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Vikal S, Meena S, Gautam YK, Kumar A, Sethi M, Meena S, Gautam D, Singh BP, Agarwal PC, Meena ML, Parewa V. Visible-light induced effective and sustainable remediation of nitro organics pollutants using Pd-doped ZnO nanocatalyst. Sci Rep 2024; 14:22430. [PMID: 39341891 PMCID: PMC11438909 DOI: 10.1038/s41598-024-72713-4] [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: 04/21/2024] [Accepted: 09/10/2024] [Indexed: 10/01/2024] Open
Abstract
Nitroaromatic compounds represent a class of highly toxic pollutants discharged into aquatic environments by various industrial activities, posing significant threats to ecological integrity and human health due to their persistent and hazardous nature. In this study, Pd-doped ZnO nanoparticles were investigated as a potential solution for the degradation of nitro organics, offering heightened photocatalytic efficacy and prolonged stability. The synthesis of Pd-doped ZnO NPs was achieved via the hydrothermal method, with subsequent analysis through XRD spectra and XPS confirming successful Pd doping within the ZnO matrix. Characterization through FESEM and HRTEM unveiled the heterogeneous morphologies of both undoped and Pd-doped ZnO nanoparticles. Additionally, UV-vis and PL spectroscopy provided insights into the optical properties, chemical bonding, and defect structures of the synthesized Pd-doped ZnO NPs. Pd doping induces a redshift in ZnO's absorption spectra, reducing the bandgap from 3.12 to 2.94 eV as Pd concentration rises from 0 to 0.2 wt.%. The photocatalytic degradation, following pseudo-first-order kinetics, achieved 90% nitrobenzene abatement (200 µg/L, pH 7) under visible light within 320 min with a catalyst loading of 16 µg/mL. The photocatalytic efficacy of 0.08 wt% Pd-doped ZnO (k = 0.058 min⁻1) exhibited a 25-fold enhancement compared to bare ZnO (k = 3.1 × 10-4 min-1). Subsequent quenching and ESR experiments identified hydroxyl radicals (OH•) as the predominant active species in the degradation mechanism. Mass spectrometry analysis unveiled potential breakdown intermediates, illuminating a plausible degradation pathway. The investigated Pd-doped ZnO nanoparticles demonstrated reusability for up to five successive treatment cycles, offering a sustainable solution to nitro organics contamination challenges.
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Affiliation(s)
- Sagar Vikal
- Smart Materials and Sensor Laboratory, Department of Physics, Chaudhary Charan Singh University, Uttar Pradesh, Meerut, 250004, India
| | - Savita Meena
- Centre of Advanced Studies, Department of Chemistry, University of Rajasthan, Jaipur, India
| | - Yogendra K Gautam
- Smart Materials and Sensor Laboratory, Department of Physics, Chaudhary Charan Singh University, Uttar Pradesh, Meerut, 250004, India.
| | - Ashwani Kumar
- Department of Physics, Regional Institute of Education (RIE), Bhubaneswar, Odisha, 751022, India.
| | - Mukul Sethi
- Centre of Advanced Studies, Department of Chemistry, University of Rajasthan, Jaipur, India
| | - Swati Meena
- Centre of Advanced Studies, Department of Chemistry, University of Rajasthan, Jaipur, India
| | - Durvesh Gautam
- Smart Materials and Sensor Laboratory, Department of Physics, Chaudhary Charan Singh University, Uttar Pradesh, Meerut, 250004, India
| | - Beer Pal Singh
- Smart Materials and Sensor Laboratory, Department of Physics, Chaudhary Charan Singh University, Uttar Pradesh, Meerut, 250004, India
| | - Prakash Chandra Agarwal
- Department of Physics, Regional Institute of Education (RIE), Bhubaneswar, Odisha, 751022, India
| | - Mohan Lal Meena
- Department of Chemical Engineering, National Institute of Technology Karnataka - Surathkal, Srinivasnagar P.O, Mangalore, Karnataka, 575025, India
| | - Vijay Parewa
- Centre of Advanced Studies, Department of Chemistry, University of Rajasthan, Jaipur, India.
