Search query: BiOBr doping

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abstract: Abstract Generally, pristine semiconductor materials are difficult to own excellent photocatalytic performance, and doping is considered an effective strategy to improve their performance. Herein, Co doped BiOBr (0 1 0) was successfully synthesized. The improved performance could be attributed to the enhanced charge separation efficiency and the expanded light absorption region. Moreover, Co doped BiOBr (0 1 0) owned relatively rough crystal surface with rich atomic defects and large specific surface area, which leaded to its excellent adsorption performance that contributed to the hole dominated degradation process. Through density functional theoretical (DFT) calculation, the effect of Co doping on electronic structure of BiOBr was investigated, indicating that an additional energy level inserted into the band gap of Co doped BiOBr, the band structure of Co doped BiOBr was more intensive than that of BiOBr, and the CBM and VBM of the Co doped BiOBr shifted towards lower energy regions. Tetracycline hydrochloride was chosen to further evaluate the photocatalytic performance of as prepared Co doped BiOBr (0 1 0) and 83% of tetracycline hydrochloride was degrade within 30 min. Finally, the visible light driven catalytic mechanism of Co doped BiOBr (0 1 0) was elucidated. Thus, a feasible strategy was proposed for the fabrication of excellent visible light driven photocatalytic materials.
author_names: Luhua Shao

Yutang Liu

Longlu Wang

Xinnian Xia

Xiang-Zhong Shen
title: Electronic structure tailoring of BiOBr (0 1 0) nanosheets by cobalt doping for enhanced visible light photocatalytic activity
year: 2020

abstract: Abstract Synergetic experimental and DFT insights of energy band structures and photogenerated rate limiting reactive species are indispensable to design impurity doped photocatalysts for photocatalytic environment remediation and solar fuels. Herein, despite the larger bandgap (Eg) of the Zn doped BiOBr samples, they exhibited superior activity to BiOBr in the photocatalytic water splitting but impaired the photodegradation of Rhodamine B under visible light illumination. Based on the spectral and electrochemical impedance characterisations and DFT simulations, the wider bandgaps of Zn doped BiOBr samples were explicitly assigned to the more positive valence band maxima (VBM) and more negative conduction band minima (CBM) The enhanced photocatalytic water splitting on the Zn doped BiOBr was arisen from the higher redox chemical potentials of charge carriers on respective CBM and VBM, suppressed back reactions and depressed recombination of photogenerated charge carriers. However, the reduced e h+ recombination on the Zn doped BiOBr cannot cancel the detrimental influences from the weaker light absorption and dye sensitisation effects, leading to slower RhB photodegradation.
author_names: Junqiu Guo

Xin Liao

Ming-Hsien Lee

Geoffrey Hyett

Chung-Che Huang

Daniel W Hewak

Sakellaris Mailis

Wei Zhou

Zheng Jiang
title: Experimental and DFT insights of the Zn doping effects on the visible light photocatalytic water splitting and dye decomposition over Zn doped BiOBr photocatalysts
venue: Applied Catalysis B: Environmental
year: 2019

abstract: Abstract Platinum loaded BiOBr with iodine doping photocatalyst (Pt/I BiOBr) was synthesized to further improve the photocatalytic activity of BiOBr. The photocatalytic test showed the bisphenol A degradation efficiency of Pt/I BiOBr under visible light was about 93% within 20 min, about 5.8, 1.5 and 1.3 times that of BiOBr, iodine doped BiOBr and platinum loaded BiOBr, respectively. The composition, morphology, optical property and dominant active radical were investigated. Based on the results, a possible mechanism was proposed. Iodine doping and platinum loading played a synergetic effect on broadening the visible light absorption range and increasing the photo induced carrier separation efficiency of BiOBr.
author_names: Tongtong Liu

