Abstract The purpose of this review is to examine the historical background and the scientific and philosophical foundations underlying the emergence and development of Russian astrobiology. In addition, it seeks to provide the international scientific community with a comprehensive account of the principal achievements of the Russian scientists whose research has contributed to the field of astrobiology. Their contributions include experimental models of prebiotic synthesis and impact-generated organics; the formulation of original theories of life’s origin; investigation of cold and glacial terrestrial ecosystems as analogs for Mars and celestial icy bodies; advances in bacterial paleontology with significant astrobiological implications. A significant amount of data produced by Soviet scientists were published exclusively in Russian journals and therefore remained largely inaccessible to the international scientific community. The review also discusses the current state and principal scientific directions of Russian astrobiology, its international cooperation, the challenges and prospects it faces, and provides a comparative analysis with the development of astrobiology in Western countries. Its primary aim is to outline the fundamental structure of astrobiology research in Russia from a retrospective perspective.
In the search for extraterrestrial intelligence (SETI), it is often assumed that intelligent life on an Earth-like exoplanet would inevitably develop the technological means for interstellar communication. This assumption ignores the critical role that fossil fuels played in driving the Industrial Revolution on Earth, which ultimately gave rise to our own advanced technological civilization (ATC) and the possibility of interstellar communication. We therefore propose that any habitable exoplanet that could potentially generate an ATC must contain sizable fossil fuel deposits, especially coal, which supplied most of the energy used in the Industrial Revolution during the 19 th century. Coal is critical because, based on an Earth-like geology, it is more accessible than the much deeper deposits of oil and gas. Without coal, it would have been impossible to tap into the vast underground deposits of oil and gas during the 20 th century. This raises the question of the inevitability of coal formation on an Earth-like exoplanet. Here we present arguments that coal formation may be unlikely, even on an Earth-like planet, because of the many contingent factors that have been recorded in the rock and biological record of our own planet, including the evolution of oxygenic photosynthesis itself, which generated the oxygen-rich atmosphere required for complex life to develop. Central to our argument is the host of highly contingent taphonomic factors, involving plate tectonics and climate, that were required to convert the tropical lycopsid swamp forests of the Pangean supercontinent to the massive coal deposits of the Carboniferous period. Finally, we discuss the need for synchronicity of the appearance of intelligent life forms and the maturation of vast deposits of coal. We conclude that the large number of contingencies involved in coal production justifies adding a term for coal to the Drake Equation for the number of ATCs in the galaxy.
The structural, mechanical, electronic, and optical properties of cubic double perovskite oxides A2TiSiO6 (A = Ca, Sr, Ba) were systematically investigated using first-principles density functional theory calculations. Structural optimization within the GGA-PBE framework confirms that all compounds crystallize in a stable cubic phase. The negative formation energies indicate thermodynamic stability and potential experimental synthesizability. Ab initio molecular dynamics (AIMD) simulations performed at 300 K further confirm the dynamical stability of all compounds under finite-temperature conditions. The Born-Huang stability criteria performed elastic constant analysis establishes mechanical stability and the derived mechanical moduli indicate the presence of rigid but brittle behavior with moderate amounts of elastic anisotropy. Calculation of the electronic band structure reveals that all the compounds are direct wide-bandgap semiconductors, with the HSE06 bandgaps of Ca2TiSiO6, Sr2TiSiO6 as well as Ba2TiSiO6 being 2.61, 2.50 and 2.37 eV, respectively. The optical property analysis has shown that they are strong in terms of their absorption in the visible-ultraviolet region, with high dielectric constants and good refractive indices, which makes them appropriate in optoelectronics and photovoltaic applications. On the whole, A2TiSiO6 double perovskites are promising for use as wide-bandgap materials in the development of superior optoelectronic devices.
