p -Cu from BSG, namely enzymatic (based on the synergistic cooperation between a feruloyl esterase and an endo -1,4-β-xylanase), alkaline and hydrothermal. The hydrothermal treatment produced the highest extraction yields (7.2 g/kgBSG and 1.4 g/kgBSG for FA and p -Cu, respectively) in a short extraction time (an hour). On the other hand, enzymatic hydrolysis extracted 4.3 g/kgBSG for FA and negligible yields for p -Cu in 4 h of incubation at 25 °C. Yields of 5.5 g/kgBSG for FA and 0.6 g/kgBSG for p -Cu were obtained in more than 5 h of alkaline treatment at 120 °C. The mass and energy balances revealed the high dependence of the operating costs on the concentration of BSG used during the extraction process, with costs of 34.5 €, 6607 € and 205.5 € per kg of FA for the chemical, enzymatic and hydrothermal extraction methods at 100 kg BSG/m3. [ABSTRACT FROM AUTHOR]

Ultrafine alumina is widely used in advanced manufacturing industry, and its form, size and dispersion have important effects on its physicochemical properties and application characteristics. However, the superfine monodisperse spherical alumina is difficult to obtain in the actual synthesis process because the alumina precursor grain grows too fast and is easy to agglomerate. In this work, ammonium sulfate was added as the synthetic raw material to improve its dispersity. When the concentration reached 40 % of the aluminum source concentration, the isometric alumina precursor with a particle size of about 35 nm was obtained under the condition of rapid cooling. The influence of ammonium sulfate on the chemical structure of the precursor was determined by Fourier Transform Infrared spectrometer (FTIR) and X-ray photoelectron spectroscopy (XPS). The effects of reactant concentration and reaction temperature on the morphology, particle size and dispersion of the precursor as well as its mechanism were discussed in detail, and the optimal synthesis method of the nano alumina precursor was obtained. Finally, two kinds of precursors were calcined at different temperatures to obtain the equiaxed γ-Al 2 O 3 with a particle size of 20 nm and the monodisperse spherical α-Al 2 O 3 with a particle size of 133 nm, respectively. In this study, nano alumina precursors were synthesized by a simple and reliable method, and monodisperse ultra-fine alumina with different particle size morphologies were obtained, which has great application prospects in precision polishing, special ceramic manufacturing, and 3D printing. [ABSTRACT FROM AUTHOR]

The present work reports an overview of the main results we have obtained from non-conventional sintering approaches towards the densification of 3mol.% yttria stabilized zirconia (3YSZ), the lessons learned from these results, and open questions that still need to be addressed. A wide range of techniques have been developed in the field of ceramic sintering, both in high temperature regime with extreme heating rates (>10 000 °C/min), as well as in very low temperatures (<400 °C) regime involving chemical reactivity to activate sintering mechanisms. In this context, we have recently explored several of these methods in order to understand and control the different sintering parameters and their impact on microstructure, crystallinity, grain boundaries and defect chemistry. Due to its complex chemistry, 3YSZ is a playground for the exploration of sintering capabilities and their influence on ceramic properties. Our recent studies in this field are presented in the present work, highlighting the effect of high heating rates through Flash Spark Plasma Sintering (Flash-SPS) and Ultra High temperature Sintering (UHS) on sintering, but also the combination of low temperature Cold Sintering Process (CSP) and the associated precursors chemistry, with Spark Plasma Sintering (SPS). It also shows the possible densification by reactive hydrothermal sintering, using hydroxide precursors, and the effect of High Pressure SPS (HP-SPS) on 3YSZ nanopowders. All of these results touch upon current trends in the field of sintering, and highlight the possibilities in terms of chemical reactivity of precursors and physical parameter control. In particular, they show the importance of defect chemistry, related to the sintering atmospheres and their impact on both microstructures and properties. [ABSTRACT FROM AUTHOR]

Organic lead halide perovskite solar cells (PSCs) have become a viable alternative for next‐generation photovoltaic systems. The significance of reproducibly processing perovskite with less defects comes from the fact that imperfections have a major impact on the solar cell's performance and long‐term stability. Although it is well known that cautious precursor processing has a significant influence on perovskite defect generation, there haven't been extensive investigations on the serial associations between precursor processing, perovskite orientation, and defect generation in PSCs. Making use of a unique precursor chemistry treatment technique that facilitates uniaxially oriented perovskite growth, it is aimed to mitigate defects of sequentially spin‐coated perovskite. Through the temperature‐dependent configurational entropic effect on coordination between iodoplumbate and dimethylsulfoxide (DMSO), a DMSO de‐intercalation processing method is developed. This method enables the induction of uniaxially‐oriented α‐FA0.9MA0.1PbI3‐xBrx (FA: formamidnium, MA: methylammomnium, x < 0.13) perovskite growth parallel to substrates. As a result, this processing delivered significant advances in power conversion efficiency (24.02%) and ambient operational stability under light. This straightforward technique provides a accesible process for producing efficient and stable perovskite solar cells, enabling uniaxially oriented perovskite fabrication without complicated procedures or additional substances. [ABSTRACT FROM AUTHOR]

• Using remote sensing data, the statistical studies related to earthquake precursors increased significantly. • Most of them emphasized the existence of abnormal behaviors in precursors. • An attempt has been made to address the advances and challenges in the way of earthquake prediction. Due to the considerable loss of life and damages caused by powerful Earthquakes, along with the strengthening of structures and disaster management systems, many researches are being conducted associated with the possibility of creating Earthquake warning systems. However, no reliable scientific report on successful Earthquake prediction has been published so far. Although there are a couple of published scientific papers indicating the detection of unusual changes in physical and chemical parameters obtained from ground stations, but due to the limitations of in-situ measurement in terms of number, location, time and cost, there was no noticeable progress in Earthquake warning. After the advent of remote sensing satellites, the number of statistical studies related to Earthquake precursors increased significantly, and most of them emphasized the existence of abnormal behaviors in physical and chemical precursors around the time (about 1–30 days before) and locations of powerful Earthquakes. In this study, an attempt has been made to address the advances and challenges in the way of Earthquake prediction using satellite data and provide a perspective of the future of these researches. It should be noted that the increase in the number of satellites designed and launched specially for Earthquake studies, the variety of available Earthquake precursors (multi-precursor analysis), the development of classic and intelligent anomaly detection and predictor algorithms (multi-method analysis), the provision of intelligent systems for the integration of various precursors (fusion and decision systems), the creation of cloud storing and processing data services (Google Earth Engine, Giovanni, etc.) and the development of intelligent user interfaces for public, have made researchers more hopeful for the appearance of low-uncertainty Earthquake warning systems in the near future. [ABSTRACT FROM AUTHOR]

