Charge separation at BiVO4/Co3O4 and BiVO4/CoOOH interfaces: Differences between dense and permeable cocatalysts

Li, Shuo; Li, Yahui; Zhang, Juan; Liu, Xiutao; Zhang, Kaixin; Song, Xi‐Ming

doi:10.1016/j.apsusc.2023.156965

Cited by 6 publications

(3 citation statements)

References 41 publications

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“…OEC not only plays important roles that traps and stores photogenerated holes but also acts as catalytic active sites for the OER. In this field, many transition metal (Ni, Co, and Fe)-based phosphate complexes, (oxy) hydroxides, and layered double hydroxides have been extensively explored. − For example, cobalt (oxy)hydroxide (CoOOH) exhibits outstanding PEC OER activity in the systems like CoOOH/TiO 2 , CoOOH/P:Fe 2 O 3 , CoOOH/BiVO 4 , and CoOOH/Ta 3 N 5 . − Especially, our previous studies indicated that CoOOH is inclined to promote holes transfer/trapping, thus increase the effective charge separation . However, the PEC performance of the α-Fe 2 O 3 -based photoelectrode still requires further promotion to meet the practical application.…”

Section: Introductionmentioning

confidence: 99%

Rational Design of CoOOH/α-Fe₂O₃/SnO₂ for Boosted Photoelectrochemical Water Oxidation: The Roles of Underneath SnO₂ and Surface CoOOH

Zheng,

Wang,

Zhu

et al. 2024

Inorg. Chem.

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Hematite (α-Fe 2 O 3 ) photoanode is a promising candidate for efficient PEC solar energy conversion. However, the serious charge recombination together with the sluggish water oxidation kinetics of α-Fe 2 O 3 still restricts its practical application in renewable energy systems. In this work, a CoOOH/α-Fe 2 O 3 /SnO 2 photoanode was fabricated, in which the ultrathin SnO 2 underlayer is deposited on the fluorine-doped tin oxide (FTO) substrate, α-Fe 2 O 3 nanorod array is the absorber layer, and CoOOH nanosheet is the surface modifier, respectively. The resulting CoOOH/α-Fe 2 O 3 /SnO 2 exhibited excellent PEC water splitting with a high photocurrent density of 2.05 mA cm −2 at 1.23 V vs RHE in the alkaline electrolyte, which is ca. 3.25 times that of bare α-Fe 2 O 3 . PEC characterizations demonstrated that SnO 2 not only could block hole transport from α-Fe 2 O 3 to FTO substrate but also could efficiently enhance the light-harvesting property and reduce the surface states by controlling the growth process of α-Fe 2 O 3 , while the CoOOH overlayer as cocatalysts could rapidly extract the photogenerated holes and provide catalytic active sites for water oxidation. Benefiting from the synergistic effects of SnO 2 and CoOOH, the efficiency of the charge recombination and the overpotential for water oxidation of α-Fe 2 O 3 are obviously decreased, resulting in the boosted PEC efficiency for water oxidation. The rational design and simple fabrication strategy display great potentials to be used for other PEC systems with excellent efficiency.

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Section: Introductionmentioning

confidence: 99%

Rational Design of CoOOH/α-Fe₂O₃/SnO₂ for Boosted Photoelectrochemical Water Oxidation: The Roles of Underneath SnO₂ and Surface CoOOH

Zheng,

Wang,

Zhu

et al. 2024

Inorg. Chem.

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“…Although elemental doping can improve the conductivity of the photoanode and promote its charge separation, it is difficult to improve the water oxidation kinetics of BiVO 4 . Accordingly, it is essential to load cocatalysts on the BiVO 4 surface to improve its water oxidation kinetics and enhance oxygen evolution reaction performance. , Co-based cocatalysts are widely used to improve the oxygen evolution kinetics of BiVO 4 because they can extract photogenerated holes, reduce the overpotential, and improve the active site. − Common Co-based cocatalysts include Co 3 O 4 , − CoOOH, ,− Co-MOF, − CoPi, etc. Huang et al developed a composite photoanode of CoO x /BiVO 4 through simple impregnation and calcination, creating a p–n heterojunction to enhance carrier separation efficiency and improve the water oxidation kinetics of BiVO 4 .…”

Section: Introductionmentioning

confidence: 99%

Synergy Effect of the Enhanced Local Electric Field and Built-In Electric Field of CoS/Mo-Doped BiVO₄ for Photoelectrochemical Water Oxidation

Guan,

Gu,

Deng

et al. 2023

Inorg. Chem.

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Bismuth vanadate is a promising material for photoelectrochemical water oxidation. However, it suffers from a low quantum efficiency, poor stability, and slow water oxidation kinetics. Here, we developed a novel photoanode of CoS/Mo-BiVO 4 with excellent photoelectrochemical water oxidation performance. It achieved a photocurrent density of 4.5 mA cm −2 at 1.23 V versus the reversible hydrogen electrode, ∼4 times that of BiVO 4 . The CoS/Mo-BiVO 4 photoanode also exhibited good stability, and the photocurrent density generated by the CoS/Mo-BiVO 4 photoanode did not significantly decrease after light irradiation for 2 h. Upon replacement of part of the V with Mo doping in BiVO 4 , the local electric field around the Mo−O bond was enhanced, thus promoting carrier separation in BiVO 4 . The CoS was deposited on the surface of Mo-BiVO 4 , forming a built-in electric field at the interface. Under the action of the bias electric field and the built-in electric field, the carriers of CoS/Mo-BiVO 4 were efficiently separated in the direction of the inverse type II heterojunction. In addition, CoS improved the light absorption and charge injection efficiency of the CoS/Mo-BiVO 4 photoanode.