This study reports a straightforward and controllable two-step hydrothermal synthesis of novel Ni9S8@NiMoO4/NF nanospherical catalysts supported on nickel foam (NF), accompanied by a systematic evaluation of their performance in the electrochemical hydrogen evolution reaction (HER). Structural characterization revealed a well-defined Ni9S8-NiMoO4 interfacial region, whose synergistic interaction, combined with the distinctive nanospherical morphology, substantially increased the electrochemically active surface area and the density of reactive sites, thereby optimizing HER kinetics. In alkaline media, the Ni9S8@NiMoO4/NF catalyst demonstrated outstanding electrocatalytic performance, delivering an overpotential of only 64.2 mV at a current density of 20 mA cm-2. The catalyst also exhibited a high double-layer capacitance of 22.2 mF cm-2, reflecting a substantial active interfacial area. Long-term durability tests showed negligible performance degradation after 165 h of continuous operation at 10 mA cm-2, underscoring the catalyst's robust structural stability and durability. X-ray photoelectron spectroscopy confirmed a uniform distribution of Ni, Mo, and S across the NF framework and revealed optimized chemical states, providing material-level evidence for the enhanced performance. Collectively, this work proposes a viable strategy for designing efficient and stable HER catalysts, contributing to the advancement of green hydrogen production and clean energy technologies.
Controlling the microstructure of electroless nickel coatings is crucial for optimizing the interfacial properties of carbon fibers. However, a systematic understanding of how dispersants can effectively leverage the refining effect of nanoparticles in composite plating systems remains lacking. This paper proposes the use of a composite dispersant, comprising polyethylene glycol (PEG) and sodium methylene bis-naphthalene sulfonate (NNO) at a 1:1 mass ratio, for nano-Al2O3 to achieve microstructure refinement of nickel coatings on carbon fiber surfaces. The results demonstrate that the composite dispersant modifies the surface state and dispersion stability of Al2O3 particles through synergistic adsorption, thereby regulating the nucleation and growth behavior of the Ni-P alloy. At an optimal composite dispersant concentration of 3 g/L, the coating exhibits the most compact structure, with Ni-P particle size refined to approximately 181 nm. The coating consists of two phases: crystalline Ni3P and amorphous Ni-P. The dual adsorption effect of the dispersant—inhibiting Al2O3 agglomeration while improving the surface wettability of carbon fibers—is key to enhancing the refinement efficiency. Conversely, excessive dispersant addition leads to deteriorated coating quality. This study provides experimental evidence for understanding the multiphase interfacial interaction mechanism involving organic additives, nanoparticles, and metal deposition, and offers a novel strategy for controlling the surface functionalization of carbon fibers.
High-entropy oxide (HEO) thin films hold significant potential for applications in spintronics and catalysis; however, their widespread utilization is hindered by weak room-temperature ferromagnetism (RTFM). Herein, we demonstrate a facile vacuum annealing strategy to enhance the RTFM of HEO thin films. (FeNiAlCrMn)O films exhibit a saturation magnetization (MS) of 5.9 emu/cm3 and a Curie temperature (TC) of 350 K after vacuum annealing at 1173 K. Mechanistic investigations reveal that the enhanced RTFM originates from an annealing-induced phase transition from rocksalt-to-spinel. Structurally, annealing facilitates cation diffusion from octahedral to tetrahedral sites, forming a highly crystalline, long-range magnetic lattice of spinel ferrite. Electronically, tetrahedral occupation shortens M-O bonds, drives electron transfer toward metal cations, and enhances orbital hybridization, thereby strengthening magnetic exchange coupling. This study provides a simple and effective strategy for tailoring the RTFM of HEO thin films.
In this study, we present new data about the cytotoxic activity of metal complexes of salinomycin with Co(II), Cu(II) and Zn(II) against human cervical cancer (HeLa) and melanoma (A375, SH-4) cell lines. The effect of the compounds on cell viability and proliferation was evaluated in short-term experiments (up to 72 h) with monolayer cultures using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) test, neutral red uptake (NR), crystal violet staining (CV) and double staining with acridine orange (AO) and propidium iodide (PI). The cytotoxic effect of the metal complexes of salinomycin was found to be comparable and even superior to that of the commercial antitumor agents cisplatin and oxaliplatin. Long-term experiments revealed the ability of the compounds to completely suppress 3D cell growth when applied at concentrations >= 3.1 mu M (for HeLa cells) and >= 6.2 & micro;M (for A375 cells). Embryonic Lep-3 cells are highly sensitive to the influence of the complexes investigated, whereas non-tumor HaCaT human keratinocytes exhibit relatively higher resistance to their cytotoxic effect compared to tumor cell lines. The Zn(II) disalinomycinate exerted the highest selectivity index among the tested compounds against melanoma cells, whereas the non-coordinated antibiotic showed pronounced selectivity toward HeLa cells.
