Photoelectrochemical water oxidation over fibrous and sponge-like BiVO4/β-Bi4V2O11 photoanodes fabricated by spray pyrolysis

Santos, Wayler S. dos; Almeida, Leandro Duarte de; Afonso, André S.; Rodríguez, Mariandry; Mesquita, João Paulo de; Monteiro, D. S.; Oliveira, Luiz C.A.; Fabris, José Domingos; Pereira, Márcio C.

doi:10.1016/j.apcatb.2015.09.034

Cited by 50 publications

(12 citation statements)

References 23 publications

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“…Both BiVO 4 [40,41] and Bi 2 S 3 [22,42,43,44] display characteristics of direct transition. The light absorption properties and the band gap of the semiconductor can be determined based on UV-Vis absorption spectra (Figure 4a).…”

Section: Resultsmentioning

confidence: 99%

Synthesis of Bi2S3/BiVO4 Heterojunction with a One-Step Hydrothermal Method Based on pH Control and the Evaluation of Visible-Light Photocatalytic Performance

Zhao

Wang²,

Zong

et al. 2017

Materials

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The band gaps of bismuth vanadate (BiVO4) and bismuth sulfide (Bi2S3) are about 2.40 eV and 1.30 eV, respectively. Although both BiVO4 and Bi2S3 are capable of strong visible light absorption, electron–hole recombination occurs easily. To solve this problem, we designed a one-step hydrothermal method for synthesizing a Bismuth sulfide (Bi2S3)/Bismuth vanadate (BiVO4) heterojunction using polyvinylpyrrolidone K-30 (PVP) as a structure-directing agent, and 2-Amino-3-mercaptopropanoic acid (l-cysteine) as a sulfur source. The pH of the reaction solution was regulated to yield different products: when the pH was 7.5, only monoclinic BiVO4 was produced (sample 7.5); when the pH was 8.0 or 8.5, both Bi2S3 and BiVO4 were produced (samples 8.0 and 8.5); and when the pH was 9.0, only Bi2S3 was produced (sample 9.0). In sample 8.0, Bi2S3 and BiVO4 were closely integrated with each other, with Bi2S3 particles formed on the surface of concentric BiVO4 layers, but the two compounds grew separately in a pH solution of 8.5. Visible-light photocatalytic degradation experiments demonstrated that the degradation efficiency of the Bi2S3/BiVO4 heterojunction was highest when prepared under a pH of 8.0. The initial rhodamine B in the solution (5 mg/L) was completely degraded within three hours. Recycling experiments verified the high stability of Bi2S3/BiVO4. The synthesis method proposed in this paper is expected to enable large-scale and practical use of Bi2S3/BiVO4.

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Section: Resultsmentioning

confidence: 99%

Synthesis of Bi2S3/BiVO4 Heterojunction with a One-Step Hydrothermal Method Based on pH Control and the Evaluation of Visible-Light Photocatalytic Performance

Zhao

Wang²,

Zong

et al. 2017

Materials

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“…BiVO4 [30,31] and in particular nano-structured BiVO4 [32,33,34], are attractive photo-anode materials for photo-catalysis and water splitting applications, but the effect of Al2O3 over-layers has not been reported previously. We have recently reported a simple "one-step" approach for the formation of BiVO4 from a paint precursor applied to tin-doped indium oxide (ITO) substrates [35] and for application of BiVO4 coatings onto titanium substrates [36].…”

Section: Introductionmentioning

confidence: 99%

Enhancing activity in a nanostructured BiVO4 photoanode with a coating of microporous Al2O3

Gromboni

Coelho

Mascaro

et al. 2017

Applied Catalysis B: Environmental

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Fx1 Highlights: • Thin alumina barrier coating can enhance photo-activity of bismuth vanadate photoanode materials • There are two distinct potential domains with different enhancement characteristics and mechanisms • The thickness of alumina films can be controlled with a sol-gel coating to provide optimized performance Abstract Nanostructured semiconductor photoanodes play an important role in solar fuel generation, and the design of the semiconductor -aqueous electrolyte interface can be crucial in enhancing the energy conversion efficiency. We have investigated the effects on photoelectrochemical oxygen evolution for monoclinic nanostructured BiVO4 films uncoated and coated with microporous sol-gel Al2O3 "over-layers". Variation of the thickness of the Al2O3 coating (formed by surface sol-gel deposition and annealing at 435 o C) led to a reduction of pseudo-capacitance and allowed optimization of the quantum efficiency. Exploration of the photocurrent enhancement as a function of applied potential reveals two distinct potential domains/mechanisms: (i) a low bias region enhancement effect (assigned to a lowering of the rate of external recombination of electrons with oxygen) and (ii) a high bias region of enhancement (assigned to higher charge carrier mobility due to less trapping in surface states).