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Saini S, Kumar K, Saini P, Sethi M, Meena P, Dandia A, Weigand W, Parewa V. Elucidating the Synergistic Promotional Mechanism of Water and Oxygen in the Aerobic C-C Homocoupling Reaction Catalyzed by Visible-Light-Derived Core-Shell Pd@A-CQDs Nanostructures. ACS APPLIED MATERIALS & INTERFACES 2024; 16:46200-46215. [PMID: 39164891 DOI: 10.1021/acsami.4c04739] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/22/2024]
Abstract
Rational design and precise synthesis of biogenic noble-metal-based catalysts possessing distinctive structure and composition play a crucial role in the chemical industry, enabling sustainable construction of an inclusive range of chemical resources. In this study, we have effectively fabricated Pd@A-CQDs through a straightforward one-pot aqueous protocol assisted by visible light employing renewable biomass-derived amine-rich carbon quantum dots (A-CQDs). The remarkable visible light harnessing capability (bandgap, ca. 2.81 eV), high density (35.7 × 1018 cm-3), and long lifetime (25 ps) of photocharge carriers and amine-rich surface in A-CQDs make them ideal candidates as both reducing and stabilizing agents, thereby facilitating the in situ construction of metallic Pd(0) nanoparticles. Comprehensive physicochemical characterizations have provided compelling evidence for the spherical morphology of Pd@A-CQDs core-shell nanostructures, with ultrathin A-CQDs shells of ca. 1.9 nm and an average diameter of 14 ± 1 nm. The effectiveness of the synthesized Pd@A-CQDs catalysts was assessed in the ligand- and base-free homocoupling reaction of arylboronic acids in water at ambient temperature. The catalytic tests demonstrated the selective production of the homocoupled compound over protodeboronation products with excellent yield and high catalyst recyclability under ambient conditions. The protocol employed exhibited a high TOF (1.05 × 10-2 mol g-1 min-1) and a low E-factor, with a remarkably low palladium loading. XPS analysis confirmed the retention of the metallic nature of the palladium core within the catalysts during the reaction. The catalytic function of the palladium core in conjunction with the A-CQDs shell, along with the promotional effects provided by water and oxygen for the formation of nucleophilic tetravalent boron, was conclusively recognized by 11B NMR and O2-TPD measurements. The obtained experimental results deliver valuable insights into the probable reaction pathway for the homocoupling reaction catalyzed by the Pd@A-CQDs catalysts. Through a comprehensive and sustainable evaluation, the current methodology exhibits superior performance compared to previously documented techniques in relation to estimated circularity and adherence to good manufacturing practices (GMP).
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Affiliation(s)
- Surendra Saini
- Centre of Advanced Studies, Department of Chemistry, University of Rajasthan, Jaipur 302004, India
| | - Krishan Kumar
- Centre of Advanced Studies, Department of Chemistry, University of Rajasthan, Jaipur 302004, India
| | - Pratibha Saini
- Centre of Advanced Studies, Department of Chemistry, University of Rajasthan, Jaipur 302004, India
- Institute Inorganic and Analytical Chemistry, Friedrich Schiller University Jena, D-07743 Jena, Germany
| | - Mukul Sethi
- Centre of Advanced Studies, Department of Chemistry, University of Rajasthan, Jaipur 302004, India
| | - Priyanka Meena
- Centre of Advanced Studies, Department of Chemistry, University of Rajasthan, Jaipur 302004, India
| | - Anshu Dandia
- Centre of Advanced Studies, Department of Chemistry, University of Rajasthan, Jaipur 302004, India
| | - Wolfgang Weigand
- Institute Inorganic and Analytical Chemistry, Friedrich Schiller University Jena, D-07743 Jena, Germany
