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Donėlienė J, Fataraitė-Urbonienė E, Danchova N, Gutzov S, Ulbikas J. The Influence of the Precursor’s Nature and Drying Conditions on the Structure, Morphology, and Thermal Properties of TiO2 Aerogels. Gels 2022; 8:gels8070422. [PMID: 35877507 PMCID: PMC9323803 DOI: 10.3390/gels8070422] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2022] [Revised: 06/23/2022] [Accepted: 07/04/2022] [Indexed: 11/16/2022] Open
Abstract
A cost-effective solution for the synthesis of high-porosity TiO2 aerogels, which can be used as a mesoporous perovskite network charge-carrier material during the manufacture of solar cells, is described. The effects of the synthesis parameters (precursor (titanium (IV) isopropoxide (TIP) and tetrabutyl orthotitanate (TBOT)), additional solvent exchange (n-hexane (nH), cyclohexane (CH), and diethyl ether (DE)), subcritical drying (800 mbar vacuum, 70 °C, 8 h), aging, and calcination on the aerogel’s structure have been investigated. Methods of XRD, FT-IR, BET, Raman, STA, SEM, UV–vis, and thermal conductivity measurements were applied to find out the relation between the synthesis conditions and the properties of the synthesized aerogels. Amorphous aerogels are polydispersed systems with the highest probability of pore diameter from 0.5 to 15 nm. An nH-exchanged, aged aerogel synthesized from the precursor TIP shows the highest diameter of pores. After calcination, the aerogels tend to crystallize into an anatase phase and the size of the crystallites depends on the precursor’s nature. Calcination leads to a significant increase in both the apparent and true density of the aerogels, and it also results in an increase in porosity and thermal conductivity.
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Affiliation(s)
- Jolanta Donėlienė
- Applied Research Institute for Prospective Technologies, Vismaliuku Str. 34, LT 10243 Vilnius, Lithuania; (E.F.-U.); (J.U.)
- JSC Modern E-Technologies, Vismaliuku Str. 34, LT 10243 Vilnius, Lithuania
- Correspondence: ; Tel.: +370-5250-0616
| | - Eglė Fataraitė-Urbonienė
- Applied Research Institute for Prospective Technologies, Vismaliuku Str. 34, LT 10243 Vilnius, Lithuania; (E.F.-U.); (J.U.)
- Faculty of Mechanical Engineering and Design, Kaunas University of Technology, Studentu Str. 56, LT 51424 Kaunas, Lithuania
| | - Nina Danchova
- Department of Physical Chemistry, Faculty of Chemistry and Pharmacy, Sofia University “St. Kliment Ohridski”, J. Bourchier Blvd. 1, 1164 Sofia, Bulgaria; (N.D.); (S.G.)
| | - Stoyan Gutzov
- Department of Physical Chemistry, Faculty of Chemistry and Pharmacy, Sofia University “St. Kliment Ohridski”, J. Bourchier Blvd. 1, 1164 Sofia, Bulgaria; (N.D.); (S.G.)
| | - Juras Ulbikas
- Applied Research Institute for Prospective Technologies, Vismaliuku Str. 34, LT 10243 Vilnius, Lithuania; (E.F.-U.); (J.U.)
- JSC Modern E-Technologies, Vismaliuku Str. 34, LT 10243 Vilnius, Lithuania
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Synthesis, Characterization, and Photocatalytic Investigation of CuFe2O4 for the Degradation of Dyes under Visible Light. Catalysts 2022. [DOI: 10.3390/catal12060623] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
The CuFe2O4 photocatalysts were synthesized by the solution combustion synthesis method, followed by heat treatment at a temperature range of 400 to 1100 °C. Later, they were characterized for application in the photodegradation of synthetic dyes under visible radiation. The X-ray diffraction results showed the presence of cubic and tetragonal phases of CuFe2O4 and secondary phases of Fe2O3 and CuO, at low temperatures. The infrared spectrum profile confirms the formation of the phases pointed out in the XRD. For most specimens, the scanning electron microscopy examination revealed a morphology similar to porous flakes and a quasi-spherical shape. On the other hand, samples heat-treated at 1100 °C displayed a plate-like morphology. The specimens’ band gap ranged from 1.49 to 1.58 eV, indicating that the material is a semiconductor. Regarding the photocatalytic efficiency, the 400 °C heat-treated samples showed better activity when the visible irradiation was used over the green malachite and rhodamine B dyes. The solution degradation rates on the first and former dyes were 56.60% and 84.30%, respectively.
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Song Q, Miao C, Sai H, Gu J, Wang M, Jiang P, Wang Y, Fu R, Wang Y. Silica-Bacterial Cellulose Composite Aerogel Fibers with Excellent Mechanical Properties from Sodium Silicate Precursor. Gels 2021; 8:gels8010017. [PMID: 35049552 PMCID: PMC8774922 DOI: 10.3390/gels8010017] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2021] [Revised: 12/20/2021] [Accepted: 12/22/2021] [Indexed: 12/22/2022] Open
Abstract
Forming fibers for fabric insulation is difficult using aerogels, which have excellent thermal insulation performance but poor mechanical properties. A previous study proposed a novel method that could effectively improve the mechanical properties of aerogels and make them into fibers for use in fabric insulation. In this study, composite aerogel fibers (CAFs) with excellent mechanical properties and thermal insulation performance were prepared using a streamlined method. The wet bacterial cellulose (BC) matrix without freeze-drying directly was immersed in an inorganic precursor (silicate) solution, followed by initiating in situ sol-gel reaction under the action of acidic catalyst after secondary shaping. Finally, after surface modification and ambient drying of the wet composite gel, CAFs were obtained. The CAFs prepared by the simplified method still had favorable mechanical properties (tensile strength of 4.5 MPa) and excellent thermal insulation properties under extreme conditions (220 °C and −60 °C). In particular, compared with previous work, the presented CAFs preparation process is simpler and more environmentally friendly. In addition, the experimental costs were reduced. Furthermore, the obtained CAFs had high specific surface area (671.3 m²/g), excellent hydrophobicity, and low density (≤0.154 g/cm3). This streamlined method was proposed to prepare aerogel fibers with excellent performance to meet the requirements of wearable applications.