The role of MA in FAMA mixed perovskite remains far from being fully understood, due to the intricate chemical evolutions in the precursor solutions. Adjusting the content of MA in FAMA mixed perovskite arbitrarily remains a great challenge. This study elucidates a synergistic effect between H+ and I− oxidation which helps to reduce the content of MA in FA‐dominated perovskite. Briefly, excessive H+ boosts the balanced and rapid assembly of MA and FA components in FA‐dominated perovskite and hampers unfavorable chemical evolution induced by nucleophilic reaction between MA and FA in the precursor solution, while I− oxidation accelerates the in situ crystallization of perovskite. Leveraging this synergistic effect, centimeter‐scaled FAxMA(1‐x)PbI3 single crystals with arbitrarily adjustable values of x are successfully fabricated. In addition, peroxyacetic acid is introduced as the additive, enabling the blade‐coated FA0.9MA0.1PbI3 perovskite solar cells (PSCs) to achieve an impressive efficiency of 23.7%. The efficiency achieved here is among the highest values for blade‐coated PSCs with FA content exceeding 90% so far. The optimized solution developed in this study achieved exceptional stability, allowing it to be stored under air conditions for over 2 months without significant degradation in cell efficiency. This outcome satisfies the requirements for commercialization. [ABSTRACT FROM AUTHOR]

The ongoing search for innovative and environmentally friendly luminescent materials coupled with customizable physical and chemical properties at the nanoscale positions carbon dots (CDots) as ideal candidates for photonic applications. However, even today, their rational design for specific applications remains elusive due to the unknown relationship between optical and structural properties. Therefore, this study aims to fill this gap by linking the chemical structure of the precursor and synthetic conditions to the final structural composition of the CDots and, by extension, to their optical properties. The study shows that while CDots are chemically stable, their optical properties, which are determined by the carbonaceous core and surface groups, are highly pH dependent. These properties, together with the long fluorescence lifetimes observed in living cells (>10 ns), make these biomass‐derived CDots promising probes for time‐resolved fluorescence imaging. [ABSTRACT FROM AUTHOR]

The propargyl cation, H2CCCH+, is a crucial hydrocarbon precursor in the chemical evolution of the interstellar medium (ISM). It serves as a key intermediate for understanding ISM hydrocarbon chemistry. This work presents state-to-state collisional rate coefficients for rotational excitation and de-excitation of ortho- and para- H2CCCH+ colliding with He at ISM-relevant temperatures (T  ≤ 60 K). We employed a high-level post-Hartree-Fock CCSD(T)-F12/aug-cc-pVTZ method to generate a 3D interaction potential energy surface (3D-PES) for the weakly bound H2CCCH+-He complex. The analytical 3D-PES was then used in close-coupling calculations to determine cross-sections for rotational excitation and de-excitation of ortho- and para- H2CCCH+ by collisions with He for kinetic energies (Ek) up to 300 cm−1. Inelastic collision rate coefficients were subsequently obtained by thermally averaging the cross-sections over a Maxwell–Boltzmann distribution of kinetic energies. Our results indicate that at very low temperatures (T  < 15 K), rotational transitions associated with Δj = Δkc = ±1, which are crucial for the identification of H2CCCH+ in astronomical surveys, exhibit the largest cross-sections. In contrast, at higher temperatures, transitions with Δj = Δkc = ±2 become more dominant. These data hold significant implications for the determination of the H2CCCH+ abundance in the ISM and improve the modelling of interstellar hydrocarbon-chain reaction pathways. [ABSTRACT FROM AUTHOR]

Electrocatalytic oxidation of glycerol, an oversupplied byproduct of the biodiesel industry, into high‐valued chemicals is alluring to diminishing current dependence on fossil energy. Formic acid is an important glycerol oxidation product that serves as a high‐energy‐density fuel and crucial precursor for the fine chemical industry while developing an electrocatalyst to efficiently convert glycerol into formic acid remains a challenge. Herein, a Cu‐doped nickel phosphide (CuxNi2–xP) electrocatalyst, achieving formate productivity of ≈11 mol m−2 h−1 at 1.54 V versus RHE over a broad glycerol concentration range (10–100 mm) is reported, which is greater than threefolds than that of Ni2P. Furthermore, CuxNi2–xP can enhance the cleavage of C─C bond in glycerol, reducing the production of intermediates and thus attaining high selectivity of formate. In situ experiments integrated with density functional theory (DFT) calculation revealed that the doping of Cu can promote the generation of NiIII─OOH species and enrich glycerol substrates in local environments on CuxNi2–xP surface, thus facilitating reaction efficiency. Finally, the study designed a membrane‐free flow electrolyzer for continuous upgrading glycerol to formate, attaining 16.4 mmol of formate coupled with 0.68 L of H2 at 1.75 V in 8 h. [ABSTRACT FROM AUTHOR]

Mussel‐inspired coating is a substrate‐independent surface modification technology. However, its application is limited by time‐consuming, tailoring specific functions require tedious secondary reaction. To overcome those drawbacks, a strategy for the rapid fabrication of diverse coatings by expanding the library of precursors using oxidation coupled with polyamine was proposed. Based on DFT simulations of the reaction pathways, a method was developed to achieve rapid deposition of coatings by coupling oxidation and polyamines, which simultaneously accelerated the oxidation of precursors and polymer chain growth. The feasibility and generalizability of the strategy was validated by the rapid coating of 10 catechol derivatives and polyamines on various substrates. The surface properties of the substrates such as functional group densities, Zeta potential and contact angles can be easily tuned. The tailored surface engineering application of the strategy was demonstrated by the heavy metal adsorbents and superwetting materials prepared through the delicate combination of different building blocks. Our strategy was flexible in terms of diverse surface engineering design which greatly enriched the connotation of mussel‐inspired technique. [ABSTRACT FROM AUTHOR]

In monolayer transition metal dichalcogenides, defects, such as chalcogen vacancies, play an important role in determining their properties. Herein, monolayer MoSe2 with varying Se vacancy concentrations is successfully prepared by adjusting the amount of the precursors during the chemical vapor deposition synthesis. The Raman and low‐temperature photoluminescence spectra are systematically studied at varying defect concentrations. Furthermore, it is found that Se vacancies introduce in‐gap electronic states, leading to distinct localized exciton emissions, which can be engineered by controlling the concentration of Se vacancies. Density functional theory calculations indicate that the observed variations in localized exciton emission are attributed to the change of defect level with increasing defect concentration. The results provide insights into the influence of varying Se vacancy concentrations on defect‐induced Raman and PL spectroscopy in MoSe2. [ABSTRACT FROM AUTHOR]