Since the synthesis of ferrocene in 1951, metallocenes have attracted attention, making the accurate prediction of their electronic structure and ionization energy crucial for understanding their photophysical and electrochemical behavior in materials and in biological systems. Here, we combined Density Functional Theory (DFT), Complete Active Space Self-Consistent Field (CASSCF), NEVPT2 (N-Electron Valence State Perturbation Theory) and Coupled Cluster approaches (CCSD, DLPNO-CCSD(T)) to study the electronic structure, ionization energies (IEs) and absorption spectra of metallocene and metallocenium complexes in the gas phase and in THF implicit solvent. DFT IEs agree closely with NEVPT2 and DLPNO-CCSD(T) values and with experiment values (deviations 0.02-0.3 eV). For CASSCF and NEVPT2, the minimal active space of the d electrons at six orbitals is not enough for the accurate prediction of the IEs, while an extended active space incorporating all 3d metal electrons plus four ligand valence electrons into 15 orbitals improves the calculated IE values. In solution, computed oxidation energies (OEs) in THF reproduce experimental values and follow the Fe > Ni > Co ordering. Substitution of metallocene complexes with chromophore units results in similar OEs. Overall, the substitution effects remain modest: the effect of substitution on OE values results in differences up to 0.2 eV. These results clarify the effect of the metal center on IE and OE values and UV-vis absorption behavior.
CuIn5Se8 is reported as a remarkable copper-deficient layer that contains ordered vacancy compounds (OVCs) for high-efficiency chalcopyrite-based solar cells; however, the understanding of its carrier characteristics has remained limited. OVCs could naturally form on the surface of chalcopyrite absorber. In this study, the carrier dynamics characteristics of OVCs were investigated by constructing a junction consisting of chalcopyrite absorber and CdS buffer layer. At first, the band structure of CuIn5Se8 was studied to determine the bandgap properties. Then, thermodynamic stability, defect formation energy, defects and carrier concentration, defect transition energy level of CuIn5Se8 and its Cd doping state (caused by CdS) were comparatively studied. The results suggest that Cd doping has different effects on the defect and carrier characteristics of OVCs with various chemical potentials. However, the OVC always remains n-type under the whole thermodynamically stable region, with contribution from the hallow-level InCu donor defect. Finally, the OVC’s carrier dynamics characteristics were assessed using the collected defect and carrier data. It is indicated that the OVC layer may contribute to the formation of a p-n homojunction in solar cells. Under selenium-rich conditions, the OVC layer increases the carrier density on the n-type side of p-n junction nearly 30-fold, which helps reduce the difference in carrier density and minority current density between two sides of the p-n junction. The conversion efficiency of the solar cell with OVC shows a 7.25% improvement when compared to the control. The distinct behavior of OVCs may serve as a valuable reference for the creation or improvement of a related functional film layer or device.
The pharmaceutical industry is a major source of pollution in wastewater effluents, characterized by chemical residues that are complex and difficult to degrade. Naproxen, a commonly detected drug in sewage effluents, exceeds safe concentrations for aquifers and is highly persistent, posing significant risks to aquatic life and ecosystems. This drug is known to cause long-term side effects in humans, such as gastrointestinal ulcers and nephrosis, associated with frequent and prolonged use. Additionally, the recent pandemic has led to a marked increase in drug consumption over a short period, exacerbating environmental contamination. Titanium dioxide has been extensively used as a photocatalyst in recent decades, proving effective in reducing these emerging pollutants. In this study, TiO2 doped with cerium was synthesized using the sol-gel method, with cerium concentrations varied at 1, 3, 5, and 10% by weight. The resulting nanocatalysts were characterized through nitrogen physisorption, scanning electron microscopy (SEM), X-ray diffraction (XRD), and UV-Vis diffuse reflectance spectroscopy. Photocatalytic activity was assessed using a UV-Vis spectrophotometer to monitor the degradation of the drugs. XRD analysis confirmed the crystallinity and anatase phase of TiO2. UV-Vis diffuse reflectance spectra indicated a decrease in bandgap energy of up to 3.00 eV compared to pure TiO2. The materials demonstrated significant degradation of naproxen (NPX) and acetaminophen (ACTP), both prepared at 30 ppm, over a 6 h reaction period.
