Copper(I) complexes exhibit efficient luminescent properties, such as thermally activated delayed fluorescence (TADF), making them attractive for applications in organic light-emitting diodes or sensors. While copper(I) complexes with 2-pyridyl phosphine ligands have been well studied, this work explores the effect of positional isomerism by using 3-pyridyl phosphine instead of 2-pyridyl phosphine, leading to a previously unreported double-bridged distorted tetrahedral structure with an unusually long average of the Cu···Cu distance of 6.238 Å. This new structural motif, enabled by the unique coordination behavior of the 3-pyridyl ligand, leads to excitation-dependent emission behavior with typical TADF behavior and photoluminescence quantum yields ranging from 0.11 to 0.83. Quantum mechanical calculations indicate that the excited-state transitions exhibit primarily metal-to-ligand and halide-to-ligand charge transfer character or a combination of both, which enhances the TADF response. This study highlights how small changes in the ligand topology can lead to fundamentally different coordination modes and photophysical response. The results offer structure-property relationships for copper(I)-based emitters and the development of future ligand derivatives for tunable optical properties.

The development of nanozymes combining high catalytic activity, mechanical robustness, and scalable fabrication is crucial for next-generation biomedical sensing. However, most current 3D-printed diagnostic platforms rely on polymeric substrates that suffer from limited reusability, weak mechanical strength, and poor long-term stability. Here, we report a sustainable and robust nanozyme system based on a 3D-printed Ti-Al─V alloy substrate, chosen for its excellent mechanical integrity, reusability, and intrinsically rough surface that promotes metal-organic framework growth. For the first time, an iron-based MOF (Fe-BTC) is directly grown on a 3D-printed Ti─Al─V substrates with in situ incorporation of phosphomolybdic acid, forming a highly active Fe-BTC-PMA nanozyme. The rough metallic substrates enable uniform MOF nucleation and strong interfacial anchoring, while electronic interactions between the Ti─Al─V substrate and the Fe-BTC-PMA framework facilitate efficient charge transfer and accelerated redox kinetics. Spectroscopic analyses, including XANES, EXAFS, and XPS, reveal PMA-induced modulation of the iron coordination environment and charge redistribution. These results are supported by kinetic studies, in situ electron paramagnetic resonance spectroscopy, and density functional theory calculations. Compared with conventional powder nanozymes, the integrated platform exhibits enhanced catalytic activity, superior stability, and excellent reusability, enabling sensitive and reliable glucose sensing.

Excitons in organic semiconductors exhibit an energy distribution due to molecular thermal motion and disordered molecular packing. In our previous work, we modeled the exciton energy distribution using a simple Gaussian function centered at the optical bandgap. By comparing the overlap area (Aex) between the model and the solution absorption spectra of the emitters, we demonstrated that emitters with a high density of band-tail states are conducive to achieving high device efficiency. Herein, we develop two new blue emitters, TCPN and NCPN, featuring hybridized local and charge transfer (HLCT) and localized excited (LE) states, respectively. We optimize the initial model, including replacing the solution absorption spectra with thin-film excitation spectra, keeping the total number of excitons constant while varying the degree of exciton dispersion, and using the overlap integral (Jex) instead of Aex. This work provides novel insights into designing high-efficiency emitters through the lens of the exciton energy distribution.

Non-stoichiometric plasmonic semiconductors such as Cu2-xS have emerged as promising materials for energy conversion applications owing to their tunable band gaps, cost-effectiveness, and ability to harvest near infrared (NIR) energy. Integrating these plasmonic semiconductors with lead halide perovskites in heterostructures enables strong plasmon-exciton coupling, resulting in enhanced light absorption and efficient interfacial charge transfer. This work presents a synthesis and investigation of the spectroscopic behaviour of non-stoichiometric Cu2-xS, CsPbBr3 nanocrystals (NCs) and their heterostructure. Femtosecond transient absorption (TA) measurements are performed at two different excitations (400 and 800 nm) to develop a fundamental understanding of the hot carrier dynamics and their extraction in the heterostructure system. The TA results confirm plasmon-induced hot-hole transfer from Cu2-xS to the valence band of CsPbBr3 at both excitations, while 400 nm excitation additionally promotes hot-electron transfer from CsPbBr3 to Cu2-xS conduction band, leading to efficient charge separation and retarded exciton recombination. These synergistic charge transfer processes establish the Cu2-xS-CsPbBr3 heterosystem as a strong candidate for high-performance optoelectronic devices.