| | - Vijay Parewa
- Centre of Advanced Studies, Department of Chemistry, University of Rajasthan, Jaipur 302004, India
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Kumar K, Saini P, Sethi M, Saini S, Gurjar A, Konar A, Dietzek-Ivanšić B, Weigand W, Parewa V. Vacancy-Engineered 1D Nanorods with Spatially Segregated Dual Redox Sites for Visible-Light-Driven Cooperative CO 2 Reduction. ACS APPLIED MATERIALS & INTERFACES 2024; 16:43498-43511. [PMID: 39115165 DOI: 10.1021/acsami.4c06834] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/23/2024]
Abstract
Cooperative CO2 photoreduction with tailored organic synthesis offers a potent avenue for harnessing concurrently generated electrons and holes, facilitating the creation of both solar fuels and specialized chemical compounds. However, controlling the crystallization and morphologies of metal-free molecular nanostructures with exceptional photocatalytic activities toward CO2 reduction remains a significant challenge. These hurdles encompass insufficient CO2 activation potential, sluggish multielectron processes, delayed charge-separation kinetics, inadequate storage of long-lived photoexcitons, unfavorable thermodynamic conditions, and the precise control of product selectivity. Here, melem oligomer 2D nanosheets (MNSs) synthesized through pyrolysis are transformed into 1D nanorods (MNRs) at room temperature with the simultaneous engineering of vacancies and morphology. Transient absorption spectral analysis reveals that vacancies in MNRs trap charges, extending charge carrier lifetimes. Additionally, carbon vacancies enhance CO2 adsorption by increasing amine functional centers. The photocatalytic performance of MNRs for CO2 reduction coupled with benzyl alcohol oxidation is approximately ten times higher (CH3OH and aromatic aldehyde production rate 27 ± 0.5 and 93 ± 0.5 mmol g-1 h-1, respectively) than for the MNSs (CH3OH and aromatic aldehyde production rate 2.9 ± 0.5 and 9 ± 0.5 mmol g-1 h-1, respectively). The CO2 reduction pathway involved the carbon-coordinated formyl pathway through the formation of *COOH and *CHO intermediates, as mapped by in situ Fourier-transform infrared spectroscopy. The superior performance of MNRs is attributed to favorable energy-level alignment, enriched amine surfaces, and unique morphology, enhancing solar-to-chemical conversion.
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Affiliation(s)
- Krishan Kumar
- Centre of Advanced Studies, Department of Chemistry, University of Rajasthan, Jaipur 302004 India
| | - Pratibha Saini
- Institute Inorganic and Analytical Chemistry, Friedrich Schiller University Jena, Jena D-07743, Germany
- Institute for Physical Chemistry (IPC), Friedrich Schiller University Jena, Jena D-07743, Germany
| | - Mukul Sethi
- Centre of Advanced Studies, Department of Chemistry, University of Rajasthan, Jaipur 302004 India
| | - Surendra Saini
- Centre of Advanced Studies, Department of Chemistry, University of Rajasthan, Jaipur 302004 India
| | - Aditya Gurjar
- Centre of Advanced Studies, Department of Chemistry, University of Rajasthan, Jaipur 302004 India
| | - Arindam Konar
- Institute for Physical Chemistry (IPC), Friedrich Schiller University Jena, Jena D-07743, Germany
| | - Benjamin Dietzek-Ivanšić
- Institute of Physical Chemistry, Friedrich Schiller University Jena, Helmholtzweg 4, Jena 07743, Germany
- Department of Functional Interfaces, Leibniz Institute of Photonic Technology (IPHT), Albert-Einstein-Str. 9, Jena 07745, Germany
- Center for Energy and Environmental Chemistry Jena (CEEC Jena), Philosophenweg 7a, Jena 07743, Germany
| | - Wolfgang Weigand
- Institute Inorganic and Analytical Chemistry, Friedrich Schiller University Jena, Jena D-07743, Germany
| | - Vijay Parewa
