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Organic molecule–two-dimensional material (OM–2D material) heterostructures are relatively an emergent class of hybrid-based electronic devices and yet have gained enormous interests. These systems hold promise towards application in the realization of electronic, optoelectronic and energy conversion devices, due to their tunable thickness, rich raw materials, flexibility, and also their capability to merge the high light absorption efficiency of organic molecules and the high carrier mobility of 2D materials. Dielectric screening effects have a large influence on electronic structure and optical properties at the OM–2D material interface due to the low intrinsic dielectric polarizability of both organic molecules and 2D materials. Here, we will review current knowledge about the dielectric screening behaviors in 2D materials and the screening effect at the OM–2D material heterointerfaces, including the physical origin of the dielectric screening effect across such interfaces, how to investigate it, and the influence of the screening effect on OM–2D material interfaces. Engineering of the dielectric screening effects in OM–2D material systems is also discussed. We conclude the review by illustrating a brief introduction of other important factors, e.g. defects, charge transfer, and hybridization, that will contribute to the screening effect and these features should be considered for the future scientific and device development of OM–2D material heterostructures. [ABSTRACT FROM AUTHOR]

Glass formation in zeolitic imidazolate frameworks (ZIFs) has garnered significant attention in the field of metal–organic frameworks (MOFs) in recent years. Numerous works have been conducted to investigate the microscopic mechanisms involved in the melting–quenching process of ZIFs. Understanding the density variations that occur during the melting process of ZIFs is crucial for comprehending the origins of glass formation. However, conducting large‐scale simulations has been challenging due to limitations in computational resources. In this work, we used deep‐learning methods to accurately construct a potential function that describes the atomic‐scale melting behavior of ZIF‐4. The results revealed the spatial heterogeneity associated with the formation of low‐density phases during the melting process of ZIF‐4. This work discusses the advantages and limitations of applying deep‐learning simulation methods to complex structures like ZIFs, providing valuable insights for the development of machine‐learning approaches in designing MOF glasses. [ABSTRACT FROM AUTHOR]

Recent advancement on hydrogen (H 2) retrieval in a mixture gas of H 2 /CO 2 based on the metal hydride (MH) technique has attracted numerous interests. In this work, we implement the lumped element model simulation to conduct a theoretical approach on the hydrogen purification process. The influence of orifice geometry and temperature of the tank, and inflow gas rate (f in) is investigated. The results show that the discharge coefficient (DC) is affected by the tank's orifice geometry. The orifice shape is increasing the value of DC , as a result, the CO 2 (impurity) outflow rate heightens during the venting process and thereby promoting to obtain a high hydrogen purity. By overcoming the exothermic/endothermic effect in the absorption/desorption step and a proper f in selection, we find an improvement in the hydrogen storage capacity (wt%) into MH and consequently the hydrogen recovery rate increases. A sharp improvement in orifice geometry and thermal conditions of the tank, and f in enhances the main targeted results (hydrogen purity and recovery rate) and ensures the proper operation of the MH technique. [ABSTRACT FROM AUTHOR]

The investigation of the electronic conduction through monosulfurdiarylethene (1S-DE) immobilized in an insulating dodecanethiol matrix on a gold surface was addressed. Scanning tunneling spectroscopy allows to probe spatially the frontier molecular orbitals of 1S-DE at 77 K. We locally extracted the electronic highest occupied molecular orbital-lowest unoccupied molecular orbital gap of 1S-DE with the value of 1.56 eV. This attempt reveals the importance of scanning tunneling spectroscopy as a tool to measure the charge transport properties of diarylethene towards the realization of a switching-based molecular device. [ABSTRACT FROM AUTHOR]