To clarify the instability behavior of the columnar microstructure in RF magnetron sputtered TiN coatings under compressive loading, experimental characterization and finite element simulation were combined to investigate the microstructural features, mechanical properties, and linear and nonlinear buckling responses of the coating. TiN coatings were deposited on cemented carbide and Si substrates by RF magnetron sputtering using a 99.9% purity TiN target. The surface and cross-sectional morphologies were characterized by field-emission scanning electron microscopy, and the nanohardness and Young's modulus were determined by nanoindentation. Based on the experimentally observed morphology and measured mechanical properties, a finite element model of the columnar structure was established in ABAQUS, and the instability responses predicted by solid, shell, and beam element models were comparatively analyzed. The results showed that the as-deposited TiN coating exhibited a dense and uniform surface and a distinct columnar microstructure in cross-section. Linear buckling analysis indicated that the first-order critical buckling loads predicted by different element models were different, among which the solid element model gave a value of 3.43 & times; 10-5 N, showing the closest agreement with the theoretical result. Furthermore, nonlinear buckling analysis was performed by introducing an initial geometric imperfection of 4 & times; 10-3 mm based on the first-order buckling mode of the solid element model. The results showed that the columnar structure became unstable at a load of 0.74 & times; 10-6 N, accompanied by irreversible deformation. These findings demonstrate that linking experimentally observed TiN columnar microstructures with microstructure-informed instability analysis provides a useful perspective for understanding the local instability behavior and potential failure tendency of sputtered coatings and offers theoretical support for the structural design and reliability evaluation of protective coatings for cutting tools.
Structural parameters for over seventy complexes of the composition Cu(eta(2)-X-1 & times;2)(Y-3) or Cu(kappa(2)-(XX2)-X-1)(Y-3) were analyzed in this work, being the third of a series of structural studies on three coordinated copper(I) complexes. Bidentate ((XX2)-X-1) with monodentate (Y-3) donor ligands build up distorted trigonal planar coordination spheres around copper(I) atoms. The bidentate ligands ((XX2)-X-1) create three-, four-, and five-membered metallocyclic rings. The three-membered are: -C-1-C-2-Cu-C-3; -B-1=B-2-Cu-Cl-3; -P equivalent to C-2-Cu-C-3, -B-1-B-2-Cu-X-3, and B-1-C-2-Cu-C-3. The X-1-Cu-X-2 angles indicate a total mean value of 44.2 degrees. The four-membered complexes are -H-1-B(H-2)-H-2-Cu-C-3; -H-1-B(Ph-2)-H-2-Cu-C-3; -(OAlO2)-Al-1-Cu-N-3; -(OCeO2)-Ce-1-Cu-N-3; -(SCP2)-C-1-Cu-C-3; -(NPN2)-P-1-Cu-C-3; -(NPS2)-P-1-Cu-P-3; -(NSiO1)-Si-1-Cu-Cl-3; --(NCS2)-C-1-Cu-C-3; -Si-1-NSi2-Cu-C-3, and (OCO2)-C-1-Cu-C-3, and show a total mean value of the L-Cu-L angles of 71.0 degrees. The five-membered are: -N-1-C=C-N-2-Cu-Y-3 (more common) and N=C-C=N-Cu-C-3. In this group, there are also copper(I) complexes in which the central Ns of five-membered metallocycle are "interlocked" in macrocycles. The X-1-Cu-X-2 angles exhibit an average value of 82.9 degrees. There is a wide variety of monodentate (Y-3) ligands in the studied complexes. The mean value of Cu-Y-3 elongates with covalent radius (& Aring;) of coordinate atoms in the sequence: 1.846(13) & Aring; (N-3, 0.75) < 1.884(21) & Aring; (O-3, 0.73) < 1.928(18) & Aring; (C-3, 0.77) < 2.126(18) & Aring; (Cl-3, 0.99) < 2.140(5) & Aring; (S-3, 1.02) < 2.194(4) & Aring; (P-3, 1.06) < 2.246(12) & Aring; (Br-3, 1.14) < 2.2445(18) & Aring; (I-3, 1.33). The data show that angular distortion from regular trigonal geometry grows in the following order: five-, four-, and three-membered.