- Centre of Advanced Studies, Department of Chemistry, University of Rajasthan, Jaipur 302004 India
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Meena S, Sethi M, Saini S, Kumar K, Saini P, Meena S, Kashyap S, Yadav M, Meena ML, Dandia A, Nirmal NK, Parewa V. Molecular surface-dependent light harvesting and photo charge separation in plant-derived carbon quantum dots for visible-light-driven OH radical generation for remediation of aromatic hydrocarbon pollutants and real wastewater. J Colloid Interface Sci 2024; 660:756-770. [PMID: 38271811 DOI: 10.1016/j.jcis.2024.01.079] [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: 10/02/2023] [Revised: 01/09/2024] [Accepted: 01/11/2024] [Indexed: 01/27/2024]
Abstract
Despite the growing emphasis on eco-friendly nanomaterials as energy harvesters, scientists are actively searching for metal-free photocatalysts to be used in environmental remediation strategies. Developing renewable resource-based carbon quantum dots (CQDs) as the sole photocatalyst to harvest visible light for efficient pollutant degradation is crucial yet challenging, particularly for addressing the escalating issue of water deterioration. Moreover, the photocatalytic decomposition of H2O2 under visible light irradiation remains an arduous task. Based on this, we designed two types of CQDs, C-CQDs (carboxylic-rich) and A-CQDs (amine-rich) with distinct molecular surfaces. Owing to the higher amount of upward band bending induced by amine-rich molecular surface, A-CQDs efficiently harvest the visible light and prevent recombination kinetics resulting in prolonged lifetimes (25 ps), and augmented charge carrier density (35.7 × 1018) of photoexcited charge carriers. A-CQDs enabled rapid visible-light-driven photolysis of H2O2 (k = 0.058 min-1) and produced higher quantity of •OH radicals (0.158 μmol/sec) for the mineralization of petroleum waste, BETX (i.e. Benzene, Ethylbenzene, Toluene and Xylene) (k = 0.017-0.026 min-1) and real textile wastewater (k = 0.026 min-1). To assess comparative toxicities of both remediated and non-remediated real wastewater samples in a time and dose depended manner, Drosophila melanogaster was used as a model organism. The findings unequivocally demonstrate the potential of remediated wastewater for watering urban forestry.
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Affiliation(s)
- Savita Meena
- Centre of Advanced Studies, Department of Chemistry, University of Rajasthan, Jaipur, India
| | - Mukul Sethi
- Centre of Advanced Studies, Department of Chemistry, University of Rajasthan, Jaipur, India
| | - Surendra Saini
- Centre of Advanced Studies, Department of Chemistry, University of Rajasthan, Jaipur, India
| | - Krishan Kumar
- Centre of Advanced Studies, Department of Chemistry, University of Rajasthan, Jaipur, India
| | - Pratibha Saini
- Centre of Advanced Studies, Department of Chemistry, University of Rajasthan, Jaipur, India; Friedrich Schiller Univ Jena, Inst Anorgan & Analyt Chem, Humboldt Str 8, D-07743 Jena, Germany
| | - Swati Meena
- Centre of Advanced Studies, Department of Chemistry, University of Rajasthan, Jaipur, India
| | - Sunidhi Kashyap
- Centre for Advanced Studies, Department of Zoology, University of Rajasthan, Jaipur, India
| | - Monika Yadav
- Centre for Advanced Studies, Department of Zoology, University of Rajasthan, Jaipur, India
| | - Mohan Lal Meena
- Department of Chemical Engineering, National Institute of Technology Karnataka, Surathkal, Mangaluru 575025, India
| | - Anshu Dandia
- Centre of Advanced Studies, Department of Chemistry, University of Rajasthan, Jaipur, India
| | - Naresh Kumar Nirmal
- Centre for Advanced Studies, Department of Zoology, University of Rajasthan, Jaipur, India
| | - Vijay Parewa
- Centre of Advanced Studies, Department of Chemistry, University of Rajasthan, Jaipur, India.
