1
|
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.
Collapse
|
3
|
Parveh F, Yourdkhani A, Poursalehi R. Photoelectrochemical properties of single-grain hematite films grown by electric-field-assisted liquid phase deposition. Dalton Trans 2022; 51:17255-17262. [DOI: 10.1039/d2dt02475f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
This article reports a modification of the conventional liquid phase deposition (C-LPD) method for the single-grain deposition of α-Fe2O3 (hematite) films into an electric-field-assisted liquid phase deposition (EA-LPD).
Collapse
Affiliation(s)
- Fatemeh Parveh
- Materials Engineering Department, Faculty of Engineering, Tarbiat Modares University, Tehran, Iran
| | - Amin Yourdkhani
- Materials Engineering Department, Faculty of Engineering, Tarbiat Modares University, Tehran, Iran
| | - Reza Poursalehi
- Materials Engineering Department, Faculty of Engineering, Tarbiat Modares University, Tehran, Iran
| |
Collapse
|
4
|
Lange MA, Khan I, Dören R, Ashraf M, Qurashi A, Prädel L, Panthöfer M, von der Au M, Cossmer A, Pfeifer J, Meermann B, Mondeshki M, Tahir MN, Tremel W. High-speed solid state fluorination of Nb 2O 5 yields NbO 2F and Nb 3O 7F with photocatalytic activity for oxygen evolution from water. Dalton Trans 2021; 50:6528-6538. [PMID: 34002749 DOI: 10.1039/d1dt00533b] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Solid state reactions are slow because the diffusion of atoms or ions through the reactant, intermediate and crystalline product phases is the rate-limiting step. This requires days or even weeks of high temperature treatment, and consumption of large amounts of energy. We employed spark-plasma sintering, an engineering technique that is used for high-speed consolidation of powders with a pulsed electric current passing through the sample to carry out the fluorination of niobium oxide in minute intervals. The approach saves time and large amounts of waste energy. Moreover, it allows the preparation of fluorinated niobium oxides on a gram scale using poly(tetrafluoroethylene) (®Teflon) scrap and without toxic chemicals. The synthesis can be upscaled easily to the kg range with appropriate sintering equipment. Finally, NbO2F and Nb3O7F prepared by spark plasma sintering show significant photoelectrocatalytic (PEC) oxygen evolution from water in terms of photocurrent density and incident photon-to-current efficiency (% IPCE), whereas NbO2F and Nb3O7F prepared by conventional high temperature chemistry show little to no PEC response. Our study is a proof of concept for the quick, clean and energy saving production of valuable photocatalysts from plastic waste.
Collapse
Affiliation(s)
- Martin Alexander Lange
- Department Chemie, Johannes Gutenberg-Universität Mainz, Duesbergweg 10-14, D-55128 Mainz, Germany.
| | - Ibrahim Khan
- Center of Excellence in Nanotechnology, King Fahd University of Petroleum & Minerals, Dhahran, 31262, Saudi Arabia
| | - René Dören
- Department Chemie, Johannes Gutenberg-Universität Mainz, Duesbergweg 10-14, D-55128 Mainz, Germany.
| | - Muhammad Ashraf
- Chemistry Department, King Fahd University of Petroleum & Materials, Dharan 31261, P.O. Box 5048, Kingdom of Saudi Arabia.
| | - Ahsanulhaq Qurashi
- Center of Excellence in Nanotechnology, King Fahd University of Petroleum & Minerals, Dhahran, 31262, Saudi Arabia
| | - Leon Prädel
- Max Planck Institute for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany
| | - Martin Panthöfer
- Department Chemie, Johannes Gutenberg-Universität Mainz, Duesbergweg 10-14, D-55128 Mainz, Germany.
| | - Marcus von der Au
- Bundesanstalt für Materialforschung und -prüfung (BAM), Anorganische Spurenanalytik, Richard-Willstätter-Straße 11, D-12489 Berlin, Germany
| | - Antje Cossmer
- Bundesanstalt für Materialforschung und -prüfung (BAM), Anorganische Spurenanalytik, Richard-Willstätter-Straße 11, D-12489 Berlin, Germany
| | - Jens Pfeifer
- Bundesanstalt für Materialforschung und -prüfung (BAM), Anorganische Spurenanalytik, Richard-Willstätter-Straße 11, D-12489 Berlin, Germany
| | - Björn Meermann
- Bundesanstalt für Materialforschung und -prüfung (BAM), Anorganische Spurenanalytik, Richard-Willstätter-Straße 11, D-12489 Berlin, Germany
| | - Mihail Mondeshki
- Department Chemie, Johannes Gutenberg-Universität Mainz, Duesbergweg 10-14, D-55128 Mainz, Germany.
| | - Muhammad Nawaz Tahir
- Chemistry Department, King Fahd University of Petroleum & Materials, Dharan 31261, P.O. Box 5048, Kingdom of Saudi Arabia.
| | - Wolfgang Tremel
- Department Chemie, Johannes Gutenberg-Universität Mainz, Duesbergweg 10-14, D-55128 Mainz, Germany.