Ultra-high-temperature ceramics (UHTCs) in the Ta-Hf-C ternary system are of significant interest for extreme aerospace and energy applications due to their melting points near 4000 degrees C. However, their synthesis typically requires extreme temperatures and pressures. This study reports a pectin-assisted low-temperature route for Ta-rich TaxHf1-xC powder synthesis via carbothermal reduction at 1500 degrees C. The effect of Ta/Hf molar ratios (2.7/1, 0.9/1, and 0.3/1) on phase evolution, crystallinity, and morphology was systematically investigated. FTIR confirmed the successful formation of homogeneous hybrid organic-inorganic precursors through the chelation of metal ions with pectin functional groups. XRD results demonstrated that the Ta-rich composition (Ta/Hf = 2.7/1) promotes the formation of a high-purity (95.87%) cubic solid solution (lattice parameter a = 4.453 angstrom) with sharp reflections and improved crystallinity. In contrast, Hf-rich samples exhibited incomplete conversion, leaving unreacted HfO2 and Ta2Hf6O17 oxide phases due to the high thermodynamic stability of hafnia. Microstructural analysis revealed quasi-spherical TaxHf1-xC particles with an average size of approximately 123 nm, together with finer residual oxide particles of about 50 nm. Overall, these results demonstrate that pectin-assisted precursor chemistry is an effective strategy for promoting low-temperature carbide formation in Ta-rich TaxHf1-xC compositions.
This work focused on synthesizing MgSiO3 (0%Mo@MgSi), 2.5%MoO3@MgSiO3 (2.5%Mo@MgSi), 5%MoO3@MgSiO3 (5%Mo@MgSi), and 10%MoO3@MgSiO3 (10%Mo@MgSi) by a single-step process utilizing butylated hydroxytoluene (BYHT) as a novel capping agent. The X-ray diffraction analysis of the synthesized nanohybrids indicated amorphous nanohybrids, while the energy-dispersive X-ray spectroscopy results illustrated variations in the MoO3 doping dosages. The 0%Mo@MgSi, 2.5%Mo@MgSi, 5%Mo@MgSi, and 10%Mo@MgSi nanohybrids exhibited average sizes of 17.6, 12.2, 11.7, and 9.9 nm, respectively, and surface areas of 43.53, 40.95, 42.17, and 44.98 m2 & centerdot;g-1, respectively. The examination of 0%Mo@MgSi, 2.5%Mo@MgSi, 5%Mo@MgSi, and 10%Mo@MgSi nanohybrids toward the oxytetracycline (OTC) sorption resulted in qt values of 72.89, 116.89, 98.39, and 78.46 mg & centerdot;g-1, respectively. The OTC sorption onto the 0%Mo@MgSi, 2.5%Mo@MgSi, 5%Mo@MgSi, and 10%Mo@MgSi aligned with the nonlinear pseudo-second order model, and both the intraparticle and liquid-film diffusion models co-influenced the OTC sorption onto the four nanohybrids. Increasing the temperature decreased OTC sorption on 2.5%Mo@MgSi, indicating exothermic sorption. The Langmuir isotherm model was more suitable than the Freundlich model for describing OTC adsorption on 2.5%Mo@MgSi. The Dubinin-Radushkevich energy (ED <= 8.0 kJ & centerdot;mol-1) and the Gibbs free energy (Delta G degrees <= 20 kJ & centerdot;mol-1) supported each other's outcomes about the OTC removal onto 2.5%Mo@MgSi being via physisorption. The Delta G degrees values increased proportionally with temperature, indicating that OTC sorption becomes more spontaneous as temperature decreases. Moreover, the 2.5%Mo@MgSi exhibited excellent stability in OTC elimination up to the third cycle.