Attributed to the high conductivity of the () face of 4H-SiC, understanding the HF-assisted wet etching mechanism of this crystal face is crucial for semiconductor processing by clarifying the influence of surface terminations and functional groups on the etching process. In this study, we performed a first-principles investigation of the stepwise HF etching process on the () face with OH or coexisting F and OH terminations. By elucidating the etching reaction pathway, we identified key transition states, intermediates, and rate-determining steps. Analysis of adsorption configurations, charge transfer, and bonding characteristics reveals that HF dissociation strongly depends on surface termination, with the activation energy on the F-OH coterminated surface (2.51 eV) markedly lower than that on the OH-terminated surface (2.86 eV). In both cases, etching favors Si over C, with Si preferentially volatilized as SiF4 rather than SiHF3, highlighting a strong selectivity for complete fluorination. Importantly, the Pt-Ni-C-N4 dual-atom catalyst, distinguished by excellent stability and economic advantage over pure Pt, lowers the energy barrier by ∼1 eV, rendering etching possible at ambient temperature. These findings shed light on termination-dependent etching behavior and guide the design of efficient low-temperature etching strategies for the nonpolar face of 4H-SiC.

The manipulation of the electrocatalyst nanoarchitecture, particularly transition metal compounds, regarding size, shape, facets, and composition, significantly enhances the electrocatalytic activity in energy transformations. This study introduces a novel methodology for the precipitation of mesoporous nanoparticles of nickel tungstate (meso-NiWO4) using direct chemical deposition from a template of Brij®78 surfactant liquid crystal. Physicochemical analyses revealed the formation of amorphous meso-NiWO4 nanoparticles with dual sizes of 10 ± 3 and 120 ± 8 nm and a specific surface area of 34.2 m2/g, exceeding that of nickel tungstate deposited in the absence of surfactant (bare-NiWO4, 4.0 m2/g). The meso-NiWO4 nanoparticles exhibit improved electrocatalytic stability, reduced charge-transfer resistance (Rct = 1.11 ohm), and a current mass activity of ~365 mA/cm2 mg at 1.6 V vs. RHE during the electrolysis of urea in alkaline solution. Furthermore, by employing meso-NiWO4 in a two-electrode urea electrolyzer, a remarkable 4.8-fold increase in the cathodic hydrogen concurrent production rate was achieved (373.40 µmol/h at a bias potential of 2.0 V), compared to that of the bare-NiWO4 catalyst. The exceptional urea oxidation electroactivity and the enhanced hydrogen evolution rate arise from substantial specific surface area and mesoporous structure, facilitating effective charge transfer and mass transport through the meso-NiWO4 catalyst. Using the surfactant liquid crystal template for electrocatalyst synthesis enables a one-pot deposition of diverse nanoarchitectures and compositions with high surface area at ambient conditions for an improved electrocatalytic and hydrogen green production process.

In this work, we use density functional theory (DFT) to thoroughly analyze the structural, electrical, optical, and thermoelectric characteristics of halide double perovskites Rb2AsAuX4 (X = Br, Cl). Both compounds' structural stability is confirmed by the optimized lattice characteristics, with Rb2AsAuBr4 showing somewhat larger cell dimensions than Rb2AsAuCl4. Indirect band gaps of 0.338 eV (Br) and 0.885 eV (Cl), which are within the optimal range for solar applications, are shown by electronic band structure simulations. Strong absorption coefficients in the visible region above 1.2 × 101 cm-1 are shown in optical spectra, suggesting great potential for solar energy harvesting. High Seebeck coefficients of up to 310μV/K (Br) and 285μV/K (Cl) at ambient temperature are shown by thermoelectric analysis, together with electrical conductivities that facilitate effective charge transfer. Thermoelectric performance is further improved by the comparatively low thermal conductivity (0.9-1.1 W/m·K). Together, our findings demonstrate Rb2AsAuX4's versatility and establish Rb2AsAuBr6 and Rb2AsAuCl4 as viable options for next optoelectronic and energy-harvesting applications.

