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Li X, Li G, Li M, Ji X, Tang C, Fu X, Jiang H, Tan X, Wang H, Hu X. Developing self-floating N-defective graphitic carbon nitride photocatalyst for efficient photodegradation of Microcystin-LR under visible light. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 895:165171. [PMID: 37379931 DOI: 10.1016/j.scitotenv.2023.165171] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/16/2023] [Revised: 06/24/2023] [Accepted: 06/25/2023] [Indexed: 06/30/2023]
Abstract
The frequent occurrence of algal blooms in water bodies leads to a significant accumulation of microcystin-LR (MC-LR). In this study, we developed a porous foam-like self-floating N-deficient g-C3N4 (SFGN) photocatalyst for efficient photocatalytic degradation of MC-LR. Both the characterization results and DFT calculations indicate that the surface defects and floating state of SFGN synergistically enhance light harvesting and photogenerated carrier migration rate. The photocatalytic process achieved a nearly 100 % removal rate of MC-LR within 90 min, while the self-floating state of SFGN maintained good mechanical strength. ESR and radical capture experiments revealed that the primary active species responsible for the photocatalytic process was OH. This finding confirmed that the fragmentation of MC-LR occurs as a result of OH attacking the MC-LR ring. LC-MS analysis indicated that majority of the MC-LR molecules were mineralized into small molecules, allowing us to infer possible degradation pathways. Furthermore, after four consecutive cycles, SFGN exhibited remarkable reusability and stability, highlighting the potential of floating photocatalysis as a promising technique for MC-LR degradation.
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Affiliation(s)
- Xin Li
- College of Environmental Science and Engineering, Central South University of Forestry and Technology, Changsha 410004, PR China
| | - Guoyu Li
- College of Environmental Science and Engineering, Central South University of Forestry and Technology, Changsha 410004, PR China
| | - Meifang Li
- College of Environmental Science and Engineering, Central South University of Forestry and Technology, Changsha 410004, PR China
| | - Xiaodong Ji
- College of Environmental Science and Engineering, Central South University of Forestry and Technology, Changsha 410004, PR China
| | - Chunfang Tang
- College of Environmental Science and Engineering, Central South University of Forestry and Technology, Changsha 410004, PR China
| | - Xiaohua Fu
- College of Environmental Science and Engineering, Central South University of Forestry and Technology, Changsha 410004, PR China
| | - Honghui Jiang
- College of Environmental Science and Engineering, Central South University of Forestry and Technology, Changsha 410004, PR China
| | - Xiaofei Tan
- College of Environmental Science and Engineering, Hunan University, Changsha 410082, PR China
| | - Hui Wang
- College of Environmental Science and Engineering, Central South University of Forestry and Technology, Changsha 410004, PR China
| | - Xinjiang Hu
- College of Environmental Science and Engineering, Central South University of Forestry and Technology, Changsha 410004, PR China.
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Preparation and characterization of M1-Nx-Cy based single atom catalysts for environmental applications. CHINESE CHEM LETT 2022. [DOI: 10.1016/j.cclet.2022.108050] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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Li G, Zeng G, Chen Z, Hong J, Ji X, Lan Z, Tan X, Li M, Hu X, Tang C. In Situ Coupling Carbon Defective C 3N 5 Nanosheet with Ag 2CO 3 for Effective Degradation of Methylene Blue and Tetracycline Hydrochloride. NANOMATERIALS (BASEL, SWITZERLAND) 2022; 12:2701. [PMID: 35957132 PMCID: PMC9370685 DOI: 10.3390/nano12152701] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/11/2022] [Revised: 07/28/2022] [Accepted: 08/01/2022] [Indexed: 06/15/2023]
Abstract
The development of novel catalysts for degrading organic contaminants in water is a current hot topic in photocatalysis research for environmental protection. In this study, C3N5 nanosheet/Ag2CO3 nanocomposites (CNAC-X) were used as efficient photocatalysts for the visible-light-driven degradation of methylene blue (MB), and tetracycline hydrochloride (TC-HCl) was synthesized for the first time using a simple thermal oxidative exfoliation and in situ deposition method. Due to the synergistic effect of nanosheet structures, carbon defects, and Z-scheme heterojunctions, CNAC-10 exhibited the highest photocatalytic activity, with photodegradation efficiencies of 96.5% and 97.6% for MB (60 mg/L) and TC-HCl (50 mg/L) within 90 and 100 min, respectively. The radical trapping experiments showed that ·O2- and h+ played major roles in the photocatalytic effect of the CNAC-10 system. Furthermore, intermediates in the photodegradation of MB and TC-HCl were investigated to determine possible mineralization pathways. The results indicated that C3N5 nanosheet/Ag2CO3 photocatalysts prepared in this work could provide an effective reference for the treatment of organic wastewater.