Yawen Wang
title: Synergistic effect of iodine doping and platinum loading on boosting the visible light photocatalytic activity of BiOBr
year: 2020

abstract: Abstract A novel composite photocatalyst of Bi/BiOBr Bi5+ was successfully developed via a facile two step procedure. The co existence of self doped Bi5+ and in situ deposited Bi(M) was evidenced by X ray diffraction, field emission transmission electron microscope and X ray photoelectron spectra. Its photocatalytic performance on the Rhodamine B (RhB) degradation under visible light irradiation displayed a significant improvement compared with that of Bi/BiOBr or BiOBr Bi5+ which was mainly attributed to the synergistic effect between Bi(M) and Bi5+ For Bi(M) enhancement of visible light absorption capacity was beneficial from surface plasmon resonance (SPR) effect while the promoted separation of photoinduced charge carriers was attributed to the formation of oxygen vacancies (OVs) and Schottky barrier. Besides, Bi(M) induced a predominant exposure of (0 1 0) facet, further enhancing photocatalytic performance. Differently, Bi5+ brought a narrowed bandgap of BiOBr in increasing the carrier density. A plausible mechanism towards RhB degradation was proposed based on analysis of electron transfer pathway and determination of dominant active species. The work offers new routes to enhance the photocatalytic performance of Bi based materials without introducing any impurities.
author_names: Siqian Chai

Han-pei Yang

Zhaoqun Gao

Ruichen Zhang

Lina Wang
title: Enhancing visible light driven photocatalytic performance of BiOBr by self doping and in situ deposition strategy: A synergistic effect between Bi5+ and metallic Bi
year: 2020

abstract: Abstract Thermostability and band gap deeply influence the photocatalytic activity of the photocatalysts. In this article, BiOBr and La doped BiOBr photocatalysts were synthesized via a solvothermal process. The obtained samples were calcinated at different temperatures. X ray diffraction (XRD) N2 physical adsorption, scanning electron microscopy (SEM) transmission electron microscopy (TEM) thermogravimetry analysis (TGA) and differential thermal analysis (DTA) were utilized to characterize the effect on thermostability after La doping. UV Visible spectroscopy, X ray photoelectron spectroscopy (XPS) photoluminescence (PL) spectroscopy, Electrochemical Impedance Spectroscopy (EIS) transient photocurrent spectroscopy and Mott Schottky (M S) plots were utilized to analyze the band gap and band edge positions of the samples. The results presented that La doping not only enhanced thermostability of BiOBr but also regulated the band gap of heterojunction to advantageous status for promoting the activity. These results could open a new way to tune the heterojunction with rare earth doping by heat treatment.
author_names: Qizhe Fan

Xin Chen

Fanyun Chen

Jian Tian

Changling Yu

Chunfa Liao
title: Regulating the stability and bandgap structure of BiOBr during thermo transformation via La doping
venue: Applied Surface Science
year: 2019

author_names: Meihua Guan

Guangmin Ren

Xiaochao Zhang

Qirui Zhang

Changming Zhang

Rui Li

Caimei Fan
title: Regulating electronic properties of BiOBr to enhance visible light response via 3d transition metals doping: DFT U calculations
year: 2020

abstract: In this work, Co2+ modification influence on the visible light induced photocatalytic performance of BiOBr was investigated. BiOBr and Co2+ doped BiOBr (Co/BiOBr) nanosheets were fabricated through a facile solvothermal way. The morphology, structure, chemical composition and optical properties of the photocatalysts were characterized by various techniques. The results confirmed the successful synthesis of Co/BiOBr nanosheets and indicated the doped Co2+ had little influence on the surface morphology and crystal structure but expanded the light absorption region. Photoelectrochemical measurements were applied to evaluate the semiconducting properties of Co/BiOBr, and the results implied that compared with the undoped sample, Co/BiOBr had higher charge transfer efficiency and smaller charge transfer resistance which were beneficial to the improvement of visible light driven photocatalytic performance. The as synthesized Co/BiOBr nanosheets exhibited excellent catalytic activity and stability in the photodecomposition of contaminants.
author_names: Wenmao Huang

Xin Hua

Yaping Zhao

Kai Li

Liping Tang

Man Zhou

Zaisheng Cai
title: Enhancement of visible light driven photocatalytic performance of BiOBr nanosheets by Co2+ doping
venue: Journal of Materials Science: Materials in Electronics
year: 2019