| |
Collapse
|
5
|
Lange MA, Khan I, Opitz P, Hartmann J, Ashraf M, Qurashi A, Prädel L, Panthöfer M, Cossmer A, Pfeifer J, Simon F, von der Au M, Meermann B, Mondeshki M, Tahir MN, Tremel W. A Generalized Method for High-Speed Fluorination of Metal Oxides by Spark Plasma Sintering Yields Ta 3 O 7 F and TaO 2 F with High Photocatalytic Activity for Oxygen Evolution from Water. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2021; 33:e2007434. [PMID: 33837999 DOI: 10.1002/adma.202007434] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/30/2020] [Revised: 12/19/2020] [Indexed: 06/12/2023]
Abstract
A general method to carry out the fluorination of metal oxides with poly(tetrafluoroethylene) (PTFE, Teflon) waste by spark plasma sintering (SPS) on a minute scale with Teflon is reported. The potential of this new approach is highlighted by the following results. i) The tantalum oxyfluorides Ta3 O7 F and TaO2 F are obtained from plastic scrap without using toxic or caustic chemicals for fluorination. ii) Short reaction times (minutes rather than days) reduce the process time the energy costs by almost three orders of magnitude. iii) The oxyfluorides Ta3 O7 F and TaO2 F are produced in gram amounts of nanoparticles. Their synthesis can be upscaled to the kg range with industrial sintering equipment. iv) SPS processing changes the catalytic properties: while conventionally prepared Ta3 O7 F and TaO2 F show little catalytic activity, SPS-prepared Ta3 O7 F and TaO2 F exhibit high activity for photocatalytic oxygen evolution, reaching photoconversion efficiencies up to 24.7% and applied bias to photoconversion values of 0.86%. This study shows that the materials properties are dictated by the processing which poses new challenges to understand and predict the underlying factors.
Collapse
Affiliation(s)
- Martin Alexander Lange
- Chemistry Department, Johannes Gutenberg-Universität, Duesbergweg 10-14, Mainz, D-55128, Germany
| | - Ibrahim Khan
- Center of Integrative Petroleum Research, King Fahd University of Petroleum & Minerals, Dhahran, 31261, Saudi Arabia
- Center of Excellence in Nanotechnology, King Fahd University of Petroleum & Minerals, Dhahran, 31262, Saudi Arabia
| | - Phil Opitz
- Chemistry Department, Johannes Gutenberg-Universität, Duesbergweg 10-14, Mainz, D-55128, Germany
| | - Jens Hartmann
- Chemistry Department, Johannes Gutenberg-Universität, Duesbergweg 10-14, Mainz, D-55128, Germany
| | - Muhammad Ashraf
- Chemistry Department, King Fahd University of Petroleum & Minerals (KFUPM), P.O. Box 5048, Dharan, 31261, Kingdom of Saudi Arabia
| | - Ahsanulhaq Qurashi
- Center of Excellence in Nanotechnology, King Fahd University of Petroleum & Minerals, Dhahran, 31262, Saudi Arabia
| | - Leon Prädel
- Max Planck Institute for Polymer Research, Ackermannweg 10, 55128, Mainz, Germany
| | - Martin Panthöfer
- Chemistry Department, Johannes Gutenberg-Universität, Duesbergweg 10-14, Mainz, D-55128, Germany
| | - Antje Cossmer
- Federal Institute for Materials Research and Testing (BAM), Division 1.1-Inorganic Trace Analysis, Richard-Willstätter-Straße 11, Berlin, D-12489, Germany
| | - Jens Pfeifer
- Federal Institute for Materials Research and Testing (BAM), Division 1.1-Inorganic Trace Analysis, Richard-Willstätter-Straße 11, Berlin, D-12489, Germany
| | - Fabian Simon
- Federal Institute for Materials Research and Testing (BAM), Division 1.1-Inorganic Trace Analysis, Richard-Willstätter-Straße 11, Berlin, D-12489, Germany
| | - Marcus von der Au
- Federal Institute for Materials Research and Testing (BAM), Division 1.1-Inorganic Trace Analysis, Richard-Willstätter-Straße 11, Berlin, D-12489, Germany
| | - Björn Meermann
- Federal Institute for Materials Research and Testing (BAM), Division 1.1-Inorganic Trace Analysis, Richard-Willstätter-Straße 11, Berlin, D-12489, Germany
| | - Mihail Mondeshki
- Chemistry Department, Johannes Gutenberg-Universität, Duesbergweg 10-14, Mainz, D-55128, Germany
| | - Muhammad Nawaz Tahir
- Chemistry Department, King Fahd University of Petroleum & Minerals (KFUPM), P.O. Box 5048, Dharan, 31261, Kingdom of Saudi Arabia
| | - Wolfgang Tremel
- Chemistry Department, Johannes Gutenberg-Universität, Duesbergweg 10-14, Mainz, D-55128, Germany
| |
Collapse
|