Features Of Electronic Structure Research Articles

Boosting BaTi4O9 photocatalytic H2 evolution activity by functionalized CuNi alloy

H2 evolution through photocatalysis possesses has the advantage for achieving the carbon neutral, that relies on the highly efficient catalysts. Non-noble metals have lower prices than noble metals, which is beneficial for their large-scale applications in industry. In this paper, functionalized CuNi alloy and BaTi4O9 (BTO) composite (CuxNiy/BTO(Z)) photocatalyst were synthesized successfully through hydrothermal calcination method. The acetates were selected the raw material to avoid the use of hazardous chemicals and pollution of photocatalysts by other elements, while also providing C=O for the photocatalyst to further enhance its photocatalytic activity. Under visible light irradiation, the photocatalytic hydrogen (H2) evolution rate of Cu3Ni/BTO is 184.14 μmol·g−1·h−1, which is 101.18 times that of pure BTO (1.82 μmol·g−1·h−1) under the same conditions. Combining density functional theory (DFT) calculations and experimental studies, it is concluded that electronic structural characteristics of BaTi4O9 and the addition of CuNi alloy could provide more electrons and improve the photocatalytic H2 evolution activity.

Hyper-Rayleigh Scattering and Third-Harmonic Scattering in Chiral Liquids: Basic Evidences and Differences with Linear Chiroptical Techniques.

Nonlinear chiroptical methods like hyper-Rayleigh optical activity (HROA) and third-harmonic optical activity (THOA) have a great potential in characterizing structure-chiroptical properties of molecular systems. Here, with these methods, we bring for the first time experimental and theoretical evidence of nonlinear chiroptical differences between enantiomers of simple chiral molecules, using exclusively linearly polarized incident light. The origin of these unexpected nonlinear chiroptical contributions comes from a new nonlinear source term of the form βOA(∇×μ(nω)), which is a bilinear coupling term including the linear chirality parameter, βOA, and the curl of the nonlinear induced electric dipole moment, μ(nω), both involving dipolar magnetic interactions. Through a simple nonlinear chiroptical model that we propose, we show that specific nonlinear chiroptical parameters can be quantified, thus bringing new insights into stereochemical and electronic structural features of molecular and supramolecular systems.

First principles investigations of optoelectronic and thermoelectric properties of novel BaMg2X2 (X = P, As, Sb) alloys for renewable energy applications

Zintl phase compounds are emerging candidates for solar cells due to their unique electronic structure and favorable optoelectronic characteristics. In the present communication, we have studied the structural, electronic, optical, and transport properties of BaMg2X2 (X = P, As, Sb) Zintl compounds. The computation of formation energy and analysis of phonon dispersion spectra confirm their favorable formation and dynamic stability. Employing modified Becke-Johnson (mBJ) potential, we elucidate the band structure for BaMg2P2, BaMg2As2, and BaMg2Sb2, revealing direct band gaps of 1.80, 1.65, and 1.35 eV, respectively. Examination of DOS spectra provides better insight regarding the contribution of 6 s-Ba, 3 s-Mg, and (3p-5p)-P/As/Sb states in forming valence and conduction bands. The scrutiny of the optical characteristics indicates compelling light absorption in the visible region, suggesting promising prospects for optoelectronic applications. Thermoelectric characteristics are evaluated using classical Boltzmann transport theory. Notably, large figure of merit values of 0.99, 0.97 and 0.95 for BaMg2P2, BaMg2As2, and BaMg2Sb2, respectively, have been observed at room temperature. These exceptional optoelectronic characteristics, coupled with outstanding ZT values, suggest the potential suitability of these compositions for solar cells and thermoelectric device applications.

Unravelling CO Activation on Flat and Stepped Co Surfaces: A Molecular Orbital Analysis.

Structure sensitivity in heterogeneous catalysis dictates the overall activity and selectivity of a catalyst whose origins lie in the atomic configurations of the active sites. We explored the influence of the active site geometry on the dissociation activity of CO by investigating the electronic structure of CO adsorbed on 12 different Co sites and correlating its electronic structure features to the corresponding C-O dissociation barrier. By including the electronic structure analyses of CO adsorbed on step-edge sites, we expand upon the current models that primarily pertain to flat sites. The most important descriptors for activation of the C-O bond are the decrease in electron density in CO's 1π orbital , the occupation of 2π anti-bonding orbitals and the redistribution of electrons in the 3σ orbital. The enhanced weakening of the C-O bond that occurs when CO adsorbs on sites with a step-edge motif as compared to flat sites is caused by a distancing of the 1π orbital with respect to Co. This distancing reduces the electron-electron repulsion with the Co d-band. These results deepen our understanding of the electronic phenomena that enable the breaking of a molecular bond on a metal surface.

