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Han SW, Yun WS, Seong S, Tahir Z, Kim YS, Ko M, Ryu S, Bae JS, Ahn CW, Kang J. Hidden Direct Bandgap of Bi 2O 2Se by Se Vacancy and Enhanced Direct Bandgap of Bismuth Oxide Overlayer. J Phys Chem Lett 2024; 15:1590-1595. [PMID: 38306160 DOI: 10.1021/acs.jpclett.3c03223] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2024]
Abstract
The Bi2O2Se surfaces are well-known to possess 50% Se vacancies, yet they have shown no in-gap states within the indirect bandgap (∼0.8 eV). We have found that the hidden in-gap states arising from the Se vacancies in a 2 × 1 pattern induce a reduced direct bandgap (∼0.5 eV). Such a reduced direct bandgap is responsible for the high electron mobility of Bi2O2Se. Moreover, the Bi oxide overlayers of the Bi thin films, formed through air exposure and annealing, unexpectedly exhibit a large direct bandgap (∼2.1 eV). The simplified fabrication of Bi oxide overlayers provides promise for improving Bi2O2Se electronic devices and enhancing photocatalytic activity.
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Affiliation(s)
- Sang Wook Han
- Basic Science Research Institute and Energy Harvest Storage Research Center, University of Ulsan, Ulsan 44610, Republic of Korea
| | - Won Seok Yun
- Convergence Research Institute, DGIST, Daegu 42988, Republic of Korea
| | - Seungho Seong
- Department of Physics, The Catholic University of Korea, Bucheon 14662, Republic of Korea
| | - Zeeshan Tahir
- Department of Semiconductor Physics and Energy Harvest-Storage Research Center, University of Ulsan, Ulsan 44610, Republic of Korea
| | - Yong Soo Kim
- Department of Semiconductor Physics and Energy Harvest-Storage Research Center, University of Ulsan, Ulsan 44610, Republic of Korea
| | - Minji Ko
- Department of Chemistry, Pohang University of Science and Technology (POSTECH), Pohang, Gyeongbuk 37673, Republic of Korea
| | - Sunmin Ryu
- Department of Chemistry, Pohang University of Science and Technology (POSTECH), Pohang, Gyeongbuk 37673, Republic of Korea
| | - Jong-Seong Bae
- Busan Center, Korea Basic Science Institute, Busan 46742, Republic of Korea
| | - Chang Won Ahn
- Basic Science Research Institute and Energy Harvest Storage Research Center, University of Ulsan, Ulsan 44610, Republic of Korea
| | - Jeongsoo Kang
- Department of Physics, The Catholic University of Korea, Bucheon 14662, Republic of Korea
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Subhiksha V, Okla MK, Sivaranjani PR, Abdel-Maksoud MA, Saleh IA, Abu-Harirah HA, Khan SS. Congregating Ag into γ-Bi 2O 3 coupled with CoFe 2O 4 for enhanced visible light photocatalytic degradation of ciprofloxacin, Cr(VI) reduction and genotoxicity studies. CHEMOSPHERE 2023; 342:140181. [PMID: 37716560 DOI: 10.1016/j.chemosphere.2023.140181] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/15/2023] [Revised: 09/12/2023] [Accepted: 09/13/2023] [Indexed: 09/18/2023]
Abstract
The work attempts to construct a highly effective γ-Bi2O3/CoFe2O4/Ag visible active photocatalyst for the enhanced degradation of ciprofloxacin (CIP) and Cr(VI) reduction. γ-Bi2O3/CoFe2O4/Ag photocatalyst was prepared by simple solid phase and co-precipitation methods. The nanosphere shaped CoFe2O4 photocatalyst are embedded on top of γ-Bi2O3 nanotriangle. The addition of Ag into γ-Bi2O3/CoFe2O4 heterojunction primitively facilitates the photocatalytic activity in higher rate. The quantitative analysis of photocatalyst possesses to have lower e-/h+ recombination rate compared to its counterparts. The prepared γ-Bi2O3/CoFe2O4/Ag photocatalyst showed 96.6% degradation of CIP in 220 min and 99.2% reduction of Cr(VI) in 120 min. Additionally, γ-Bi2O3/CoFe2O4/Ag showed outstanding recyclability and long-term stability with a degradation efficiency of 96.5% even after six cycles. The intermediate products formed were identified and the degradation pathway was elucidated by gas chromatography-mass spectrometry analysis. Total organic carbon measurement was carried over to assess the efficiency of complete degradation and the removal percentage was found to be 98%. The end product toxicity study towards bacteria was proven to have less toxicity level when compared to parent compound. Lastly, the genotoxicity of γ-Bi2O3/CoFe2O4/Ag photocatalyst was tested in Allium cepa and the results confirmed to have no cause of toxicity impacts. Overall, the work not only tends to provide a highly visible active γ-Bi2O3/CoFe2O4/Ag photocatalyst, but also attributes to have no further negative imprints in the environment.