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Meena S, Sethi M, Meena S, Saini P, Kumar K, Saini S, Shekhawat S, Meena ML, Dandia A, Lin SD, Parewa V. Dopant-driven recombination delay and ROS enhancement in nanoporous Cd 1-xCu xS heterogeneous photocatalyst for the degradation of DR-23 dye under visible light irradiation. ENVIRONMENTAL RESEARCH 2023; 231:116181. [PMID: 37207730 DOI: 10.1016/j.envres.2023.116181] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/21/2023] [Revised: 04/11/2023] [Accepted: 05/15/2023] [Indexed: 05/21/2023]
Abstract
Developing an efficient heterogeneous photocatalyst for environmental remediation and treatment strategies using visible light harvesting processes is promising but challenging. Herein, Cd1-xCuxS materials have been synthesized and characterized by precise analytical tools. Cd1-xCuxS materials exhibited excellent photocatalytic activity for direct Red 23 (DR-23) dye degradation in visible light irradiation. The operational parameters, like dopant concentration, photocatalyst dose, pH, and initial concentration of dye were investigated during the process. The photocatalytic degradation process follows pseudo-first-order kinetics. As compared to other tested materials, 5% Cu doped CdS material revealed superior photocatalytic performance for the degradation of DR-23 (k = 13.96 × 10-3 min-1). Transient absorption spectroscopy, EIS, PL, and transient photocurrent indicated that adding copper to the CdS matrix improved the separation of photo-generated charge carriers by lowering the recombination rate. Spin-trapping experiments recognized the photodegradation primarily based on secondary redox products, i.e., hydroxyl and superoxide radicals. According to by Mott-Schottky curves, photocatalytic mechanism and photo-generated charge carrier density were elucidated regarding dopant-induced valence and conduction bands shifting. Thermodynamic probability of radical formation in line with the altered redox potentials by Cu doping has been discussed in the mechanism. The identification of intermediates by mass spectrometry study also showed a plausible breakdown mechanism for DR-23. Moreover, samples treated with nanophotocatalyst displayed excellent results when tested for water quality metrics such as DO, TDS, BOD, and COD. Developed nanophotocatalyst shows high recyclability with superior heterogeneous nature. 5% Cu-doped CdS also exhibit strong photocatalytic activity for the degradation of colourless pollutant bisphenol A (BPA) under visible light (k = 8.45 × 10-3 min-1). The results of this study offer exciting opportunities to alter semiconductors' electronic band structures for visible-light-induced photocatalytic activity for wastewater treatment.
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Affiliation(s)
- Savita Meena
- Centre of Advanced Studies, Department of Chemistry, University of Rajasthan, Jaipur, India
| | - Mukul Sethi
- Centre of Advanced Studies, Department of Chemistry, University of Rajasthan, Jaipur, India
| | - Swati Meena
- Centre of Advanced Studies, Department of Chemistry, University of Rajasthan, Jaipur, India
| | - Pratibha Saini
- Centre of Advanced Studies, Department of Chemistry, University of Rajasthan, Jaipur, India; Friedrich Schiller Univ Jena, Inst Anorgan & Analyt Chem, Humboldt Str 8, D-07743, Jena, Germany
| | - Krishan Kumar
- Centre of Advanced Studies, Department of Chemistry, University of Rajasthan, Jaipur, India
| | - Surendra Saini
- Centre of Advanced Studies, Department of Chemistry, University of Rajasthan, Jaipur, India
| | - Sumita Shekhawat
- Department of Physics, Kanoria PG Mahila Mahavidyalaya, Jaipur, India
| | - Mohan Lal Meena
- Department of Chemical Engineering, National Taiwan University of Science and Technology, Taipei, 10607, Taiwan
| | - Anshu Dandia
- Centre of Advanced Studies, Department of Chemistry, University of Rajasthan, Jaipur, India
| | - Shawn D Lin
- Department of Chemical Engineering, National Taiwan University of Science and Technology, Taipei, 10607, Taiwan
| | - Vijay Parewa
- Centre of Advanced Studies, Department of Chemistry, University of Rajasthan, Jaipur, India.
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