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Ali SA, Ahmed J, Mao Y, Ahmad T. Symbiotic MoO 3-SrTiO 3 Heterostructured Nanocatalysts for Sustainable Hydrogen Energy: Combined Experimental and Theoretical Simulations. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2023; 39:12692-12706. [PMID: 37639496 DOI: 10.1021/acs.langmuir.3c01418] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/31/2023]
Abstract
Highly efficient Z-scheme MoO3-SrTiO3 heterostructured nanocatalytic systems were engineered via a sol-gel chemical route and exploited in green H2 energy synthesis via overall water splitting. The optical and electronic investigations corroborated the enhancement of the optoelectronic properties of SrTiO3 after the incorporation of MoO3. Emergence of the interfacial charge transfer between SrTiO3 and MoO3 is the driving force, which synergistically triggered the catalytic efficiency of MoO3-SrTiO3 heterostructures. The substitution of Ti4+ by Mo6+ ions led to the suppression of Ti3+ mid-gap states, as the potential involved in the Mo6+/Mo5+ reduction is higher than that in Ti4+/Ti3+. Theoretical studies were employed in order to comprehend the mechanism behind the advancement in the catalytic activity of MoO3-SrTiO3 porous heterostructures, which also possessed a higher surface area. 2% MoO3-SrTiO3 exhibited the optimum catalytic response toward H2 evolution via photochemical, electrochemical, and photo-electrochemical water splitting. 2% MoO3-SrTiO3 evolved H2 at the fourfold higher rate than SrTiO3 with phenomenal 16.06% AQY during photochemical water splitting and photo-degraded MB dye at nearly 88% against the 42% degradation in SrTiO3-led photocatalysis. Electrochemical and photo-electrochemical investigations also manifested the superiority of 2% MoO3-SrTiO3 toward HER, as it exhibited accelerated current and photocurrent densities of 25.02 and 27.45 mA/cm2, respectively, at the 1 V potential. EIS studies demonstrated the improved charge separation efficiency of MoO3-SrTiO3 heterostructures. This work highlights the multi-dimensional approach of obtaining green H2 energy as the sustainable energy source using MoO3@SrTiO3 heterostructures.
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Affiliation(s)
- Syed Asim Ali
- Nanochemistry Laboratory, Department of Chemistry, Jamia Millia Islamia, New Delhi 110025, India
| | - Jahangeer Ahmed
- Department of Chemistry, College of Science, King Saud University, P.O. Box 2455, Riyadh 11451, Saudi Arabia
| | - Yuanbing Mao
- Department of Chemistry, Illinois Institute of Technology, 3105 South Dearborn Street, Chicago, Illinois 60616, United States
| | - Tokeer Ahmad
- Nanochemistry Laboratory, Department of Chemistry, Jamia Millia Islamia, New Delhi 110025, India
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Freimann SA, Housecroft CE, Constable EC. Nanoparticulate Perovskites for Photocatalytic Water Reduction. NANOMATERIALS (BASEL, SWITZERLAND) 2023; 13:2094. [PMID: 37513106 PMCID: PMC10386032 DOI: 10.3390/nano13142094] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/28/2023] [Revised: 07/11/2023] [Accepted: 07/15/2023] [Indexed: 07/30/2023]
Abstract
SrTiO3 and BaTiO3 nanoparticles (NPs) were activated using H2O2 or aqueous HNO3, and pristine and activated NPs were functionalized with a 2,2'-bipyridine phosphonic acid anchoring ligand (1), followed by reaction with RuCl3.3H2O and bpy, RhCl3.3H2O and bpy, or RuCl3.3H2O. The surface-bound metal complex functionalized NPs were used for the photogeneration of H2 from water, and their activity was compared to related systems using TiO2 NPs. The role of pH during surface complexation was found to be important. The NPs were characterized using Fourier transform infrared (FTIR) and solid-state absorption spectroscopies, thermogravimetric analysis mass spectrometry (TGA-MS), and matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS), and the dihydrogen generation was analyzed using gas chromatography-mass spectrometry (GC-MS). Our findings indicate that extensively functionalized SrTiO3 or BaTiO3 NPs may perform better than TiO2 NPs for water reduction.