Atomic layer deposition (ALD) has been successfully used for the deposition of palladium (Pd) thin films and nanostructures, with a wide range of applications in fields such as microelectronics, energy conversion, sensors, catalysis, membranes, and sensing devices. Thanks to the self-saturating and surface-selective nature of ALD, it allows for precise control of the amount of Pd deposited on challenging surfaces with different precursor chemistries and customizable processing conditions. This technique can produce low-dimensional nanostructures such as single atoms, nanoclusters, core/shell nanoparticles, and ultrathin continuous films. This article provides an overview of the Pd ALD processes and studies reported to date, highlighting the various precursor chemistries used and the intended applications of the prepared nanostructures. This review opens up prospects and demonstrates the potential of using Pd nanomaterials produced through ALD in real devices. [ABSTRACT FROM AUTHOR]

In monolayer transition metal dichalcogenides, defects, such as chalcogen vacancies, play an important role in determining their properties. Herein, monolayer MoSe2 with varying Se vacancy concentrations is successfully prepared by adjusting the amount of the precursors during the chemical vapor deposition synthesis. The Raman and low‐temperature photoluminescence spectra are systematically studied at varying defect concentrations. Furthermore, it is found that Se vacancies introduce in‐gap electronic states, leading to distinct localized exciton emissions, which can be engineered by controlling the concentration of Se vacancies. Density functional theory calculations indicate that the observed variations in localized exciton emission are attributed to the change of defect level with increasing defect concentration. The results provide insights into the influence of varying Se vacancy concentrations on defect‐induced Raman and PL spectroscopy in MoSe2. [ABSTRACT FROM AUTHOR]

Starting from poly(4-vinylpyridine) ((P4VP)n), poly(2-vinylpyridine) ((P2VP)n), and [N=P(O2CH2CF3)]m-b-P2VP20 block copolymers, a series of metal-containing homopolymers, (P4VP)n⊕MXm, (P2VP)n⊕MXm, and [N=P(O2CH2CF3)]m-b-P2VP20]⊕MXm MXm = PtCl2, ZnCl2, and Eu(NO3)3, have been successfully prepared by using a direct and simple solution methodology. Solid-state pyrolysis of the prepared metal-containing polymeric precursors led to the formation of a variety of different metallic and metal oxide nanoparticles (Pt, ZnO, Eu2O3, and EuPO4) depending on the composition and nature of the polymeric template precursor. Thus, whereas Eu2O3 nanostructures were obtained from europium-containing homopolymers ((P4VP)n⊕MXm and (P2VP)n⊕MXm), EuPO4 nanostructures were achieved using phosphorus-containing block copolymer precursors, [N=P(O2CH2CF3)]m-b-P2VP20]⊕MXm with MXm = Eu(NO3)3. Importantly, and although both Eu2O3 and EuPO4 nanostructures exhibited a strong luminescence emission, these were strongly influenced by the nature and composition of the macromolecular metal-containing polymer template. Thus, for P2VP europium-containing homopolymers ((P4VP)n⊕MXm and (P2VP)n⊕MXm), the highest emission intensity corresponded to the lowest-molecular-weight homopolymer template, [P4VP(Eu(NO3)3]6000, whereas the opposite behavior was observed when block copolymer precursors, [N=P(O2CH2CF3)]m-b-P2VP20]⊕MXm MXm= Eu(NO3)3, were used (highest emission intensity corresponded to [N=P(O2CH2CF3)]100-b-[P2VP(Eu(NO3)3)x]20). The intensity ratio of the emission transitions: 5D0 → 7F2/5D0 → 7F1, suggested a different symmetry around the Eu3+ ions depending on the nature of the polymeric precursor, which also influenced the sizes of the prepared Pt°, ZnO, Eu2O3, and EuPO4 nanostructures. [ABSTRACT FROM AUTHOR]

Countering improvised explosive devices (C-IED) is a significant theme of the twenty-first century, particularly in regions with limited governance and a fragile rule of law. Many strands of activity are involved, with human interaction proving difficult to predict. However, Bayesian belief updating (used across several academic fields to provide insight into human behaviours) has never been considered. Given the breadth of C-IED, this research focusses on a state affected by conflict, and where illicit diversion of explosive chemical precursors (ECP) for IED manufacture is supported by the population. It aims to represent (both visually and probabilistically) a methodology by which human relationships could be better understood, thereby promoting belief updating as new evidence becomes available. Such belief updating would refine focus and improve resource mobilisation. [ABSTRACT FROM AUTHOR]

The 3D cross-flower-like Co-Ni-MOF was prepared by chemical precipitation method, and the Co-Ni-Fe-LDHs composite was formed by directly growing on its surface through ion exchange strategy. The unique hollow structure of the 3D cross flower shape and the synergistic effect between Co-Ni-Fe-LDHs significantly enhance the charge transfer efficiency, thereby improving the OER performance. [Display omitted] • Co-Ni-Fe-LDHs directly grew on Co-Ni-MOF to form novel 3D cross-flower morphology catalyst. • The Co-Ni-Fe-LDHs nanosheets accelerate electron transfer, thereby improving OER kinetics. • Co-Ni-Fe-LDHs will hold promise for the development of electrocatalytic materials. In this study, we synthesized novel three-dimensional (3D) cross-flowered Co-Ni metal–organic framework (Co-Ni-MOF) precursors using the chemical precipitation method. Subsequently, we obtained Co-Ni-Fe layered double hydroxides (Co-Ni-Fe-LDHs) through an ion exchange strategy, which preserved their original morphology while consisting of ultrathin layered hydroxide nanosheets. The interlayer spacing of the LDH lamellar structure was finely tuned by varying the ratios of Co to Ni. The results demonstrated that Co-Ni-Fe LDHs, characterized by a unique three-dimensional cross-shaped structure and an optimal composition ratio of Co2+:Ni2+ = 2:1, exhibited increased interlayer spacing. This structural characteristic contributed to their excellent electrochemical performance, positioning them as optimal electrode materials for catalytic oxygen evolution reactions (OER). Our observations revealed that Co-Ni-Fe-LDHs exhibited remarkable OER activity, characterized by a low Tafel slope of 41.82 mV dec−1, a low overpotential of 322 mV at a current density of 10 mA cm−2, and outstanding stability over a 48-hour period. In-situ Raman spectroscopy results indicated that the active site of the composite was γ-CoOOH. Additionally, the room temperature stirring and standing strategy employed in this study is easier to scale up and yields a higher quantity of reaction products compared to traditional high-temperature and high-pressure conditions. This investigation provides novel insights into the design and fabrication of Co-Ni-Fe-LDHs catalyst with 3D cross-flower structures, demonstrating enhanced electrocatalytic activity and commendable stability. These findings suggest promising applications in the field of electrolyzed water. [ABSTRACT FROM AUTHOR]

