Oxygen-deficient metal oxide nanostructures for photoelectrochemical water oxidation and other applications

Wang, Gongming; Ling, Yichuan; Li, Yat

doi:10.1039/c2nr32222f

Cited by 359 publications

(277 citation statements)

References 104 publications

(198 reference statements)

Supporting

Mentioning

262

Contrasting

Order By: Relevance

“…As the Mott-Schottky plot was developed based on ap lanar electrode model, the deviation from al inear profile is commonly observedw hen it is used for nanostructured electrode. We chose the linear region in the range of 0.3-0.6 Vv ersus Ag/AgCl to calculate the slope and donor density.T he slopes determined from the plots could be used to estimate the donor densities by using Equation (1): [29] …”

Section: Resultsmentioning

confidence: 99%

“…With the structural dimension being smaller than the hole diffusion length, nanoporous BiVO 4 has shown an increased f.W ea lso demonstrate as imple and effective approacht os ignificantly enhancet he PEC properties of the BiVO 4 photoanode by modifying the oxygen content. The donor density and surface properties of BiVO 4 were thus improvedb yi ntroducingo xygen vacancies [29] (OVs). H-BiVO 4Àx obtainedt hrough thermalh ydrogenation under am ild H 2 atmosphere showed substantially enhanced electrochemical performance compared to that of pristine nanoporous BiVO 4 .…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Efficient Photoelectrochemical Water Oxidation over Hydrogen‐Reduced Nanoporous BiVO₄ with Ni–B_i Electrocatalyst

Gan

Rajeeva

et al. 2015

ChemElectroChem

View full text Add to dashboard Cite

BiVO4 is one of the most promising candidates for photoanodes in solar water splitting. However, the poor charge‐separation yield in BiVO4 has limited its photochemical activity. Here, we overcome this limitation by constructing a nanoporous morphology that effectively inhibits bulk carrier recombination as well as undergoes controlled introduction of oxygen vacancies through hydrogenation. In comparison to pristine BiVO4, hydrogen‐treated BiVO4 (H‐BiVO4−x) exhibits a superior photocurrent and electron‐hole separation yield, owing to enhanced carrier density and conductivity. In addition, we adopt a layer of nickel–borate (Ni–Bi) complex on the H‐BiVO4−x surface as an oxygen evolution catalyst to improve the water oxidation kinetics. The Ni–Bi/H‐BiVO4−x photoanode results in a large cathodic shift (350 mV) in the onset potential for water oxidation at pH 9. Moreover, the photoanodes exhibit high performance in the low‐bias regime and achieve a maximum power point of 0.82 % (photon‐to‐current efficiency) for solar water oxidation at potentials as low as 0.79 V versus RHE with a photocurrent of 2.26 mA cm−2. We attribute these improved photoelectrochemical performances to the enhanced charge separation, higher carrier density, better conductivity of H‐BiVO4−x, and the role of Ni–Bi as a hole conductor, facilitating photogenerated electron mobilization.

show abstract

Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Efficient Photoelectrochemical Water Oxidation over Hydrogen‐Reduced Nanoporous BiVO₄ with Ni–B_i Electrocatalyst

Gan

Rajeeva

et al. 2015

ChemElectroChem

View full text Add to dashboard Cite

show abstract

“…Metal oxides with nonstoichiometric oxygen are in great demand as their ionic conductivity can be improved by controlling the excess oxygen anions or vacancies. [53] Imaging of point defects by TEM is often very challenging and is not suitable to provide a quantitative measure of the point defect concentration and structure. Firstly, TEM relies on diffraction and interference effect and is therefore not very sensitive to randomly distributed point defects.…”

Section: Point Defectsmentioning

confidence: 99%

What Can Electron Microscopy Tell Us Beyond Crystal Structures?

