Oxygen vacancies and p-n heterojunction modified BiOBr for enhancing donor density and separation efficiency under visible-light irradiation

Wang, Zhiqiang; Wang, Hui; Wu, Xiang-Feng; Chang, Tian-Long

doi:10.1016/j.jallcom.2020.155025

Cited by 32 publications

(7 citation statements)

References 48 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…BiOM (M = Cl, Br, I) present extraordinary photocatalytic properties among many semiconductor photocatalysts. They attract many studies because of their particular layered crystal structure (tetragonal) and the built-in electric field. − However, as photocatalysts, pure BiOCl and BiOBr have a large bandgap and almost cannot absorb the visible light; BiOI has a moderate bandgap, but the visible light absorption is still very limited. , In addition, all BiOM have a high recombination rate for the photogenerated electrons and holes . Therefore, many methods were applied to decrease the recombination of the electron–hole pairs and enhance the absorption of visible light further to improve their activities. ,, Defect engineering and constructing heterojunctions are two popular and promising methods for enhancing the activity of BiOM.…”

Section: Introductionmentioning

confidence: 99%

“…They attract many studies because of their particular layered crystal structure (tetragonal) and the built-in electric field. − However, as photocatalysts, pure BiOCl and BiOBr have a large bandgap and almost cannot absorb the visible light; BiOI has a moderate bandgap, but the visible light absorption is still very limited. , In addition, all BiOM have a high recombination rate for the photogenerated electrons and holes . Therefore, many methods were applied to decrease the recombination of the electron–hole pairs and enhance the absorption of visible light further to improve their activities. ,, Defect engineering and constructing heterojunctions are two popular and promising methods for enhancing the activity of BiOM. For constructing a heterojunction, lots of experimental studies, such as BiOCl/BiOI, BiOCl/WO 3, BiOCl/Bi 2 O 3, BiOCl/Bi 2 S 3, BiOCl/Fe 2 O 3, BiOCl/Sn 3 O 4, BiOBr/Bi 2 O 3, , BiOI/Bi 2 O 3, BiOI/C 3 N 4 , and so on, have been carried out until now.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Novel Z-Scheme BiOM_1–xI_x (M = Cl, Br)/β-Bi₂O₃-(001) and BiOI/β-Bi₂O₃-(001) Heterojunction Photocatalysts with O Vacancies: A Study on the Hybrid Density Functional Approach

et al. 2022

View full text Add to dashboard Cite

In this paper, the heterostructures between the BiOM (M = Cl, Br, I) (001) and the β-Bi2O3 (001) crystal facet, denoted as BiOM/β-Bi2O3, are reasonably constructed. The hybrid density functional approach investigates their electronic structures, optical absorption, band alignments, and photocatalytic activities. It is found that I-doped BiOM (M = Cl, Br) can make the type I heterostructures BiOM (M = Cl, Br)/β-Bi2O3 change to the direct Z-scheme with increasing I doping concentration. Under a higher I doping concentration, the BiOCl1–x I x /β-Bi2O3 has a stronger reduction potential than the BiOBr1–x I x /β-Bi2O3. Significantly, the BiOI/β-Bi2O3 is the direct Z-scheme heterojunction. Combining the direct Z-scheme heterostructure characters of BiOM1–x I x (M = Cl, Br)/β-Bi2O3 and BiOI/β-Bi2O3 with appropriate band alignments, their electrons and holes can be excited and separated highly effectively. The BiOM1–x I x (M = Cl, Br) or BiOI part has a higher reduction ability, gathers electrons, and works as the reduction catalyst. In contrast, the β-Bi2O3 part has a higher oxidation ability, gathers holes, and works as the oxidation catalyst. Remarkably, the O vacancy in bismuth oxyhalides can further improve the direct Z-scheme alignment structure, accelerate the separation and migration of the photogenerated electron–hole pairs, and also enormously intensify the visible light absorption. The synergistic effect of the direct Z-scheme band alignment character and O vacancy makes the BiOCl28/32I4/32(VO)/β-Bi2O3 and BiOI (VO)/β-Bi2O3 present superior photocatalytic activities. The calculated results can provide insights into the designs and preparations of the visible light response BiOM (M = Cl, Br, I)-based semiconductor photocatalysts.