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Affiliation(s)
- Sven A Freimann
- Department of Chemistry, University of Basel, Mattenstrasse 22, BPR 1095, Postfach, 4002 Basel, Switzerland
| | - Catherine E Housecroft
- Department of Chemistry, University of Basel, Mattenstrasse 22, BPR 1095, Postfach, 4002 Basel, Switzerland
| | - Edwin C Constable
- Department of Chemistry, University of Basel, Mattenstrasse 22, BPR 1095, Postfach, 4002 Basel, Switzerland
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Influence of synthesis procedures on the preparation of strontium titanate nanoparticles and photocatalytic application for methylene blue degradation. REACTION KINETICS MECHANISMS AND CATALYSIS 2023. [DOI: 10.1007/s11144-023-02375-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/02/2023]
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Siebenhofer M, Viernstein A, Morgenbesser M, Fleig J, Kubicek M. Photoinduced electronic and ionic effects in strontium titanate. MATERIALS ADVANCES 2021; 2:7583-7619. [PMID: 34913036 PMCID: PMC8628302 DOI: 10.1039/d1ma00906k] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/29/2021] [Accepted: 10/17/2021] [Indexed: 06/14/2023]
Abstract
The interaction of light with solids has been of ever-growing interest for centuries, even more so since the quest for sustainable utilization and storage of solar energy became a major task for industry and research. With SrTiO3 being a model material for an extensive exploration of the defect chemistry of mixed conducting perovskite oxides, it has also been a vanguard in advancing the understanding of the interaction between light and the electronic and ionic structure of solids. In the course of these efforts, many phenomena occurring during or subsequent to the illumination of SrTiO3 have been investigated. Here, we give an overview of the numerous photoinduced effects in SrTiO3 and their inherent connection to electronic structure and defect chemistry. In more detail, advances in the fields of photoconductivity, photoluminescence, photovoltages, photochromism and photocatalysis are summarized and their underlying elemental processes are discussed. In light of recent research, this review also emphasizes the fundamental differences between illuminating SrTiO3 either at low temperatures (<RT) or at high temperatures (>200 °C), where in addition to electronic processes, also photoionic interactions become relevant. A survey of the multitude of different processes shows that a profound and comprehensive understanding of the defect chemistry and its alteration under illumination is both vital to optimizing devices and to pushing the boundaries of research and advancing the fundamental understanding of solids.
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Affiliation(s)
- Matthäus Siebenhofer
- Institute of Chemical Technologies and Analytics, Vienna University of Technology Austria
- CEST Centre of Electrochemistry and Surface Technology, Wr. Neustadt Austria
| | - Alexander Viernstein
- Institute of Chemical Technologies and Analytics, Vienna University of Technology Austria
| | | | - Jürgen Fleig
- Institute of Chemical Technologies and Analytics, Vienna University of Technology Austria
| | - Markus Kubicek
- Institute of Chemical Technologies and Analytics, Vienna University of Technology Austria
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Kitchamsetti N, Didwal PN, Mulani SR, Patil MS, Devan RS. Photocatalytic activity of MnTiO 3 perovskite nanodiscs for the removal of organic pollutants. Heliyon 2021; 7:e07297. [PMID: 34189324 PMCID: PMC8220322 DOI: 10.1016/j.heliyon.2021.e07297] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2021] [Revised: 05/07/2021] [Accepted: 06/09/2021] [Indexed: 11/20/2022] Open
Abstract
MTO nanodiscs synthesized using the hydrothermal approach were explored for the photocatalytic removal of methylene blue (MB), rhodamine B (RhB), congo red (CR), and methyl orange (MO). The disc-like structures of ~16 nm thick and ~291 nm average diameter of stoichiometric MTO were rhombohedral in nature. The MTO nanodiscs delivered stable and recyclable photocatalytic activity under Xe lamp irradiation. The kinetic studies showed the 89.7, 80.4, 79.4, and 79.4 % degradation of MB, RhB, MO, and CR at the rate constants of 0.011(±0.001), 0.006(±0.001), 0.007(±0.0007), and 0.009 (±0.0001) min-1, respectively, after the 180 min of irradiation. The substantial function of photogenerated holes and hydroxide radicals pertaining to the dye removal phenomena is confirmed by radical scavenger trapping studies. Overall, the present studies provide a way to develop pristine and heterostructure perovskite for photocatalysts degradation of various organic wastes.