By exploiting the electronic capabilities of the N‐heterocyclic boryloxy (NHBO) ligand, we have synthesized "naked" acyclic gallyl [Ga{OB(NDippCH)2}2]− and indyl [In{OB(NDippCH)2}2]− anions (as their [K(2.2.2‐crypt)]+ salts) through K+ abstraction from [KGa{OB(NDippCH)2}2] and [KIn{OB(NDippCH)2}2] using 2.2.2‐crypt. These systems represent the first O‐ligated gallyl/indyl systems, are ultimately accessed from cyclopentadienyl GaI/InI precursors by substitution chemistry, and display nucleophilic reactivity which is strongly influenced by the presence (or otherwise) of the K+ counterion. [ABSTRACT FROM AUTHOR]

The results of molecular dynamics simulation of the crystal structure of the currently most studied CQDs, based on cadmium selenide nanoparticles, are presented, and issues concerning the structure of the ligand shell of these nanoparticles, primarily made of trioctylphosphine (TOP) and trioctylphosphine oxide (TOPO) molecules, which act as a medium and as precursors in the chemical reaction that results in the formation of CQDs, are discussed in detail. [ABSTRACT FROM AUTHOR]

Ethylene and propylene, as essential precursors in the chemical industry, have been playing a pivotal role in the production of various value-added chemicals that find wide applications in diverse sectors, such as polymer synthesis, lithium-ion battery electrolytes, antifreeze agents and pharmaceuticals. Nevertheless, traditional methods for olefin functionalization including chlorohydrination and epoxidation involve energy-intensive steps and environment-detrimental by-products. In contrast, electrocatalysis is emerging as a promising and sustainable approach for olefin oxidation via utilizing renewable electricity. Recent advancements in energy storage and conversion technologies have intensified the research efforts toward designing efficient electrocatalysts for the selective oxidation of ethylene and propylene, highlighting the shift towards more sustainable production methods. Herein, we summarize recent progress in the electrocatalytic oxidation of ethylene and propylene, focusing on achievement in catalyst design, reaction system selection and mechanism exploration. We figure out the advantages of different oxidation methods for improved performance and discuss the various types of catalysts like noble metals, non-noble metals, metal oxides and carbon-based materials, in facilitating the electrochemical oxidation of ethylene and propylene. Finally, we also provide an overview of current challenges and problems requiring further works. [ABSTRACT FROM AUTHOR]

A simple, solvent‐free arginine‐catalyzed aldol dimerization of levulinic acid was achieved via the simultaneous formation of a eutectic mixture. Dimers of levulinic acid are valued as biomass‐derived fine chemical precursors, with potential to upgrade to bio‐jet fuels or N‐containing functional chemicals. Typically, these dimers are produced as isomeric mixtures using high temperatures and a variety of solid inorganic catalysts or mineral acids. In this study, an organocatalytic and regioselective dimerization was achieved at 22 % conversion on either a bench or kilogram scale using mild temperatures and only L‐arginine as both a co‐solvent and catalyst. The intricate H‐bonding network comprising the eutectic solvent was harnessed to produce only one product, minimizing side reactivity and preserving the reactants for recycling. [ABSTRACT FROM AUTHOR]

Halide perovskites have been proven to have enormous potential for further flexible optoelectronic devices. However, the repeated mechanical bending and tolerance to moisture corrosion remain a critical challenge for flexible perovskite devices. Solution chemistry of a precursor is the basis for the preparation of high-quality perovskite films and can significantly enhance the lasing performance and humidity stability of perovskites. Herein, from the perspective of solvent engineering, two ionic liquids (ILs) of methylammonium acetate (MAAc) and methylammonium propionate (MAP) were introduced to prepare high-quality MAPbBr3 perovskite films. The as-prepared MAPbBr3 perovskite films exhibit not only enhanced amplified spontaneous emission (ASE) performance but also the excellent mechanical reliability even in a humid environment. Especially, the MAAc-based MAPbBr3 perovskite film possesses the morphology optimization, defect passivation, simultaneous improvements in ASE, and bending durability due to the stronger coordination capacity and reactivity between MAAc and Pb2+. Our work provides an effective strategy for flexible perovskite based photonic devices fueled by the remarkable mechanical reliability. [ABSTRACT FROM AUTHOR]

AgBiS2 has been considered by researchers as a new-generation photovoltaic material because of its ideal bandgap, environment-friendliness and wide absorption range. Although it has shown great development potential in solar cell devices, due to the lack of systematic exploration and research on precursor solution chemistry, the performance of AgBiS2 solar cells prepared by the precursor solution method lags behind those of colloidal solution–processed cells. Herein, we report a pre-nucleation strategy that involves controlling the precursor solution at the molecular level. The pre-nucleation strategy results in faster nucleation of the AgBiS2 crystals during crystallization, resulting in AgBiS2 thin films with larger grains, fewer defects and more homogeneous cation disorder. The improved quality of the AgBiS2 thin films resulted in high-performance AgBiS2 thin film solar cells with a JSC of up to 30.9 mA cm−2 and a record high PCE of 3.68%. This work provides a feasible method for the preparation of AgBiS2 thin film solar cells based on the precursor solution. [ABSTRACT FROM AUTHOR]

The global strategy to reduce waste production implies development of recycling technologies and conversion of various waste into value‐added products. Fly ash is an industrial waste produced in a large amount. It comprised an aluminosilicate cenosphere, which seems perspective as a support for heterogeneous catalysts. Here we report the preparation and application of heterogeneous silver nanocatalysts deposited on cenosphere in the epoxidation reaction, a relevant process for preparation of valuable organic precursors and target chemicals. Reductive wet deposition method yields Ag nano‐dispersed coating of improved quality represented by Ag particles of about 2.7 nm on the surface of the microspheres size of 50–250 microns for catalytic synthesis of styrene‐oxide. The 0.1 mmol/g Ag/cenosphere provided best catalytic results with threefold excess of tret‐butyl hydroperoxide in acetonitrile at 80 °C. Comparison of fly ash cenosphere with other supports suggests that low porosity of microspherical support allows for an easier access of reagents to active sites of the catalyst and significantly increases the yield of epoxide and selectivity of the reaction. [ABSTRACT FROM AUTHOR]

