Au-doped BiVO4 nanostructure-based photoanode with enhanced photoelectrochemical solar water splitting and electrochemical energy storage ability

Reddy, Ch. Venkata; Reddy, I. Neelakanta; Koutavarapu, Ravindranadh; Reddy, Kakarla Raghava; Shim, Jaesool; Bai, Cheolho

doi:10.1016/j.apsusc.2021.149030

Cited by 38 publications

(25 citation statements)

References 48 publications

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“…This is due to the strong electron‐withdrawing ability of Au and the formation of Fe 3 O 4 . [ 4b,17a,32a,37 ]…”

Section: Resultsmentioning

confidence: 99%

“…This indicates that the existence of Fe 3 O 4 and Au has a significant impact on the electronic structure of CoFe‐LDH, and such alteration can improve electrocatalytic activity. [ 4b,37a,38 ] In addition, the atomic percentage calculated from XPS indicates the content of Au in Fe 3 O 4 /Au/CoFe‐LDH‐600 is 1.9 at% (Table S2, Supporting Information).…”

Section: Resultsmentioning

confidence: 99%

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Bi‐Functional Fe₃O₄/Au/CoFe‐LDH Sandwich‐Structured Electrocatalyst for Asymmetrical Electrolyzer with Low Operation Voltage

Sun

Zhou

You

et al. 2021

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The reduction of the overall electrolysis potential to produce hydrogen is a critical target for fabricating applicable hydrogen evolution cells. Sandwich‐structured Fe3O4/Au/CoFe‐LDH is synthesized via a spontaneous galvanic displacement reaction. A series of structural characterizations indicate the successful synthesis of sandwich‐structured Fe3O4/Au/CoFe‐LDH electrocatalyst. The trace amount of Au laying between Fe3O4 and CoFe‐LDH significantly improves the intrinsic conductivity and catalytic activity of the composite catalyst. In‐depth investigations indicate that Fe3O4 and CoFe‐LDH are responsible for the electrocatalytic hydrogen evolution reaction (HER) whereas Au is responsible for the electrocatalytic glucose oxidation (GOR). The electrocatalytic tests indicate Fe3O4/Au/CoFe‐LDH offers excellent electrocatalytic activity and stability for both HER and GOR, even at high current density (i.e., 1000 mA cm−2). Further electrochemistry examinations in a two‐compartment cell with a two‐electrode configuration show that Fe3O4/Au/CoFe‐LDH can significantly reduce the overall potential for this asymmetrical cell, with only 0.48 and 0.89 V required to achieve 10 mA cm−2 current density with and without iR‐compensation, which is the lowest overall potential requirement ever reported. The design and synthesis of Fe3O4/Au/CoFe‐LDH pave a new way to electrochemically produce hydrogen and gluconate under extremely low cell voltage, which can readily match with a variety of solar cells.

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“…This is due to the strong electron‐withdrawing ability of Au and the formation of Fe 3 O 4 . [ 4b,17a,32a,37 ]…”

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Bi‐Functional Fe₃O₄/Au/CoFe‐LDH Sandwich‐Structured Electrocatalyst for Asymmetrical Electrolyzer with Low Operation Voltage

Sun

Zhou

You

et al. 2021

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“…Under AM1.5 illumination (100 mW/cm 2 ), its theoretical photocurrent density ( J ph ) is 7.5 mA/cm 2 , which corresponds to a solar-to-hydrogen (STH) conversion efficiency of 9.2% . However, the onset potential ( V on ) and platform photocurrent of BVO are limited by factors such as high surface recombination rate, poor conductivity, and slow water oxidation kinetics. , To solve these problems, several strategies have been developed and investigated, such as heteroatomic doping to improve the conductivity, construction of heterojunctions to promote charge separation, morphology regulation, decoration with a noble metal or semimetal, , and cocatalyst modification. , …”

Section: Introductionmentioning

confidence: 99%

“…7 However, the onset potential (V on ) and platform photocurrent of BVO are limited by factors such as high surface recombination rate, poor conductivity, and slow water oxidation kinetics. 8,9 To solve these problems, several strategies have been developed and investigated, such as heteroatomic doping to improve the conductivity, 10 construction of heterojunctions to promote charge separation, 11 morphology regulation, 12 decoration with a noble metal or semimetal, 13,14 and cocatalyst modification. 15,16 Doping with metal and nonmetal elements, such as Mo, W, In, N, B, and S, has been widely used to ameliorate the PEC performance of BVO.…”

Section: ■ Introductionmentioning

confidence: 99%

Defective Metal–Organic Framework Assisted with Nitrogen Doping Enhances the Photoelectrochemical Performance of BiVO₄

Wang

Chen

et al. 2021

ACS Appl. Energy Mater.

