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Pooja P, Chin A. Remarkably fast and reusable photocatalysis by UV annealed Cu 2O-SnO 2 p-n heterojunction. CHEMOSPHERE 2024; 349:140787. [PMID: 38008294 DOI: 10.1016/j.chemosphere.2023.140787] [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: 08/06/2023] [Revised: 10/30/2023] [Accepted: 11/21/2023] [Indexed: 11/28/2023]
Abstract
Powdered micro- or nano-particles photocatalyst has separation and recovery challenges, which may create a second pollution to environment and harmful to animals. To address those issues, SnO2, Cu2O and Cu2O-SnO2 p-n heterojunction thin films are formed on glass substrates using efficient co-sputtering method that is commonly employed for large-area high-definition display panel. Using first-order kinetics, 100 °C ultraviolet (UV) annealed Cu2O-SnO2 p-n heterojunction shows the superb fast degradation rate constant of 0.21 and 0.16 min-1 for methylene blue (MB) and methyl orange (MO) organic dyes, respectively, as photogenerated electron-hole pairs is increased. Record best degradation rate constants of 0.19 and 0.11 min-1 for respective MB and MO are still achieved even after four repeated cycles. The 100 °C UV annealed Cu2O-SnO2 film catalyst displays greater degradation efficiency in both dyes, reaching 100% degradation at room temperature after 30 and 35 min of illumination for MB and MO respectively. The scavenger experiments show that hydroxyl (·OH) and superoxide radicals (·O2-) are the major active species in the degradation of dye. The 100 °C UV annealed Cu2O-SnO2 film catalyst showed stability as well as reusability towards the dye degradation. As a result, the present work delivers an effective way to enhance the photocatalytic performance and also an easy recovery of the catalyst, which can be explored for various emerging pollutants.
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Affiliation(s)
- Pheiroijam Pooja
- Department of Electronics Engineering, National Yang Ming Chiao Tung University, Hsinchu 300, Taiwan
| | - Albert Chin
- Department of Electronics Engineering, National Yang Ming Chiao Tung University, Hsinchu 300, Taiwan.
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p-n heterojunction constructed by γ-Fe 2O 3 covering CuO with CuFe 2O 4 interface for visible-light-driven photoelectrochemical water oxidation. J Colloid Interface Sci 2023; 639:464-471. [PMID: 36827912 DOI: 10.1016/j.jcis.2023.02.042] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2022] [Revised: 01/20/2023] [Accepted: 02/09/2023] [Indexed: 02/13/2023]
Abstract
Fe2O3 is a promising n-type semiconductor as the photoanode of photoelectrochemical water-splitting method due to its abundance, low cost, environment-friendly, and high chemical stability. However, the recombination of photogenerated holes and electrons leads to low solar-to-hydrogen efficiency. In this work, to overcome the recombination issue, a p-type semiconductor, CuO, is introduced underneath the γ-Fe2O3 to synthesize γ-Fe2O3/CuO on the FTO substrate. Along with the formation of p-n heterojunction, CuFe2O4 is in situ generated at the interface of γ-Fe2O3 and CuO. The existence of Cu2O in CuO and CuFe2O4 promotes the charge transfer from CuO to γ-Fe2O3 and within CuFe2O4, respectively, resulting in creating an internal electric field in γ-Fe2O3/CuO and leading to the conduction band of CuO bending up and γ-Fe2O3 bending down. Additionally, Cu(II) in CuFe2O4 contributes to fast electron capture. Consequently, the charge transfer efficiency and charge separation efficiency of photo-generated holes are promoted. Hence, γ-Fe2O3/CuO exhibits an enhanced photocurrent density of 13.40 mA cm-2 (1.9 times higher than γ-Fe2O3). The photo corrosion resistance of CuO is dramatically increased with the protection of CuFe2O4, resulting in superior high chemical stability, i.e. 85% of the initial activity remains after a long-term test.