Abstract CO 2 curing can greatly enhance the properties of concrete while actively sequestering CO 2 . However, the influencing mechanisms of CO 2 curing on the passivation film of steel bars in concrete remains unclear. In this study, the passivation and depassivation behaviors of steel bars in CO 2 -cured mortar were investigated via electrochemical measurements, and the microscopic morphology and chemical composition of the passivation film were examined using scanning electron microscopy (SEM) equipped with energy-dispersive spectroscopy (EDS), and X-ray photoelectron spectroscopy (XPS). The results demonstrate that CO 2 curing can accelerate the passivation of steel bars, which can be attributed to the higher oxygen partial pressure around the steel bars when compared to standard curing. Although the thickness of passivation film on steel bars in CO 2 -cured specimens (4.06 nm) is less than that in standard-cured specimens (4.73 nm), the charge transfer resistance in CO 2 -cured specimens (458.54 kΩ·cm 2 ) is higher than that in standard-cured specimens (384.49 kΩ·cm 2 ). Specifically, the dense and ordered microstructure observed by SEM, together with the relatively high Fe 2+ /Fe 3+ atomic ratio (0.90 vs. 0.63) of the passivation film detected by XPS, contributes to the enhanced electrochemical stability. In addition, it is found that CO 2 curing significantly delays the depassivation onset of steel bars in mortar when subjected to chloride drying-wetting cycles, with the depassivation of standard-cured specimens initiating after 18 cycles and that of CO 2 -cured specimens being postponed to 30 cycles. Consequently, the protective performance of the passivation film in CO 2 -cured specimens surpasses that in standard-cured specimens despite the slightly thinner thickness.

The liquid-solid interface plays a fundamental role in a wide range of phenomena, including reaction kinetics, charge transfer, and fluid behavior. However, the underlying physicochemical mechanisms governing these interfacial interactions remain a topic of ongoing debate. Recently, the concept of the triboelectric nanogenerator probe (TENG probe) has been introduced to investigate the charge transfer at liquid-solid interfaces by recording the triboelectrification of liquid droplets sliding on insulating surfaces with both spatial and temporal resolution. Variations in interfacial properties directly influence charge transfer dynamics, such as ion concentration, chemical composition, flow rate, and structure of electric double layer (EDL), making the TENG probe a powerful and sensitive tool for quantitative studying charge transfer at liquid-solid interfaces. This review summarizes the fundamental principles and key features of TENG probes and highlights their applications in liquid-solid charge transfer studies, in situ chemical analysis, fluid status monitoring, and sensing systems. The perceived challenges and opportunities that face this multidisciplinary research field are also outlined, with special attention on experimental efforts linking chemical, physical, and mechanical factors in liquid-solid interfacial charge transfer dynamics.

A luminescent Au(I) coordination polymer, [AuCl(1-AdmNH2)]n was synthesized under mild conditions via spontaneous reduction of HAuCl4 by excess 1-adamantylamine (1-AdmNH2). The resulting needle-like, hydrophobic solid exhibits intense red phosphorescence (λem≈ 680nm) under UV light (254nm). Single-crystal X-ray diffraction reveals linear Au(I) chains stabilized by aurophilic interactions and hydrogen bonding. The needles have diameters around 500nm and lengths of tens of microns. Photophysical studies, including quantum yield (QY ≈ 2.4%), microsecond-scale lifetimes, and time-dependent density functional theory (TD-DFT) calculations, indicate a triplet-state phosphorescence mechanism involving metal-centered (MC) and ligand-to-metal-metal charge transfer (LMMCT) transitions. The material exhibits thermal stability up to 160°C but degrades in coordinating solvents, forming gold nanoparticles. When evaluated for luminescent thermometry, it shows high sensitivity up to 160°C, a performance unprecedent among non-lanthanide-based coordination polymers. It remains operational up to 100°C with a sensitivity not previously achieved in coordination polymer (CPs) systems.