[Display omitted] In recent years, the research on intrinsically safe aqueous zinc-ion batteries (AZIBs) has gained significant attention. However, the commercialization of AZIBs is hindered because of the formation of dendrites in them and undesired hydrogen evolution reaction (HER) at their anode. MXene is a promising two-dimensional material that can inhibit dendrite growth and undesired HER at the anode when used as a protective layer for the anode in AZIBs. MXene's surface functional groups play a crucial role in this protective function. However, the working mechanisms of these surface functional groups have not been thoroughly understood. Based on first-principles calculations and molecular dynamics simulation, we investigated the mechanisms of MXene with nine surface functional groups, including oxygen and halogen elements, as an anode protection layer. We checked their structural stability, electronic structure, adsorption energy, HER reaction free energy, Zn2+ diffusion energy barriers, coordination number of Zn2+- H 2 O and diffusion coefficients of Zn2+. The MXene species with -S and -O functional groups exhibit good electrical conductivity and greatly adsorb Zn2+. Conversely, MXene species with halogen-functional groups significantly inhibit HER reactions. MXene materials with -Se functional group have the best desolvation effect (ΔCN = 0.31), while those with -I end group have the fastest ability to diffuse zinc ion. This research provides a theoretical guidance for the design of MXene based anode protection layers, which can help to develop dendrite-free and low side-reaction AZIBs. [ABSTRACT FROM AUTHOR]

There are works have reported the crystal structures and mechanical properties of ferrite cement (C4AF) at the atomic scale with deviation owing to the omission of the Coulomb interaction effect (Ueff) between 3d electrons of Fe in C4AF. In this work, the DFT+U method was used to evaluate its effect on their electronic structures and mechanical properties of C4AF with two different phases I2mb (C4AF‐I) and Pnma (C4AF‐P). The FeO bonds of the two phases are all weaker and display Ueff due to the presence of Fe ions. The mechanical properties of C4AF calculated using DFT+U method significantly differ from those obtained without considering Ueff, in which the former shows lower inferior mechanical properties than the latter. This work presents a comparative study the effect of Coulomb interaction to the internal electronic structures and mechanical properties, which will pave the way for designing high hydration reaction cement and high toughness materials. [ABSTRACT FROM AUTHOR]

[Display omitted] Tricobalt tetroxide (Co 3 O 4) has been developed as a promising photocatalyst material for various applications. Several reports have been published on the self-modification of Co 3 O 4 to achieve optimal photocatalytic performance. The pristine Co 3 O 4 alone is inadequate for photocatalysis due to the rapid recombination process of photogenerated (PG) charge carriers. The modification of Co 3 O 4 can be extended through the introduction of doping elements, incorporation of supporting materials, surface functionalization, metal loading, and combination with other photocatalysts. The addition of doping elements and support materials may enhance the photocatalysis process, although these modifications have a slight effect on decreasing the recombination process of PG charge carriers. On the other hand, combining Co 3 O 4 with other semiconductors results in a different PG charge carrier mechanism, leading to a decrease in the recombination process and an increase in photocatalytic activity. Therefore, this work discusses recent modifications of Co 3 O 4 and their effects on its photocatalytic performance. Additionally, the modification effects, such as enhanced surface area, generation of oxygen vacancies, tuning the band gap, and formation of heterojunctions, are reviewed to demonstrate the feasibility of separating PG charge carriers. Finally, the formation and mechanism of these modification effects are also reviewed based on theoretical and experimental approaches to validate their formation and the transfer process of charge carriers. [ABSTRACT FROM AUTHOR]

As a flexible porous material, the amorphous behavior of zeolitic imidazolate framework‐8 (ZIF‐8) has garnered considerable interest. However, the association between its strain behavior and topology has not yet been exhaustively studied computationally. We perform molecular dynamic simulations on both ZIF‐8 and its topological silicate isomer sodalite (SOD) to investigate the pressure‐induced development of the mid‐ and short‐range structures. We find that both ZIF‐8 and SOD undergo two successive transformations. The first is the amorphization process, which is characterized by the breakdown of the mid‐range structure without a significant change in the elastic modulus. The other type of densification involves a change in the short‐range structure, during which the mechanical properties are improved as the short‐range disorder increases. [ABSTRACT FROM AUTHOR]

