ACS Applied Energy Materials最新文献

Organic–metal halide hybrids have advantageous luminous qualities and can be processed at low temperatures. These materials present a sustainable, cost-efficient, and effective solution for X-ray scintillators compared to all-inorganic scintillators. However, challenges, such as surface photon scattering and difficult uniformity control of the scintillator surface, continue to impede resolution improvement. In this study, we present a melt-quenching process to incorporate a zero-dimensional hybrid halide (MTP)₂MnBr₄ (methyltriphenylphosphonium bromide = MTPBr) into a microporous silicon substrate (3 × 3 cm). The (MTP)₂MnBr₄ glass embedded microporous silicon substrate scintillator screen achieves exceptional X-ray performance metrics by exploiting its outstanding luminescence properties, high optical transparency, and effective photon wave guidance via microporous arrays on screen surfaces. It delivers a high X-ray light yield of 16,840 photons/MeV, with a low detection limit of 135 nGy/s, and achieves an exceptional X-ray imaging spatial resolution of 25 lp/mm. Furthermore, the (MTP)₂MnBr₄ single crystal grown via low-temperature evaporation shows remarkable retention of radioluminescence intensity and an exceptional light yield of 60,790 photons/MeV. This approach combines low toxicity, ease of processing, scalability, low detection limit, significant light yield, and high spatial resolution, making it suitable for widespread adoption in various X-ray applications.

Hybrid electrodes that reconcile diffusion and surface-controlled redox are essential for high-power and durable storage. Herein, we engineer reduced graphene oxide (rGO) by covalently grafting anthraquinone (AQ) motifs to create dual-function materials that operate efficiently in supercapacitors and lithium-ion batteries (LIBs). Two precursors─2-aminoanthraquinone (AAQ) and 2-(bis(4-aminophenyl)amino)anthracene-9,10-dione (APAAD)─were coupled to graphene oxide and chemically reduced to yield AQ-rGO and APAD-rGO. FT-IR and X-ray photoelectron spectroscopy confirm amide linkages, while powder X-ray diffraction shows enlarged interlayer spacings of 0.930 (AQ-rGO) and 1.280 nm (APAD-rGO). Electrochemical analyses reveal pseudocapacitive behavior with medium-dependent kinetics. In aqueous supercapacitors, cyclic-voltammetry b-values of 0.553 (AQ-rGO) and 0.526 (APAD-rGO) indicate diffusion-influenced charge storage. In LIB system, the b-value increases to 0.85 and 0.82, respectively, with capacitive fractions of ∼77% and ∼69% at 0.5–1.0 mV s^–1, reflecting accelerated surface redox and shortened ion paths. Temperature-dependent impedance spectroscopy gives activation energies of 32.7 kJ mol^–1 (AQ-rGO) and 26.7 kJ mol^–1 (APAD-rGO), consistent with galvanostatic intermittent titration analysis, showing higher Li⁺ diffusivity in APAD-rGO. Furthermore, the electrochemical performance mirrors these kinetics. As a supercapacitor, the anthraquinone-grafted rGO demonstrates a specific capacitance of 60 F g^–1 up to 70 cycles under a scan rate of 5 mV s^–1. As a LIB cathode, APAD-rGO delivers 129.7 mA h g^–1 at 50 mA g^–1, maintains a rate capability from 100 to 2000 mA g^–1, and sustains 1000-cycle durability with excellent stability. This cathode outperforms the rGO cathode with 45 mA h g^–1 under a 50 mA g^–1 current density. As anodes, AQ-rGO and APAD-rGO, respectively, provide initial capacities of 403 and 340 mA h g^–1, stabilize at 345 and 283 mA h g^–1 after 100 cycles, and operate up to 2000 mA g^–1 with progressive activation. Overall, quinone grafting activates dense redox sites, tunes transport length scales, and bridges capacitive and diffusion storage in carbon frameworks.

