Crystals

Research

36 pages, 12229 KiB

Open AccessArticle

Synthesis, Characterization of Dy₂NdSbO₇/Bi₂WO₆ Heterojunction Photocatalyst and the Application for the Photocatalytic Degradation of Chlorpyrifos under Visible Light Irradiation

by Jingfei Luan, Liang Hao, Ye Yao, Yichun Wang, Guangmin Yang and Jun Li

Crystals 2024, 14(1), 55; https://doi.org/10.3390/cryst14010055 - 30 Dec 2023

Cited by 3 | Viewed by 1431

Abstract

A groundbreaking photocatalytic nanomaterial, Dy₂NdSbO₇, was fabricated smoothly using the hydrothermal synthesis technique for the first time. Apart from that, Dy₂NdSbO₇/Bi₂WO₆ heterojunction photocatalyst (DBHP) was initially fabricated using the solvothermal fabrication technique. [...] Read more.

A groundbreaking photocatalytic nanomaterial, Dy₂NdSbO₇, was fabricated smoothly using the hydrothermal synthesis technique for the first time. Apart from that, Dy₂NdSbO₇/Bi₂WO₆ heterojunction photocatalyst (DBHP) was initially fabricated using the solvothermal fabrication technique. X-ray diffractometer, Fourier-transform infrared spectrometer, Raman spectrometer, UV-visible spectrophotometer, X-ray photoelectron spectrometer, inductively coupled plasma optical emission spectrometer, transmission electron microscope, and X-ray energy dispersive spectroscopy have been applied to evaluate and investigate the thetastructure, morphology, and physicochemical properties of synthesized samples. The results confirmed that the pyrochlore-type crystal structures of Dy₂NdSbO₇ belonged to the Fd3m space group with the cubic crystal system and the β-pyrochlore-type crystal structures of Bi₂WO₆ which belonged to the Pca21 space group with orthorhombic crystal system. Under visible light exposure for 155 min (VLP-155min) using DBHP in the capacity of the photocatalytic nanomaterial, the removal efficiency of chlorpyrifos (CPS) saturation reached 100%. Comparison of CPS removal efficiency after VLP-155min revealed that DBHP exhibited higher removal efficiency than Dy₂NdSbO₇, Bi₂WO₆, or N-doped TiO₂ photocatalyst, with removal efficiency 1.15 times, 1.23 times, or 2.55 times higher, respectively. Furthermore, the oxidizing capability of free radicals was investigated using trapping agents. Results demonstrated that superoxide anions exhibited the strongest oxidative capability, followed by hydroxyl radicals and holes. The results presented in this study lay a robust groundwork for future investigations and advancements in the field of highly efficient heterostructure material. These findings have significant implications for the development of environmental remediation strategies and provide valuable insights into sustainable solutions for addressing CPS contamination. Full article

(This article belongs to the Special Issue Advanced Nanomaterials for Photocatalytic Technologies)

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23 pages, 4046 KiB

Open AccessArticle

Facile Synthesis of Ni-Doped ZnO Nanostructures via Laser-Assisted Chemical Bath Synthesis with High and Durable Photocatalytic Activity

by Samer H. Zyoud, Vanga Ganesh, Che Azurahanim Che Abdullah, Ibrahim S. Yahia, Ahed H. Zyoud, Atef F. I. Abdelkader, Malek G. Daher, Mohamed Nasor, Moyad Shahwan, Heba Y. Zahran, Mahmoud S. Abd El-sadek, Elbadawy A. Kamoun, Saleh M. Altarifi and Mohamed Sh. Abdel-wahab

Crystals 2023, 13(7), 1087; https://doi.org/10.3390/cryst13071087 - 12 Jul 2023

Cited by 13 | Viewed by 3183

Abstract

Pure and Ni-doped (1%, 2%, and 3%) nanostructures were synthesized using a novel laser-assisted chemical bath synthesis (LACBS) technique. For the first time, LACBS was used to create a doping solution utilizing a 7 W blue laser with a 444.4 nm wavelength and [...] Read more.