show abstract

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Novel Z-Scheme BiOM_1–xI_x (M = Cl, Br)/β-Bi₂O₃-(001) and BiOI/β-Bi₂O₃-(001) Heterojunction Photocatalysts with O Vacancies: A Study on the Hybrid Density Functional Approach

et al. 2022

View full text Add to dashboard Cite

show abstract

“…Evidently, these recorded UV-vis absorption spectra exhibit similar profiles with an admirable absorption edge at approximately 500 nm which arises from the O 2− /Br − → Bi 3+ charge transfer transitions. As is known, through implementing the function of αhv = A(hv − E g ) n (herein, hv denotes the energy, α refers to absorption coefficient, A is regarded as constant and n value is related to the category of semiconductor), [49,50] the E g value of semiconductor can be evaluated. Herein, the n value for BiOBr particles is 2 since it is ascribed to indirect semiconductor.…”

Section: Resultsmentioning

confidence: 99%

Tailoring of Visible Light Driven Photocatalytic Activities of Flower‐Like BiOBr Microparticles Towards Wastewater Purification Application

Wang

Duan

et al. 2021

Adv Materials Inter

View full text Add to dashboard Cite

compounds based on semiconductors, such as TiO 2 , MoO 3 , ZnO, WO 3 , etc., [7][8][9][10] have been synthesized. Note that, the energy band gaps (E g ) of these aforementioned semiconductors are relatively large (i.e., E g > 3 eV) which makes them can only be excited by ultraviolet light. As is known, the ultraviolet light occupies only around 5% energy of sunlight and the residual energy is taken up by other lights, in which visible light takes up 45% and near-infrared light occupies 50%. [11,12] In view of the fact that these above photocatalytic materials are not able to efficiently harvest the sunlight, it is urgent to search for novel semiconductors that can utilize the sunlight more efficiently. To better harvest the sunlight, researchers tried to combine different semiconductors together so as to form heterojunction photocatalysts, such as ZnFe 2 O 4 /NCDs/Ag 2 CO 3 , MoO 3−x / NCNs, CdIn 2 S 4 /W 18 O 49 , MgIn 2 S 4 /CdS, etc. [13][14][15][16] resulting in admirable photocatalytic activities. However, some complex synthetic processes and special reagents are required to prepare the heterojunction compounds, leading to high cost. Thereby, extra efforts should be made to further modify the photocatalytic performances of semiconductor.Recently, bismuth-containing semiconductors, such as Bi 2 MoO 6 , BiVO 4 , BiOX (X = F, Cl, Br, I), (BiO) 2 CO 3 , etc., [17][18][19][20][21][22] have been extensively investigated as photocatalysts since they possess relatively small E g value and can harvest visible light to realize photodegradation aside from the ultraviolet light. Huang et al. revealed that the Bi 4 NbO 8 X (X = Cl, Br) nanosheets had admirable photocatalytic performance under visible light irradiation. [23] Upon solar light irradiation, Liu et al., found that the BiOI nanoplates can not only degrade tetracycline efficiently but also its photocatalytic behaviors are able to be modified via introducing vacancy. [24] Moreover, on the basis of the BiOX, Chen et al., had constructed series of heterojunction compounds and found that they can degrade pollutants easily under visible light irradiation. [25][26][27][28][29][30][31][32][33] Thus, the bismuthcontaining semiconductors are expected to be promising photocatalysts to realize wastewater purification. In comparison with other bismuth-containing semiconductors, BiOX, which pertains to the V-VI-VII ternary compounds with layered structures, has been widely researched owing to its exciting features including proper E g values, high stability, good photocatalytic Photocatalysis acts as an important role in controlling wastewater purification. However, it is still a huge challenge to obtain highly-efficient visible light driven photocatalysts. Herein, flower-like BiOBr microparticles with splendid photocatalytic activities are developed. The electronic structure of BiOBr host is explored via the first-principles density function theory. Besides, the impact of some external factors on the photocatalytic properties of BiOBr compounds is studied. In comparison, t...

show abstract

“…( Liu et al, 2014 ; Roger et al, 2017 ) In conclusion, the development of efficient photoanode materials is of great significance for constructing a practical PEC water splitting system. Various semiconductors including TiO 2 ( Crake et al, 2017 ; Zeng et al, 2020 ), ZnO ( Han et al, 2015 ; Hong et al, 2015 ), α -Fe 2 O 3 ( Dotan et al, 2011 ; Huang et al, 2016 ), WO 3 ( Huang et al, 2017 ; Li et al, 2018 ), BiVO 4 ( Wang et al, 2017a ; Wang Q. et al, 2018 ) and BiOBr ( Wang Z.-Q. et al, 2020 ) etc.…”

Section: Introductionmentioning

confidence: 99%

Fabrication of Cocatalyst NiO-Modified BiVO4 Composites for Enhanced Photoelectrochemical Performances

Wang

2022

Front. Chem.