Aims Cytidine, as an important commercial precursor in the chemical synthesis of antiviral and antitumor drugs, is in great demand in the market. Therefore, the purpose of this study is to build a microbial cell factory with high cytidine production. Methods and results A mutant E. coli NXBG-11-F34 with high tolerance to uridine monophosphate structural analogs and good genetic stability was obtained by atmospheric room temperature plasma (ARTP) mutagenesis combined with high-throughput screening. Then, the udk and rihA genes involved in cytidine catabolism were knocked out by CRISPR/Cas9 gene editing technology, and the recombinant strain E. coli NXBG-13 was constructed. The titer, yield, and productivity of cytidine fermented in a 5 l bioreactor were 15.7 g l−1, 0.164 g g−1, and 0.327 g l−1 h−1, respectively. Transcriptome analysis of the original strain and the recombinant strain E. coli NXBG-13 showed that the gene expression profiles of the two strains changed significantly, and the cytidine de novo pathway gene of the recombinant strain was up-regulated significantly. Conclusions ARTP mutagenesis combined with metabolic engineering is an effective method to construct cytidine-producing strains. [ABSTRACT FROM AUTHOR]

Biomass resources are often disposed of inefficiently and it causes environmental degradation. These wastes can be turned into bio‐products using effective conversion techniques. The synthesis of high‐value bio‐products from biomass adheres to the principles of a sustainable circular economy in a variety of industries, including agriculture. Recently, fluorescent carbon dots (C‐dots) derived from biowastes have emerged as a breakthrough in the field, showcasing outstanding fluorescence properties and biocompatibility. The C‐dots exhibit unique quantum confinement properties due to their small size, contributing to their exceptional fluorescence. The significance of their fluorescent properties lies in their versatile applications, particularly in bio‐imaging and energy devices. Their rapid and straight‐forward production using green/chemical precursors has further accelerated their adoption in diverse applications. The use of green precursors for C‐dot not only addresses the biomass disposal issue through a scientific approach, but also establishes a path for a circular economy. This approach not only minimizes biowaste, which also harnesses the potential of fluorescent C‐dots to contribute to sustainable practices in agriculture. This review explores recent developments and challenges in synthesizing high‐quality C‐dots from agro‐residues, shedding light on their crucial role in advancing technologies for a cleaner and more sustainable future. [ABSTRACT FROM AUTHOR]

This study presents a novel approach in the realm of catalytic organic synthesis by integrating biomass catalytic conversion with organic synthesis techniques. Utilizing N-acetylglucosamine as the primary feedstock, the first phase of the research involves its catalytic transformation into 5-hydroxymethylfurfural (HMF). The subsequent phase employs a condensation reaction between HMF and 3,3-Dimethyl-2-butanone to synthesize a new compound, (E)-1-(5-(hydroxymethyl) furan-2-yl)-4,4-dimethylpent-1-en-3-one. This two-step process not only demonstrates the feasibility of converting biomass into valuable chemical precursors but also exemplifies the synthesis of novel compounds through green chemistry principles. The successful execution of this methodology offers fresh insights and opens new avenues for advancements in catalytic organic synthesis, emphasizing sustainability and efficiency. [ABSTRACT FROM AUTHOR]

The article discusses the increasing misuse of fentanyl, a synthetic opioid, in the United States and its role in the opioid crisis. It highlights the need for laboratory detection of fentanyl use in various settings, such as emergency departments and substance-use disorder treatment programs. The article also provides information on different fentanyl immunoassays available for laboratory testing and suggests that laboratories should consider their specific needs and perform evaluation and validation studies before implementing an assay. It concludes by recommending the use of mass spectrometry to confirm positive immunoassay results and suggests monitoring changes in fentanyl immunoassays and their use in patient populations. [Extracted from the article]

Microalgal biomass can be utilized for the production of value-added chemicals and fuels. Within this research, Chlorella vulgaris biomass left behind after the extraction of lipids and proteins was converted to valuable sugars, organic acids and furanic compounds via hydrolysis/dehydration using dilute aqueous sulfuric acid as a homogeneous catalyst. Under mild conditions, i.e., low temperature and low sulfuric acid concentration, the main products of hydrolysis/dehydration were monomeric sugars (glucose and xylose) and furanic compounds (HMF, furfural) while under more intense conditions (i.e., higher temperature and higher acid concentration), organic acids (propionic, formic, acetic, succinic, lactic, levulinic) were also produced either directly from sugar conversion or via intermediate furans. As a second valorization approach, the residual microalgal biomass was converted to value-added sugar alcohols (sorbitol, glycerol) via hydrogenation/hydrogenolysis reactions over metallic ruthenium catalysts supported on activated carbons (5%Ru/C). It was also shown that a low concentration of sulfuric acid facilitated the conversion of biomass to sugar alcohols by initiating the hydrolysis of carbohydrates to monomeric sugars. Overall, this work aims to propose valorization pathways for a rarely utilized residual biomass towards useful compounds utilized as platform chemicals and precursors for the production of a wide variety of solvents, polymers, fuels, food ingredients, pharmaceuticals and others. [ABSTRACT FROM AUTHOR]

2D transition metal dichalcogenides (TMDs) for advanced logic transistor technologies are deposited by various modifications of the chemical vapor deposition (CVD) method using a wide variety of precursors. Being a major electrical performance limiter, the TMD crystal grain size strongly differs between the various CVD precursor chemistries from nano‐ to millimeter‐sized crystals. However, it remains unclear how the CVD precursor chemistry affects the nucleation density and resulting TMD crystal grain size. This work postulates guiding principles to design a CVD process for highly crystalline TMD deposition using a quantitative analytical model benchmarked against the literature. The TMD nucleation density reduces favorably under low supersaturation conditions where the metal precursor sorption on the starting surface is reversible and the corresponding metal precursor desorption rate exceeds the overall deposition rate. Such reversible precursor adsorption guarantees efficient long‐range gas‐phase lateral diffusion of precursor species in addition to short‐range surface diffusion, which vitally increases crystal grain size. The proposed model explains the large spread in experimentally observed TMD nucleation densities and crystal grain sizes for state‐of‐the‐art CVD chemistries. Ultimately, it empowers the reader to interpret and modulate precursor adsorption and diffusion reactions through designing CVD precursor chemistries. [ABSTRACT FROM AUTHOR]