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Affiliation(s)
- Qiqi Song
- School of Chemistry and Chemical Engineering, Inner Mongolia University of Science & Technology, Baotou 014010, China; (Q.S.); (C.M.); (J.G.); (M.W.); (P.J.); (Y.W.); (Y.W.)
- Inner Mongolia Engineering Research Center of Comprehensive Utilization of Bio-Coal Chemical Industry, Inner Mongolia University of Science & Technology, Baotou 014010, China
- Aerogel Functional Nanomaterials Laboratory, Inner Mongolia University of Science & Technology, Baotou 014010, China
| | - Changqing Miao
- School of Chemistry and Chemical Engineering, Inner Mongolia University of Science & Technology, Baotou 014010, China; (Q.S.); (C.M.); (J.G.); (M.W.); (P.J.); (Y.W.); (Y.W.)
- Inner Mongolia Engineering Research Center of Comprehensive Utilization of Bio-Coal Chemical Industry, Inner Mongolia University of Science & Technology, Baotou 014010, China
- Aerogel Functional Nanomaterials Laboratory, Inner Mongolia University of Science & Technology, Baotou 014010, China
| | - Huazheng Sai
- School of Chemistry and Chemical Engineering, Inner Mongolia University of Science & Technology, Baotou 014010, China; (Q.S.); (C.M.); (J.G.); (M.W.); (P.J.); (Y.W.); (Y.W.)
- Inner Mongolia Engineering Research Center of Comprehensive Utilization of Bio-Coal Chemical Industry, Inner Mongolia University of Science & Technology, Baotou 014010, China
- Aerogel Functional Nanomaterials Laboratory, Inner Mongolia University of Science & Technology, Baotou 014010, China
- Correspondence: (H.S.); (R.F.)
| | - Jie Gu
- School of Chemistry and Chemical Engineering, Inner Mongolia University of Science & Technology, Baotou 014010, China; (Q.S.); (C.M.); (J.G.); (M.W.); (P.J.); (Y.W.); (Y.W.)
- Inner Mongolia Engineering Research Center of Comprehensive Utilization of Bio-Coal Chemical Industry, Inner Mongolia University of Science & Technology, Baotou 014010, China
- Aerogel Functional Nanomaterials Laboratory, Inner Mongolia University of Science & Technology, Baotou 014010, China
| | - Meijuan Wang
- School of Chemistry and Chemical Engineering, Inner Mongolia University of Science & Technology, Baotou 014010, China; (Q.S.); (C.M.); (J.G.); (M.W.); (P.J.); (Y.W.); (Y.W.)
- Inner Mongolia Engineering Research Center of Comprehensive Utilization of Bio-Coal Chemical Industry, Inner Mongolia University of Science & Technology, Baotou 014010, China
- Aerogel Functional Nanomaterials Laboratory, Inner Mongolia University of Science & Technology, Baotou 014010, China
| | - Pengjie Jiang
- School of Chemistry and Chemical Engineering, Inner Mongolia University of Science & Technology, Baotou 014010, China; (Q.S.); (C.M.); (J.G.); (M.W.); (P.J.); (Y.W.); (Y.W.)
- Inner Mongolia Engineering Research Center of Comprehensive Utilization of Bio-Coal Chemical Industry, Inner Mongolia University of Science & Technology, Baotou 014010, China
- Aerogel Functional Nanomaterials Laboratory, Inner Mongolia University of Science & Technology, Baotou 014010, China
| | - Yutong Wang
- School of Chemistry and Chemical Engineering, Inner Mongolia University of Science & Technology, Baotou 014010, China; (Q.S.); (C.M.); (J.G.); (M.W.); (P.J.); (Y.W.); (Y.W.)
- Inner Mongolia Engineering Research Center of Comprehensive Utilization of Bio-Coal Chemical Industry, Inner Mongolia University of Science & Technology, Baotou 014010, China
- Aerogel Functional Nanomaterials Laboratory, Inner Mongolia University of Science & Technology, Baotou 014010, China
| | - Rui Fu
- School of Chemistry and Chemical Engineering, Inner Mongolia University of Science & Technology, Baotou 014010, China; (Q.S.); (C.M.); (J.G.); (M.W.); (P.J.); (Y.W.); (Y.W.)
- Inner Mongolia Engineering Research Center of Comprehensive Utilization of Bio-Coal Chemical Industry, Inner Mongolia University of Science & Technology, Baotou 014010, China
- Aerogel Functional Nanomaterials Laboratory, Inner Mongolia University of Science & Technology, Baotou 014010, China
- Correspondence: (H.S.); (R.F.)
| | - Yaxiong Wang
- School of Chemistry and Chemical Engineering, Inner Mongolia University of Science & Technology, Baotou 014010, China; (Q.S.); (C.M.); (J.G.); (M.W.); (P.J.); (Y.W.); (Y.W.)
- Inner Mongolia Engineering Research Center of Comprehensive Utilization of Bio-Coal Chemical Industry, Inner Mongolia University of Science & Technology, Baotou 014010, China
- Aerogel Functional Nanomaterials Laboratory, Inner Mongolia University of Science & Technology, Baotou 014010, China
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