A combination of semiconductors with noble metal nanoparticles is an effective way to improve photocatalytic hydrogen evolution performance via the plasmonic effect by near-field enhancement and hot electron injection. The effectiveness of this approach to organic semiconductors is often compromised by an inefficient electron transfer process at the metal-polymer interface that limits hot electron utilization. Herein, we rationally designed a novel pyrene-sulfone polymer (PSP) composite system that enables firm anchoring of gold nanospheres through electrostatic interactions and coordination effects, thereby establishing efficient pathways for plasmon-induced charge transfer. The size and loading of gold nanospheres were systematically tuned to optimize photocatalytic performance. Our investigation reveals that PSP combined with 8 wt.% 60nm gold nanospheres exhibited the optimal hydrogen production rate of 72.41mmol h-1 g-1, 4.6 fold of that for pure PSP (∼15.66mmol h-1 g-1). In situ XPS, ultrafast transient absorption spectroscopy, and temperature-dependent PL measurements confirm that the synergetic effect of reduced exciton binding energy and hot electron injection effectively promotes carrier generation for the photocatalytic process.

Designing nonfullerene acceptors with tailored absorption and energy levels is critical for indoor and ternary organic photovoltaic (OPV) applications. Here, we report two blueshifted Y‐series acceptors, Y6‐iso and Y6‐O‐iso, derived from the benchmark Y6 molecule through fluorine isomerization on the IC‐type terminal group and alkoxy side‐chain substitution. Fluorine isomerization from the conventional 5,6‐ to the 4,5‐positions reduces the intramolecular charge transfer (ICT) strength, inducing a blueshift while maintaining molecular planarity and charge transport properties. The alkoxy side chain enables a resonance between the oxygen atom and the terminal group, presumably disrupting the original electronic communication between the central fused‐ring core and the terminal group. This effect further diminishes ICT, producing a pronounced blueshift and elevating the lowest unoccupied molecular orbital (LUMO) level, effectively aligning the absorption with indoor light‐emitting diode (LED) spectra. Consequently, the PM6:Y6‐O‐iso binary achieves a power conversion efficiency of 25.3% under 2000 Lx and 23.7% under 500 Lx LED illumination. When incorporated as a guest molecule in PM6:Y6 ternary devices, both acceptors improve V OC and complement the absorption of Y6, yielding power conversion efficiency of 18.0% and 18.4%, respectively. These results demonstrate a rational molecular design strategy, highlighting fluorine isomerization and alkoxy substitution as effective approaches to optimize nonfullerene acceptors for versatile indoor and ternary OPV applications.

Free-electron lasers (FELs) enable the study of the ultrafast dynamics of photocatalytic reactions by time-resolved X-ray photoelectron spectroscopy (tr-XPS) with femtosecond time resolution. In an optical pump - soft X-ray probe photoemission experiment conducted at the free-electron laser in Hamburg (FLASH), we observed the ultrafast oxidation of CO to CO2 on rutile TiO2(110) by monitoring the O 1s core level region. Within 800± 250 fs after laser excitation, CO2 as a product of the photooxidation of CO is detected. Based on density functional theory calculations, we propose that the oxygen activation pathway for the CO oxidation is initiated via an O2-TiO2 charge transfer complex directly excited by the 770 nm pump laser. Our results give insight into the fundemental understanding of photocatalytic processes of TiO2 polymorphs relevant for the design of more efficient photoctalaysts.

This study aims to clarify the linear response excitation mechanisms and characteristics of the explosive 1-methyl-3,5-dinitro-1,2,4-triazole (MDNT) in the implicit solvent dimethyl sulfoxide (DMSO) when transitioning from the ground state to the 20 lowest-energy excited states. In the ground state MDNT molecule, there exists a steric hindrance effect within the triazole ring and between the nitro oxygen (O) and the azole ring nitrogen (N). Ahydrogen bond dominated by dispersion interaction is formed between the nitro O and the methyl hydrogen (H). Among the 20 low-energy excited states, S5, S7, S9, S10, S11, and S12 are significant bright states (with an oscillator strength of 0.01), and the remaining 14 are dark states (weakly allowed transitions, not observable in conventional UV-vis spectra). Note that this differs from the d-d transitions in transition metal complexes, where an f of 0.001 may still be weakly observable. The lifetimes of the six bright states are all in the nanosecond ranges (S10 is the longest, reaching 4.93 ns; S11 is the shortest, only 0.7 ns). S11 requires an excitation energy of 6.47 eV and corresponds to the maximum absorption peak. In terms of the excitation mechanism, S0 → S5/S7/S12 is a C-N π → N-O π charge transfer excitation (CT), S0 → S11 is a C-N π → N-O π local excitation (LE), and S0 → S9/S10 is a local excitation (LE) of the lonepair electrons n → N-O π* of the nitro O. This study provides a theoretical reference for the research on the electronic excitation mechanism and decomposition behavior of energetic materials. The Gaussian16 software is used for optimization and calculation, and the Multiwfn and VMD programs are applied for further processing and visualization. Using the time-dependent density functional theory (TDDFT) at the M06-2X/6-311G(d) level, the linear response electron excitation of MDNT in implicit solvent DMSO was investigated.

