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Photocatalytic water splitting has attracted extensive attention for its bright prospects in producing clean hydrogen energy. To realize efficient solar-to-hydrogen energy conversion, it is important to explore a photocatalyst with high electron-hole separation and wide-range solar absorption. Herein, a novel twodimensional metal-hydride, LuH₃, is designed and its viability as an efficient photocatalyst for overall water splitting is evaluated in the present work. It reveals that LuH₃ monolayer is an isotropic semiconductor with a direct band gap of 2.56 eV, decreased to 1.872 eV in a bilayer, exhibiting strong absorption efficiency for ultraviolet, visible, and near-infrared regions. Besides, it has favorable valence and conduction band positions for water redox reactions of O₂/H₂O and H⁺/H₂, high carrier mobility, and significant charge separation capability due to the orientation-dependent distribution in band edges, which play vital roles to enhance photocatalytic performance. The higher partial charge densities on H_1b and H_2d in HOMO lead to amore potent oxidation reaction, facilitating the reduction reaction and the production of hydrogen. In particular, LuH3 monolayer is flexible and sensitive to external stress. Applying both isotropic and uniaxial strain has a limited impact on achieving favorable band alignments with water redox potentials, providing distinct opportunities for various applications. In both acidic and alkaline environments, LuH3 monolayer shows significant potential for efficient photocatalysis in the context of overall water splitting. Furthermore, LuH3, a van der Waals material, can exfoliate from multilayered or bulk forms with a cleavage energy of 1.07 J/m², which is three times higher than the experimentally measured 0.37 J/m² for graphite. These findings highlight the potential of LuH₃ monolayer as an efficient solar-spectrum water-splitting photocatalyst, with implications for sustainable energy conversion technologies utilizing solar energy for clean and renewable hydrogen fuel generation.

An extensive amount of research has been focused on the development of state-of-the-art methodologies for drug administration. In this study, we have utilized density functional theory (DFT) for assessing the ability of a Twin monolayer of boron nitride and graphene, i.e., Twin-BN and Twin-Gr monolayer, as a carrier for delivering four anticancer drugs (ACDs) 5-fluorouracil (5-FU), gemcitabine (GC), cyclophosphamide (CP), and mercaptopurine (6-MP). Also, the properties of all drug molecules along with the Twin-BN and Twin-Gr and the complex of the ACD-Twin-BN/Gr monolayer were investigated to explore the usefulness of the Twin-BN and Twin-Gr monolayer as ACD carrier. The interaction between the monolayers and ACDs confirmed that the adsorption is feasible as the adsorption energy ranged from -0.41 eV to -0.95 eV in the case of Twin-BN, while it ranged from -0.43 eV to -0.61 eV in the case of Twin-Gr. Additionally, the change in the band gap of the Twin-BN and Twin-Gr monolayers after the adsorption of ACDs was considerable. We can conclude that among both monolayers, Twin-BN can be utilized as a highly effective carrier for delivering ACDs. Our findings showed that the monolayer Twin-BN could be explored as a drug transporter for highly efficient carrying of the considered ACDs.

The high-pressure phases of aluminium (Al) and sodium (Na) substituted metal carbides are investigated using the first-principles cluster expansion technique. By analysing the formation enthalpy within the convex hull of Na_1−xAl_xC₂ compositions at 100 GPa, the thermodynamically stable structures of these mixtures are determined. Electronic properties are then explored to identify signs of superconductivity in the candidate phases. Notably, Na_0.1667Al_0.8333C₂ and Na_0.6Al_0.4C₂ exhibit superconductivity with critical temperatures (T_c) of 14.7 K and 20.1 K, respectively, at varying pressures. These findings suggest the potential for T_c superconductors by reducing the required pressure. At 60 GPa, Na_0.1667Al_0.8333C₂ shows a T_c of 20.9 K, emphasising the stabilising effect of aluminium substitution under moderate pressure. These results provide insights into the exploration of superconductivity in carbon-based quantum materials with aluminium substitution and the influence of pressure.

