Zinc-ion batteries (ZIBs) employing aqueous electrolytes have emerged as one of the most promising alternatives to lithium-ion batteries (LIBs). Nonetheless, the development of ZIBs is hindered by the scarcity of cathode materials with suitable electrochemical properties. In this work, we investigate the unique properties of zinc vanadate oxide (ZnV2O4, ZVO) and zinc vanadate sulfide (ZnV2S4, ZVS) compounds as cathode materials, focusing on their crystal structures, electrochemical performance, spectroscopic features and potential applications in ZIBs. Additionally, we investigate a new cathode material, zinc vanadate selenide (ZnV2Se4, ZVSe), constructed by replacing sulfur with selenium in the ZVS cubic structure. Our findings reveal that these compounds exhibit distinct electronic and electrochemical properties, although they have similar magnetic properties due to the fact that vanadium has the same oxidation state in all three compounds. On average, ZVS stands out as the most promising candidate for ZIBs cathodes, followed by ZVO. ZVSe, shows lower electrochemical performance and also has the obvious drawback of being more costly than the sulfur- and oxygen-based compounds. Our theoretical results align closely with available experimental data, both for electrochemical properties as well as x-ray and photoelectron spectroscopy, where a comparison can be made. 

The increasing demand for sustainable energy storage has driven significant interest in zinc-ion batteries (ZIBs) as a cost-effective and environmentally friendly alternative to lithium-ion batteries (LIBs). In this study, we present a computationally driven approach to accelerate the discovery and design of cathode materials for rechargeable ZIBs, combining data filtering techniques with ab initio simulations. By screening 153 902 inorganic compounds from the Materials Project database, we identify eight promising candidates for cathode materials, among which ZnCrO4, ZnMnO3, and ZnMoO4 exhibit the most favorable electrochemical properties for large-scale applications, and where ZnCrO4 has not been discussed before, neither theoretically nor experimentally. These materials demonstrate minimal volumetric changes (less than 6%) during charge–discharge cycles, high theoretical specific capacities, elevated energy densities, high voltages, and reduced ionic diffusion barriers, all of which are critical for optimizing ZIB performance. Our findings highlight the potential of high-throughput computational screening to accelerate the development of next-generation energy storage materials, providing valuable insights for future experimental validation.

Acidochromic materials possess significant potential for the development of molecular switches, acid sensors, smart displays, and erasable/reprintable media. The semiconductive nature of conjugated polymers exhibiting such a behavior makes them ideal for use in electronic devices. In this study, we present a comparative investigation of three indacenodithiophene-based conductive polymers, containing azo, imine, and vinyl bonds (namely, PIDT-BAB, PIDT-BIB, and PIDT-BVB, respectively). We examined the alterations in the spectral properties of these polymers upon exposure to trifluoroacetic acid (TFA). The acidochromic response of PIDT-BAB and PIDT-BIB is indicated by DFT calculations to occur via protonation at the nitrogen atom. PIDT-BIB demonstrated heightened sensitivity to TFA. Conversely, PIDT-BVB did not display acidochromic properties in the film but was responsive to TFA in solution through acid doping. Repeated exposure of polymer films was used to examine the robustness of the polymers over 50 cycles. DFT calculations showed an increase in the planarity of PIDT-BAB and PIDT-BIB backbones as a result of protonation. This effect was particularly strong in PIDT-BAB, resulting in an unusually large bathochromic shift of 510 nm. The corresponding pink-to-transparent transition is particularly interesting for applications in sensors. Our findings provide valuable guidelines for the design of conjugated polymers tailored for acidochromic devices.

Aqueous-processable materials are desired to produce and commercialize eco-friendly organic solar cells. Despite the achievement of developing aqueous soluble electron donor and acceptor polymers by incorporating polar side chains (SCs), the efficiency of the greenest devices is lower than that of state-of-the-art technology processed on halogenated solvents. To investigate the impact of different substituents on structural and optical properties in solution, we considered the backbone of the PTQ10 polymer with alkyl and alkoxy SCs. We simulated oligomer chains at low and high concentration conditions via classical molecular dynamics simulations, considering both a water/ethanol mixture and chloroform as solvents. Combining an unsupervised machine learning technique and density functional theory calculations, we validated the system size for quantum calculations and investigated the impact of SCs on the excited states. Then, following the sequential QM/MM approach, we determined the absorption spectra of each polymer. From the simulations at high concentrations, we observed the stacking of different oligomers, suggesting that polymer chains already showed aggregation in solution. This is consistent with our experimental findings, as we measured a red shift of the PTQ(8bO2) spectrum when changing from a chloroform mixture to an aqueous mixture. Finally, we investigated idealized dimer interface models, whose presence of electron-donating and electron-accepting groups results in mixed signatures in the absorption spectra, widening our understanding of polymer aggregation.