This study presents, for the first time, a comprehensive investigation of phosphoric acid impregnation in electrospun poly[2,2’-(m-phenylene)-5,5′-bibenzimidazole] (m-PBI) membranes and a comparison with the dense counterpart. The kinetics and thermodynamics of acid adsorption were systematically explored by varying concentration, temperature, and contact time. To this aim, a tailored experimental protocol was developed to dynamically quantify the amount of adsorbed acid and to prevent acid leaching phenomena. Electrospun membranes were found to reach Acid Doping Levels (ADL) as high as 12.9 mol H₃PO₄/mol PBI within only 10 min, far exceeding the typical maximum of 2.3 mol acid/mol polymer observed in conventional cast membranes after 24 h of immersion. A postdoping washing step with methanol used to distinguish between “free” (loosely held) phosphoric acid and “bound” (chemically or strongly hydrogen-bonded) acid showed that electrospun membranes retained a significant amount of bound acid compared to cast membranes, highlighting their superior stability. Adsorption isotherms were effectively described using Liu’s model, which allowed the extraction of equilibrium constants and thermodynamic parameters, indicating an endothermic adsorption mechanism. Kinetic analysis based on a reactive adsorption model yielded a reaction order of 1.91 and an activation energy of 26.6 kJ/mol. In addition, preliminary in-plane proton conductivity measurements under anhydrous conditions showed promising electrochemical performances for the acid-doped electrospun membranes, with conductivities up to 132 mS/cm at 150 °C, significantly higher than those of cast membranes (91 mS/cm). These results demonstrate a direct correlation between fibrous morphology, adsorption mechanisms, and functional properties of the membranes for next-generation fuel cell applications.

Two sets of high-quality epitaxial ruthenium oxide (RuO₂) thin films with different thicknesses were synthesized in situ on cost-competitive sapphire substrates by using a pulsed laser deposition technique. The first set of films, with a thickness of 40 nm and a sheet resistance of 15.7 Ω/□, was prepared using 2100 laser pulses, while the second set of films, with a thickness of 87 nm and a sheet resistance of 6.7 Ω/□, was prepared using 4800 laser pulses. All other deposition parameters were kept the same. The post-deposition structural and morphological measurements showed that both sets of films grew at the same growth rate, had the same crystallinity, similar grain boundary density, and slightly different surface roughness. The thicker RuO₂ films achieved an overpotential of 280 mV for the oxygen evolution reaction at a current density of 100 μA/cm², comparable to or exceeding the performance of films grown on more expensive substrates. Comparatively, the thinner RuO₂ films, which have a significantly higher charge transfer resistance (250 Ω versus 100 Ω for thick films), display a higher overpotential of 320 mV. These results indicate that the lower electrical resistance of thicker films promotes charge transfer through the film body, leading to superior electrocatalytic properties.

A single lithium-ion conductive poly(lithium borate ester) water-soluble binder (PAA-MBLi) was utilized in the graphite anode with the motive of tuning the solid electrolyte interphase (SEI) and enhancing the ionic conductivity. The prelithiated binder and the boron-functionalized SEI enhanced the Li-ion kinetics with a low SEI and charge-transfer resistance, low activation energy, and a high diffusion coefficient. These enhancements enabled fast charging with a discharge capacity of 72 mAh/g at 5C and a capacity retention of 82.9% after 1400 cycles. The anodic half cells with PAA-MBLi exhibited a capacity retention of 80.4% after 750 cycles at 1C with a maximum capacity of 323 mAh/g. It also showed a 95.8% capacity retention after 100 cycles with a high mass loading of 5.55 mg/cm² at 0.2C and an appreciable initial Coulombic efficiency of 83.9%, indicating a thin SEI with minimum irreversible capacity loss. The PAA-MBLi binder exhibited a remarkable ionic conductivity of 8.160 × 10^–5 S cm^–1 and a high lithium transference number of 0.831 at 25 °C. The PAA-MBLi binder is also expected to reduce HF formation in the cell by consuming the fluoride ions and forming a B–F bond in the SEI, as indicated by the X-ray photoelectron spectroscopy spectra.

Organic solar cells (OSCs) have undergone rapid development over the past few decades owing to their high efficiency, mechanical flexibility, and potential for low-cost large-scale fabrication. Machine learning (ML) models capable of accurately predicting the power conversion efficiency (PCE) of OSCs can greatly accelerate the discovery of high-performance donor and acceptor materials. In this work, we developed ML models for PCE prediction by introducing a set of complementary molecular descriptors and performing a comprehensive descriptor selection. The resulting models achieved the highest test set R² value of 0.82 and average R² value of 0.76 on an updated mixed experimental data set, representing one of the best accuracies reported to date for OSC PCE prediction. Validation using published experimental data confirmed the model’s strong predictive accuracy and generalizability. Our results highlight that the proposed OPT3D descriptors effectively complement the structural information missing from RDKit and Morgan fingerprint descriptors. This study demonstrates that the development of complementary molecular descriptors is critical for improving ML model accuracy in molecular material research and provides a promising approach for the rational design of high-efficiency OSC materials.