Ba4@Sn56]36- as a Main-Group Second-Order Superatom. Interpenetrated Dodecahedrons as a Three-Dimensional Cluster-of-Clusters Structure.

Superatomic clusters are relevant species to further understanding of bonding and structural properties of atomically precise molecular nanoparticles. Here, we explore the characteristics of ligand-free [Ba4@Sn56]36- Zintl-ion, as a three-dimensional aggregate of clusters featuring four fused Ba@Sn19 building units as an extension of the understanding in linear and cyclic superatomic cluster arrays. We provide a rational picture of the electronic shell in [Ba4@Sn56]36- as a cluster-of-clusters motif through the recently introduced second-order superatom approach, as a three-dimensional aggregation of superatomic clusters where their shells are able to interact. The electronic structure features both tangential and radial shells from the four building Ba@Sn19 units, leading to a set of 1S'21P'61D'101F'14 and higher angular momentum shells and a second set of 2S'22P'62D'102F'142G'8 second-order shells. Thus, the current approach serves to encourage the rationalization of molecular materials conceived from cluster building blocks toward a rational guide for synthetic efforts.

Morphologically tailored NiMn2O4nanocubic material for high energy-power density asymmetric supercapacitor and non-enzymatic H2O2 sensing

Developing an advanced material for energy storage and sensors is considered a key solution to meet future energy demands and economic challenges. The inverse spinel-structured NiMn2O4 emerges as a promising electrode material for next-gen energy storage due to its notable power capability, high energy density, and excellent cyclic stability. Nanostructuring enhances features not achievable in bulk materials, with a mixed morphology of nano-cubic and nanoflakes optimizing surface-to-volume ratio for effective use in energy storage devices. The addition of PVP as a surfactant, transforms the diffusion-controlled behavior to a capacitive mechanism, enhancing energy density and cyclic stability. Electrodes exhibit a specific capacitance of 816 F g−1 at 1 A g−1 and stable cyclic behavior over 5000 cycles in 1 M KOH. The constructed ASC device shows 96% cyclic stability over 10,000 cycles, maintaining an energy density of 8.8 Wh kg−1 at 6400 W kg−1 and reaching a maximum of 36.55 Wh kg−1 at 400 W kg−1. Electronic structural characteristics explained through density functional theory (DFT) contribute insights. Furthermore, the non-enzymatic NiMn4/GCE H2O2 sensor demonstrates high sensitivity, a low detection limit, and remarkable selectivity against various biological interferences across a broad concentration range.

Detecting Visible to Near-Infrared II Light via CsPbBr3 Nanocrystals/Y6 Heterojunctions.

In the endeavor to develop advanced photodetectors (PDs) with superior performance, all-inorganic perovskites, recognized for their outstanding photoelectric properties, have emerged as highly promising materials. Due to their unique electronic structure and band characteristics, the majority of all-inorganic perovskite materials are not sensitive to near-infrared (NIR) light. Here, we demonstrate the fabrication of a high-performance broadband PD comprising CsPbBr3 perovskite NCs/Y6 planar heterojunctions. The incorporation of Y6 not only facilitates charge transfer from CsPbBr3 NCs to Y6 for enhancing photodetection performance under visible illumination but also broadens the absorption spectrum range of the whole device toward the NIR regime. As a result, the heterojunction PD exhibits a photo-to-dark-current ratio above 105, a dynamic range of 149.5 dB, and an impressive lowest detection limit of incident power density of 1.6 nW/cm2 under 505 nm illumination. In the NIR regime, where photon energy is below the bandgap of CsPbBr3, electron-hole pairs can still be produced in the Y6 layer even when illuminated at 1120 nm. Consequently, photodetection is uniquely possible in PDs that incorporate heterojunctions when the illumination wavelength is longer than 565 nm. At 850 nm, the heterojunction device is capable of detecting light with power densities as low as 1.3 μW/cm2 corresponding to a LDR of 99.8 dB. The exceptional performance is attributed to the creation of a heterojunction between CsPbBr3 NCs and Y6. These findings propose a novel approach for developing broadband PDs based on perovskite NC materials.

Selective Orbital Coupling: An Adsorption Mechanism in Single-Atom Catalysis.