This article contains the results of research on the development of a Cf/C-UHTC carbon fabric composite based on a viscose precursor and a combined matrix consisting of partially sintered ceramics in a system consisting of HfCeHfB2eNbCeNbB2eTiCeTiB2eB4CeSiC, amorphous carbon, and pyrocarbon. The SiC fraction does not exceed 8.5e9.0 wt%. In its initial state, the composite has open porosity, with apparent and true densities of 18e22%, 2.25e2.29 g/cm³ and 2.79e2.91 g/cm³, respectively. The bending strength and the elasticity modulus are 27.8 ± 0.7 MPa and 7.8 ± 0.2 GPa, respectively, and the fracture strain is 0.85 ± 0.05%. The tests for resistance to oxidation and ablation were carried out in a gas dynamic flow regime and non-equilibrium air plasma heating at flow rates of 4.5e4.8 km/s and breaking enthalpy of 45 e50 MJ/kg. Heating was performed in the temperature range Tw = 1400e2700 °C at the critical point on the front surface of the samples. The average linear ablation rate and mass loss rate of the composite are 6.3 ± 0.3 mm/s and 6.22 ± 0.44 mg/s. The estimated value of the conductivity factor is 0.280e0.285 W/(m K). The performance ability of the composite arises from the formation and evolution of a passivating heterogeneous oxide film consisting mainly of titanium niobate Ti2Nb10O29, mixed solutions of Hf1-xTixO2, (Ti1-xHfx)1-yNbyOz and (Ti1-xHfx)NbO4 with broad homogeneity ranges, and also encapsulated carbide and boride particles. It is shown that the oxidation resistance of the composite increases as a result of the transition through a number of phases into a liquid state as the working temperature increases. [ABSTRACT FROM AUTHOR]

Pisha sandstone (PS) is a special interbedded rock in the middle reaches of the Yellow River that experiences severe weathering and is loose and broken. Due to severe multiple erosion events, the Pisha sandstone region is called "the most severe water loss and soil erosion in the world" and "the ecological cancer of the earth". As a special pozzolanic mineral, PS has the potential to be used as precursors for the synthesis of green and low-carbon geopolymer gel materials and applied in ecological restoration. This paper aims to undertake a phase review of the precursors for geopolymer gel materials. The genesis and distribution, physical and chemical characterization, erosion characteristics, and advances in the ecological restoration of PS are all summarized. Furthermore, current advances in the use of PS for the synthesis of geopolymer gel materials in terms of mechanical properties and durability are discussed. The production of Pisha sandstone geopolymer gels through the binder jetting technique and 3D printing techniques is prospected. Meanwhile, the prospects for the resource application of PS in mine rehabilitation and sustainable ecology are discussed. In the future, multifactor-driven comprehensive measures should be further investigated in order to achieve ecological restoration of the Pisha sandstone region and promote high-quality development of the Yellow River Basin. [ABSTRACT FROM AUTHOR]

Transition metal complexes of N-substituted guanidinates are widely studied due to their intriguing structures, reactivities, and bonding as homogeneous catalysts and precursors for chemical vapor deposition. In this manuscript, we have isolated a family of pincer complexes, [Pd{κ3(CNN)(OC(O)R′)}] (CNN = N-picolyl-N′,N′′-diarylguanidinate(1−); aryl = 2-RC6H4; R = Me and CF3; R′ = CF3, Me and tBu; A) and studied their reactions with XylN≡C (Xyl = 2,6-Me2C6H3) and PPh3 (Ls′) with the objective of understanding the substituent effects of the pincer complexes upon the nature of the products. In this endeavour, we were able to isolate the respective cationic [Pd{κ3(CNN)(L)}][OC(O)R′] (B) and neutral [Pd{κ3(CNN)(C≡NXyl)}] (CNN = N-picolinoyl-N′,N′′-diarylguanidinate(2−); D) complexes with the latter complexes formed from the former through carboxylate-assisted N–H activation followed by –CH2– → –C(O)– oxygenation of the 2-picolyl unit in the guanidinate(1−) ligand, which is induced by atm. O2. An elusive intermediate, [Pd{κ3(CNN)(C≡NXyl)}] (CNN = N-picolyl-N′,N′′-di(2-tolyl)guanidinate(2−); C) formed during B → D transformation was successfully isolated. The new complexes were fully characterised and the molecular structures of nine complexes were determined by X-ray crystallography. Various intermediates formed during the oxygenation were mapped out using the model complexes through DFT calculations. The solution behaviour of A was studied by multinuclear NMR and their utility as catalysts in Suzuki–Miyaura coupling reactions and base-free cycloisomerization of 4-pentynoic acid was briefly explored. The carboxylate-assisted N–H activation and oxygenation of the Pd(II) bound guanidinate(1−/2−) ligands reported herein represent the redox active behaviour of the ligand towards atm. O2 for the first time. [ABSTRACT FROM AUTHOR]

The versatile uses of Copper(II) Fluoride (CuF2) are well known; these include its usage as a precursor in chemical synthesis as well as its contribution to the creation of sophisticated materials and electronics. There are interesting opportunities to study the interactions between these elements because of their unique crystal structure, which contains copper ions and fluoride anions. Its potential in optoelectronic devices and conductive qualities also make it a viable material for next-generation technologies. To better understand the structural properties of CuF2 and how they affect its entropy, we present new Zagreb indices in this study and use them to calculate entropy measures. We also build a regression model to clarify the relationship between the calculated indices and entropy levels. The findings of our investigation offer significant understanding regarding the ability of the suggested Zagreb indices to extract meaningful content and their correlation with entropy in the context of CuF2. This information is important for understanding CuF2 alloys and for exploring related complex materials. [ABSTRACT FROM AUTHOR]

4-(4-nitrophenyl)thiomorpholine, the title compound, has been used as a precursor for the corresponding 4-thiomorpholinoaniline, which is a useful building block in medicinal chemistry. The crystal and molecular structures of the title compound, however, have not been described thus far. We synthesized the title compound by means of a nucleophilic aromatic substitution reaction of 4-fluoronitrobenzene and thiomorpholine and structurally characterized it by X-ray crystallography, DFT calculations, and Hirshfeld surface analysis. In the crystal, the molecule exhibits an approximately CS-symmetric structure, with the nitrogen-bound 4-nitrophenyl group in a quasi axial position on the six-membered thiomorpholine ring in a low-energy chair conformation. The solid-state structure of the title compound is markedly different from that of its morpholine analogue. This can be ascribed to the formation of centrosymmetric dimers through intermolecular C–H···O weak hydrogen bonds involving the methylene groups adjacent to the sulfur atom and face-to-face aromatic stacking. [ABSTRACT FROM AUTHOR]