Lithium-ion batteries (LIBs) are widely used due to their high cyclability and stability. However, the high cost of raw materials has spurred interest in sodium-ion batteries (SIBs) as a cost-effective alternative. Despite this, SIBs suffer from lower energy density and poorer cyclability, leaving them in a developmental stage. The formation of the solid electrolyte interphase (SEI) is critical for battery performance as it stabilizes the electrode and prevents further solvent degradation during cycling. This study investigated the SEI formation mechanism in sodium-based EC/DEC electrolyte by monitoring the evolution of volatile products and comparing them with those in lithium-based electrolytes under Ar and O₂ atmospheres using online electrochemical mass spectrometry and vibrational spectroscopy. It was demonstrated that the SEI forms via similar reaction pathways in both sodium- and lithium-based electrolytes. However, Na⁺ lead to more significant ethylene (C₂H₄) evolution during this process. Upon introducing O₂ into the operating environment, carbon dioxide (CO₂) and water were produced during the initial cycle. At the same time, the amount of C₂H₄ evolved was significantly lower than under Ar. The results indicate that in the presence of O₂, the superoxide (O₂^–) generated during the oxygen reduction reaction (ORR) alters the decomposition of EC molecules into two pathways. Because O₂^– is more stable in sodium-based electrolytes, a larger fraction of O₂^– participates in the decomposition of EC. This alters the electrochemical reduction reaction (ERR) pathway of C₂H₄ generated from EC decomposition to an ORR pathway that yields CO₂. We also found that specific additives, such as vinylene carbonate (VC) and fluoroethylene carbonate (FEC), can improve SEI stability in SIBs by inhibiting solvent decomposition and promoting the formation of a denser, stronger SEI. These findings provide valuable insights into the development of stable SEI, particularly for advancing the performance of SIBs.

The wittichenite-type compound (Cu₃BiS₃, CBS) shows great potential for photovoltaic and solar-to-fuel applications due to its favorable optoelectronic properties. However, precise control over composition and phase stability in thin films remains challenging to achieve due to phase complexity and a limited kinetic stability window. This research focuses on obtaining homogeneous and stable CBS phases with ideal composition through a simple sulfurization process of an oxide Cu–Bi–O (CBO) precursor film in the thermodynamically permissible temperature range (350–425 °C). The findings confirm successful conversion of oxide film to the wittichenite phase, free of secondary phases, at 350 °C with a direct bandgap energy of 1.61 eV. The energy band positions from photoelectron spectroscopy show favorable energetics toward water splitting and CO₂ reduction. Photoelectrochemical performance of a prototype CBS/TiO₂ heterojunction device demonstrates a photocurrent density of 0.12 mA/cm² and 0.96 mA/cm² for water splitting and CO₂ reduction, respectively. The presented method can be further explored to fabricate CBS films in various configurations for PEC and solar cell devices.

Aqueous zinc-based batteries (AZBs) are considered promising for grid-scale energy storage owing to their low cost, safety, and eco-friendliness. The practical applications, however, are limited by zinc dendrite growth and parasitic side reactions at the anode. This work presents a strategy of employing glucose as an electrolyte additive to tailor the Zn²⁺ solvation environment. This modification successfully suppresses dendrite growth and improves the electrochemical reversibility of Zn plating/stripping. Mechanistically, glucose disrupts the hydrogen-bond network among water molecules and attenuates the hydration of Zn²⁺, leading to an optimized solvation structure. The electrolyte with 150 mM glucose, Zn||Cu cells achieve a high Coulombic efficiency of 98.8% and sustain 450 stable cycles at 1 mA cm^–2. Correspondingly, Zn||Zn symmetric cells exhibit dendrite-free operation for over 1050 h with a low overpotential of 40 mV. Furthermore, Zn||V₂O₅ full cells deliver outstanding cycling stability, retaining a capacity of 68 mAh g^–1 after 1000 cycles at 1C. This study offers a general and effective additive approach for developing advanced electrolytes in aqueous ZIBs.

1T–2H MoSe₂ was grown in situ on Ti₃C₂T_x MXene to develop a Pt-free HER electrocatalyst with enhanced interfacial charge transfer. The optimized composite delivers an overpotential of 68 mV at 10 mA cm^–2 and a Tafel slope of 74 mV dec^–1, along with excellent cycling stability of over 1000 cycles, showing negligible decay. The composite has an increased metallic 1T content and suppressed Mo⁶⁺ surface oxides. Electrochemical measurements reveal a substantially reduced charge-transfer resistance (R_ct ∼ 31 Ω) and a large ECSA (C_dl = 22.6 mF cm^–2). The catalyst showed improved activity, high TOF values, and a hydrogen-coverage profile consistent with a Volmer–Tafel pathway.