Quantitative understanding of the chemisorption on single-atom catalysts (SACs) by their electronic properties is crucial for the catalyst design. However, the physical mechanism is still under debate. Here, the CO catalytic oxidation on single transition metal (i.e., Sc, Ti, V, Cr, Mn, Fe, Co, Ni) dopants is used as a theoretical model to explore the correlations between the characteristics of electronic structures and the chemisorption on SACs. For these metal dopants, their atomic d orbitals form several nondegenerate and localized electronic states that are found to be selectively coupled with the π* orbital of the adsorbed O2, which we defined as selective orbital coupling. Based on the selective orbital coupling, we find that the alignment between the selected d state and the π* state determines the bond strength, regardless of the electron occupation number of the selected d states; the electron transfer to form M-O bonding can be provided by the support. Such electron transfer can be related with the electronic metal-support interaction. We attribute the origin of the chemisorption mechanism to the coexistence of the localized orbital of the single transition metal and the continuous energy band of the Au support. Finally, we illustrate how this mechanism dominates the variation trend of the reaction barriers. Our results unravel a fundamental adsorption mechanism in SAC systems.

Synthesis, structure, photophysical properties and DFT investigation of novel Zn(II) complexes bearing π-extended 8-hydroxyquinoline-derived ligands

Six new Zn(II) complexes (Zn1–Zn6) were synthesized from 2,4-diaryl-8-hydroxyquinoline derivatives (HQ1–HQ6) and structurally characterized by ESI-MS, 1H NMR spectra and SC XRD. The analysis of NMR and XRD results revealed that all the complex geometries are tetrahedral in which the ligands coordinated with Zn(II) via the N and O atoms. The investigation of photophysical properties showed that the ligands themself are non-fluorescent, while the complexes displayed a strong emission at 597–628 nm, characterized by a fluorescence quantum yield of 0.36–0.98 with a large Stokes shift of 174–202 nm, except complex Zn2. Notably, the quantum yields of the complexes in the solvents and emission intensity in the solid state tend to increase in the presence of electron-donating substituents. Quantum chemical computations were conducted to investigate the electronic structure and optical characteristics of the compounds, yielding outcomes consistent with experimental observations.

Recent Advances in Application of 1D Nanomaterials for Photocatalytic Nitrogen Fixation

Ammonia, as the second most-produced chemical worldwide, serves diverse roles in the industrial and agricultural sectors. However, its conventional production via the Haber–Bosch process poses significant challenges, including high energy consumption and carbon dioxide emissions. In contrast, photocatalytic nitrogen (N2) fixation, utilizing solar energy with minimal emissions, offers a promising method for sustainable ammonia synthesis. Despite ongoing efforts, photocatalytic nitrogen fixation catalysts continue to encounter challenges such as inadequate N2 adsorption, limited light absorption, and rapid photocarrier recombination. This review explores how the electronic structure and surface characteristics of one-dimensional nanomaterials could mitigate these challenges, making them promising photocatalysts for N2 fixation. The review delves into the underlying photocatalytic mechanisms of nitrogen fixation and various synthesis methods for one-dimensional nanomaterials. Additionally, it highlights the role of the high surface area of one-dimensional nanomaterials in enhancing photocatalytic performance. A comparative analysis of the photocatalytic nitrogen fixation capabilities of different one-dimensional nanomaterials is provided. Lastly, the review offers insights into potential future advancements in photocatalytic nitrogen fixation.

Investigation of hexagonal boron nitride monolayer with pores as an anode material for sodium-ion batteries

The hexagonal boron nitride monolayer (h-BNML) used as an anode material for metal-ion batteries was assumed pristine form. However, inspired by the imperfections in natural materials, this study investigates the effect of defects on the electrochemical properties of h-BNML. Within the current piece of research, h-BNML with pores is introduced to develop an anode material for sodium ion battery (SIBs) by undertaking density-functional theory (DFT) computations. During the diffusion and storage process of Na ions, the pores effect was thoroughly investigated. The boron atoms were removed from the structure of the pure h-BNML in order to form the h-BNML with pores, which mimicked the pore formation. Based on the DFT results, after the pore formation, the h-BNML retained its planarity. Following the introduction of vacancies, significant alterations occurred in the electronic structure characteristics of h-BNML within the pores, facilitating the effective adsorption of Na ions within the pore. The results of quantum theory of atoms in molecules indicated that there were interactions between the pores and Na ions through an electrostatic-type attraction. The h-BNML with pores was capable of retaining a large number of Na ions at its surface without any change in its planar structure. This led to an increase in its theoretical specific capacity, which increased with porosity. Hence, unlike the pure h-BNML, the pore formation improved the diffusion of Na ions. This can be promising to designing highly efficient anodes for SIBs. The methodological approach in this study can be used for tailoring porous BN materials for SIBs.

