Enhancement of Titania Photoanode Performance by Sandwiching Copper between Two Titania Layers

Vacancies in semiconductors can play a versatile role in boosting their photocatalytic activity. In this work, a novel TiO2/Cu/TiO2 sandwich structure is designed and constructed. Abundant vacancies were introduced in TiO2 lattice by Cu reduction under heat treatment. Meanwhile, Cu atom could diffuse into TiO2 to form Cu-doped TiO2. The synergistic effect between oxygen vacancies and Cu atoms achieved about 2.4 times improved photocurrent of TiO2/Cu/TiO2 sandwich structure compared to bare TiO2 thin film. The enhanced photoactivity may be attributed to regulated electron structure of TiO2 by oxygen vacancies and Cu dopant from experimental results and density functional theory calculations. Oxygen vacancies and Cu dopant in TiO2 formed through copper metal reduction can introduce impurity levels and narrow the band gap of TiO2, thus improve the visible light response. More importantly, the Cu2+ and oxygen vacancies in TiO2 lattice can dramatically increase the charge density around conduction band and promote separation of photo-induced charge carriers. Furthermore, the oxygen vacancies on the surface may serve as active site for sufficient chemical reaction. This work presents a novel method to prepare doped metal oxides catalysts with abundant vacancies for improving photocatalytic activity.

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Study on the adsorption selection of CH$$_4$$ on CuO (110) versus (111) surfaces: a density functional theory study

SN Applied Sciences ◽

10.1007/s42452-021-04386-x ◽

2021 ◽

Vol 3 (4) ◽

Author(s):

Long Lin ◽

Linwei Yao ◽

Shaofei Li ◽

Zhengguang Shi ◽

Kun Xie ◽

...

Keyword(s):

Density Functional Theory ◽

Adsorption Capacity ◽

Active Sites ◽

Density Functional ◽

Oxygen Vacancies ◽

Density Functional Theory Calculations ◽

Density Functional Theory Study ◽

Functional Theory ◽

Strong Adsorption ◽

Selection Of

AbstractFinding the active sites of suitable metal oxides is a key prerequisite for detecting CH$$_4$$ 4 . The purpose of the paper is to investigate the adsorption of CH$$_4$$ 4 on intrinsic and oxygen-vacancies CuO (111) and (110) surfaces using density functional theory calculations. The results show that CH$$_4$$ 4 has a strong adsorption energy of −0.370 to 0.391 eV at all site on the CuO (110) surface. The adsorption capacity of CH$$_4$$ 4 on CuO (111) surface is weak, ranging from −0.156 to −0.325 eV. In the surface containing oxygen vacancies, the adsorption capacity of CuO surface to CH$$_4$$ 4 is significantly stronger than that of intrinsic CuO surface. The results indicate that CuO (110) has strong adsorption and charge transfer capacity for CH$$_4$$ 4 , which may provide experimental guidance.

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Computational investigation of Zn-doped and undoped SrEu2Fe2O7 as potential mixed electron and proton conductors

RSC Advances ◽

10.1039/d0ra08097g ◽

2020 ◽

Vol 10 (66) ◽

pp. 39988-39994

Author(s):

Zongzi Jin ◽

Ranran Peng ◽

Yunpeng Xia ◽

Zhenbin Wang ◽

Wei Liu

Keyword(s):

Density Functional Theory ◽

Density Functional ◽

Oxygen Vacancies ◽

Density Functional Theory Calculations ◽

Proton Conductors ◽

Computational Investigation ◽

Functional Theory ◽

Proton Defects

Density functional theory calculations are employed to investigate the formation and conducting behaviors of oxygen vacancies and proton defects in Ruddlesden–Popper oxide SrEu2Fe2O7.

