The introduction of GW approximation to the electron's self‐energy by Hedin in 1960s, where G and W denote one‐particle Green's function screened Coulomb interaction, respectively, facilitates computation quasiparticle energies through Dyson's equation. method can also help us determine electron–hole which is a functional derivative with respect function, excellent accuracy, its combination Bethe–Salpeter equation, derived from two‐particle powerful tool study electronic excitations optical...

Graphitic carbon nitride (g-C3N4), a metal-free two-dimensional photocatalyst, has drawn increasing attention due to its application in photocatalytic water splitting. However, quantum efficiency is limited by the poor performance of oxygen evolution reaction (OER). Therefore, it important clarify behavior photogenerated holes OER. In this work, we investigate energy level alignment using GW method and exciton properties Bethe-Salpeter equation within ab initio many-body Green's function...

OH radicals can be produced <italic>via</italic> direct water photolysis through concerted proton and electron transfer.

As a typical photocatalyst, TiO2 has been intensively studied for water splitting. However, the mechanism, especially how photogenerated holes participate in, behind reaction remains highly debated. It is fundamental to identify capability of groups at TiO2/water interface attract holes. In this work, we applied first-principles many-body Green's function theory investigate behaviors free and coupled electron–hole pairs three kinds interfaces. Our calculations show that interaction between...

Silver nanowires (Ag NWs) are a promising material for building various sensors and devices at the nanoscale. However, fast precise placement of individual Ag NWs is still challenge today. Atomic force microscopy (AFM) has been widely used to manipulate nanoparticles, yet this technology encounters many difficulties when being applied movement as well other soft one-dimensional (1D) materials, since samples easily distorted or even broken due friction adhesion on substrate. In paper, two...

Doping is an effective way to extend the optical absorption of TiO2 visible range. by carbon has been found enhance water splitting efficiency significantly in experiment. However, mechanism behind this elusive. Using ab initio many-body Green's function theory, we find that C2 dimer formed on surface produces a shallow delocalized occupied Ti 3d state just below bottom conduction bands. Therefore, band-gap narrowing carbon-doped caused opposite shifts both valence and bands simultaneously,...

A proposed mechanism for photocatalytic water splitting on the rutile TiO₂(110) surface.

Photo-oxidation of CH₃OH on TiO₂ has been extensively studied in order to understand the fundamental principles heterogeneous photocatalysis.

Reaction process of photocatalytic water splitting on graphitic carbon nitride.

Defects play crucial roles in the photonic and chemical activities of ${\mathrm{TiO}}_{2}$. The origin deep band-gap defect state ${S}_{bg}$ rutile ${\mathrm{TiO}}_{2}$(110) surface has remained controversial for quite a long time. Using many-body Green's function theory, we believe that can be attributed only to $\ensuremath{\sigma}$ bonds formed between $3d$ orbitals at Ti interstitial, while nonbonded states from oxygen vacancy polaron, which are held responsible by present prevailing...

Many kinds of modification techniques have been developed to improve the quantum efficiency graphitic carbon nitride (CN) for photocatalytic water splitting in recent years. In this work, we theoretically propose incorporate polyyne (−C≡C−)n between heptazine ring and tertiary amino group CN form covalent organic frameworks (COFs) as a new strategy further enhance ability CN. These COFs allow fine-tuning their electronic optical properties by altering quantity C≡C bonds. They could fulfill...

We present a combination of many-body Green's function theory and Förster-Dexter to estimate the excitation energy transfer (EET) coupling in both isolated condensed systems. This approach employs accurate wave functions excitons, which are derived from Bethe-Salpeter equation, donor acceptor set up electronic terms. Dexter coupling, arises exchange-correlation effect, is evaluated based on GW method state-of-the-art ab initio for description self-energy. applicable various situations,...

Metallic hydrogen is a long-desired material. However, the pressure needed to metallize difficult access experimentally. We demonstrated that high-density of confined in (8,0) single-wall carbon nanotube (SWNT) can be metallized at relative low 163.5 GPa, due "physical compression" effect SWNT. Through mimicking experimental measurements specific heat nanowire, we showed electronic has clear jump around 225 K, verifying superconducting transition this critical temperature. The very well...

Fission of the lowest-energy singlet exciton (S1) to two triplet excitons (T1) in pentacene has been expected be a promising means for increasing quantum efficiency solar cells. Experiments find that S1 and T1 dissociate at quite different time scales donor/acceptor interface. Using pentacene/TiO2 heterojunction as model, we investigate dissociation by combination many-body Green's function theory time-dependent Schrödinger equation. Singlet higher-energy (Tn) could same timescale ∼100 fs,...

Using the GW method within many-body perturbation theory, we investigate electronic properties of rutile (011) surfaces with different reconstruction patterns. We find that keeping Ti:O ratio on reconstructedsurface to 1:2 enlarges bandgap surface ca. 4.0 eV. Increasing content O atoms in can turn into a semi-metal. For some surfaces, it is important apply self-consistent calculation get correct charge distributions for frontier orbitals, which are relevant photocatalytic behavior TiO2.

Due to the unique properties of 2D materials, TiO2 nanosheet has been widely studied for applications in photocatalysis and electrochemical energy storage. Just as its counterpart 3D crystal, defects are also expected play an important role nanosheet. In this work, by GW method Bethe–Salpeter equation (BSE) we systematically investigate excited-state lepidocrocite-type (L-TiO2) Our results show that computed electronic band gap ultraviolet (UV) absorption edge perfect deviate from experiment...

Water clusters are an important species in the environment and atmosphere take part various chemical biological reactions. How their optical properties vary with size is still open question. Using GW method Bethe-Salpeter equation within ab initio many-body Green's function theory, we study electronic excitations a series of water (H2O)n n = 1-48. We find that absorption peaks blueshift increasing cluster due to reducing electron-hole binding energy which arises from enhanced screening...

The unreconstructed (001) surface seems to have superior reactivity than the reconstructed shapes.

Precise placement of individual nano scale objects is an essential requirement nanodevices fabrication. Although the recently developed nanomanipulation technology based on Atomic force microscope (AFM) has realized automatic movement rigid nanoparticles, it was not applicable to nanowires due complicated behaviors flexible one-dimensional material. To improve efficiency manipulation, this work proposes a highly automated manipulation method. The new method allows sample identification and...