Zirconium carbide (ZrC) and hafnium carbide (HfC) have been identified as ultrahigh temperature ceramics with excellent thermal conductivity performance. The temperature profiles of ZrC and HfC have been studied; however, the temperature‐dependent of solid solution of (Zr0.5Hf0.5)C is still lacking. Herein, we report the temperature‐dependent elastic and thermodynamic properties of (Zr0.5Hf0.5)C using first‐principles calculations. The covalent characters of ZrC, HfC, and (Zr0.5Hf0.5)C are weakened at high temperatures by analyzing their respective electronic structures. In addition, the equilibrium volumes at different temperatures can be determined from the energy–volume (E–V) curves under the quasi‐harmonic approximation. Throughout the temperature ranges studied, the HfC material shows the highest bulk modulus and lowest thermal expansion. When T > 1000 K, (Zr0.5Hf0.5)C exhibits better shear and Young's modulus performance close to HfC and shows the highest anisotropy. The lattice thermal conductivity decreased as temperature increased for ZrC, HfC, and (Zr0.5Hf0.5)C, and (Zr0.5Hf0.5)C has the smallest lattice thermal conductivity. These results provide fundamental and useful information for the practical application of ZrC, HfC, and (Zr0.5Hf0.5)C. [ABSTRACT FROM AUTHOR]

An emerging prospect of solution-processed organic–inorganic hybrid halide perovskites is promising for next generation x-ray imaging applications. Herein, the optical and x-ray scintillation properties of lead-free two-dimensional perovskite crystals are reported, i.e. X2MnCl4 (X = PEA, PPA). At room temperature (RT), the photoluminescence (PL) spectra of both crystals show a peak around 600 nm with the lifetime between 3 and 4 µs, making them applicable for scintillator in x-ray imaging applications. Materials with a small electronic band gap of about 2 eV may allow a good promise for high-light-yield scintillators. On the other hand, x-ray luminescence (XL) measurements for both crystals show no spectra at RT, while those at 10 K exhibit the similar features observed in PL spectra. Temperature-dependent XL intensities reveal thermal quenching behaviour with activation energies between 40 and 54 meV. Thermoluminescence (TL) and glow curves in both crystals show residual luminescence background as slow as 1648 s and some deep traps with energies as large as 190 meV. Thermal quenching and TL measurements of both crystals are the opposite of those of PEA2PbCl4 crystals. Although some properties may not be beneficial for scintillators, the small differences of scintillation properties in both crystals may provide direction for the new designs of high-light-yield lead-free perovskite single crystal scintillators. [ABSTRACT FROM AUTHOR]

To date, the piezoelectric field has been demonstrated as a promising approach to inhibit the recombination of photogenerated carrier in photocatalyst applications. Herein we propose a MoS 2 /Bi 4 O 5 Br 2 /PVDF-HFP piezo-photocatalytic film in the organic pollutants remediation. MoS 2 /Bi 4 O 5 Br 2 as the photocatalytic material is incorporated to poly (vinylidene fluoride-co-hexafluoropropylene)(PVDF-HFP) as the supporting layer via a simple phase transition method. The polarised electric field generated on PVDF-HFP and MoS 2 /Bi 4 O 5 Br 2 under aeration synergised with the built-in electric field formed between MoS 2 /Bi 4 O 5 Br 2 Z-scheme heterojunction to promote the interfacial charge transfer. The degradation rates of rhodamine B (RhB) and tetracycline hydrochloride (TC) under aeration and visible light irradiation in 60 min reached 98.9% and 92.2%, respectively. Meanwhile, density functional theory calculations (DFT) further demonstrated the effective charge separation and transfer induced by the Z-scheme charge transfer mechanism constructed by MoS 2 composite with Bi 4 O 5 Br 2 , as well as the synergistic effect of the double electric field in favour of suppressing carrier recombination. This work provides an interesting solution for effectively combining piezoelectric catalysis with photocatalysis. [Display omitted] • MoS 2 /Bi 4 O 5 Br 2 forms a Z-scheme heterojunction that retains a high redox capacity. • Piezoelectric field and built-in electric field synergistically enhance photocatalytic performance. • Utilizing aeration as the driving force to generate the piezoelectric effect is simple and energy efficient. • DFT calculations confirm the double electric field effect of the photocatalytic system. [ABSTRACT FROM AUTHOR]