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“…Cocatalysts aim to reduce the band gap of the formed composite, improving the optical response of the photocatalytic material and suppressing the recombination rate of photogenerated charges by sinking photogenerated charges (i.e., holes and/or electrons), and, in turn, maximizing the surface population of charge carriers on the newly formed composite photocatalyst [17,[19][20][21]. In photodeposition, the procedure utilizes the photogenerated charges formed by the photocatalyst itself.…”

Section: Introductionmentioning

confidence: 99%

Enhancing the Photocatalytic Performance of BiVO4 for Micropollutant Degradation by Fe and Ag Photomodification

Popović,

Sharifi,

Kraljić Roković

et al. 2023

Processes

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Wider application of BiVO4 (BVO) for photocatalytic water treatment is primarily limited by its modest photocatalytic effectiveness, despite its appropriately narrow band gap for low-cost, sunlight-facilitated water treatment processes. In this study, we have photomodified an isotype BVO, consisting of a tetragonal zircon and monoclinic scheelite phase, with Fe (Fe@BVO) and Ag (Ag@BVO) ionic precursors under UV illumination in an aqueous ethanol solution in order to assess their effect on the opto-electronic properties and effectiveness for the removal of ciprofloxacin (CIP). Fe@BVO failed to demonstrate enhanced effectiveness over pristine BVO, whereas all Ag@BVO achieved improved CIP degradation, especially 1% Ag@BVO. At pH 4 and 6, 1% Ag@BVO demonstrated nearly 24% greater removal of CIP than BVO alone. Photomodification with Fe created surface oxygen vacancies, as confirmed by XPS and Mott–Schottky analysis, which facilitated improved electron mobility, although no distinct Fe-containing phase nor Fe-doping was detected. On the other hand, the introduction of mid-band gap states by oxygen vacancies decreased the reducing power of the photogenerated electrons as the flat band potentials were shifted to more positive values, thus likely negatively impacting superoxide formation. In contrast, Ag-photomodification (Ag@BVO) resulted in the formation of Ag2O/AgO and Ag nanoparticles on the surface of BVO, which, under illumination, generated hot electrons by surface plasmon resonance and enhanced the mobility of photogenerated electrons. Our research underscores the pivotal role of photogenerated electrons for CIP degradation by BiVO4-based materials and emphasizes the importance of appropriate band-edge engineering for optimizing contaminant degradation.

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Charge separation at BiVO4/Co3O4 and BiVO4/CoOOH interfaces: Differences between dense and permeable cocatalysts

Cited by 6 publications

References 41 publications

Rational Design of CoOOH/α-Fe₂O₃/SnO₂ for Boosted Photoelectrochemical Water Oxidation: The Roles of Underneath SnO₂ and Surface CoOOH

Rational Design of CoOOH/α-Fe₂O₃/SnO₂ for Boosted Photoelectrochemical Water Oxidation: The Roles of Underneath SnO₂ and Surface CoOOH

Synergy Effect of the Enhanced Local Electric Field and Built-In Electric Field of CoS/Mo-Doped BiVO₄ for Photoelectrochemical Water Oxidation

Enhancing the Photocatalytic Performance of BiVO4 for Micropollutant Degradation by Fe and Ag Photomodification

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Charge separation at BiVO4/Co3O4 and BiVO4/CoOOH interfaces: Differences between dense and permeable cocatalysts

Cited by 6 publications

References 41 publications

Rational Design of CoOOH/α-Fe2O3/SnO2 for Boosted Photoelectrochemical Water Oxidation: The Roles of Underneath SnO2 and Surface CoOOH

Rational Design of CoOOH/α-Fe2O3/SnO2 for Boosted Photoelectrochemical Water Oxidation: The Roles of Underneath SnO2 and Surface CoOOH

Synergy Effect of the Enhanced Local Electric Field and Built-In Electric Field of CoS/Mo-Doped BiVO4 for Photoelectrochemical Water Oxidation

Enhancing the Photocatalytic Performance of BiVO4 for Micropollutant Degradation by Fe and Ag Photomodification

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Rational Design of CoOOH/α-Fe₂O₃/SnO₂ for Boosted Photoelectrochemical Water Oxidation: The Roles of Underneath SnO₂ and Surface CoOOH

Rational Design of CoOOH/α-Fe₂O₃/SnO₂ for Boosted Photoelectrochemical Water Oxidation: The Roles of Underneath SnO₂ and Surface CoOOH

Synergy Effect of the Enhanced Local Electric Field and Built-In Electric Field of CoS/Mo-Doped BiVO₄ for Photoelectrochemical Water Oxidation