In this study, we report the synthesis and characterization of three Cu(I) complexes bearing functionalized dipyridylamine ligands and DPEphos. Structural analysis confirms a distorted tetrahedral coordination environment around the metal center. Photophysical studies in DMSO show similar absorption profiles (lambda abs approximate to 341-343 nm) with ligand-centered and MLCT transitions, while emission spans the visible region (lambda emi = 410-483 nm) and is strongly influenced by ligand substitution, with the CF3 derivative displaying a marked red shift. Emission is insensitive to oxygen and exhibits short lifetimes (tau approximate to 14.9-15.3 ns), suggesting short-lived 1MLCT excited states. Biological evaluation in A375 melanoma cells reveals that all complexes exhibit low-micromolar cytotoxicity under dark conditions (IC50 = 3.33-4.92 mu M). Notably, only the CF3-substituted complex shows a significant light-induced enhancement of activity upon irradiation at 390 nm (IC50 = 1.18 mu M), indicating photoactivation.
Mercury pollution from artisanal and small-scale gold mining remains one of the most persistent environmental threats due to the high toxicity, mobility, and bioaccumulation of Hg(II). In this work, Colombian banana pseudostem waste is valorized into a lignocellulosic carbocatalyst through pyrolysis at 500 degrees C followed by MnCO3-derived MnOx functionalization, producing a sustainable material for Hg(II) remediation. The transformation of the biomass leads from a fibrous structure (similar to 25 mu m) to a pyrolyzed carbon matrix (9.56 mu m), and finally to a heterogeneous Mn-modified system with bimodal particle distribution (similar to 25 mu m and similar to 0.85 mu m), the latter being associated with highly dispersed MnOx redox-active domains. Structural and textural analyses reveal that Mn incorporation significantly enhances surface properties, increasing the BET surface area from 140.8 to 213 m(2) g(-1) while reducing pore size to the meso-microporous range (similar to 1.9 nm). Importantly, the material retains intrinsic minerals such as Ca, Mg, K, and Si, which contribute to surface basicity and ion-exchange capacity, supporting additional Hg(II) interaction pathways. Optical and electronic characterization shows a wide band gap semiconductor behavior (approximate to 3.4 eV) and a conduction band position at -0.892 V vs. NHE, sufficiently negative to thermodynamically drive Hg2+ reduction to Hg-0 under UV-A irradiation. Hg(II) quantification was validated using a UV-Vis method based on the Hg2+-dipicolinic acid (DPA) complex, confirming stable complex formation with 1:2 stoichiometry (Hg2+:DPA) and high analytical reliability (R-2 = 0.948, LOD = 1.85 mg L-1). Photocatalytic experiments demonstrated negligible Hg(II) reduction under UV-A light in the absence of catalyst, whereas the carbon-based materials enabled significant Hg transformation through adsorption-assisted photoinduced electron transfer. Electrochemical analyses (Rct approximate to 11 Omega) confirmed efficient charge transport, while cyclic voltammetry evidenced reversible Mn(IV)/Mn(III)/Mn(II) redox cycling, which sustains electron mediation during photocatalysis. Overall, pristine biochar acts primarily through adsorption driven by oxygenated functional groups and porous structure, whereas Mn-functionalized biochar operates via a synergistic adsorption-photocatalytic mechanism. In this system, MnOx species function as redox-active centers that facilitate electron transfer from the carbon matrix to Hg(II), while the conductive lignocellulosic-derived framework enhances charge mobility. The combination of structural carbon stability, dispersed Mn active sites, and inherent mineral functionality establishes a highly efficient and sustainable carbocatalyst, demonstrating a green and scalable approach for mercury remediation in mining-impacted regions.