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Affiliation(s)
- V Subhiksha
- Department of Oral Medicine and Radiology, Saveetha Dental College and Hospitals, Saveetha Institute of Medical and Technical Sciences (SIMATS), Chennai, 600077, Tamil Nadu, India
| | - Mohammad K Okla
- Botany and Microbiology Department, College of Science, King Saud University, P.O. Box 2455, Riyadh, 11451, Saudi Arabia
| | - P R Sivaranjani
- School of Engineering, University of Guelph, Guelph, ON, N1G 2W1, Canada
| | - Mostafa A Abdel-Maksoud
- Botany and Microbiology Department, College of Science, King Saud University, P.O. Box 2455, Riyadh, 11451, Saudi Arabia
| | | | - Hashem A Abu-Harirah
- Department of Medical Laboratory Sciences, Faculty of Allied Medical Sciences, Zarqa University, Zarqa, 13110, Jordan
| | - S Sudheer Khan
- Department of Oral Medicine and Radiology, Saveetha Dental College and Hospitals, Saveetha Institute of Medical and Technical Sciences (SIMATS), Chennai, 600077, Tamil Nadu, India.
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Ramazanov S, Sobola D, Ţălu Ş, Orudzev F, Arman A, Kaspar P, Dallaev R, Ramazanov G. Multiferroic behavior of the functionalized surface of a flexible substrate by deposition of Bi 2 O 3 and Fe 2 O 3. Microsc Res Tech 2022; 85:1300-1310. [PMID: 34820938 DOI: 10.1002/jemt.23996] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2021] [Revised: 10/07/2021] [Accepted: 11/10/2021] [Indexed: 02/05/2023]
Abstract
Thin films of bismuth and iron oxides were obtained by atomic layer deposition (ALD) on the surface of a flexible substrate poly(4,4'-oxydiphenylene-pyromellitimide) (Kapton) at a temperature of 250°C. The layer thickness was 50 nm. The samples were examined by secondary-ion mass spectrometry, and uniform distribution of elements in the film layer was observed. Surface morphology, electrical polarization, and mechanical properties were investigated by atomic force microscope, piezoelectric force microscopy, and force modulation microscopy. The values of current in the near-surface layer varied in the range of ±80 pA when a potential of 5 V was applied. Chemical analysis was performed by X-ray photoelectron spectroscopy, where the formation of Bi2 O3 and Fe2 O3 phases, as well as intermediate phases in the Bi-Fe-O system, was observed. Magnetic measurements were carried out by a vibrating sample magnetometer that showed a ferromagnetic response. The low-temperature method of functionalization of the Kapton surface with bismuth and iron oxides will make it possible to adapt the Bi-Fe-O system to flexible electronics.