Advanced oxidation processes are emerging technologies for the decomposition of organic pollutants in various types of water by harnessing solar energy. The purpose of this study is to examine the physicochemical characteristics of tungsten(VI) oxide (WO3) photoanodes, with the aim of enhancing oxidation processes in the treatment of water. The fabrication of WO3 coatings on conductive fluorine-doped tin oxide (FTO) substrates was achieved through a wet coating process that utilized three different liquid formulations: a dispersion of finely milled WO3 particles, a fully soluble WO3 precursor (acetylated peroxo tungstic acid), and a combination of both (applying a brick-and-mortar strategy). Upon subjecting the WO3 coatings to firing at a temperature of 450 °C, it was observed that their properties exhibited marked variations. The fabricated photoanodes are examined using a range of analytical techniques, including profilometry, thermo-gravimetric analysis (TGA), X-ray diffraction (XRD), and voltammetry. The experimental data suggest that the layers generated through the combination of particulate ink and soluble precursor (referred to as the brick-and-mortar building approach) display advantageous physicochemical properties, rendering them suitable for use as photoanodes in photoelectrochemical cells. [ABSTRACT FROM AUTHOR]

Spray Pyrolysis (SP), a low-cost chemical procedure was employed to deposit ZnO thin films under optimum conditions at 350 °C using a predetermined precursor concentration of 0.1 M. This study investigates how post-air annealing affects the structural, compositional, morphological, optical, and electrical properties of ZnO thin films. The deposited films were heated by air at 400, 450 and 500 °C for 1 h. X-ray diffraction, scanning electron microscope, x-ray dispersive spectroscopy, Raman spectroscopy, Fourier Transform Infrared Spectroscopy, optical spectroscopy, and Hall effect studies were conducted to investigate how post-air annealing alters the properties of the as-deposited film. XRD measurements show that annealing resulted in the growth of polycrystalline hexagonal wurtzite without the formation of any other phases in ZnO films. When heated to 500 °C, the estimated crystallite size of the as-deposited film increased from 6.22 nm to 6.57 nm. The SEM show the creation of compact and tightly packed films, as well as the visible network of large grains during annealing. Raman and FTIR studies have validated the chemical structure, molecular interactions, and formation of chemical bonds in ZnO thin films. Optical studies show that the energy band gap widens during annealing. Optical profilometer studies verified the uniformity of the deposited film surface. According to Hall effect analysis, conversion of p to n type occurs at an annealing temperature of 450 °C. A ZnO-based MOS gas sensor was found to have better selectivity towards C2H5OH than other test gases such as NH3, NO2, and H2S. At room temperature, the sensor response and recovery time is shorter for NH3 than for C2H5OH test gas. In environmental monitoring, the present gas sensor can detect ethanol. [ABSTRACT FROM AUTHOR]

Foams from fossil fuel-based raw materials have been developed into crucial industrial products for a wide range of applications. However, they come with sustainability and environmental challenges. Bio-based foams hold promises for replacing fossil fuel-based foams because of their low cost, superior thermal insulation performance, superior fire resistance, eco-friendliness, bio-sourced origin, and environmental sustainability. This study synthesized rigid bio-based foams from plant-derived precursor chemicals: furfuryl alcohol (FA) and polyol produced from lignin. FA was obtained from reducing furfural derived from maize cobs via acid hydrolysis. Eight bio-based foams were obtained by varying the catalyst concentration and the ratio of FA to the lignin-based polyol and subsequently characterized. Resulting bio-based foams had compressive resistance: 14–16 MPa, water absorption capacity: 24.12–332.14%, density: 0.247–0.886 g/cm3, and moisture content: 7.90–9.7%. Scanning electron microscopy images revealed that the foam cellular morphology was closed cells with the cell diameter between 10 and 200 µm. Thermogravimetric analysis data showed that maximum thermal degradation in the produced foams occurred between 457.4 and 453 °C. The outlined results indicated that the foams are suitable for thermal insulation, construction, and floral purposes due to their high thermal stability, high water absorption capacity, and high compressive strength. [ABSTRACT FROM AUTHOR]

The molecule glycerol (H3gly) plays a key role in sustainable and green chemistry. Having been discovered for over 200 years and produced from vegetable oils and animal fats by hydrolysis, saponification and transesterification reactions, this natural triol is today employed in a wide range of cosmetic, food, polymer and pharmaceutical applications. Moreover, it is an essential C3 precursor in the chemical industry, used in the production of several intermediates and it avoids the need for petroleum-based precursors. Less famous but just as exciting, in the domain of coordination chemistry, glycerol is also proving to be a suitable ligand, capable of binding to one or more metal centres, either directly in its triol H3gly form (rather rare), or in its various deprotonated glycerolate forms, such as [H2gly]−, [Hgly]2− and [gly]3− (in most cases). Since the 1970s, various molecular structures prepared from glycerol and metallic and organometallic precursors, ranging from mononuclear complexes to sophisticated aggregates and coordination polymers, have been isolated and characterised. On the basis of the single-crystal X-ray diffraction structures described so far in the literature and deposited in the Cambridge Structural Database, in this structural inventory, we review the different modes of coordination of glycerol and glycerolates with metals. [ABSTRACT FROM AUTHOR]

In a single step, nitrogen‐doped activated carbons have been synthesized using walnut shells and urea as precursors by chemical activation with K2CO3. The textural and elemental properties such as surface area, micropore volume, nitrogen content, and yield were optimized in a multivariable way using a central composite design of experiments 23, varying the urea‐nutshell ratio, K2CO3 ratio, and activation temperature. Activated carbon doped with the highest nitrogen presented a surface area of 895 m2 g−1, a micropore volume of 0.22 cm3 g−1, and a nitrogen content of 4.11 %. Furthermore, the yield of 13.85 % at urea impregnation ratio 1.56 gUrea gNutshell−1, activating agent ratio 1.4 gK2CO3 gCarbon−1, and temperature of 591 °C, being the temperature and the urea impregnation ratio the significant variables in the responses evaluated. The best‐activated carbon doped with nitrogen presented a CO2 adsorption capacity of 2.78 mol kg−1, reversible adsorption‐desorption, and selectivity against nitrogen of 33.2 molCO2/molN2, superior to a commercial activated carbon with similar textural properties at the same experimental conditions and being in the order of magnitude as activated carbons synthesized under similar conditions. [ABSTRACT FROM AUTHOR]

The QuEChERS approach was optimized for extracting cholesterol oxidation products in cheese, followed by LC-APCI-MS/MS analysis. Optimization of the method, including evaluations of saponification step, sample weight, and d-SPE purification resulted in good recoveries for each analyte, ensuring a reliable determination of these contaminants in cheese samples. In addition, the method was successfully validated by testing linearity of response, analytical limits (LOD and LLOQ), and precision. Sliced cheese samples wrapped in various packaging materials underwent a challenging test to simulate refrigerated storage conditions under fluorescent light, inducing photo-oxidative stress. The validated QuEChERS method revealed that only seasoned hard cow's cheese showed an increase in the concentration of 7-ketocholesterol and its chemical precursors, 7β-hydroxycholesterol, and 7α-hydroxycholesterol, reaching levels of 0.45, 0.35, and 0.35 µg g−1, respectively. Conversely, opaque packaging and the use of a double film were found to be effective in preventing the formation of COPs in cheese samples subjected to photo-oxidative stress, such as smoked cheese and melted cheese slices (sottilette). A trade-off must be found between ensuring cheese protection and meeting the consumer's desire to see the product. [ABSTRACT FROM AUTHOR]

