Structural, electronic and optical features of molybdenum-doped bismuth vanadium oxide

Merupo, Victor Ishrayelu; Velumani, S.; Oza, Goldie; Makowska‐Janusik, M.; Kassiba, A.

doi:10.1016/j.mssp.2014.12.057

Cited by 56 publications

(29 citation statements)

References 32 publications

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“…The peak shifts to lower wavenumber and broadens with either Mo or Gd alloying, as has been observed previously. 44,50 The peak shift is even more pronounced with Mo and Gd co-alloying. This shift may be indicative of a lowered V-O bond length, which is the interpretation used for Mo +6 and W +6 substitution onto the V +5 site, 15 but our observed shifting of this peak does not directly correlate with Mo concentration, for example along the Mo-Gd co-alloying lines the peak continues to shift downward as the concentration of Mo decreases, indicating a different cause for the alteration of this vibrational mode.…”

Section: Optical and Structural Trendsmentioning

confidence: 97%

Combinatorial alloying improves bismuth vanadate photoanodes via reduced monoclinic distortion

Newhouse

Guevarra

Umehara

et al. 2018

Energy Environ. Sci.

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Improving the efficiency of solar-power oxygen evolution is both critical for development of solar fuels technologies and challenging due to the broad set of properties required of a solar fuels photoanode. Bismuth vanadate, in particular the monoclinic clinobisvanite phase, has received substantial attention and has exhibited the highest radiative efficiency among metal oxides with a band gap in the visible range. Efforts to further improve its photoelectrochemical performance have included alloying one or more metals onto the Bi and/or V sites, with progress on this frontier stymied by the difficulty in computational modelling of substitutional alloys and the high dimensionality of co-alloying composition spaces. Since substituional alloying simultaneously changes multiple materials properties, understanding the underlying cause for performance improvements is also challenging, motivating our application of combinatorial materials science techniques to map photoelectrochemical performance of 948 unique bismuth vanadate alloy compositions comprising 0 to 8% alloys of P, Ca, Mo, Eu, Gd, and W along with a variety of compositions from each pairwise combination of these elements. Upon identification of substantial improvements in the (Mo,Gd) co-alloying space, structural mapping was performed to reveal a remarkable correlation between performance and a lowered monoclinic distortion. First-principles density functional theory calculations indicate that the improvements are due to a lowered hole effective mass and hole polaron formation energy, and collectively, our results identify the monoclinic distortion as a critical parameter in the optimization and understanding of bismuth vanadate-based photoanodes. IntroductionThe production of fuels via photoelectrochemistry (PEC) has been recognized as a promising method for capturing and storing intermittent solar energy, in particular as renewable transportation fuels. 1 Regardless of the fuel to be generated, the oxygen evolution reaction at the photoanode is critical; hence development of stable, efficient, n-type semiconductors composed of earth abundant elements and producible by scalable, cost-effective methods has received increasing research attention. [2][3][4] Bismuth vanadate, BiVO4, in particular has become the oxide semiconductor serving as the platform to develop and demonstrate a toolkit of techniques for improving and understanding the fundamental properties and photoelectrochemical performance of novel oxide-based semiconductors, despite its non-optimal bandgap. 2,5 As recently reviewed, the methods of improving the properties include heterojunction formation, alloying or doping, hydrogen or nitrogen annealing, nanostructuring to enhance charge collection, microstructuring for photon management, and surface coating to passivate surface defects and enhance catalysis. 3,4,[6][7][8][9] The highest performing BVO-based photoanodes reported to date have all incorporated several of these strategies in order to produce photocurrent densities in the range of app...

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Section: Optical and Structural Trendsmentioning

confidence: 97%

Combinatorial alloying improves bismuth vanadate photoanodes via reduced monoclinic distortion

Newhouse

Guevarra

Umehara

et al. 2018

Energy Environ. Sci.