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Affiliation(s)
- Guoyu Li
- College of Environmental Science and Engineering, Central South University of Forestry and Technology, Changsha 410004, China
| | - Genying Zeng
- College of Environmental Science and Engineering, Central South University of Forestry and Technology, Changsha 410004, China
| | - Zhangkai Chen
- College of Environmental Science and Engineering, Central South University of Forestry and Technology, Changsha 410004, China
| | - Jiaming Hong
- College of Environmental Science and Engineering, Central South University of Forestry and Technology, Changsha 410004, China
| | - Xiaodong Ji
- College of Environmental Science and Engineering, Central South University of Forestry and Technology, Changsha 410004, China
| | - Zhiqiang Lan
- College of Environmental Science and Engineering, Central South University of Forestry and Technology, Changsha 410004, China
| | - Xiaofei Tan
- College of Environmental Science and Engineering, Hunan University, Changsha 410082, China
- Key Laboratory of Environmental Biology and Pollution Control, Hunan University, Ministry of Education, Changsha 410082, China
| | - Meifang Li
- College of Environmental Science and Engineering, Central South University of Forestry and Technology, Changsha 410004, China
| | - Xinjiang Hu
- College of Environmental Science and Engineering, Central South University of Forestry and Technology, Changsha 410004, China
| | - Chunfang Tang
- College of Environmental Science and Engineering, Central South University of Forestry and Technology, Changsha 410004, China
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Aziz FFA, Jalil AA, Hassan NS, Fauzi AA, Azami MS, Jusoh NWC, Jusoh R. A review on synergistic coexisting pollutants for efficient photocatalytic reaction in wastewater remediation. ENVIRONMENTAL RESEARCH 2022; 209:112748. [PMID: 35101397 DOI: 10.1016/j.envres.2022.112748] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/23/2021] [Revised: 12/26/2021] [Accepted: 01/13/2022] [Indexed: 06/14/2023]
Abstract
With the tremendous development of the economy and industry, the pollution of water is becoming more serious due to the excessive chemical wastes that need to remove thru reduction or oxidation reactions. Simultaneous removal of dual pollutants via photocatalytic redox reaction has been tremendously explored in the last five years due to effective decontamination of pollutants compared to a single pollutants system. In a photocatalysis mechanism, the holes in the valence band can remarkably promote the oxidation of a pollutant. At the same time, photoexcited electrons are also consumed for the reduction reaction. The synergistic between the reduction and oxidation inhibits the recombination of electron-hole pairs extending their lifetime. In this review, the binary pollutants that selectively removed via photocatalysis reduction or oxidation are classified according to heavy metal-organic pollutant (HM/OP), heavy metal-heavy metal (HM/HM) and organic-organic pollutants (OP/OP). The intrinsic between the pollutants was explained in three different mechanisms including inhibition of electron-hole recombination, ligand to metal charge transfer and electrostatic attraction. Several strategies for the enhancement of this treatment method which are designation of catalysts, pH of mixed pollutants and addition of additive were discussed. This review offers a recent perspective on the development of photocatalysis system for industrial applications.
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Affiliation(s)
- F F A Aziz
- School of Chemical and Energy Engineering, Faculty of Engineering, Universiti Teknologi Malaysia, 81310, UTM, Johor Bahru, Johor, Malaysia
| | - A A Jalil
- School of Chemical and Energy Engineering, Faculty of Engineering, Universiti Teknologi Malaysia, 81310, UTM, Johor Bahru, Johor, Malaysia; Centre of Hydrogen Energy, Institute of Future Energy, 81310, UTM, Johor Bahru, Johor, Malaysia.