We have studied the magnetodielectric response of Y2Cu2O5, the so-called blue phase in the Y2O3-CuO-BaO phase diagram. Based on symmetry principles, we predict and demonstrate magneto-dielectric coupling on a single crystal sample. We report an anomaly in the dielectric constant at the ordering temperature of the Cu spins. We probe the magnetic field-induced phase transitions between four different magnetic phases using magneto-capacitance measurements, demonstrating relatively strong magnetodielectric coupling. We observe an increase in dielectric constant in the spin-flip phase where there exists spontaneous magnetization. We construct a detailed magnetic phase diagram. The magnetodielectric coupling is analyzed in terms of striction induced by symmetric superexchange and optical phonon frequency shifts. [ABSTRACT FROM AUTHOR]

Renewed interest has brought significant attention to tune coherently the electronic and optical properties of hybrid organic–inorganic perovskites (HOIPs) in recent years. Tailoring the intimate structure–property relationship is a primary target toward the advancement of light-harvesting technologies. These constructive progresses are expected to promote staggering endeavors within the solar cells community that needs to be revisited. Several considerations and strategies are introduced mainly to illustrate the importance of structural stability, interfacial alignment, and photo-generated carriers extraction across the perovskite heterostructures. Here, we review recent strides of such vast compelling diversity in order to shed some light on the interplay of the interfacial chemistry, photophysics, and light-emitting properties of HOIPs via molecular engineering or doping approach. In addition, we outline several fundamental knowledge processes across the role of charge transfer, charge carrier extraction, passivation agent, bandgap, and emission tunability at two-dimensional (2D) level of HOIPs/molecule heterointerfaces. An extensive range of the relevant work is illustrated to embrace new research directions for employing organic molecules as targeted active layer in perovskite-based devices. Ultimately, we address important insights related to the physical phenomena at the active molecules/perovskites interfaces that deserve careful considerations. This review specifically outlines a comprehensive overview of surface-based interactions that fundamentally challenges the delicate balance between organic materials and perovskites, which promotes bright future of desired practical applications. [ABSTRACT FROM AUTHOR]

In the past decades, perovskite-based materials have demonstrated excellent performances in a wide range of applications, including chemosensing. Owing to their unique structure-property relationship, chemosensing applications have become a point of interest that intrigued researchers from various backgrounds. Recently, several studies have reported the application of perovskite in chemosensing using various methods and analytes. However, the development for stable, sensitive, and selective chemosensors requires multiple approaches and considerations. In this review, the recent progress on perovskite-based chemosensor is summarized, with regards to different sensing mechanisms and target analytes subject to detection. Several aspects and fundamental factors affecting the chemosensor designs are also briefly discussed. In addition to the type of perovskites (including oxide, all inorganic halide, and hybrid organic-inorganic halide perovskites), perovskite design should also consider the structural dimensionality as an important factor that influenced the chemical and physical properties of the materials. We describe the upcoming challenges and limitations that could potentially be encountered in the development of perovskite chemosensors to provide some potential solutions and outlook. The future prospect of perovskite-based chemosensors is expected to rise due to continued interests and attention, which might pave the way for the advancement of innovative sensing technology. [Display omitted] • Chemosensor applications using perovskite materials is still at the early stage. • Designs for the future applications show many potential aspects. • Stability of perovskites remain the primary concern as sensors for analytes. • Dimensionality and nanostructures increase sensitivity and selectivity of sensors. • Enhancements for the sensing signals from low concentration analytes are needed. [ABSTRACT FROM AUTHOR]

