Aqueous zinc-ion batteries (AZIBs) have attracted considerable research interest in recent years due to their facile fabrication, environmental friendliness, inherent safety, and non-toxicity. Among various cathode candidates, V2O5 stands out as a promising material owing to its layered structure that facilitates ion migration, high theoretical capacity, and multivalent redox capability. However, the practical application of V2O5 is severely hindered by phase transitions during Zn2+ intercalation/deintercalation, leading to poor cycling stability, along with inherently sluggish diffusion kinetics and low electronic conductivity. In response to these problems, Na+-doped V2O5 was prepared via a hydrothermal method in this work. The results indicate that Na+ doping effectively stabilized the crystal structure and enhanced the electrical conductivity of V2O5. Among the investigated compositions, the Na0.328V2O5 electrode exhibited highly reversible Zn2+ storage performance, delivering a specific capacity of 428.33 mAh g−1 at 0.1 A g−1, along with excellent long-term cycling stability, retaining 82.4% of its initial capacity after 1500 cycles at 2 A g−1. This work provides a promising strategy for developing stable, high-capacity cathode materials for advanced AZIBs.
Phenolic pollutants and their transformation products pose persistent ecological risks in aquatic environments; therefore, both degradation efficiency and toxicity evolution are critical considerations in advanced oxidation processes. In this study, systematically investigated the UV/H2O2 treatment of phenol, 2,4-dichlorophenol (2,4-DCP), and p-nitrophenol (p-NP) using a combination of photodegradation experiments, liquid chromatography–mass spectrometry (LC-MS), density functional theory (DFT), transition-state theory (TST), intrinsic reaction coordinate (IRC) calculations, and toxicity assessment. Under the tested conditions, UV/H2O2 substantially enhanced the degradation of all three pollutants compared with UV irradiation or H2O2 alone, and irradiation at 254 nm yielded higher degradation efficiencies than at 185 nm. A synthetic complex water matrix reduced both the parent-pollutant degradation efficiency and COD removal, highlighting the importance of water-matrix effects. Fe2+ enhanced degradation by promoting the generation of additional •OH from H2O2, whereas carbonate species inhibited the degradation of all three pollutants. The effects of NO3− and Cl− were compound-dependent. LC-MS analysis and quantum-chemical calculations supported degradation pathways involving hydroxylation, dechlorination, denitration, quinone formation, and subsequent ring-opening. Diffusion-corrected kinetic analysis further showed that the initial •OH reactions can proceed through several competing low-barrier radical adduct formation pathways rather than being dominated by a single reaction site. Toxicity evaluation demonstrated that toxicity evolution was endpoint-dependent: although continued oxidation could generate less toxic ring-opening products, several aromatic intermediates exhibited higher toxicity in both computational and experimental measurements. These results provide a mechanistic framework linking molecular structure, water-matrix effects, transformation pathways, and toxicity evolution during UV/H2O2 treatment of phenolic pollutants.
This study evaluates the oxidation behavior and combustion stability of heavy oil under heated air conditions through laboratory-scale oxidation experiments (using self-designed apparatus) and thermogravimetric analysis. The objective was to determine the oxidation threshold, identify the stable combustion temperature window, and assess the influence of selected additives on thermal oxidation characteristics. Heated air exposure experiments were performed to monitor gas-phase and solid-phase temperature evolution during combustion initiation. The minimum oxidation threshold was identified at approximately 530 °C, with a distinct transition from smoldering to self-sustained flame combustion. A stable combustion regime was observed within the range of 530–630 °C. Thermogravimetric analysis revealed multi-stage oxidation behavior, with the main high-temperature oxidation peak occurring near 550–560 °C. Additive-containing systems exhibited modified oxidation profiles and altered apparent activation energies. The results provide a laboratory screening framework for assessing oxidation propensity and combustion stability of heavy oil systems relevant to in situ combustion applications.
The two-photon photodynamic therapy (TP-PDT), as an emerging cancer treatment, arises due to its deep penetration and less side effects. In this work, the sulfur-substituted cytosine analogue (xxC1) is proposed based on the previously synthesized quasi-intrinsic C1 (BPP) molecule. Our calculations revealed that the C1 (BPP) possesses efficient photoluminescence around 377 nm, which shows little difference from that of experiment. However, the sulfur substitution brings fluorescence quenching and enhanced intersystem crossing (ISC) process, which is characterized by the rapid ISC rates (KISC), reduced singlet-triplet energy gap (ΔEST) and increased spin-orbit coupling (SOC) constants. Then, the T1-formation with prolonged lifetime (τT ∼ ms) facilitates the generation of reactive oxygen species (ROS) by examining the ionization potential and electron affinity (electron exchange for Type I mechanisms), as well as the T1 energy (energy transfer for Type II mechanisms). Besides, the effects of base pairing and deoxyribose linkage on the TP-PDT performance are demonstrated to evaluate the application of quasi-intrinsic photosensitizer under biological environment.
Angle-resolved quantum time delays are reported for the state-to-state isotopic exchange collisions 17O + 16O16O(v=0,j=1)→16O + 16O17O(v′=0,j′=2) and 18O + 16O16O(v=0,j=1)→16O + 16O18O(v′=0,j′=2). They were calculated using an exact time-independent quantum method, analyzed as functions of collision energy and as a function of center-of-mass scattering angle, and compared with the corresponding differential cross sections. Pronounced isotopic effects are observed. The 17O isotopic variant exhibits large positive and negative time-delay magnitudes together with strong oscillatory structures. Correlations are observed in the angular distributions.