N-Heterocyclic Carbene to Actinide d-Based π-bonding Correlates with Observed Metal-Carbene Bond Length Shortening Versus Lanthanide Congeners.

Comparison of bonding and electronic structural features between trivalent lanthanide (Ln) and actinide (An) complexes across homologous series' of molecules can provide insights into subtle and overt periodic trends. Of keen interest and debate is the extent to which the valence f- and d-orbitals of trivalent Ln/An ions engage in covalent interactions with different ligand donor functionalities and, crucially, how bonding differences change as both the Ln and An series are traversed. Synthesis and characterization (SC-XRD, NMR, UV-vis-NIR, and computational modeling) of the homologous lanthanide and actinide N-heterocyclic carbene (NHC) complexes [M(C5Me5)2(X)(IMe4)] {X = I, M = La, Ce, Pr, Nd, U, Np, Pu; X = Cl, M = Nd; X = I/Cl, M = Nd, Am; and IMe4 = [C(NMeCMe)2]} reveals consistently shorter An-C vs Ln-C distances that do not substantially converge upon reaching Am3+/Nd3+ comparison. Specifically, the difference of 0.064(6) Å observed in the La/U pair is comparable to the 0.062(4) Å difference observed in the Nd/Am pair. Computational analyses suggest that the cause of this unusual observation is rooted in the presence of π-bonding with the valence d-orbital manifold in actinide complexes that is not present in the lanthanide congeners. This is in contrast to other documented cases of shorter An-ligand vs Ln-ligand distances, which are often attributed to increased 5f vs 4f radial diffusivity leading to differences in 4f and 5f orbital bonding involvement. Moreover, in these traditional observations, as the 5f series is traversed, the 5f manifold contracts such that by americium structural studies often find no statistically significant Am3+vs Nd3+ metal-ligand bond length differences.

Ab-initio insights into the physical properties of XIr3 (X = La, Th) superconductors: A comparative analysis

Here we report the structural, elastic, bonding, thermo-mechanical, optoelectronic and superconducting state properties of recently discovered XIr3 (X = La, Th) superconductors utilizing the density functional theory (DFT) using two different exchange-correlations functionals. The elastic, bonding, thermal and optical properties of these compounds are investigated for the first time. The calculated lattice and superconducting state parameters are in reasonable agreement to those found in the literature. In the ground state, both the compounds are mechanically stable and possess highly ductile character, high machinability, low Debye temperature, low bond hardness and significantly high melting point. The thermal conductivities of the compounds are found to be very low which suggests that they can be used for thermal insulation purpose. The population analysis and charge density distribution map confirm the presence of both ionic and covalent bonds in the compounds with ionic bond playing dominant roles. The calculated band structure and DOS profiles indicate metallic character of XIr3 compounds. It is also found from the DOS profile that the Ir 5d-states dominate near the Fermi level. Unlike the significant anisotropy observed in elastic and thermal properties, all the optical constants of XIr3 compounds exhibit almost isotropic behavior. The optical parameters’ profiles correspond very well with the electronic band structure and DOS features. We have estimated the superconducting transition temperature (Tc) of XIr3 compounds in this work. The calculated values of Tc for LaIr3 and ThIr3 compounds are 4.91 K and 5.01 K, respectively. We have compared and contrasted all the physical properties of XIr3 (X = La, Th) compounds in this study.

A New Co(II)-coordination Polymer: Fluorescence Performances, Loaded with Paclitaxel-hydrogel on Breast Cancer and Molecular Docking Study.