Zhou

Greer

2016

Eur J Inorg Chem

View full text Add to dashboard Cite

Transmission electron microscopy is a powerful tool to directly image crystal structures. Not only that, it is often used to reveal crystal size and morphology, crystal orientation, crystal defects, surface structures, superstructures, etc. However, due to the 2D nature of TEM images, it is easy to make mistakes when we try to recover a 3D structure from them. Scanning electron microscopy is able to provide information on the parti-

show abstract

“…In recent years, the role of oxygen vacancies and Ti 3+ in the photocatalytic activity of TiO2 has been of great interest [35][36][37][38][39][40][41][42][43][44][45][46][47][48][49][50] . While characterisation of TiO2-based photocatalysts uses standard techniques such as UV-vis spectroscopy, valence band XPS, dye degradation insights into the dynamics of electrons and holes and defects can be obtained from Transient Absorption Spectroscopy (TAS) [51][52][53][54][55] and photoluminescence (PL) [56][57][58] .…”

Section: Figure 1: Schematic Cartoon Of the Processes Involved In Phomentioning

confidence: 99%

Design of Novel Visible Light Active Photocatalyst Materials: Surface Modified TiO₂

et al. 2016

View full text Add to dashboard Cite

Type of publicationArticle (peer-reviewed) AbstractThis progress review describes our work on the design of new TiO2 based photocatalysts. The key concept is the formation of composite structures through the modification of anatase and rutile TiO2 with molecular-sized nanoclusters of metals oxides. Our density functional theory (DFT) level simulations have been compared with experimental work synthesizing and characterizing surface modified TiO2. We use DFT to show that nanoclusters of metal oxides such as TiO2, SnO/SnO2, PbO/PbO2, ZnO and CuO are stable when adsorbed at rutile and anatase surfaces and can lead to a significant red shift in the absorption edge which will induce visible light absorption; this is the first requirement for a useful photocatalyst. We determine the origin of the red shift and the fate of excited electrons and holes. For p-block metal oxides the oxidation state of Sn and Pb can be used to modify the magnitude of the red shift and its mechanism. We describe comparisons of recent experimental studies of surface modified TiO2 that validate our DFT simulations. These nanocluster-modified TiO2 structures 2 form the basis of a new class of photocatalysts which will be useful in oxidation reactions and with a correct choice of nanocluster modified can be applied to other reactions.

show abstract

Oxygen-deficient metal oxide nanostructures for photoelectrochemical water oxidation and other applications

Cited by 359 publications

References 104 publications

Efficient Photoelectrochemical Water Oxidation over Hydrogen‐Reduced Nanoporous BiVO₄ with Ni–B_i Electrocatalyst

Efficient Photoelectrochemical Water Oxidation over Hydrogen‐Reduced Nanoporous BiVO₄ with Ni–B_i Electrocatalyst

What Can Electron Microscopy Tell Us Beyond Crystal Structures?

Design of Novel Visible Light Active Photocatalyst Materials: Surface Modified TiO₂

Contact Info

Product

Resources

About

Oxygen-deficient metal oxide nanostructures for photoelectrochemical water oxidation and other applications

Cited by 359 publications

References 104 publications

Efficient Photoelectrochemical Water Oxidation over Hydrogen‐Reduced Nanoporous BiVO4 with Ni–Bi Electrocatalyst

Efficient Photoelectrochemical Water Oxidation over Hydrogen‐Reduced Nanoporous BiVO4 with Ni–Bi Electrocatalyst

What Can Electron Microscopy Tell Us Beyond Crystal Structures?

Design of Novel Visible Light Active Photocatalyst Materials: Surface Modified TiO2

Contact Info

Product

Resources

About

Efficient Photoelectrochemical Water Oxidation over Hydrogen‐Reduced Nanoporous BiVO₄ with Ni–B_i Electrocatalyst

Efficient Photoelectrochemical Water Oxidation over Hydrogen‐Reduced Nanoporous BiVO₄ with Ni–B_i Electrocatalyst

Design of Novel Visible Light Active Photocatalyst Materials: Surface Modified TiO₂