Mechanism of photocatalytic water oxidation on small TiO<sub>2</sub> nanoparticles

Muuronen, Mikko; Parker, Shane M.; Berardo, Enrico; Le, Alexander; Zwijnenburg, Martijn A.; Furche, Filipp

doi:10.1039/c6sc04378j

Cited by 62 publications

(54 citation statements)

References 44 publications

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“…Metal-ligand charge-transfer complexes in solution have been studied in surfacehopping, but, despite the name, these are quite shortrange and the overlap between the donor and acceptor orbitals is appreciable [125,126] so GGAs gave reasonably good results. Photo-induced proton-coupled electron transfer processes in photocatalytic activity on small TiO 2 clusters has also successfully been studied, using global hybrids [127], shedding light on the catalytic rates and mechanisms. In general, the underestimated energies of TDDFT for charge-transfer excitations over long range in large systems using standard xc approximations would create havoc in surface-hopping, as the potential energy curves will have incorrect slopes and relative gaps, yielding erroneous nuclear dynamics.…”

Section: Charge-transfer Dynamicsmentioning

confidence: 99%

Charge transfer in time-dependent density functional theory

Maitra

2017

J. Phys.: Condens. Matter

134

151

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Charge transfer plays a crucial role in many processes of interest in physics, chemistry, and biochemistry. In many applications the size of the systems involved calls for time-dependent density functional theory (TDDFT) to be used in their computational modeling, due to its unprecedented balance between accuracy and efficiency. However, although exact in principle, in practise approximations must be made for the exchange-correlation functional in this theory, and the standard functional approximations perform poorly for excitations which have a long-range charge-transfer component. Intense progress has been made in developing more sophisticated functionals for this problem, which we review. We point out an essential difference between the properties of the exchange-correlation kernel needed for an accurate description of charge-transfer between open-shell fragments and between closed-shell fragments. We then turn to charge-transfer dynamics, which, in contrast to the excitation problem, is a highly non-equilibrium, non-perturbative, process involving a transfer of one full electron in space. This turns out to be a much more challenging problem for TDDFT functionals. We describe dynamical step and peak features in the exact functional evolving over time, that are missing in the functionals currently used. The latter underestimate the amount of charge transferred and manifest a spurious shift in the charge transfer resonance position. We discuss some explicit examples.

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Section: Charge-transfer Dynamicsmentioning

confidence: 99%

Charge transfer in time-dependent density functional theory

Maitra

2017

J. Phys.: Condens. Matter

134

151

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“…Water splitting using a photo‐electrochemical (PEC) junction is one of the most promising methods for a sustainable energy supply and was first reported in 1972 . During the past few decades, metal oxide have been widely researched for PEC water splitting because of its excellent performance, including suitable band edge positions, tunable bandgaps, high stability, and low cost . However, there are still some shortcomings that need to be solved, such as poor light absorption during visible light and low surface charge injection efficiency .…”

Section: Optical Applications Of Ion Implantationmentioning

confidence: 99%

A Review of Recent Applications of Ion Beam Techniques on Nanomaterial Surface Modification: Design of Nanostructures and Energy Harvesting

Zhan

Song

et al. 2019

Small

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properties because of their special struc ture. When the materials reach a nano meter size, the electrical, optical, magnetic, and other properties of the materials will be altered greatly because of the small size effect, quantum size effect, sur face and boundary effects, and Coulomb blockade effect. [1] Currently, nanomaterials have been widely applied in many fields, including computers, catalysis, sensors, energy, and environmental protection. [2][3][4][5][6][7][8][9][10][11] As the demand increases, people aspire to fabricate nanomaterials with greater prop erties. Many methods have been used to improve the properties of nanomaterials, including doping, surface reconstruc tion, semiconductor composite, and metal nanoparticle embedding. [12][13][14][15][16][17][18][19][20] These days, ion beam techniques, including ion implantation, irradiation, and focused ion beam (FIB), have been extensively used to modulate the properties of nanomaterials. Moreover, ion beam techniques are regarded as a promising technique for doping and surface modification. Compared with doping during growth and diffusion, ion implantation is more controllable and reproducible. In addition, ion implantation is also an effective method for embedding nanoclusters in body materials. Moreover, ion irradiation is an effective method to modulate the morphology and surface structure of the mate rials. Therefore, via using this technique, various properties of nanomaterials can be tailored. FIB is typically used for the in situ study of ionirradiated materials. Figure 1 shows the applications of ion beam techniques for nanomaterial surface modification.Ion implantation, as an ion beam technique, has been extensively applied to the modulation of nanomaterial sur faces. Moreover, the technique has also been extensively used in the field of microelectronics. Ion implantation has replaced diffusion as a doping method to introduce dopants into the semiconductors. As an industrial technique, it exhibits high controllability and accuracy. In contrast to other doping strat egies, almost all elements can be introduced into the target materials by ion implantation and it does not introduce other impurity elements. In addition, ion implantation is not restricted by the solid solubility of elements in the mate rials. Ion implantation can be described as a collision process Nanomaterials have gained plenty of research interest because of their excellent performance, which is derived from their small size and special structure. In practical applications, to acquire nanomaterials with high performance, many methods have been used to modulate the structure and components of materials. To date, ion beam techniques have extensively been applied for modulating the performance of various nanomaterials. Energetic ion beams can modulate the surface morphology and chemical components of nanomaterials. In addition, ion beam techniques have also been used to fabricate nanomaterials, including 2D materials, nanoparticles, and nanowires. Compared with conventional metho...