Self Cite

View full text Add to dashboard Cite

In this work, NiO modified BiVO4 (BiVO4/NiO) nanocomposite was synthesized using hydrothermal and calcination method. The composite of BiVO4/NiO, further employed as a low-overpotential photoanode, was consisted of BiVO4 nanoparticles and NiO nanosheets, in which the BiVO4 nanoelectrode served as the matrix for the attachment of NiO nanosheets. Photoelectrochemical (PEC) tests show that BiVO4/NiO displayed improved PEC performance compared with pure BiVO4. The BiVO4/NiO photoanode delivers a photocurrent density of 1.2 mA/cm2 at 1.23 V vs. RHE in a Na2SO4 electrolyte under an AM 1.5G solar simulator, which is 0.3 mA/cm2 higher than pure BiVO4 photoanode. Meanwhile, the onset potential also generates a 350 mV cathodic shift. The enhanced performance of the BiVO4/NiO nanocomposite is attributed to NiO unique lamellar structure capable of providing a large number of active sites. Measurements of electrochemical impedance spectra (EIS) and the incident photon-to-current efficiency (IPCE) illustrate that the enhanced PEC activities are ascribed to the improved charge carrier separation/transport and the promoted water oxidation kinetics furnished by the decoration of NiO cocatalyst.

show abstract

Oxygen vacancies and p-n heterojunction modified BiOBr for enhancing donor density and separation efficiency under visible-light irradiation

Cited by 32 publications

References 48 publications

Novel Z-Scheme BiOM_1–xI_x (M = Cl, Br)/β-Bi₂O₃-(001) and BiOI/β-Bi₂O₃-(001) Heterojunction Photocatalysts with O Vacancies: A Study on the Hybrid Density Functional Approach

Novel Z-Scheme BiOM_1–xI_x (M = Cl, Br)/β-Bi₂O₃-(001) and BiOI/β-Bi₂O₃-(001) Heterojunction Photocatalysts with O Vacancies: A Study on the Hybrid Density Functional Approach

Tailoring of Visible Light Driven Photocatalytic Activities of Flower‐Like BiOBr Microparticles Towards Wastewater Purification Application

Fabrication of Cocatalyst NiO-Modified BiVO4 Composites for Enhanced Photoelectrochemical Performances

Contact Info

Product

Resources

About

Oxygen vacancies and p-n heterojunction modified BiOBr for enhancing donor density and separation efficiency under visible-light irradiation

Cited by 32 publications

References 48 publications

Novel Z-Scheme BiOM1–xIx (M = Cl, Br)/β-Bi2O3-(001) and BiOI/β-Bi2O3-(001) Heterojunction Photocatalysts with O Vacancies: A Study on the Hybrid Density Functional Approach

Novel Z-Scheme BiOM1–xIx (M = Cl, Br)/β-Bi2O3-(001) and BiOI/β-Bi2O3-(001) Heterojunction Photocatalysts with O Vacancies: A Study on the Hybrid Density Functional Approach

Tailoring of Visible Light Driven Photocatalytic Activities of Flower‐Like BiOBr Microparticles Towards Wastewater Purification Application

Fabrication of Cocatalyst NiO-Modified BiVO4 Composites for Enhanced Photoelectrochemical Performances

Contact Info

Product

Resources

About

Novel Z-Scheme BiOM_1–xI_x (M = Cl, Br)/β-Bi₂O₃-(001) and BiOI/β-Bi₂O₃-(001) Heterojunction Photocatalysts with O Vacancies: A Study on the Hybrid Density Functional Approach

Novel Z-Scheme BiOM_1–xI_x (M = Cl, Br)/β-Bi₂O₃-(001) and BiOI/β-Bi₂O₃-(001) Heterojunction Photocatalysts with O Vacancies: A Study on the Hybrid Density Functional Approach