Extraction of ⁹⁰Sr from groundwaters is of great significance in energy and ecological environment. Phosphate minerals have been proposed as a suitable matrix for the in-situ remediation of radionuclides from groundwaters by encouraging co-precipitation. However, the understanding of how Sr²⁺ precipitate into phosphate minerals affected by grain growth has not been fully resolved. In this work, the precipitation reaction of Sr₅(PO₄)₃OH and SrHPO₄ were studied based on experiments and PHREEQC simulation. Some specific issues such as the precipitation reaction kinetics and the phase evolution during grain growth were discussed in detail, along with investigating the chemical stability of obtained precipitations before and after calcination. The results show that pH appears to be a prevailing factor with a recommended pH = 8 ∼ 11 to obtain the stability domain of Sr₅(PO₄)₃OH and SrHPO₄ to remove Sr²⁺ with a removal rate over 98 %. Interestingly, SrHPO₄ is more likely to preferentially nucleate at pH = 8 solution compared to Sr₅(PO₄)₃OH, and the poorly crystalline SrHPO₄ tends to disappear over time. TEM and SAXS results show the plate-like nanoparticles of SrHPO₄ are wrapped into the rod-like particles of Sr₅(PO₄)₃OH during the grain growth, and the inner SrHPO₄ can react with Sr₅(PO₄)₃OH to form Sr₃(PO₄)₂ at temperature over 600 ℃. This observation is inconsistent with the previous grain growth result of poorly crystalline SrHPO₄, where it is believed to recrystallize into more stable Sr₅(PO₄)₃OH crystals over time. Moreover, the Sr-O binding energy plays an important role in controlling the degradation of Sr₅(PO₄)₃OH, Sr₃(PO₄)₂, SrHPO₄ and β-Sr₂P₂O₇.

Advanced structural predictions, driven by first-principles calculations, facilitate the realization of a superconducting state under reduced pressure conditions while maintaining structural integrity. Scandium hexahydride (ScH₆) exhibits structural stabilities under high pressure, adopting hexagonal and body-centered cubic structures that lead to high-temperature superconductivity. In this study, we theoretically provide a crucial reference for boron-nitrogen-substituted hydrogen above 100 GPa. Subsequently, Sc(BN)₃ demonstrates significant structural stability, observed up to 200 GPa. Utilizing the stochastic self-consistent harmonic approximation sheds light on the influence of thermally excited lattice vibrations on the crystal structure of Sc(BN)₃, emphasizing the impact of quantum ionic effects. These findings underscore the distinctive anharmonic behavior of Sc(BN)₃, indicating its potential to facilitate boron-nitrogen-substituted hydrogen, which could find widespread applications in SC, achieving a critical temperature of 32.8 K under 150 GPa.

The exceptional photophysical and electronic properties of 2D hybrid perovskites possess potential applications in the field of solar energy harvesting. The present work focuses on the two systems, exhibiting the Dion–Jacobson phase of 2D perovskite consisting of methylammonium (MA) and formamidinium (FA) cations at A-site and 3-(aminomethyl)pyridinium (3AMPY) as ring-shaped organic spacer. Altering A-site cations creates a distortion of inorganic layers and hydrogen bond interactions. It has been noted that the angles of Pb–I–Pb and I–Pb–I are more symmetric (close to 180°) for (3AMPY)(MA)Pb₂I₇ compared to (3AMPY)(FA)Pb₂I₇ and result in increase of bandgap from 1.51 to 1.58 eV. This further leads to a significant difference in Rashba splitting energy under the influence of spin-orbit coupling effects, where the highest splitting (36 meV) is calculated for conduction band edge of the (3AMPY)(FA)Pb₂I₇, suggesting the promising applications toward spintronics. The calculated absorption spectra cover the range from 300 to 450 nm, indicating significant optical activity of 2D (3AMPY)(MA)Pb₂I₇ and (3AMPY)(FA)Pb₂I₇ in the visible and ultraviolet regions, which bodes well for their application in advanced optoelectronic devices. The bandgap and high absorption coefficients present more than 30% of theoretical power conversion efficiency for both systems, as calculated from the spectroscopic-limited maximum efficiency.