Cycloparaphenylenes (CPP) and their heteroatom-doped derivatives are emerging as interesting nanocarriers due to their adjustable electronic structures and π-conjugated frameworks. This study used density functional theory (DFT) to examine the structural, electrical, and adsorption characteristics of virgin CPP, nitrogen-doped CPP (N-CPP), and oxygen-doped CPP (O-CPP) in relation to two anticancer agents, hydroxyurea (HU) and thioguanine (TG). Geometry optimization verified the inherent stability of all carriers, whereas doping induced localized distortions that increased reactivity. Electronic tests indicated a consistent decrease in the energy gap after medication adsorption. HU functioned as a weak electron donor, resulting in little gap narrowing, whereas TG operated as a robust electron acceptor, causing substantial band-gap quenching-particularly in TG@O-CPP, where the gap practically disappeared, resulting in metallic-like behavior. Adsorption energies (−0.10 to −1.13 eV) and recovery periods revealed divergent kinetics: HU complexes desorbed almost quickly, while TG demonstrated more robust binding and extended residence lengths, especially on O-CPP. Charge-transfer research validated the contrasting donor–acceptor functions of HU and TG, supported by global reactivity indices indicating heightened electrophilicity and reduced hardness upon TG adsorption. The findings identify TG@O-CPP as the most promising system, with improved adsorption strength, substantial charge transfer, notable band-gap reduction, and adjustable electrical responsiveness. These results provide significant insights for the systematic design of CPP-based nanostructures in biosensing applications that need rapid reaction and in drug-delivery systems that require controlled release.

Quantum well (QW)-enhanced plasmonic substrates have been demonstrated to improve the blinking fluorescence of spontaneously blinking fluorophores, which enhances the localization precision and density for single-molecule localization microscopy (SMLM). The QW-enhanced plasmonic substrate consists of a three-repeat InGaN QW structure covered by Al nanoparticles. In addition to the localized surface plasmon enhancement produced by Al nanoparticles, InGaN QWs with tunable discrete energy levels and a high-density surface charge distribution can facilitate additional charge transfer resonances. This effect further enhances the local surface plasmon resonance around the Al nanoparticles. Moreover, the interaction between the high-density surface charges of the InGaN QWs and the oscillating electrons of the Al nanoparticles can lead to another type of surface plasmon enhancement effect. Therefore, the blinking intensity and event frequency are significantly increased, resulting in improved SMLM image resolution under the wide-field fluorescence excitation. With multiple fluorescence enhancement effects, the QW-enhanced plasmonic substrate enables SMLM imaging of phosphorylated epidermal growth factor receptors (EGFRs) in A549 lung cancer cells to quantitatively investigate the inhibition of EGFR tyrosine kinase. Furthermore, this QW-enhanced plasmonic substrate can reduce the excitation power needed for SMLM imaging at an acceptable resolution.

Representative for the {MNO}8 series of metal-nitrosyl compounds, the neutral {CoNO}8 cobalt nitrosyl complex [Co(fpin)NO(phen)] (1) with fpin = perfluoropinacolate(2-) and phen = phenanthroline(0) exhibits a single photoinduced linkage isomer (PLI) that can be generated by irradiation with red light. The high population of 80% PLI enables the unambiguous determination of its structure as a bent κO isonitrosyl Co-O-N with a Co-O-N angle of 123.1(3)° compared to the bent κN nitrosyl Co-N-O ground state with an angle of 121.199(14)°. While the photoswitching in this diamagnetic {CoNO}8 complex is triggered by a metal-to-ligand charge transfer transition like in the well-known {MNO}6 complexes, the vibrational response is opposite, yielding a blue-shift of the N-O stretching vibration upon isonitrosyl PLI generation in {MNO}8 and a red-shift in {MNO}6. First-principles DFT calculations, performed on the photocrystallography models, provide results consistent with the observed structures and vibrational spectra. Additionally, the analysis of the Bader charges shows that the charge on the NO is more positive in the PLI compared to the GS for both the {MNO}8 and {MNO}6 complexes. Hence, the experimental vibrational spectra should not be directly used as sole evidence to derive underlying structures or electron density changes.