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BiVO4 is a promising n-type semiconductor for photoelectrochemical (PEC) water splitting, which can serve as a photoanode. However, severe surface recombination and slow water oxidation kinetics hinder the realization of its highly theoretical PEC performance. Single-atom catalyst-like metal–organic frameworks (MOFs) and their derived metal oxides have been broadly investigated to enhance the kinetics of BiVO4 photoanodes. According to the principle of catalysis, only coordinatively unsaturated atoms can participate in the catalytic reaction. Herein, a defective cobalt-based MOF (d-CoMOF) with missing linker defects is modified onto the surface of N-doped BiVO4 (N:BVO) photoanodes. The photocurrent density of d-CoMOF/N:BVO is 3.59 times higher than that of pristine BVO (0.56 mA/cm2) at 1.23 VRHE. The onset potential of d-CoMOF/N:BVO shows a cathodic shift of 300 mV relative to BVO. The roles of the d-CoMOF overlayer and N doping are experimentally revealed. The d-CoMOF modification and N doping could increase the electron density, passivate the surface states, and promote the catalysis kinetics of BVO. Thus, the kinetic parameters, such as the charge separation/injection efficiency, onset potential, and photocurrent density, are significantly enhanced. This work provides a way to use MOFs for PEC water splitting by the introduction of defects.

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“…The above-mentioned charge transfer processes at the electrode/electrolyte interface in PEC water splitting occur in the subnanosecond time regime, which are difficult to characterize with conventional experimental methods such as cyclic voltammetry (CV). Up to now, several advanced methods have been proposed for exploring these processes in the PEC system, including scanning electrochemical microscopy (SECM), , transient absorption spectroscopy (TAS), ,− transient photocurrent spectroscopy (TPC), ,,, and electrochemical impedance spectroscopy (EIS). ,,, Using these methods, some important parameters such as the dynamics of photogenerated carriers and diffusion length can be obtained. However, compared with the other three spectroscopic techniques, SECM, as an in situ monitoring tool, has obvious advantages in studying the reaction kinetics of ultrafast reactions due to its simple operation and high spatial and temporal resolution. , …”

Section: Introductionmentioning

confidence: 99%

Effect of a Cocatalyst on a Photoanode in Water Splitting: A Study of Scanning Electrochemical Microscopy

et al. 2021

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With a proper band gap of ∼2.4 eV for solar light absorption and suitable valence band edge position for oxygen evolution, scheelite-monoclinic bismuth vanadate (BiVO 4 ) has become one of the most attractive photocatalysts for efficient visible-light-driven photoelectrochemical (PEC) water splitting. Several studies have indicated that surface modification of BiVO 4 with a cocatalyst such as NiFe layered double hydroxide (LDH) can significantly increase the PEC water splitting performance of the catalyst. Herein, we experimentally investigated the charge transfer dynamics and charge carrier recombination processes by scanning electrochemical microscopy (SECM) with the feedback mode on the surface of BiVO 4 and BiVO 4 /NiFe-LDH as model samples. The ratio of rate constants for photogenerated hole (k h+ 0 ) to electron (k e− 0 ) via the photocatalyst of BiVO 4 /NiFe-LDH reacting with the redox couple is found to be five times larger than that of BiVO 4 under illumination. In this case, the ratio of the rate constants k h+ 0 /k e− 0 stands for the interfacial charge recombination process. This implies the cocatalyst NiFe-LDH suppresses the electron back transfer greatly and finally reduces the surface recombination. Control experiments with cocatalysts CoPi and RuO x onto BiVO 4 further verify this conclusion. Therefore, the SECM characterization allows us to make an overall analysis on the function of cocatalysts in the PEC water splitting system.

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Au-doped BiVO4 nanostructure-based photoanode with enhanced photoelectrochemical solar water splitting and electrochemical energy storage ability

Cited by 38 publications

References 48 publications

Bi‐Functional Fe₃O₄/Au/CoFe‐LDH Sandwich‐Structured Electrocatalyst for Asymmetrical Electrolyzer with Low Operation Voltage

Bi‐Functional Fe₃O₄/Au/CoFe‐LDH Sandwich‐Structured Electrocatalyst for Asymmetrical Electrolyzer with Low Operation Voltage

Defective Metal–Organic Framework Assisted with Nitrogen Doping Enhances the Photoelectrochemical Performance of BiVO₄

Effect of a Cocatalyst on a Photoanode in Water Splitting: A Study of Scanning Electrochemical Microscopy

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Au-doped BiVO4 nanostructure-based photoanode with enhanced photoelectrochemical solar water splitting and electrochemical energy storage ability

Cited by 38 publications

References 48 publications

Bi‐Functional Fe3O4/Au/CoFe‐LDH Sandwich‐Structured Electrocatalyst for Asymmetrical Electrolyzer with Low Operation Voltage

Bi‐Functional Fe3O4/Au/CoFe‐LDH Sandwich‐Structured Electrocatalyst for Asymmetrical Electrolyzer with Low Operation Voltage

Defective Metal–Organic Framework Assisted with Nitrogen Doping Enhances the Photoelectrochemical Performance of BiVO4

Effect of a Cocatalyst on a Photoanode in Water Splitting: A Study of Scanning Electrochemical Microscopy

Contact Info

Product

Resources

About

Bi‐Functional Fe₃O₄/Au/CoFe‐LDH Sandwich‐Structured Electrocatalyst for Asymmetrical Electrolyzer with Low Operation Voltage

Bi‐Functional Fe₃O₄/Au/CoFe‐LDH Sandwich‐Structured Electrocatalyst for Asymmetrical Electrolyzer with Low Operation Voltage

Defective Metal–Organic Framework Assisted with Nitrogen Doping Enhances the Photoelectrochemical Performance of BiVO₄