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“…[20] The process consists in ac oncerted interplay not only of the inherentp roperties of the photocatalyst but also of water adsorptiona nd hydrogen bonding among water molecules ( Figure 4). However,t he mechanism underlying this simple reactionh as been recently highlightedb ym eanso fT ully surface hopping and time-dependent density functional theory.…”

Section: Influence On the Dynamics Of The Photogenerated Chargesmentioning

confidence: 99%

“…However,t he mechanism underlying this simple reactionh as been recently highlightedb ym eanso fT ully surface hopping and time-dependent density functional theory. [20] The process consists in ac oncerted interplay not only of the inherentp roperties of the photocatalyst but also of water adsorptiona nd hydrogen bonding among water molecules ( Figure 4).…”

Section: Influence On the Dynamics Of The Photogenerated Chargesmentioning

confidence: 99%

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Influence of Surface‐Related Phenomena on Mechanism, Selectivity, and Conversion of TiO₂‐Induced Photocatalytic Reactions

2018

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Heterogeneous photocatalysis is the result of an inextricable connection of several factors differently contributing to the overall process. Photon absorption is the “sine qua non” condition for the reaction to occur. In fact, photons can be considered as immaterial reactants, and all of the phenomena related to the interaction of light–matter play a prominent role. However, other factors contribute in a concerted way to address the reaction, so that the relative contribution of each of them is often difficult to evaluate. In this framework, the present paper highlights some aspects of the interaction of TiO2 surface‐adsorbate species that could be underestimated and their influence on the conversion, selectivity, and mechanisms of photocatalytic reactions. To this aim, some paradigmatic examples on the adsorption of water and organics on TiO2 are reported.

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Mechanism of photocatalytic water oxidation on small TiO₂ nanoparticles

Abstract: Nonadiabatic molecular dynamics simulations suggest an excited state electron proton transfer mechanism and explain the observation of mobile hydroxyl radicals.

Cited by 62 publications

References 44 publications

Charge transfer in time-dependent density functional theory

Charge transfer in time-dependent density functional theory

A Review of Recent Applications of Ion Beam Techniques on Nanomaterial Surface Modification: Design of Nanostructures and Energy Harvesting

Influence of Surface‐Related Phenomena on Mechanism, Selectivity, and Conversion of TiO₂‐Induced Photocatalytic Reactions

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Mechanism of photocatalytic water oxidation on small TiO2 nanoparticles

Abstract: Nonadiabatic molecular dynamics simulations suggest an excited state electron proton transfer mechanism and explain the observation of mobile hydroxyl radicals.

Cited by 62 publications

References 44 publications

Charge transfer in time-dependent density functional theory

Charge transfer in time-dependent density functional theory

A Review of Recent Applications of Ion Beam Techniques on Nanomaterial Surface Modification: Design of Nanostructures and Energy Harvesting

Influence of Surface‐Related Phenomena on Mechanism, Selectivity, and Conversion of TiO2‐Induced Photocatalytic Reactions

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Mechanism of photocatalytic water oxidation on small TiO₂ nanoparticles

Influence of Surface‐Related Phenomena on Mechanism, Selectivity, and Conversion of TiO₂‐Induced Photocatalytic Reactions