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Enhanced visible light photocatalytic activity of anatase TiO2 through C, N, and F codoping

Canadian Journal of Physics ◽

10.1139/cjp-2013-0036 ◽

2014 ◽

Vol 92 (1) ◽

pp. 71-75 ◽

Cited By ~ 6

Author(s):

Zongbao Li ◽

Wang Xia ◽

Lichao Jia

Keyword(s):

Photocatalytic Activity ◽

Visible Light ◽

Density Functional ◽

Light Response ◽

Anatase Tio2 ◽

Functional Theory ◽

Visible Light Response ◽

Elemental Doping ◽

Visible Light Photocatalytic ◽

Good Agreement

The electronic and optical properties of pure, C-doped, (C, F)-codoped, (C, N)-codoped, and (C, N, F)-codoped anatase TiO2 are investigated by using density functional theory (DFT). The results indicate that elemental doping creates a much more efficient and stable photocatalyst than pristine, which narrows the band gap of TiO2 and realizes its visible light response activity. With the incorporation of F into (C, N)-codoped TiO2, strong visible light absorption and photocatalytic activity are further increased. It also verifies the reliability of our calculations for good agreement with the experimental results in the optical absorption of (C, N)-codoped and (C, N, F)-codoped.

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Mechanistical investigation on the self-enhanced photocatalytic activity of CuO/Cu2O hybrid nanostructures by density functional theory calculations

Physical Chemistry Chemical Physics ◽

10.1039/c6cp03977d ◽

2016 ◽

Vol 18 (40) ◽

pp. 27967-27975 ◽

Cited By ~ 12

Author(s):

Feiyu Diao ◽

FengHui Tian ◽

Wenshuang Liang ◽

Honglei Feng ◽

Yiqian Wang

Keyword(s):

Density Functional Theory ◽

Photocatalytic Activity ◽

Hybrid System ◽

Density Functional ◽

Density Functional Theory Calculations ◽

Hybrid Nanostructures ◽

The Self ◽

Functional Theory ◽

Photocatalytic Mechanism

The photocatalytic mechanism of a Cu2O/CuO hybrid system is investigated by density functional theory calculations.

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Anisotropic vacancy-mediated phonon mode softening in Sm and Gd doped ceria

Physical Chemistry Chemical Physics ◽

10.1039/c8cp00559a ◽

2018 ◽

Vol 20 (15) ◽

pp. 10048-10059 ◽

Cited By ~ 6

Author(s):

Dong-Hyuk Jung ◽

Ji-Hwan Lee ◽

Mehmet Emin Kilic ◽

Aloysius Soon

Keyword(s):

First Principles ◽

Density Functional ◽

Oxygen Vacancies ◽

Phonon Mode ◽

Density Functional Theory Calculations ◽

Functional Theory ◽

Mode Softening ◽

Dynamics Simulations ◽

And Diffusion ◽

Diffusion Properties

The structural, vibrational, and diffusion properties of different ceria-based systems (including oxygen vacancies and rare-earth dopants (Sm or Gd)) have been examined using both first-principles density-functional theory calculations and finite-temperature molecular dynamics simulations.

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Band gap narrowing in nitrogen-doped La2Ti2O7 predicted by density-functional theory calculations

Physical Chemistry Chemical Physics ◽

10.1039/c5cp00157a ◽

2015 ◽

Vol 17 (14) ◽

pp. 8994-9000 ◽

Cited By ~ 25

Author(s):

Junying Zhang ◽

Wenqiang Dang ◽

Zhimin Ao ◽

Scott K. Cushing ◽

Nianqiang Wu

Keyword(s):

Density Functional Theory ◽

Photocatalytic Activity ◽

Band Gap ◽

Density Functional ◽

Energy State ◽

Density Functional Theory Calculations ◽

Functional Theory ◽

Nitrogen Doped ◽

Band Gap Narrowing ◽

Visible Light Photocatalytic

NS co-existing with VO in La2Ti2O7 narrows the band gap and removes the localized energy state, leading to a strong visible light photocatalytic activity and enhancement of the UV performance.

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ACCEPTOR MODULATED DEFECT AND ELECTRONIC STRUCTURES IN FERROELECTRIC LEAD TITANATE: AN AB INITIO STUDY

Functional Materials Letters ◽

10.1142/s1793604708000228 ◽

2008 ◽

Vol 01 (02) ◽

pp. 121-126 ◽

Cited By ~ 2

Author(s):

ZHEN ZHANG ◽

PING WU ◽

LI LU ◽

CHANG SHU

Keyword(s):