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Affiliation(s)
- Narasimharao Kitchamsetti
- Department of Metallurgy Engineering and Materials Science, Indian Institute of Technology Indore, Simrol, Indore 453552, India
| | - Pravin N. Didwal
- Department of Materials Science and Engineering, Chonnam National University, 77, Yongbongro, Bukgu, Gwangju, 61186, South Korea
| | - Sameena R. Mulani
- Department of Metallurgy Engineering and Materials Science, Indian Institute of Technology Indore, Simrol, Indore 453552, India
| | - Madhuri S. Patil
- Department of Metallurgy Engineering and Materials Science, Indian Institute of Technology Indore, Simrol, Indore 453552, India
| | - Rupesh S. Devan
- Department of Metallurgy Engineering and Materials Science, Indian Institute of Technology Indore, Simrol, Indore 453552, India
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Evaluation of Efficient and Noble-Metal-Free NiTiO3 Nanofibers Sensitized with Porous gC3N4 Sheets for Photocatalytic Applications. Catalysts 2021. [DOI: 10.3390/catal11030385] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
One-dimensional nickel titanate nanofibers (NiTiO3 NFs) were synthesized and loaded with acetic acid-treated exfoliated and sintered sheets of graphitic carbon nitride (AAs-gC3N4) to fabricate a unique heterogeneous structure. This novel fabrication method for porous AAs-gC3N4 sheets using acetic acid-treated exfoliation followed by sintering provided gC3N4 with a surface area manifold larger than that of bulk gC3N4, with an abundance of catalytically active sites. Hybrid photocatalysts were synthesized through a two-step process. Firstly, NiTiO3 NFs (360 nm in diameter) were made by electrospinning, and these NiTiO3 NFs were sensitized with exfoliated gC3N4 sheets via a sonication process. Varying the weight ratio of NiTiO3 fibers to porous AAs-gC3N4 established that NiTiO3 NFs containing 40 wt% of porous AAs-gC3N4 exhibited optimal activity, i.e., removal of methylene blue and H2 evolution. After 60 min exposure to visible light irradiation, 97% of the methylene blue molecules were removed by the hybrid photocatalyst, compared with 82%, 72%, and 76% by pristine AAs-gC3N4, NiTiO3 NFs, and bulk gC3N4, respectively. The optimal structure also displayed excellent H2 evolution performance. The H2 evolution rate in the optimal sample (152 μmol g−1) was 2.2, 3.2 and 3-fold higher than that in pure AAs-gC3N4 (69 μmol g−1), NiTiO3 NFs (47 μmol g−1) and bulk gC3N4 (50 μmol g−1), respectively. This clearly shows that the holey AAs-gC3N4 nanosheets interacted synergistically with the NiTiO3 NFs. This extended the lifetime of photogenerated charge carriers and resulted in superior photocatalytic activity compared with pristine NiTiO3 NFs and bulk gC3N4. The higher Brunauer-Emmett-Teller surface area and the presence of many catalytically active sites also enhanced the photocatalytic performance of the hybrid sample. Moreover, through photoluminescence and photocurrent response analysis, a significant decrease in the recombination losses of the hybrid photocatalysts was also confirmed. Thus, this is a novel strategy to fabricate highly efficient photocatalysts with precisely tunable operating windows and enhanced charge separation.
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Botsa SM, Jagadeesh Babu M, Suresh P, Kalyani P, Venkateswararao B, Muralikrishna R. Spherical NiWO4-reduced graphene oxide nanocomposite for effective visible light driven photocatalytic activity for the decolourisation of organic pollutants. ARAB J CHEM 2020. [DOI: 10.1016/j.arabjc.2020.09.017] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022] Open
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Zhang M, Salvador PA, Rohrer GS. Influence of pH and Surface Orientation on the Photochemical Reactivity of SrTiO 3. ACS APPLIED MATERIALS & INTERFACES 2020; 12:23617-23626. [PMID: 32330005 DOI: 10.1021/acsami.0c04351] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
The photochemical reactivity of the SrTiO3 surface is affected by the pH of the surrounding aqueous solution. Scanning electron microscopy and atomic force microscopy have been used to quantify the amount of silver that is photochemically reduced on the surfaces of (100), (110), and (111) oriented crystals as a function of pH. For all orientations, the reactivity increases from pH 3, reaches a maximum, and then decreases at higher pH. The pH associated with the maximum reactivity depends on the crystallographic orientation of the surface. The results indicate that the solution pH influences the charge on the SrTiO3 surface. The amount of surface charge influences band bending within SrTiO3, and the maximum reactivity is achieved at a surface charge where neither the photocathodic nor the photoanodic reaction limit the overall reaction rate.
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Affiliation(s)
- Mingyi Zhang
- Department of Materials Science and Engineering, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, United States
| | - Paul A Salvador
- Department of Materials Science and Engineering, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, United States
| | - Gregory S Rohrer
- Department of Materials Science and Engineering, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, United States
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Photocatalytic Treatment of Pharmaceuticals in Real Hospital Wastewaters for Effluent Quality Amelioration. WATER 2019. [DOI: 10.3390/w11102165] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
The presence of pharmaceutically active compounds (PhACs) in the wastewater effluents has confirmed that conventional wastewater treatment technologies are not sufficiently effective in the pharmaceuticals’ removal. The objective of the present study was to evaluate and compare the photocatalytic degradation of PhACs using TiO2-P25, graphitic carbon nitride (g-C3N4, CN) and a heterojunction of perovskite strodium titanate and graphitic carbon nitride SrTiO3/g-C3N4 (20% g-C3N4, 20CNSTO) photocatalytic materials, in hospital wastewater effluents, by simulated solar irradiation. The experiments were performed by using real wastewater samples collected from the university hospital wastewater treatment plant (WWTP) effluent of Ioannina city (Northwestern Greece) and inherent pharmaceutical concentration levels. The analysis of the samples was accomplished by solid phase extraction followed by liquid chromatography-Orbitrap high-resolution mass spectrometry. In the cases of TiO2 and CN, more than 70% of the initial concentration (e.g., venlafaxine) was degraded after 90 min, while 20CNSTO presented lower photocatalytic performance. Furthermore, some compounds were sporadically detected (e.g., fluoxetine) or their concentrations remained stable during the photocatalytic treatment time period (e.g., trimethoprim). In total 11 transformation products (TPs) were formed along the degradation processes and were identified by using liquid chromatography high resolution mass spectrometry.
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