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Comparative Study of SnO2 and ZnO Semiconductor Nanoparticles (Synthesized Using Randia echinocarpa) in the Photocatalytic Degradation of Organic Dyes. Symmetry (Basel) 2022. [DOI: 10.3390/sym14101970] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Symmetry in nanomaterials is essential to know the behavior of their properties. In the present research, the photocatalytic properties of SnO2 and ZnO nanoparticles were compared for the degradation of the cationic dyes Methylene Blue (MB) and Rhodamine B (RB). The nanoparticles were obtained through a green synthesis process assisted by Randia echinocarpa extracts; they were then analyzed through Fourier transform infrared spectroscopy (FT-IR) and X-ray diffraction (XRD) to characterize their structure. Transmission electron microscopy (TEM) was used to identify the morphology and disclose nanoparticle size, and the optical properties were studied through Ultraviolet–visible spectroscopy (UV–Vis). The results show that the synthesized SnO2 and ZnO nanomaterials have quasispherical morphologies with average sizes of 8–12 and 4–6 nm, cassiterite and wurtzite crystal phases, and band gap values of 3.5 and 3.8 eV, respectively. The photocatalytic activity yielded 100% degradation of the MB and RB dyes in 210 and 150 min, respectively. ZnO performed higher photocatalytic degradation of the cationic dyes than SnO2 due to a higher content of Randia echinocarpa extracts remaining after the green synthesis process.
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Joy Prabu H, Varghese R, Johnson I, John Sundaram S, Dhayal Raj A, Rajagopal R, Kuppusamy P, Sathya R, Kaviyarasu K. Laser induced plant leaf extract mediated synthesis of CuO nanoparticles and its photocatalytic activity. ENVIRONMENTAL RESEARCH 2022; 212:113295. [PMID: 35452668 DOI: 10.1016/j.envres.2022.113295] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/13/2022] [Revised: 04/02/2022] [Accepted: 04/09/2022] [Indexed: 06/14/2023]
Abstract
Metal nanoparticles furnished by the green synthesis approach have exhibited fascinating attributes owing to their biocompatibility with biomolecules, and their rapid environmentally friendly synthesis. On copper oxide (CuO) nanoparticles, a laser induced bio reduction work has been accomplish using Centella asiatica aqueous extract at room temperature is the pioneer in the field. This synthesis technique is easy, fruitful, eco-friendly, and counterfeit for the size-tunable synthesis of diverse shapes of stable copper nanoparticles. UV-visible spectroscopy, Field Emission Scanning Electron Microscopy (FESEM), Fourier Transform Infrared Spectroscopy (FTIR), Energy - Dispersive X-ray Spectroscopy (EDX), X-ray diffraction (XRD) and photodegradation study have astounding properties of regulating the formation, crystalline nature, and morphology of an integrated specimen. Moreover, the obtained copper oxide nanoparticle has the tendency to decrease the absorbance maximum value of methylene blue because of the catalytic activity posed by these nanoparticles on the reduction of methylene blue by Centella asiatica. It has been studied and confirmed by UV-visible spectrophotometer, and it has been recognised as an electron relay effect.
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Affiliation(s)
- H Joy Prabu
- Department of Physics, Centre for Nanosciences and Applied Thermodynamics, St. Joseph's College (Autonomous), Tiruchirappalli, 620002, Tamil Nadu, India.
| | - Rintu Varghese
- Department of Physics, Bharata Mata College, Thrikkakara, Kochi, 682021, Kerala, India
| | - I Johnson
- Department of Physics, Centre for Nanosciences and Applied Thermodynamics, St. Joseph's College (Autonomous), Tiruchirappalli, 620002, Tamil Nadu, India
| | - S John Sundaram
- Department of Physics, Sacred Heart College (Autonomous), Tirupattur, 635601, Tamil Nadu, India
| | - A Dhayal Raj
- Department of Physics, Sacred Heart College (Autonomous), Tirupattur, 635601, Tamil Nadu, India
| | - Rajakrishnan Rajagopal
- Department of Botany and Microbiology, College of Science, King Saud University, Riyadh, Saudi Arabia
| | - Palaniselvam Kuppusamy
- Department of Animal Biotechnology, Jeonbuk National University, Jeonju, 54896, South Korea
| | - Rengasamy Sathya
- Department of Microbiology, Centre for Research and Development, PRIST University, Thanjavur, 613403, Tamil Nadu, India
| | - K Kaviyarasu
- UNESCO-UNISA Africa Chair in Nanosciences/Nanotechnology Laboratories, College of Graduate Studies, University of South Africa (UNISA), Muckleneuk Ridge, PO Box 392, Pretoria, South Africa; Nanosciences African Network (NANOAFNET), Materials Research Group (MRG), IThemba LABS-National Research Foundation (NRF), 1 Old Faure Road, 7129, PO Box 722, Somerset West, Western Cape Province, South Africa.
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Alhammadi S, Mun BG, Gedi S, Minnam Reddy VR, Rabie AM, Sayed MS, Shim JJ, Park H, Kim WK. Effect of silver doping on the properties and photocatalytic performance of In2S3 nanoparticles. J Mol Liq 2021. [DOI: 10.1016/j.molliq.2021.117649] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
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