Carbazole-based self-assembled monolayer (SAM) materials as hole transport layers (HTL) have led organic solar cells (OSCs) to state-of-the-art photovoltaic performance. Nonetheless, the impact of the alkyl spacer length of SAMs remains inadequately understood. To improve the knowledge, four dichloride-substituted carbazole-based SAMs (from 2Cl-2PACz to 2Cl-5PACz) with spacer lengths of 2-5 carbon atoms is developed. Single crystal analyses reveal that SAMs with shorter spacers exhibit stronger intermolecular interactions and denser packing. The molecular conformation of SAMs significantly impacts their molecular footprint and coverage on ITO. These factors result in the highest coverage of 2Cl-2PACz and the lowest coverage for 2Cl-3PACz on ITO. OSCs based on PM6:L8-BO with 2Cl-2PACz as HTL achieved high efficiencies of 18.95% and 18.62% with and without methanol rinsing of the ITO/SAMs anodes, corresponding to monolayer and multilayer structures, respectively. In contrast, OSCs utilizing the other SAMs showed decreased efficiencies as spacer length increased. The superior performance of 2Cl-2PACz can be attributed to its shorter spacer, which reduces series resistance, hole tunneling distance, and barrier. This work provides valuable insights into the design of SAMs for high-performance OSCs.

The interfacing 2D materials are promising candidates for excellent anodes focusing on energy storage Li-battery. With van der Waals gaps, these materials present genuine ion diffusion channels for lithium. In this context, we explore the incorporation of Li atoms in the WSSe/Silicene heterostructure employing ab initio calculations. It is worth mentioning that the pristine interface has a metallic behavior. Our findings reveal that intercalated lithium is more energetically favorable than it adsorbed on the surfaces of heterostructure and their counterparts. To access the lithium ionic diffusion on the material, two distinct migration barriers were examined, where the lowest had an ionic diffusion energy barrier of 0.34 eV. One interesting finding consists of an open circuit voltage (OCV) for the former case, which shows a small variation, indicating a low deviation of voltages for a small Li concentration. The results indicate a maximum volume expansion of only 0.86%, which suggests favorable structural tolerance, essential to electrode application. The interface layered 2D materials based on WSSe/Silicene demonstrated an optimistic approach as a Li-ion battery anode. 

While the interest in hydrogen photocatalysis from organic semiconductors is rapidly growing, there is a necessity to achieve hydrogen production without platinum (Pt), considering its price, availability and toxicity. In this work, this is demonstrated that high hydrogen evolution reaction (HER) efficiencies can be achieved without the use of Pt. A series of low-cost conjugated polymers are designed around the dibenzothiophene-S,S-sulfoxide (BTSO) unit, and self-assembled as nanoparticles in water via the nanoprecipitation technique. This is highlighted that how side chain engineering, nanoparticle morphology and pH influence the hydrogen evolution rate. Optoelectronic properties are improved through a Donor-Acceptor structure, resulting in an unprecedented hydrogen evolution reaction rate of 209 mmol g-1 h-1 in the absence of Pt. A clear correlation between high efficiencies and number of BTSO units within the polymer backbone can be established. The design rules pioneer the design of future organic materials is presented for a cost-efficient and sustainable hydrogen photocatalysis.