CO2 adsorption on subnanometric metal clusters is highly sensitive to the computational protocol used to describe the potential energy surface, particularly when several low-lying geometries and spin states are accessible. In this work, CO2 adsorption on Cu-4 and Sc-4 clusters was investigated using density functional theory (DFT) to evaluate how the choice of functional/basis-set protocol, spin multiplicity, initial geometry, and vibrational stability affects the predicted adsorption behavior. Four representative computational protocols (TPSSh, r(2)SCAN-3c, PBE-D4/def2-TZVP, and PBE0-SDD) were assessed for isolated clusters and cluster-CO2 complexes. The lowest harmonic vibrational frequency, omega(min), was used as a diagnostic criterion to distinguish true minima from unstable or weakly defined stationary points. Selected cases were also cross-checked using the ORCA and Gaussian quantum-chemistry packages to assess whether comparable computational settings yielded consistent stationary-point character. The results show that Cu-4 generally exhibits weak CO2 binding, whereas Sc-4 displays stronger but more protocol-dependent adsorption, consistent with its higher structural flexibility and more pronounced Lewis-acid character. Low-frequency and imaginary modes were found in several optimized structures, indicating that adsorption energies should not be interpreted without prior vibrational validation. The comparison also shows that variations in functional/basis-set treatment and spin multiplicity can alter both the optimized geometry and the predicted adsorption strength. Therefore, CO2 adsorption on small metal clusters should be discussed using combined structural, vibrational, and energetic criteria rather than electronic adsorption energies alone. Overall, this study provides a protocol-oriented framework for evaluating the reliability of DFT predictions in CO2 adsorption on Cu-4 and Sc-4 clusters.
With the rapid development of the photovoltaic industry, the issue of high-value conversion and utilization of end-of-life photovoltaic modules emerges. This study proposes using them in silicon-air batteries and designs a one-step pretreatment process to obtain two types of anode materials: AB@Si and TC@Si. Additionally, to enhance the electrochemical performance of retired crystalline silicon from PV modules as anodes for silicon-air batteries and improve their mass conversion efficiency, this study introduces Triton X-100 into the KOH electrolyte to inhibit chemical corrosion of the anodes and investigates the mechanism of action of Triton X-100. The results indicate that the surfaces of AB@Si and TC@Si exhibit a pyramidal structure, demonstrating excellent passivation resistance when used in silicon-air batteries, with maximum mass conversion efficiencies of 3.5% and 1.83%, respectively. Under the influence of Triton X-100, the maximum mass conversion efficiencies reach 6.39% and 3.09%, respectively. Polarization curves and mass loss under non-current conditions indicate that Triton X-100 primarily affects the chemical corrosion process of the silicon anode, while its impact on electrochemical corrosion is negligible. Results from contact angle measurements and adsorption energy calculations indicate that Triton X-100 adsorbs onto the silicon surface via benzene ring groups or OH groups, reducing hydrophilicity and delaying the self-corrosion process of silicon, thereby improving the battery ' s discharge lifespan and mass conversion efficiency.
The pure and xDy(3+)-doped SrMoO4 series (x = 0.5, 1.0, 1.5 and 2.0 at.%) were synthesized using a direct mechanochemical route. We found that a milling speed of 850 rpm and a milling time of 30 min result in a complete chemical reaction at different concentrations of dopant ions. The phase formation, structural units, and optical properties of the obtained samples were investigated by XRD, IR, UV-Vis and PL analyses. It has been established that Dy2O3 mainly influences the lattice parameters, unit cell volumes, crystallite sizes, and microstrains. The symmetry of MoO4 groups was investigated using IR spectroscopy, and it showed that pure and Dy3+-doped SrMoO4 samples are built up of deformed structural units. The calculated optical band gap of the obtained crystal phases decreases with increasing concentrations of Dy3+ ions. The host SrMoO4 matrix shows broad blue emission centered at 430 nm under an excitation wavelength of 230 nm. All doped samples display a strong yellow emission at 570 nm, belonging to the F-4(9/2) -> H-6(13/2) transition of Dy3+ ions. The highest luminescence intensity was observed when the concentration of the Dy3+ ion was 0.5 at.%. The mechanism of concentration quenching was mainly caused by the electric dipole-dipole interaction. The calculated CIE chromaticity coordinates of the doped samples fall in the yellow range. This study demonstrates that mechanochemical treatment is an appropriate route for the fast preparation of yellow phosphors.