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Affiliation(s)
- Shikhgasan Ramazanov
- Faculty of Chemistry, Department of Physical and Organic Chemistry, Dagestan State University, Makhachkala, Russia
| | - Dinara Sobola
- Department of Physics, Faculty of Electrical Engineering and Communication, Brno University of Technology, Brno, Czech Republic
- Academy of Sciences ČR, Institute of Physics of Materials, Brno, Czech Republic
| | - Ştefan Ţălu
- The Technical University of Cluj-Napoca, The Directorate of Research, Development and Innovation Management (DMCDI), Cluj-Napoca, Romania
| | - Farid Orudzev
- Faculty of Chemistry, Department of Physical and Organic Chemistry, Dagestan State University, Makhachkala, Russia
| | - Ali Arman
- Vacuum Technology Research Group, ACECR, Sharif University Branch, Tehran, Iran
| | - Pavel Kaspar
- Department of Physics, Faculty of Electrical Engineering and Communication, Brno University of Technology, Brno, Czech Republic
| | - Rashid Dallaev
- Department of Physics, Faculty of Electrical Engineering and Communication, Brno University of Technology, Brno, Czech Republic
| | - Guseyn Ramazanov
- Faculty of Technology, Course "Design", Dagestan State Technical University, Makhachkala, Russia
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High efficiency degradation of tetracycline and rhodamine B using Z-type BaTiO3/γ-Bi2O3 heterojunction. Sep Purif Technol 2021. [DOI: 10.1016/j.seppur.2021.119666] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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An intratumoral injectable nanozyme hydrogel for hypoxia-resistant thermoradiotherapy. Colloids Surf B Biointerfaces 2021; 207:112026. [PMID: 34384974 DOI: 10.1016/j.colsurfb.2021.112026] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2021] [Revised: 07/30/2021] [Accepted: 08/04/2021] [Indexed: 12/15/2022]
Abstract
Hypoxia in local tumors leads to the failure or resistance of radiotherapy (RT) and high-dose RT will cause systemic reactions and local radiation damage. As a non-chemotherapeutic intervention, photothermal therapy (PTT) can remove tumor tissues through thermal ablation as well as effectively improve the microenvironment of hypoxic cells. Therefore, the combined use of PTT and RT (thermoradiotherapy) has urgently become an efficient treatment. In this work, by encapsulating prussian blue (PB) nanoparticles in agarose hydrogel, we developed an injectable hybrid light-controlled hydrogel system as a PB reservoir and release controller (PRC) which can realize single injection and multiple treatments in vivo. Under the irradiation of 808 nm near-infrared (NIR) laser, PB nanoparticles convert laser energy into heat energy, causing degradation of agarose hydrogel and the release of PB nanoparticles. Due to the excellent photothermal properties of PB, photothermal treatment in the NIR Biological Windows can greatly enhance the sensitivity of tumor cells to RT. Meanwhile, PB nanoparticles can also be a nanozyme to drive the decomposition of endogenous hydrogen peroxide (H2O2), and then generate oxygen (O2) to improve the tumor hypoxic microenvironment, achieving the further enhancement of the radiation sensitivity. Notably, this study is the first design to utilize hydrogel for thermoradiotherapy. Both in vitro and in vivo experiments, the PRC demonstrated excellent effects of PTT-RT, good stability and biocompatibility, indicating our nanoplatform promote the development of anti-cancer combination thermoradiotherapy with greater clinical significance.
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Gandhi AC, Lai CY, Wu KT, Ramacharyulu PVRK, Koli VB, Cheng CL, Ke SC, Wu SY. Phase transformation and room temperature stabilization of various Bi 2O 3 nano-polymorphs: effect of oxygen-vacancy defects and reduced surface energy due to adsorbed carbon species. NANOSCALE 2020; 12:24119-24137. [PMID: 33242052 DOI: 10.1039/d0nr06552h] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
We report the grain growth from the nanoscale to microscale and a transformation sequence from Bi →β-Bi2O3→γ-Bi2O3→α-Bi2O3 with the increase of annealing temperature. The room temperature (RT) stabilization of β-Bi2O3 nanoparticles (NPs) was attributed to the effect of reduced surface energy due to adsorbed carbon species, and oxygen vacancy defects may have played a significant role in the RT stabilization of γ-Bi2O3 NPs. An enhanced red emission band was evident from all the samples attributed to oxygen-vacancy defects formed during the growth process in contrast with the observed white emission band from the air annealed Bi ingots. Based on our experimental findings, the air annealing induced oxidation of Bi NPs and transformation mechanism within various Bi2O3 nano-polymorphs are presented. The outcome of this study suggests that oxygen vacancy defects at the nanoscale play a significant role in both structural stabilization and phase transformation within various Bi2O3 nano-polymorphs, which is significant from theoretical consideration.
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