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“…However, despite its promising characteristics as photoabsorber material, BiVO 4 has limitations which yet have to be overcome for an efficient PEC device. Several studies demonstrated that utilising W or Mo as dopants significantly enhance the PEC performance of n‐type BiVO 4 photoanodes . This effect is due to improvement of the electronic conductivity of the base material upon addition of transition metals as dopants resulting in an enhancement of charge carriers separation which decreases the probability of its recombination in bulk .…”

Section: Introductionmentioning

confidence: 99%

“…Several studies demonstrated that utilising W or Mo as dopants significantly enhance the PEC performance of n‐type BiVO 4 photoanodes . This effect is due to improvement of the electronic conductivity of the base material upon addition of transition metals as dopants resulting in an enhancement of charge carriers separation which decreases the probability of its recombination in bulk . Modification of the BiVO 4 ‐electrolyte junction by means of oxygen evolution catalysts (OEC) diminishes efficiency losses associated with surface recombination and improves the activity towards the OER under illumination.…”

Section: Introductionmentioning

confidence: 99%

Tuning Light‐Driven Water Splitting Efficiency of Mo‐Doped BiVO₄: Optimised Preparation and Impact of Oxygen Evolution Electrocatalysts

et al. 2019

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We present airbrush spray-coating as a reproducible method for the preparation of Mo-doped BiVO 4 (Mo : BiVO 4 ) as photoabsorber with different layer thicknesses and Mo content. Optimisation of layer thickness is aiming on diminishing limitations by the electronic conductivity within the photoabsorber, thus increasing the incident photon to current efficiency (IPCE) of the samples. Furthermore, the Mo to V ratio leading to the highest photocurrent density was determined, and the optimised Mo : BiVO 4 samples were decorated with a variety of oxygen evolution reaction (OER) electrocatalysts such as cobalt phosphate and layered double hydroxides. A mass loading gradient of NiÀ Fe LDH was sprayed on top of the Mo : BiVO 4 photoanode for optimisation of the OER catalyst loading. The photocurrent density was enhanced by up to 5.8 times at 0.8 V vs. RHE in comparison with the pristine Mo : BiVO 4 sample in absence of any OER electrocatalyst.[a] J.

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“…Meanwhile, Bi 25 VO 40 presents a higher activity than that prepared by calcination method, 16 probably due to its narrower band gap than the latter (2.61 eV). Noteworthily, though having weaker light adsorption ability in 450-800 nm and wider band gap energy, BiVO 4 shows the optimal photodegradation rate [97.3%, Fig. 5(a)], which may be ascribed to its larger specific surface area (52.4 m 2 /g) than that of Bi 25 VO 40 (19.8 m 2 /g).…”

Section: Methodsmentioning

confidence: 99%

Composition‐Controlled Synthesis of Bismuth Vanadate Photocatalysts via a Facile Electrochemical Method

Qian

et al. 2016

J. Am. Ceram. Soc.

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Bismuth vanadate compounds including BiVO4, Bi25VO40, and the composite Bi25VO40/Bi7V11O9 with photocatalytic properties were firstly synthesized via a facile electrochemical strategy. The amount of NaOH in the electrolyte and electric currents were discovered to be crucial variables to the composition, morphology, and crystallinity of the products. Monoclinic phase BiVO4 and Bi25VO40 with sillenite structure can be obtained at 2 A with NaOH concentration of 0–10−4 and 0.1–0.4M, respectively. The acquirement of Bi25VO40/Bi7V11O9 can be achieved with electric current 3–5 A in an electrolyte containing 0.4M NaOH. All the electrosynthesized samples exhibit good visible‐light‐driven photocatalytic activity in the degradation of rhodamine B, much higher than that of the commercial TiO2 (P25).

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Structural, electronic and optical features of molybdenum-doped bismuth vanadium oxide

Cited by 56 publications

References 32 publications

Combinatorial alloying improves bismuth vanadate photoanodes via reduced monoclinic distortion

Combinatorial alloying improves bismuth vanadate photoanodes via reduced monoclinic distortion

Tuning Light‐Driven Water Splitting Efficiency of Mo‐Doped BiVO₄: Optimised Preparation and Impact of Oxygen Evolution Electrocatalysts

Composition‐Controlled Synthesis of Bismuth Vanadate Photocatalysts via a Facile Electrochemical Method

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Structural, electronic and optical features of molybdenum-doped bismuth vanadium oxide

Cited by 56 publications

References 32 publications

Combinatorial alloying improves bismuth vanadate photoanodes via reduced monoclinic distortion

Combinatorial alloying improves bismuth vanadate photoanodes via reduced monoclinic distortion

Tuning Light‐Driven Water Splitting Efficiency of Mo‐Doped BiVO4: Optimised Preparation and Impact of Oxygen Evolution Electrocatalysts

Composition‐Controlled Synthesis of Bismuth Vanadate Photocatalysts via a Facile Electrochemical Method

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Tuning Light‐Driven Water Splitting Efficiency of Mo‐Doped BiVO₄: Optimised Preparation and Impact of Oxygen Evolution Electrocatalysts