Abstract Engineering optical properties, such as luminescence purity and charge transfer, is crucial for harnessing the application potential of atomically thin transition metal dichalcogenides (TMDCs). While electrostatic gating is widely applied to gain charge control in TMDC monolayers, charge transfer can also be engineered via coupling of TMDC monolayers to semiconductor III/V, organic, or van der Waals interfaces. This confers great advantages, such as ease in implementation and compatibility in device integration. Here, we shed light on the optical properties of many-particle complexes emerging at the GaInP/MoSe 2 interface as a highly relevant material combination to manipulate the optical properties of TMDCs in integrated photonic devices. Our study verifies its nature as a type II hetero-interface, which bears the feasibility to display disorder-free photoluminescence (PL). Through optical absorption measurements, we verify that the charged complexes acquire substantial oscillator strength. Furthermore, temperature-dependent PL, supported by a microscopic theory framework, evidences the suppression of the characteristic carrier recoil effect that was previously observed in the PL of trions in TMDCs. These phenomena allow us to identify the optical signatures at the TMDC-GaInP interface as Fermi polaron quasiparticle resonances, which are of high importance in researching Bose–Fermi mixtures in condensed matter systems.

Oxidase-like colorimetric sensors based on crystalline vanadates show great potential for polyphenol detection without H2O2. However, most inorganic nanozymes possess multienzyme activities and follow the "on-to-off" sensing mode, limiting sensitivity and accuracy in complex matrices. Herein, a flower-like α-Ag3VO4 nanozyme was synthesized via a Tollens reagent-mediated method. Distinct from conventional vanadate-based materials, it activates O2 molecules adsorbed on its oxygen-defective (010) surface through 0.86 eV energy transfer, thereby exerting exclusive oxidase-like activity with O2•- and 1O2 as electron acceptors. EGCG accelerates charge transfer and boosts catalytic activity by over 6-fold within 1 min, allowing for an "off-to-on" colorimetric sensor. This unique phenomenon enables the construction of a rapid colorimetric sensor based on an "off-to-on" signal model, which differs fundamentally from reported nanozyme-based colorimetric systems for reducing targets. Compared with the widely used aluminum chloride method (detection limit, LOD = 3.54 μM), the proposed sensor exhibits excellent specificity, superior sensitivity (LOD = 0.16 μM) for EGCG, and comparable accuracy in real sample analysis. This work not only provides a synthetic chemistry approach to tailor the enzyme-like activity of inorganic materials but also offers a promising platform for the sensitive detection of reducing polyphenols.

Rare-earth (RE) elements are often employed to optimize electrocatalytic performance due to their tunable electronic structures and surface properties. Herein, a yttrium oxide-doped Pt-based catalyst (Pt-Y2O3/C) is engineered for the electrocatalytic methanol oxidation reaction (MOR), and the surface Y/Pt atomic ratio is precisely modulated to optimize its performance. Pt-Y2O3/C-2 (1/0.17 Pt/Y atomic ratio, Pt loading of 4.73 wt %) exhibits optimal mass activity (MA) for MOR, 5.10 A mgPt-1 in 1.0 M KOH with 1.0 M CH3OH, obviously outperforming commercial 20 wt % Pt/C by a factor of ∼12.8. It also shows superior CO-poisoning tolerance and stability; its MA for the MOR remains at 3.80 A mgPt-1 after the 10 000 s stability test. Integrated characterization results demonstrate that Y2O3 doping induces an electronic interaction with Pt, thereby reducing the electron density of Pt and optimizing its electronic structure, attenuating the adsorption of CO* intermediates at the Pt sites. Y2O3 doping also decreased the charge transfer resistance (Rct) in the MOR. The superior MOR performance of the Pt-Y2O3/C-2 catalyst originates from its uniformly sized Pt-Y2O3 nanoparticles and unique electronic effect. This work highlights the regulatory role of the rare-earth metal in Pt-based catalysts for the MOR, offering a general strategy for achieving excellent catalytic performance.