Advanced structural forecasting of alloy hydrides, particularly through cluster expansion combined with first-principles calculations, opens up new possibilities for discovering novel phases in transition metal alloy hydrides like (Zr,Hf)H3. Within this framework, significant findings have been made for compounds Zr7HfH24, Zr4Hf2H18, Zr2Hf2H12, and Zr2Hf4H18, which demonstrate thermodynamic stability at 100 GPa. All identified structures exhibit metallic properties, suggesting a promising pathway to superconductivity. In terms of superconducting properties, Zr7HfH24, Zr4Hf2H18, Zr2Hf2H12, and Zr2Hf4H18 show critical temperatures (T c) of 15.9, 14.6, 8.2, and 12.8 K, respectively, at 100 GPa. Notably, Zr4Hf2H18 achieves the highest T c within the (Zr,Hf)H3 series, reaching approximately 17 K at 150 GPa. Our analysis of the superconducting state is based on H-rich criteria under specific conditions, revealing that hydrogen's contribution to the partial density of states is lower than that of hafnium and zirconium. The investigation also finds that these structures lack H clathrate configurations or H2-like molecular units, suggesting they are unlikely to reach near-room-temperature T c. These results highlight how structural frameworks supported by H or H2-like molecules could potentially enhance superconductivity. Additionally, the alignment of the vibrational modes of the alloy with those observed in hafnium suggests that Hf-substituted Zr alloys support superconductivity and offer theoretical feasibility for achieving higher critical temperatures across a broader range of alloying combinations.

Recent discoveries in high-pressure chemistry have revealed a greater richness in the interaction between transition metals and nitrogen, particularly with the synthesis of various metal nitrides. In this study, we investigate novel Sr-N phases under varying moderate pressures, employing evolutionary algorithms (EAs) and based on first-principles calculations to explore their thermodynamic, structural, and electronic characteristics. Our comprehensive analysis includes assessments of thermodynamic stability based on convex hulls and confirmation of dynamical stability through phonon calculations. Through these analyses, we identify four stable structures-SrN, SrN₂, SrN₃, and SrN₄-along with their corresponding pressure-induced structures presented in a phase diagram. Electronic band structure calculations offer insights into the electronic behaviors of these phases under different pressures. Notably, in the cases of SrN₃ and SrN₄, the high PDOS at the Fermi energy suggests the potential for superconductivity (SC) in these phases. Furthermore, our study unveils the superconducting behavior of SrN₄ within the pressure range of 10-50 GPa, with a peak T_c reaching 13.7 K at 10 GPa. This observation reflects an enhancement of T_c under pressure, attributed to the introduction of nitrogen. These findings provide valuable insights into the diverse Sr-N phases under pressure obtained from evolutionary algorithms and predict the possibility of SC in certain phases, opening avenues for further exploration in metal nitrides under pressures.

Theoretical investigation of hydrogenation processes has applied to magnesium diborides under ambient conditions, which identified two structurally stable phases, i.e, Mg4B6H2 4 B 6 H 2 and Mg4B4H4. 4 B 4 H 4 . These identifications were evaluated through assessments of their lattice dynamics stability using density functional perturbation theory. Both phases exhibit metallic behavior within their electronic band structures. Our findings showcase the significant impact of anisotropic Migdal-Eliashberg calculations, enhancing the superconducting properties within this system and resulting in a notably higher T c of 34 K. Mg4B4H4 4 B 4 H 4 exhibits superconductivity with a T c of 17 K under atmospheric conditions, as determined by anisotropic Migdal-Eliashberg calculations. Our study underscores the wide range of structural variations achievable through the hydrogenation of MgB2 2 and highlights the crucial importance of hydrogen atom placement within these structures. In addition, the calculation result indicates the influence of band dispersion characteristics on Fermi velocity, a factor attributed to both anharmonicity and harmonicity, which plays a pivotal role in determining the superconducting properties of these materials.

Exploring superconducting materials stands as a pivotal pursuit in condensed matter physics, particularly, the investigation of superconductivity in two-dimensional metal hydrides is of paramount importance due to its intriguing nature. Our study focuses on elucidating the metallic state of van der Waals layered TM-H (TM = Ti, Zr, Hf) compounds, a key factor in predicting their superconducting (SC) characteristics. Leveraging an evolutionary algorithm rooted in density functional theory, we predicted the structures of hydrides, including Ti2H2, Ti2H4, Zr2H2, Zr2H4, Zr2H5, Hf2H2, Hf2H4, Hf2H5, and determined their energetically stable structures. Along with exploring the potential for SC, we conducted a comprehensive examination of relevant electronic properties. A significant aspect addressed was the influence of anharmonic phonon properties in determining the stochastic self-consistent harmonic approximation. These findings underscore the pivotal role of anharmonicity in determining the SC of two-dimensional metal hydrides.