In this work, we investigate the excited-state intramolecular proton transfer (ESIPT) of chrysin, apigenin and their C7-OH deprotonated forms. In contrast to the barrierless ESIPT of the neutral flavonoids, the anions exhibit significant barriers and a less stable tautomer (T*) state relative to normal (N*). Hydrogen bonds between the C7-O− group and water lower the ESIPT barrier. Furthermore, we establish a linear correlation between the ESIPT barrier height and the N*/T* energy difference. These findings provide a deep insight into the role of intermolecular hydrogen bonds on ESIPT of neutral and anionic flavonoids.
ZnGa2O4 nanostructures were synthesized via a solid-state reaction method. XRD with Rietveld refinement confirmed single-phase ZnGa2O4 for the 1300 °C sample. SEM revealed a transition from nanorod-like structures to densely packed cobbled particles. FTIR identified ZnO and GaO vibration modes, while photoluminescence showed reduced emission for the 1300 °C sample. UV–Vis indicated a wide band gap (∼4.4 eV). Electrochemical studies in 1 M KOH showed pseudocapacitive behavior and capacitance of 192 F/g. The symmetric supercapacitor device delivered an energy density of 27.5 Wh/kg and a power density of 4500 W/kg with ∼80% retention after 10,000 cycles.
Aqueous zinc-ion batteries suffer from dendrite growth and side reactions (hydrogen evolution, corrosion) on zinc anodes. To address these challenges, we introduce pentanone into 2 M ZnSO4 electrolyte. This additive modulates the solvation structure to suppress water-induced parasitic reactions and promotes preferential Zn (002) deposition, yielding a flat, uniform morphology. Consequently, the Zn||Zn symmetric cell achieves exceptional cycling stability (1300 h at 1 mA cm−2, 350 h at 2 mA cm−2 with 2 mA h cm−2). This work demonstrates effective interface modulation via electrolyte engineering for highly reversible zinc anodes in high-performance aqueous zinc batteries.
Using density functional theory, we systematically investigate the electronic and magnetic evolution of CrI3 from a 0D quantum dot to a dimer and a 1D periodic chain. All systems maintain a robust local moment of 3 μB per Cr atom and exhibit strong intra-atomic exchange splitting (∼0.9 eV), yielding spin-dependent semiconducting gaps with large exchange splitting. Ferromagnetic inter-dot coupling (J = 333 meV) ensures magnetic stability. Flat, localized frontier bands and spin-asymmetric semiconducting gaps highlight their potential as voltage-tunable spin filters in molecular spintronic devices.
We have used computational chemistry to study the interactions between selected amino acid (AA) and oligomeric microplastic (MP) models. The complexation is often characterized by hydrogen bonding, with the binding energies qualitatively correspond with the number of intermolecular hydrogen bonds. Indeed, strong AA–MP binding is quantitatively characterized by sizable non-dispersion contributions. In the binding of a larger real-world complex, hydrogen bonds and cation–aromatic interactions are also prominent. Assessment of low-cost methods shows that r2SCAN-D4/ma-def2-TZVPP and g-xTB provide good performance for their respective cost and may be suitable for a larger-scale study of related AA–MP systems.
The removal of propyne (C3H4) from propylene (C3H6) is essential for polymer-grade C3H6 but remains challenging due to their similar physicochemical properties. Herein, we report a cage-based metal-organic framework, [Fe2Co(μ3-O)(BTB)4/3(BPDC)(H2O)3]n (Fe2Co-MOF), featuring a two-fold interpenetrated framework and permanent porosity for preferential C3H4 over C3H6. At 298 K, Fe2Co-MOF exhibits a higher uptake of C3H4 than C3H6, reaching 91.5 cm3 g−1 at 0.1 bar and 207.4 cm3 g−1 at 1 bar. Experimental results and GCMC simulations indicate stronger host-guest interactions with C3H4, highlighting Fe2Co-MOF as a promising adsorbent for preferential adsorption of C3H4 over C3H6.
Nanostructured Mg-doped Fe₂O₃/ZnO heterojunction thin films were fabricated by low-cost spin-coating and hydrothermal methods for sunlight-driven methylene blue degradation. XRD and FTIR confirmed hematite Fe₂O₃ and wurtzite ZnO phases. UV–visible analysis showed enhanced visible-light absorption, while calculated band edges indicated Type-I straddling alignment. SEM revealed morphological evolution from compact ZnO grains to dense Fe₂O₃-based rod-like/nanoneedle structures, and cross-sectional SEM confirmed direct bilayer contact. PL spectra showed reduced emission for the heterojunction, indicating suppressed radiative recombination. The Mg doped Fe₂O₃/ZnO film achieved 95% degradation under natural solar irradiation, attributed to optical, morphological, and interfacial synergistic effects.
We investigated self-assembly of amphiphilic patchy nanoplates in a nanoslit at equilibrium and under shear using hybrid molecular dynamics simulations with hydrodynamic interactions. Binary mixtures of one- and two-patch nanoplates with patch arrangements were examined. Under strong confinement, Type WW formed dimers and exhibited a broad number-density profile with a maximum slightly away from the slit center, whereas weaker confinement promoted elongated aggregates. Types NN-I and NN-II formed off-center layered structures. Under shear, NN clusters broke up with increasing shear rate, while WW aggregates remained stable owing to their wider attractive patches, demonstrating tunability through patch design, confinement, and shear.