• S-g-C 3 N 4 nanoflake with a large specific surface area of 189.26 m2 g−1 was prepared. • The proposed S-g-C 3 N 4 /GCE sensor exhibited excellent performance for Pb2+ detection. • The high selectivity can be attributed to a strong interaction via S Pb bond. • The strong interaction between S-g-C 3 N 4 interface and Pb2+ was confirmed by DFT. An optimum large specific surface area of sulfur-doped graphitic carbon nitride nanoflakes modified glassy carbon electrode (S-g-C 3 N 4 /GCE) is reported with promising lead ion (Pb2+) detection capability. This sensor was designed and fabricated using thermal polycondesation reaction. In terms of high selectivity Pb2+ performance, we noted that the sensor exhibited appreciable detection limit of 3.0 × 10−9 mol L−1 (S/N = 3) within the ionic specimen concentration range of 7.5 × 10−8 ~ 2.5 × 10−6 mol L−1 and 2.5 × 10−6 ~ 1 × 10−3 mol L−1. Corroborated by DFT calculations, we propose that the strong interaction of S-g-C 3 N 4 interface and Pb2+ plays an important role to generate the aforementioned sensing characteristics. In practice, we conceived high detection of Pb2+ ions that reside in lake-water and mineral samples in which percentage recovery of 88–103 can be obtained under high repetition rate. Thus, S-g-C 3 N 4 /GCE can be considered as sensitive and selective electrochemical sensor for a reliable detecting heavy metal ions in domestic sewage and industrial wastewater. [ABSTRACT FROM AUTHOR]

Taking the advantage of the good matching of the valence and conduction bands of carbon nitride (g-C 3 N 4) and copper oxide (CuO), we successfully fabricated a two-dimensional (2D) step-scheme heterojunction of g-C 3 N 4 /CuO via hydrothermal and pyrolysis techniques. The potential of applying this heterojunction in a high-performance electrochemical sensor for environmental hormone nonylphenol (NP) detection was investigated. An amperometric analysis resulted in a linear response on the g-C 3 N 4 /CuO modified sensor for NP ranges from 3.00 × 10−8 to 5.12 × 10−6 mol L−1 with a detection limit (S/N = 3) of 1.20 × 10−8 mol L−1. This excellent electrochemical performance could be attributed to a built-in electric field effect at the 2D step-scheme heterojunction interface, thereby boosting the interfacial charge transfer and improving the sensitivity of NP detection. The proposed sensor demonstrated a high selectivity for NP even in the presence of several common environmental hormones. This finding can be attributed to the unique electronic structure of NP molecule and its strong interaction with the 2D g-C 3 N 4 /CuO step-scheme heterojunction, as verified by density functional theory (DFT) calculations. This work provides new insights about the gradient energy band for fabricating highly-efficient electrochemical sensor, and paves the way for its potential applications in monitoring crucial environmental components. [ABSTRACT FROM AUTHOR]

Bismuth‐based ternary halides have recently gained a lot of attention as lead‐free perovskite materials. However, photovoltaic performances of these devices remain poor, mostly due to their low‐dimensional crystal structure and large bandgap. Here, a dynamic hot casting technique to fabricate silver bismuth iodide‐based perovskite solar cells under an ambient atmosphere with power conversion efficiencies above 2.5% is demonstrated. Silver bismuth iodides are 3D analogs of complex ternary bismuth halides with a suitable bandgap for a single junction solar cell. As far as it is known, these results represent the highest efficiency for solution processed air‐stable lead‐free perovskite solar cells. The enhanced solar cell performance via this dynamic hot casting technique can be attributed to long carrier lifetimes, micrometer‐sized crystalline grains, and pinhole free thin‐film formation with uniform morphology. This work provides a new direction for fabrication of solution‐processed lead‐free perovskite solar cells with a rapid fabrication strategy irrespective of the processing environment. A dynamic hot casting technique is presented to fabricate silver bismuth iodide‐based perovskite solar cells under an ambient atmosphere with power conversion efficiencies above 2.5%. The enhanced solar cell performance can be ascribed to pin‐hole free thin‐film formation with uniform morphology, micrometer‐sized crystalline grains, and long carrier lifetime. [ABSTRACT FROM AUTHOR]