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“…In state-ofthe-arts ystems, metal oxidess uch as a-Fe 2 O 3 , [3] WO 3 , [4] and BiVO 4 [5] have been reported as promising n-type photoanodes for the oxygen evolution half-reaction( OER), whereas the ptype metal oxides CuO [6] and Cu 2 O [7] have been extensively studied as photocathode for the hydrogen evolution half-reaction (HER). In state-ofthe-arts ystems, metal oxidess uch as a-Fe 2 O 3 , [3] WO 3 , [4] and BiVO 4 [5] have been reported as promising n-type photoanodes for the oxygen evolution half-reaction( OER), whereas the ptype metal oxides CuO [6] and Cu 2 O [7] have been extensively studied as photocathode for the hydrogen evolution half-reaction (HER).…”

Section: Introductionmentioning

confidence: 99%

“…In ad ual-absorber p/n PEC cell, the photogenerated minority holes in the n-type photoanode oxidizew ater to O 2 while the minority electrons in the p-type photocathode migrate to the photoelectrode/aqueous solution interface to reduce H + ions to H 2 .T hus, to oxidize water the valenceb and edge potentialo ft he photoanodem ust be sufficiently positive (higher than the O 2 /H 2 Or edox potential), whereas the conduction band edge of the photocathode must be more negative than that of the H + /H 2 redox pair for the overall water splitting to occur.T he majority of electrons and holes recombine at the ohmic contacts that connectt he photoelectrodes. In state-ofthe-arts ystems, metal oxidess uch as a-Fe 2 O 3 , [3] WO 3 , [4] and BiVO 4 [5] have been reported as promising n-type photoanodes for the oxygen evolution half-reaction( OER), whereas the ptype metal oxides CuO [6] and Cu 2 O [7] have been extensively studied as photocathode for the hydrogen evolution half-reaction (HER). The abundance of those chemical elements in the Earth's crust, the band-gap energies in the visible range of the spectrum,a nd the proper energy levelso ft he valence and conduction bands make theseo xidesa ttractive to be combined in p/n PEC cells for stand-alone water splitting.…”

Section: Introductionmentioning

confidence: 99%

Bismuth Vanadate Photoelectrodes with High Photovoltage as Photoanode and Photocathode in Photoelectrochemical Cells for Water Splitting

et al. 2018

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Using dual-photoelectrode photoelectrochemical (PEC) devices based on earth-abundant metal oxides for unbiased water splitting is an attractive means of producing green H fuel, but is challenging, owing to low photovoltages generated by PEC cells. This problem can be solved by coupling n-type BiVO with n-type Bi V O to create a virtual p/n junction due to the formation of a hole-inversion layer at the semiconductor interface. Thus, photoelectrodes with high photovoltage outputs were synthesized. The photoelectrodes exhibited features of p- and n-type semiconductors when illuminated under an applied bias, suggesting their use as photoanode and photocathode in a dual-photoelectrode PEC cell. This concept was proved by connecting a 1 mol % W-doped BiVO /Bi V O photoanode with an undoped BiVO /Bi V O photocathode, which produced a high photovoltage of 1.54 V, sufficient to drive stand-alone water splitting with 0.95 % efficiency.

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Photoelectrochemical water oxidation over fibrous and sponge-like BiVO4/β-Bi4V2O11 photoanodes fabricated by spray pyrolysis

Cited by 50 publications

References 23 publications

Synthesis of Bi2S3/BiVO4 Heterojunction with a One-Step Hydrothermal Method Based on pH Control and the Evaluation of Visible-Light Photocatalytic Performance

Synthesis of Bi2S3/BiVO4 Heterojunction with a One-Step Hydrothermal Method Based on pH Control and the Evaluation of Visible-Light Photocatalytic Performance

Enhancing activity in a nanostructured BiVO4 photoanode with a coating of microporous Al2O3

Bismuth Vanadate Photoelectrodes with High Photovoltage as Photoanode and Photocathode in Photoelectrochemical Cells for Water Splitting

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