In the current context of the increasing incidence of breast cancer, we aim to develop an efficient drug carrier for breast cancer by constructing an innovative complex consisting of a metal-organic framework (MOF) and a hydrogel. The aim of this initiative is to provide new ideas and tools for breast cancer treatment strategies through scientific research, so as to address the current challenges in breast cancer treatment. In the present study, by employment of a new Co(II)-based coordination polymer with the chemical formula of [Co(H2O)(CH3OH)L]n (1) (H2L = 5-(1H-tetrazol-5-yl)nicotinic acid) was solvothermally synthesized by reaction of Co(NO3)2·6H2O a mixed solvent of MeOH and water. The characteristics of ligand-based absorption and emission, as unveiled by ultraviolet and fluorescence spectroscopy tests, offer insights into the distinctive electronic transitions and structural features originating from the ligand in compound 1. Using natural polysaccharide hyaluronic acid (HA) and carboxymethyl chitosan (CMCS) as raw materials, HA/CMCS hydrogels were successfully prepared by chemical method and their internal morphology was studied by scanning electron microscopy. Using paclitaxel as a drug model, we further designed and synthesized a novel metal gel particle-loaded paclitaxel drug and evaluated its inhibitory effect on breast cancer cells. Finally, the hypothesized interactions between the complex and the receptor have been confirmed through molecular docking simulation, and multiple polar interactions have been verified, which further proves the potential anti-cancer capability and excellent bioactivity. Based on this, this composite material prepared from a novel Co(II)-coordinated polymer with paclitaxel hydrogel could provide a useful pathway for the identification and treatment of breast cancer.

First-Principles Investigations of the Electronic Structure and Mechanical Characteristics of Nd3+-Doped YAlO3 Crystals

Near-infrared laser radiation based on Nd3+-doped yttrium ortho-aluminate (Nd:YAlO3, Nd:YAP) has garnered significant interest regarding solid-state lasers. Nevertheless, the crystal microstructures and electronic characteristics of Nd:YAP are still unclear, and the unique physical properties underlying its enormous applications require clarification. In this study, we conducted first-principles calculations at the atomic level to explore the electronic properties and mechanical characteristics of both pure YAP and Nd3+-doped YAP. The results suggest that the substitution of the Y3+ ion site with the Nd3+ impurity ion induces slight structural distortion in the YAP crystal lattice. An impurity band emerges between the original conduction band and the valence band, attributed to the 4f orbital of the Nd3+ ion, exerting a substantial influence on the narrowing of the band gap. Through an analysis of the mechanical characteristics of both pure YAP and Nd:YAP, we conclude that the incorporation of Nd3+ atoms leads to a reduction in the mechanical properties of YAP to a certain extent. Our study can serve as a foundational data source for investigations into material performance, especially for the application of Nd:YAP in solid-state laser systems.

Electron‐Deficient Boron‐Doped g‐C3N4 as an Efficient and Robust Photocatalyst for Visible‐Light Driven Hydrogen Evolution from Water Splitting

AbstractElemental doping is considered to be a promising approach for altering the electronic structure, optical absorbance, and charge separation characteristics of graphitic carbon nitride (g‐C3N4, termed as CN), thus boosting its photocatalytic performance for practical applications. Herein, a series of boron (B) doped g‐C3N4 (named as BCN) photocatalysts are developed via one‐step pyrolysis of a mixture of urea and 3‐methoxycarbonyl‐5‐nitriophenylboronic acid (MCNPBA). The results show that B‐atoms have been successfully incorporated into the g‐C3N4 network. The as‐synthesized BCN‐x (x shows the weight content of MCNPBA) photocatalysts are evaluated in photocatalytic hydrogen (H2) evolution from water splitting under visible‐light (λ ≥ 420 nm). The optimized BCN‐10 sample shows a maximum H2 evolution rate of 1789.93 µmol h─1 g─1, which is 6.2 times higher than that of g‐C3N4 (289.73 µmol h─1 g─1). This is attributed to the fact that the electron‐deficient B‐atoms are lewis acids that trap electrons, which in turn expands visible‐light absorption, narrows the bandgap, and prevents the recombination of photogenerated charge carriers. Moreover, B‐doping can readily modify the valence and conduction band positions of g‐C3N4, therefore augmenting the photocatalytic H2 evolution activity. This paper presents a unique rational framework for developing other functionalized electron‐deficient elemental‐doping g‐C3N4‐based photocatalysts for practical applications in solar‐to‐fuel conversion.

Unveiling diverse coordination-defined electronic structures of reconstructed anatase TiO2(001)-(1 × 4) surface

Transition metal oxides (TMOs) exhibit fascinating physicochemical properties, which originate from the diverse coordination structures between the transition metal and oxygen atoms. Accurate determination of such structure-property relationships of TMOs requires to correlate structural and electronic properties by capturing the global parameters with high resolution in energy, real, and momentum spaces, but it is still challenging. Herein, we report the determination of characteristic electronic structures from diverse coordination environments on the prototypical anatase-TiO2(001) with (1 × 4) reconstruction, using high-resolution angle-resolved photoemission spectroscopy and scanning tunneling microscopy/atomic force microscopy, in combination with density functional theory calculation. We unveil that the shifted positions of O 2s and 2p levels and the gap-state Ti 3p levels can sensitively characterize the O and Ti coordination environments in the (1 × 4) reconstructed surface, which show distinguishable features from those in bulk. Our findings provide a paradigm to interrogate the intricate reconstruction-relevant properties in many other TMO surfaces.