abstract: Abstract Ciprofloxacin (CIP) has been a serious threat to the ecological environment and human health due to extensive application and persistence. Low concentrations of CIP can cause toxic effects on the surface and ground waters. It is critical to fabricate accurate and sensitive detection platform of CIP. Herein, a photoelectrochemical detecting platform of CIP has been constructed using metallic Bi self doping BiOBr (Bi/BiOBr) composites. The Bi/BiOBr composites can be synthesized by a facile ethylene glycol (EG) assisted solvothermal method. The metallic Bi nanoparticles can evenly distribute on the surface of BiOBr microspheres. In order to the incorporation of metallic Bi nanoparticles, the Bi/BiOBr composites exhibit excellent photoabsorption property and photoelectric conversion efficiency in visible region. Consequently, the result of photoelectrochemical measurements shows that the photocurrent density of Bi/BiOBr composites is superior to pure BiOBr. The increased photoelectrochemical properties of Bi/BiOBr composites are attributed to the efficient separation of electron hole pairs and rapid electrons transfer. In addition, the photoelectrochemical sensor based on Bi/BiOBr composites has been constructed for sensitively detecting CIP. The photoelectrochemical sensor exhibits a good linear relationship, a low detect limitation and relatively stability for monitoring CIP.
author_names: Pengcheng Yan

Li Xu

Desheng Jiang

Henan Li

Jiexiang Xia

Qi Zhang

Mingqing Hua

Huaming Li
title: Photoelectrochemical monitoring of ciprofloxacin based on metallic Bi self doping BiOBr nanocomposites
year: 2018

abstract: N/Ti3+ co doping multiphasic TiO2/BiOBr heterojunctions (NT TBx) were prepared by one step in situ hydrothermal processes. The crystal phase, morphology, component, and optical properties of the heterojunctions were characterized by X ray diffraction, scanning electron microscope, transmission electron microscope, X ray photoelectron spectroscopy, and Ultraviolet visible diffuse reflectance spectroscopy techniques, respectively. The as prepared samples exhibit better sonocatalytic activity for the degradation methylene blue, Rhodamine B, and p Nitrophenol aqueous solution compared with pristine TiO2 and N/Ti3+ co doping multiphasic TiO2. Especially, the highest degradation ratio of methylene blue was achieved for NT TB0.3 up to 98.2% after 50 min under ultrasonic irradiation. The high sonocatalytic activity has been kept after four cycles with the tiny decline, indicating the excellent stability of the as prepared samples. The improvement of sonocatalytic activity could be attributed to the formation of doping level and multiphasic TiO2/BiOBr heterojunctions, which account for the absorption of long wavelength light and the electron hole pair separation, respectively. Furthermore, superoxide radical (O2 was demonstrated to be the main reactive species for the degradation of methylene blue under ultrasonic irradiation. This study provides a facile fabrication procedure for N/Ti3+ co doping multiphasic TiO2/BiOBr heterojunctions and demonstrates an efficient route to promote the application of TiO2 in addressing environment related issues.
author_names: Y Yao

Mingxuan Sun

Xiaojiao Yuan

Yuanhua Zhu

Xiao-jing Lin

Sambandam Anandan
title: One step hydrothermal synthesis of N/Ti3+ co doping multiphasic TiO2/BiOBr heterojunctions towards enhanced sonocatalytic performance.
venue: Ultrasonics sonochemistry
year: 2018

abstract: Abstract Under UV irradiation, self doped Bi 5+ is evidenced to be generated on the surface of BiOBr nanosheets, but with well preserved crystal structure and morphology compared with pure counterpart. Bi 5+ self doping BiOBr (BiOBr 4) exhibits distinct photocatalytic mode for dyes degradation, as compared with pure BiOBr nanosheets. These photodegradation distinctions are mainly due to the simultaneous occurrence of two photoinduced hole (h mediated oxidation processes on the BiOBr surfaces: (1) a portion of photoexcited h participates in the photocatalytic oxidation of dyes, and (2) partial h involves the oxidation of Bi 3+ to Bi 5+ Notably, BiOBr 4 nanosheets comparatively show superior photocatalytic activity for the phenol decomposition as well as the bacterial inactivation. Besides Bi 5+ induced narrowed bandgap and enhanced light adsorption capacity, significantly, the oxidative Bi 5+ acts as electron traps to promote the photoexcited electron hole separation and accelerate h migration, resulting in the considerable photocatalytic enhancement of BiOBr 4 nanosheets. These novel findings will not only give new insights into the photocatalytic mechanism but also explore new route to enhance photocatalytic performance of Bi based materials.
author_names: Dan Wu

Songtao Yue

Wei Wang

Tiacheng An

Guiying Li

Liqun Ye

Ho Yin Yip

Po Keung Wong
title: Influence of photoinduced Bi related self doping on the photocatalytic activity of BiOBr nanosheets
year: 2017