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In this study, we investigate the crystal structure, surface energy, and atomic arrangement of Cu2O. Understanding these properties is crucial for exploring the potential applications and understanding the behavior of this material. We employ the Wulff construction method and an artificial neural network (ANN) model to analyze the relative surface energies of different crystal facets and predict the surface energy of Cu2O. The ANN model exhibits excellent performance, demonstrating its effectiveness in predicting material properties and providing automated feature-learning and nonlinear-modeling capabilities. Moreover, we analyze the atomic arrangements on various crystal facets and observe the presence of oxygen atoms on the {100} facet, as well as exposed under-coordinated copper atoms on the {111} and {110} facets. High-index facets such as {211} exhibit a higher atomic step density and screw dislocation density. By precisely controlling the synthesis process, it is possible to manipulate the proportion of high-index facets. These findings highlight the significance of understanding the surface energy and atomic arrangement of Cu2O crystals for comprehending their properties and surface reactions. In summary, this study provides valuable insights into the crystal structure, surface energy, and atomic arrangement of Cu2O, offering inspiration for its properties and potential applications. The combination of the Wulff construction method and ANN modeling provides a comprehensive understanding of Cu2O crystals and their surface behavior, contributing to the field of materials science and laying the foundation for various future applications utilizing the unique properties of Cu2O. [ABSTRACT FROM AUTHOR]

Control and design of reaction conditions to acquire desirable morphology is a complex and difficult process. In principle, one can always predict the equilibrium morphologies of nanoparticles once the specific surface energies of exposed crystallographic facets become available. However, the surface energies can be easily changed by environmental conditions, and are rarely measured. As a result, we employ the k-nearest neighbors (KNN) model to predict surface energies from experimentally observed equilibrium morphologies of rutile TiO2, which may provide guidelines for the rational design and synthesis of rutile TiO2 micro-/nanocrystals with desired morphologies. [ABSTRACT FROM AUTHOR]

Spatial decoupling of light absorption and catalytic reaction is a promising approach to improve the efficiency and stability of Si photoelectrodes. Herein, patterned Ag dots (PADs) are fabricated as the front electrode on a glass layer on commercial SiNx‐coated monocrystalline p‐n+ Si by an industrial manufacture strategy. It is found that the electron tunneling glass layer offers excellent protection to Si photocathode in an acidic electrolyte (0.5 M H2SO4). The SiNx layer for antireflection and surface passivation also resists the corrosive electrolyte. Under 1 sun (AM 1.5G) illumination, PADs‐decorated photocathode with a 0.75 mm dot‐spacing exhibits a saturation photocurrent of 36.1 mA cm−2 and a photovoltage of 0.61 V when Pt is electrodeposited as the hydrogen evolution catalyst on PADs. The applied bias photo‐to‐current conversion efficiency (ABPE) reaches 9.7%. This performance is enabled by the simultaneous optimization of light absorption and collection of photoexcited electrons. The photocurrent can remain stable for about 100 h at 0 V versus the reversible hydrogen electrode (RHE). This study identifies a new combination of multifunctional spatial‐decoupling layers that is efficient in both light absorption, transfer of photoexcited electrons, and stable in an acidic electrolyte. [ABSTRACT FROM AUTHOR]

Improving the high‐rate performance of spinel lithium titanate (Li4Ti5O12, LTO) is one of the critical requirements to promote its practical application in Li‐ion batteries (LIBs). Herein, the possible Li+ ion diffusion routes in LTO are theoretically analyzed and compared by computational investigation. The calculations show that the most feasible diffusion path for Li+ ions is along the [110] direction indicated by the lowest energy barrier. Inspired by this prediction, ultrathin [110]‐confined LTO nanoflakes are rationally prepared through a function‐led targeted synthesis. The [110] orientation of the material sufficiently provides preferable transport channels which can promote the anisotropic diffusion of lithium ions within LTO nanoflakes. Furthermore, the ultrathin 2D nanostructure effectively shortens the diffusion length along the [110] direction, facilitating ion transport across the nanoflakes and thus improving the diffusion kinetics. Owing to these unique features, the LIB composed of optimized [110]‐confined LTO exhibits remarkable high rate capability and long‐term cycling stability, with a capacity of 146 mAh g‐1 at an ultrahigh rate of 100 C and a capacity retention of 88% even after 1500 cycles at 50 C. The as‐prepared [110]‐confined LTO nanoflakes have promising applications and show commercial viability for high‐power facilities. [ABSTRACT FROM AUTHOR]

The practical applications of non‐aqueous lithium‐oxygen batteries are impeded by large overpotentials and unsatisfactory cycling durability. Reported here is that commonly encountered fatal problems can be efficiently solved by using a carbon‐ and binder‐free electrode of titanium coated with TiO2 nanotube arrays (TNAs) and gold nanoparticles (AuNPs). Ultraviolet irradiation of the TNAs generates positively charged holes, which efficiently decompose Li2O2 and Li2CO3 during recharging, thereby reducing the overpotential to one that is near the equilibrium potential for Li2O2 formation. The AuNPs promote Li2O2 formation, resulting in a large discharge capacity. The electrode exhibits excellent stability with about 100 % coulombic efficiency during continuous cycling of up to 200 cycles, which is due to the carbon‐ and binder‐free composition. This work reveals a new strategy towards the development of highly efficient oxygen electrode materials for lithium‐oxygen batteries. [ABSTRACT FROM AUTHOR]

A binder-free electrode consisting of Pd clusters and vanadium oxide (VO) has been prepared via gas-phase-cluster beam deposition on carbon cloth. The Pd clusters largely improve the stability of the VO-Pd-based electrode, which can be reversibly and continuously cycled for more than 120 cycles in a Li–O2 based battery. [ABSTRACT FROM AUTHOR]