Theoretical study on the electrocatalytic CO2 reduction mechanisms using carbon-nanotube-supported carbon-based single metal atom catalysts

In this study, five Ni-doped carbon-based single metal atom catalysts supported by carbon nanotubes, which can be used for electrocatalytic CO2 reduction, were constructed. According to their structures, these catalysts include one Ni phthalocyanine (NiPc) molecule, two di- and tri-coordinated Ni-doped carbon nanoribbons, and two di-/tri-coordination Ni-doped graphene, which are denoted as NiPc/CNT, H2(H3)-Ni/CNT, 2(3)-Ni/CNT respectively. We first optimized their structures and studied the adsorption characteristics of CO2 on these catalysts with PBE+D3 method. Additionally, the electronic structure characteristics were then calculated, and the electrocatalytic mechanisms of CO2 reduction to CO, HCOOH, CH3OH and CH4 using these catalysts were studied in detail. It is found that the electrocatalytic activities of these five catalysts for reducing CO2 follow the order of 2-Ni/CNT>3-Ni/CNT>H3-Ni/CNT>H2-Ni/CNT>NiPc/CNT. As can be seen, the di-coordination catalysts perform best, followed by the tri-coordination catalysts, while the four-coordination NiPc-based catalyst performs worst. Moreover, graphene-based materials have stronger catalytic activities than their nanoribbon counterparts. Apart from these facts, these five catalytic materials may exhibit product selectivity at different limiting potentials, and specific reaction products can therefore be synthesized by controlling the potentials. We simultaneously investigated the mechanism of competing hydrogen evolution reactions in the electrocatalytic reduction of CO2 with five catalysts, and in order to inhibit the competing hydrogen evolution reactions and improve the efficiency of CO2 electrocatalytic reduction, the acidity of the solution can be appropriately reduced. We hope that our present work can provide a theoretical foundation for the future design and synthesis of novel carbon-based electrocatalyst for efficient CO2 reduction.

2D Ni2P/N-doped graphene heterostructure as a Novel electrocatalyst for hydrogen evolution reaction: A computational study

The main prerequisite for designing electrocatalysts with favorable performance is to examine the links between electronic structural features and catalytic activity. In this work, Ni2P as a model electrocatalyst and one of the most potent catalysts for hydrogen evolution reaction (HER) was utilized to develop various Ni2P and carbon-based (graphene and N-doped graphene) heterostructures. The characteristics of such structures (Ni2P, graphene, N-doped graphene, Ni2P/graphene, and Ni2P/N-doped graphene), including binding energies, the projected density of states (PDOS), band structure, charge density difference, charge transfer, Hirshfeld charge analysis, and minimum-energy path (MEP) towards HER were calculated and analyzed by density functional theory (DFT) approach. The coupling energy values of hybrid systems were correlated with the magnitude of charge transfer. The main factors driving a promising water-splitting reaction were explained by the data of PDOS, band structures, and charge analysis, including the inherent electronegativity of the N species alongside shifting the Fermi level toward the conductive band. It was also shown that a significant drop occurs in the HER energy barrier on Ni2P/graphene compared to the pristine Ni2P due to N doping on the graphene layer in the Ni2P/N-doped graphene heterostructure.

Excited State Calculations of Cu-Doped Anatase TiO2 (101) and (001) Nanofilms

Excited state calculations are performed to predict the electronic structure and optical absorption characteristics of Cu-doped anatase TiO2 nanofilms, focusing on their (101) and (001) surface terminations. Using model structures that successfully represent the equilibrium positions of deposited Cu atoms on the TiO2 surface, a comprehensive analysis of the absorption spectra for each considered model is made. The proposed modeling reveals phenomena when photogenerated electrons from TiO2 tend to accumulate in the vicinity of the deposited Cu atoms exposed to photon energies surpassing the band gap of TiO2 (approximately 3.2 eV). The crucial transition states that are essential for the creation of potential photocatalytic materials are identified through detailed calculations of the excited states. These insights hold substantial promise for the strategic design of advanced photocatalytic materials. The obtained results provide a base for subsequent analyses, facilitating the determination of heightened surface reactivity, photostimulated water splitting, and antibacterial properties.