We herein undertook a multiscale approach combining molecular dynamics (MD) simulations of solution-processed polymer bulk with sequential quantum mechanics/molecular mechanics (s-QM/MM) calculations to assess the influence of structural disorder and environmental effects on the electronic structure of conjugated donor-acceptor (D-A) polymers in bulk phase. As a case study, PF5-Y5 polymer bulk formation is modeled via gradual solvent removal under ambient conditions. The electronic structure is analyzed using state-of-the-art electronic structure methods, including optimally tuned range-separated hybrids (OT-DFT), double-hybrid functionals, and the second order algebraic diagrammatic construction (ADC(2)) method as a reference. Environmental effects are accounted for using both implicit and explicit electrostatic embedding models. Our findings reveal that structural disorder at the D-A interfaces reduces frontier orbital overlap and narrows the fundamental gap by localizing the orbitals, primarily due to significant LUMO stabilization on the acceptor unit. This effect enhances the charge-transfer (CT) character of low-lying singlet and triplet states within the OT-DFT approach, while double hybrid methods preserve a more localized nature. Disorder reshapes the energetic gaps between singlet-singlet and singlet-triplet excited states and increases its energetic disorder, with CT-rich states being particularly sensitive. Explicit electrostatic embedding further amplifies CT character and disorder in singlets while preserving triplet localization. These effects contribute to spectral broadening and help explain a shoulder feature in the visible region, linking it to structural disorder and ambient anisotropy alongside CT excitations. The choice of QM method and environment treatment in QM/MM simulations is critical, neglecting anisotropy in the surroundings can influence the excited-state descriptions in D-A materials. This work advances our theoretical understanding of organic photovoltaics by highlighting these interrelated effects.

The potential impact of end-group (EG) in non-fullerene acceptor (NFA) on enabling green solvent-processable polymer solar cells (PSCs) remains underexplored, offering opportunities for advancements in environmentally friendly PSC development. Herein, the EG of 1 ',1 '-dicyanomethylene-4-fluoro-5-thienyl-3-indanone (IC-FT) is developed by modifying the state-of-the-art of Y6 derivative NFA, BTP-4F, resulting in two novel NFAs, namely BTP-FT and BTP-2FT. Distinctively, this study reveals that it is the noncovalent F<middle dot><middle dot><middle dot>S interaction, other than the commonly believed strong hydrogen bonding of F<middle dot><middle dot><middle dot>H that plays a key role in determining the final molecular conformation, as confirmed by means of 2D NMR study and Gibbs free energy calculations. The asymmetric BTP-FT possesses an upshifted lowest unoccupied molecular orbital level and enhances solubility in toluene. Consequently, it can mitigate phase separation, promote the formation of nanofibrillar morphology, facilitate exciton dissociation, and ultimately enhance the performance of the PSCs, achieving a high open circuit voltage of 0.900 V and a power conversion efficiency (PCE) of 17.56%. Furthermore, the ternary blend PM6:BTP-FT:BTP-4F achieves an enhance PCE of 18.39% in devices processed from toluene. This study offers a novel perspective on NFA design for high-efficiency and eco-friendly processable PSCs by enriching the array of electron-withdrawing EGs on NFA molecules.

The development of high-performance and cost-effective cathode materials is critical for advancing aluminum-ion battery (AIB) technology as a sustainable alternative to lithium-ion batteries. In this study, we employed a rapid screening strategy that integrates data-driven filtering with ab initio density functional theory (DFT) calculations to accelerate the discovery of promising AIB cathodes. Utilizing an extensive dataset of over 154,500 inorganic compounds from the Materials Project (MP) database, candidate materials were systematically evaluated based on criteria including thermodynamic stability, theoretical specific capacity, electrical conductivity, environmental compatibility, and economic feasibility. This approach led to the identification of six promising cathode materials: AlCuS2, AlCuSe2, AlFe2O4, AlFeO3, AlVO3, and AlMnO3. Among these, AlFeO3 and AlMnO3 emerged as the most promising candidates, exhibiting outstanding electrochemical performance with high specific capacities (614.59 mAh/g and 618.88 mAh/g, respectively), significant operating voltages (3.61 V and 3.41 V), and superior energy densities (2218.67 Wh/kg and 2110.38 Wh/kg). These materials also demonstrated minimal volume changes during charge-discharge cycles, ensuring structural stability for long-term battery operation. Additionally, AlCuS2 and AlCuSe2 were identified as viable cathodes for aqueous electrolyte systems due to their lower operating voltages. The results highlight the efficacy of combining computational screening with ab initio calculations in expediting cathode material discovery. This study provides a pathway for future experimental validation and further optimization, paving the way for the development of next-generation AIBs with improved performance, sustainability, and economic viability.