6-Aminocaproic acid and adipic acid are the key value-added chemical precursors in the pharmaceutical, solvent and polyamide industry, including nylon-6, and nylon-6, 6. An enzymatic interconversion of the two precursors can provide a convenient and eco-friendly biosynthetic route to each of the precursors and thus, require analysis of the reaction process. Herein, an in vitro enzymatic method was employed to convert the two precursors while most studies so far have focused on the whole cell bioconversion to investigate the process. 4-Aminobutyrate aminotransferase was utilized to mediate the reactions between 6-aminocaproic acid and the intermediate 6-oxohexanoic acid with the aid of pyridoxal 5'-phosphate and amine donor/acceptor. 6-Oxohexanoate dehydrogenase was utilized for the reaction from 6-oxohexanoic acid to adipic acid with NADP+. A range of reaction conditions were investigated including the type of amine donor, pH conditions, the concentrations of enzyme and amine donor/acceptor. The optimum condition resulted in 78% yield for the reaction from 6-oxohexanoic acid to 6-aminocaproic acid. The yield for the one-pot, two-step enzymatic cascade from 6-aminocaproic acid via 6-oxohexanoate intermediate to adipic acid was 88%, which was higher than the yield for each individual step in the cascade, with 31% and 32%, for the first and second step, respectively. Furthermore, structural analysis on the active site of the 4-aminobutyrate aminotransferase docked with a range of amine donors implicates the optimal donor is glutamate in accordance with the experimental data and suggests enzyme engineering possibilities for more readily available donors to facilitate the industrial application of the process. [ABSTRACT FROM AUTHOR]

The aim of this study was to investigate a tailor‐made metal precursor and its chemical properties to tune the properties of supported metal nanoparticles (NPs) and their catalytic performance when used as Diesel Oxidation Catalyst (DOC). The formation of extremely small Pt NPs from a new halide‐free Pt complex was investigated, namely bis(oxalato)platinate, H2[Pt(C2O4)2]. The size evolution of the supported NPs, from the formation upon the Pt precursor decomposition on γ‐alumina to the sintering of the NPs at high temperatures, was followed by thermogravimetric analysis coupled with mass spectrometry (TG‐MS) and differential scanning calorimetry (DSC), transmission electron microscopy (TEM) and diffuse reflectance infrared Fourier transform (DRIFT) spectroscopy. A correlation between the NPs' size of the catalyst and the performance for the CO, C3H6, C3H8 and NO oxidation reactions pointed out a retained activity during test cycles, showing low sensitivity to the test conditions applied (i. e., temperature and gas composition). The overall catalytic performance was better in the fresh catalysts compared to the reference catalyst prepared from platinum nitrate, Pt(NO3)4. In particular, the different dispersion of the Pt NPs over the support obtained from the two precursors was identified as the reason for the different catalytic performance, retaining small NPs size after the tests cycles. [ABSTRACT FROM AUTHOR]

Hydrothermal gasification of fuel pellets obtained from co-pelletized agricultural residues such as barley straw, canola hull and oat hull was performed in a batch reactor. The effects of process conditions such as temperature (300–500 °C), reaction time (20–60 min) and feed-to-water mass ratio (1:05–1:15) were investigated to optimize the gasification process for large gas yields. The maximum yield of gas was attained at the temperature, reaction time and feed-to-water mass ratio of 500 °C, 60 min and 1:10, respectively. The highest hydrogen gasification efficiency (113%), hydrogen selectivity (52%), cold gasification efficiency (41%) and heating value of gas (920 kJ/Nm3) were found for the hydrothermal gasification of canola hull pellet at the optimal conditions. The temperature was the most paramount variable followed by reaction time and feed-to-water mass ratio. Physicochemical characterization of hydrochar produced at higher gasification temperatures revealed higher carbon content, thermal stability, alkalinity and structural deformity. The liquid products obtained from hydrothermal gasification of canola hull pellets also showed the presence of partially degraded or reformed organic compounds, which can be extracted as precursors for value-added chemicals. • Gasification of biomass pellets was performed in subcritical and supercritical water. • Gasification was optimized for temperature, reaction time and feed-to-biomass ratio. • Effects of parameters on gas yields: temperature > reaction time > feed-to-biomass ratio. • High carbon content and thermal stability were found in hydrochar with temperature. • Liquid products from gasification of biomass pellets contained chemical building blocks. [ABSTRACT FROM AUTHOR]

A mathematical modelling of cubic autocatalytic reactions with precursor chemicals and linear decay are studied. The model is associated with the diffusion, which is treated in a 1 -D reactor. In this model, reactants are delivered by two mechanisms: diffusion across the cell boundaries and degradation of precursor chemical abundant within the reactor. The semi-analytical solutions are derived for the concentration of dimensionless reactant and dimensionless autocatalyst in the cubic autocatalytic reaction-diffusion equations for the time dependent and time independent by using the Homotopy analysis technique. The obtained semi-analytical solutions are then compared with the numerical simulation and found to be very good fit for all values of the dimensionless parameters. [ABSTRACT FROM AUTHOR]

Context: Area-selective atomic layer deposition (AS-ALD) is a thin film deposition technique developed using conventional ALD by considering the surface chemical nature of the substrate. Selecting appropriate precursors is a critical step in developing an efficient AS-ALD process with high deposition selectivity. However, the current efficiency of research on viable AS-ALD precursors is limited because of the absence of theoretical design rules for precursor chemical structures. In this study, our objective is to propose molecular design principle for precursors for AS-ALD, particularly focusing on achieving high deposition selectivity of oxides on diverse substrates. Current preliminary results suggest that ML-based prediction model may provide a fundamental molecular-level understanding of the reactivity of metal oxide precursors, that can be useful for efficient selection of suitable precursors for AS-ALD. Methods: We employ density functional theory (DFT) calculations and machine learning (ML) techniques to analyze the relationship between the structure and the surface reactivity of the precursor. Considering DFT calculation data (M06L/def2-tzvp, Gaussian 09 and Orca 4.0) and information on precursor structures, artificial neural networks (ANN, neuralnet, R) are applied to identify critical descriptors of the AS-ALD process. Furthermore, we utilize this ANN model to predict precursor reactivity according to surface terminations. [ABSTRACT FROM AUTHOR]

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