| | - N S Hassan
- School of Chemical and Energy Engineering, Faculty of Engineering, Universiti Teknologi Malaysia, 81310, UTM, Johor Bahru, Johor, Malaysia
| | - A A Fauzi
- School of Chemical and Energy Engineering, Faculty of Engineering, Universiti Teknologi Malaysia, 81310, UTM, Johor Bahru, Johor, Malaysia
| | - M S Azami
- Faculty of Science, Universiti Teknologi Malaysia, 81310, UTM, Johor Bahru, Johor, Malaysia
| | - N W C Jusoh
- Department of Chemical and Environmental Engineering, Malaysia-Japan International Institute of Technology, Universiti Teknologi Malaysia, Jalan Sultan Yahya Petra, 54100, Kuala Lumpur, Malaysia
| | - R Jusoh
- Faculty of Chemical and Process Engineering Technology, College of Engineering Technology, Universiti Malaysia Pahang, 26300, Gambang, Kuantan, Pahang, Malaysia
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Iron Carbon Catalyst Initiated the Generation of Active Free Radicals without Oxidants for Decontamination of Methylene Blue from Waters. Catalysts 2022. [DOI: 10.3390/catal12040388] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
In conventional oxidation technologies for treatment of contaminated waters, secondary pollution of the aqueous environment often occurs because of the additional oxidants generated during the process. To avoid this problem, Fe/NG catalyst composites without additives were developed in this study for decontamination of methylene blue (MB) from waters. The Fe/NG catalyst, composed of carbon nitride and iron chloride (FeCl3·6H2O), was prepared by high temperature pyrolysis. It is an exceptionally efficient, recoverable, and sustainable catalyst for degradation of organic matter. The morphological characteristics, chemical structure, and surface properties of the catalyst composites were investigated. The catalyst exhibited high MB removal efficiency (100%) within 30 min under ambient temperature and dark conditions. The experiments indicated that an MB degradation effect was also applicable under most acid–base conditions (pH = 2–10). The characterization results using electron spin resonance and analysis of intermediate products demonstrated that free radicals such as ·OH and ·O2− were produced from the Fe/NG composites in the heterogeneous system, which resulted in the high MB degradation efficiency. Moreover, the catalysis reaction generated reducing substances, triggering iron carbon micro-electrolysis to spontaneously develop a microcurrent, which assisted the degradation of MB. This study demonstrates the feasibility of Fe/NG catalysts that spontaneously generate active species for degrading pollutants in an aqueous environment at normal temperature, providing an attractive approach for treating organic-contaminated waters.
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Aziz FFA, Jalil AA, Hassan NS, Fauzi AA, Azami MS. Simultaneous photocatalytic reduction of hexavalent chromium and oxidation of p-cresol over AgO decorated on fibrous silica zirconia. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2021; 285:117490. [PMID: 34091265 DOI: 10.1016/j.envpol.2021.117490] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/22/2021] [Revised: 05/09/2021] [Accepted: 05/28/2021] [Indexed: 06/12/2023]
Abstract
The co-existence of heavy metals and organic compounds including Cr(VI) and p-cresol (pC) in water environment becoming a challenge in the treatment processes. Herein, the synchronous photocatalytic reduction of Cr(VI) and oxidation of pC by silver oxide decorated on fibrous silica zirconia (AgO/FSZr) was reported. In this study, the catalysts were successfully developed using microemulsion and electrochemical techniques with various AgO loading (1, 5 and 10 wt%) and presented as 1, 5 and 10-AgO/FSZr. Catalytic activity was tested towards simultaneous photoredox of hexavalent chromium and p-cresol (Cr(VI)/pC) and was ranked as followed: 5-AgO/FSZr (96/78%) > 10-AgO/FSZr (87/61%) > 1-AgO/FSZr (47/24%) > FSZr (34/20%). The highest photocatalytic activity of 5-AgO/FSZr was established due to the strong interaction between FSZr and AgO and the lowest band gap energy, which resulted in less electron-hole recombination and further enhanced the photoredox activity. Cr(VI) ions act as a bridge between the positive charge of catalyst and cationic pC in pH 1 solution which can improve the photocatalytic reduction and oxidation of Cr(VI) and pC, respectively. The scavenger experiments further confirmed that the photogenerated electrons (e-) act as the main species for Cr(VI) to be reduced to Cr(III) while holes (h+) and hydroxyl radicals are domain for photooxidation of pC. The 5-AgO/FSZr was stable after 5 cycles of reaction, suggesting its potential for removal of Cr(VI) and pC simultaneously in the chemical industries.
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Affiliation(s)
- F F A Aziz
- School of Chemical and Energy Engineering, Faculty of Engineering, Universiti Teknologi Malaysia, 81310, UTM Johor Bahru, Johor, Malaysia
| | - A A Jalil
- School of Chemical and Energy Engineering, Faculty of Engineering, Universiti Teknologi Malaysia, 81310, UTM Johor Bahru, Johor, Malaysia; Centre of Hydrogen Energy, Institute of Future Energy, 81310, UTM Johor Bahru, Johor, Malaysia.
| | - N S Hassan
- School of Chemical and Energy Engineering, Faculty of Engineering, Universiti Teknologi Malaysia, 81310, UTM Johor Bahru, Johor, Malaysia
| | - A A Fauzi
- School of Chemical and Energy Engineering, Faculty of Engineering, Universiti Teknologi Malaysia, 81310, UTM Johor Bahru, Johor, Malaysia
| | - M S Azami
- Faculty of Science, Universiti Teknologi Malaysia, 81310, UTM Johor Bahru, Johor, Malaysia
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Zheng X, Li Y, Peng H, Huang Z, Wang H, Wen J. Efficient solar-light photodegradation of tetracycline hydrochloride using BiVO4/MoO3 composites. Colloids Surf A Physicochem Eng Asp 2021. [DOI: 10.1016/j.colsurfa.2021.126599] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
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