Electronic Structures ◽

Defect Structure ◽

Density Functional ◽

Oxygen Vacancies ◽

Density Functional Theory Calculations ◽

Functional Theory ◽

Charge Effects ◽

Isolated Point ◽

Point Defect Structure ◽

Domain Pinning

Defects and electronic structures of the aliovalent acceptors substituted lead titanates were studied using density functional theory calculations. Three types of defect structures are identified in 3d transition metal and the group IIB and VB elements substituted systems. Cr substitute and oxygen vacancies are found to be dissociated from each other, forming an isolated point defect structure. In contrast, all other substitutes favor the immobile acceptor–oxygen–vacancy–acceptor defect clusters which weaken the space charge effects by limiting the motions of oxygen vacancies. Furthermore, two distinct defect-cluster structures (along the z direction and in the xy plane, respectively) are observed. We conclude that the defect structure in the xy plane induces head-to-head polarization patterns, which make the domain pinning effects even weaker. The electronic structures due to elements substitutions are also investigated and compared.

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A strategy for enhancing the photoactivity of g-C3N4-based single-atom catalysts via sulphur doping: a theoretical study

Physical Chemistry Chemical Physics ◽

10.1039/d1cp00192b ◽

2021 ◽

Vol 23 (11) ◽

pp. 6632-6640

Author(s):

Yanqing Guo ◽

Meng Xia ◽

Mingkun Zhang ◽

Jing Zou ◽

Yue You ◽

...

Keyword(s):

Density Functional Theory ◽

Photocatalytic Activity ◽

Density Functional ◽

Carbon Nitride ◽

Theoretical Study ◽

Density Functional Theory Calculations ◽

Graphitic Carbon Nitride ◽

Single Atom ◽

Functional Theory ◽

The Density Functional Theory

The sulphur-doping strategy was proposed to enhance the incorporation of single Pt atoms in monolayer graphitic carbon nitride and the density functional theory calculations verified it has superb photocatalytic activity.

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First Principle Study of Na and P Co-Doped Heptazine Based Monolayer g-C3N4

Materials Science Forum ◽

10.4028/www.scientific.net/msf.978.369 ◽

2020 ◽

Vol 978 ◽

pp. 369-376

Author(s):

Deepak K. Gorai ◽

T.K. Kundu

Keyword(s):

Density Functional ◽

Light Response ◽

Density Functional Theory Calculations ◽

Molecular Orbitals ◽

First Principle ◽

Functional Theory ◽

P Elements ◽

Co Doping ◽

Principle Density Functional Theory ◽

Co Doped

Elements doping is a powerful way to alter the electronic structure and enhancing the photo catalytic activity of materials by relaxing the surrounding chemical bonds and forming new chemical bond. In this work, we have performed, the first principle density functional theory calculations to investigate the geometric, electronic and optical properties of pristine, Na-doped and P-doped as well as Na and P (Na/P) co-doped heptazine based monolayer graphitic carbon nitride (g-C3N4). The co-doping process results in significantly narrow band gap of g-C3N4. The optical absorption shows better visible-light response compare to pristine g-C3N4. After doping the highest occupied molecular orbitals (HOMO) and lowest unoccupied molecular orbitals (LUMO) show strong delocalization and indicates photo generated electron/hole (e-/h+) pair disunion abilities of doped systems are superior than pristine heptazine based monolayer g-C3N4. Thus the co-doping with Na and P elements is an effective technique to boost the photocatalytic performance of heptazine based monolayer g-C3N4.

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A DFT+U study of the catalytic degradation of 1,2-dichloroethane over CeO2

Physical Chemistry Chemical Physics ◽

10.1039/c7cp08322j ◽

2018 ◽

Vol 20 (8) ◽

pp. 5856-5864 ◽

Cited By ~ 1

Author(s):

Li-Li Yin ◽

Guanzhong Lu ◽

Xue-Qing Gong

Keyword(s):

Density Functional Theory ◽

Density Functional ◽

Oxygen Vacancies ◽

Density Functional Theory Calculations ◽

Catalytic Degradation ◽

Bond Breaking ◽

Surface Oxygen ◽

Coulomb Interactions ◽

Functional Theory ◽

Adsorption Sites

The catalytic degradation of 1,2-dichloroethane (DCE) at CeO2(111) have been investigated by periodic density functional theory calculations corrected by on-site Coulomb interactions, and the surface oxygen vacancies were found to be important by providing the adsorption sites as well as charge transfer to favor the C–Cl bond breaking.

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