Pure and Ni-doped (1%, 2%, and 3%) nanostructures were synthesized using a novel laser-assisted chemical bath synthesis (LACBS) technique. For the first time, LACBS was used to create a doping solution utilizing a 7 W blue laser with a 444.4 nm wavelength and a continuous beam. The Ni-doping concentration was varied by changing the amount of Ni precursor added. All samples were analyzed using XRD, SEM, EDX, FTIR, UV–Vis, and photocatalysis tests for photodegradation under blue laser illumination. XRD was used to confirm that the tested ZnO had a hexagonal wurtzite structure. The crystallite size decreased as the Ni-doping concentration rose. EDX experiments were conducted to analyze the elemental characteristics of the pure and Ni-doped (1%, 2%, and 3%) nanostructures. The existence of nanoscale hexagonal structures was confirmed through SEM studies. The band gap values of the pure and Ni-doped ZnO nanostructures decreased as the doping concentration increased. FTIR studies were conducted to examine the functional groups of the pure and doped samples. The produced materials exhibited excellent photocatalytic performance toward the degradation of MB organic dye, an example of a pollutant found in wastewater. Full article

(This article belongs to the Special Issue Advanced Nanomaterials for Photocatalytic Technologies)

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16 pages, 5171 KiB

Open AccessArticle

Nanocrystalline Sulfided NiMoW Catalyst Supported on Mesoporous Aluminas for the Hydrodesulfurization of 4,6-Dimethyldibenzothiophene

by Radostina Palcheva, Luděk Kaluža, Tanya Petrova, Lubomir Dimitrov, Daniela Karashanova, Georgi Tyuliev and Květuše Jirátová

Crystals 2023, 13(3), 543; https://doi.org/10.3390/cryst13030543 - 22 Mar 2023

Cited by 1 | Viewed by 1780

Abstract

Tri-metallic NiMoW catalysts prepared by impregnating mesoporous aluminas (pore sizes of ~9 nm and surface areas of ~225 m²/g) obtained by sol-gel (NiMoW/Al) and hydrothermal (NiMoW/Al_HYDT) processes were investigated in the hydrodesulfurization (HDS) of thiophene and 4,6-dimethyldibenzothiophene (4,6-DMDBT) at [...] Read more.

Tri-metallic NiMoW catalysts prepared by impregnating mesoporous aluminas (pore sizes of ~9 nm and surface areas of ~225 m²/g) obtained by sol-gel (NiMoW/Al) and hydrothermal (NiMoW/Al_HYDT) processes were investigated in the hydrodesulfurization (HDS) of thiophene and 4,6-dimethyldibenzothiophene (4,6-DMDBT) at H₂ pressures of 1 MPa and 5.0 MPa, respectively. The supports and catalysts were characterized by N₂ physisorption, X-ray diffraction (XRD), scanning electron microscopy (SEM), ultraviolet-visible diffuse reflectance spectroscopy (UV-Vis DRS), temperature-programmed reduction (TPR), X-ray photoelectron spectroscopy (XPS), and high-resolution transmission electron microscopy (HRTEM). The NiMoW/Al_HYDT catalyst, which was the most active in both test HDS reactions, was characterized by a pore size of 7.5 nm, whereas the pore size of the catalyst on sol-gel alumina (NiMoW/Al) was only 4.8 nm. Moreover, the NiMoW/Al_HYDT catalyst exhibited reduction peaks shifted to a lower temperature during TPR, indicating weaker metal support interactions, a higher degree of Mo (79%) and W (48%) sulfidation, and an optimal layer slab length distribution of Mo(W)S₂ nanocrystals preferentially between 2–4 nm with an average layer stacking of 1.7 compared to the NiMoW/Al counterpart. Full article

(This article belongs to the Special Issue Advanced Nanomaterials for Photocatalytic Technologies)

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9 pages, 1686 KiB

Open AccessArticle

Photocatalytic Efficiency of TiO₂/Fe₂O₃ and TiO₂/WO₃ Nanocomposites

by Federico Giuffrida, Lucia Calcagno, Gianni Pezzotti Escobar and Massimo Zimbone

Crystals 2023, 13(3), 372; https://doi.org/10.3390/cryst13030372 - 22 Feb 2023

Cited by 2 | Viewed by 2155

Abstract

The photocatalytic proprieties of TiO₂/FeO₃ and TiO₂/WO₃ nanocomposites have been investigated using methylene blue as a pollutant. We propose a non-conventional approach for material preparation, i.e., the Doctor Blade technique, which is an easy and inexpensive method [...] Read more.

The photocatalytic proprieties of TiO₂/FeO₃ and TiO₂/WO₃ nanocomposites have been investigated using methylene blue as a pollutant. We propose a non-conventional approach for material preparation, i.e., the Doctor Blade technique, which is an easy and inexpensive method for coating materials. Several drawbacks related to the use of powders can be alleviated by using solid substrates, and this deposition method allows us to take advantage of the high surface area of nanoparticles, avoiding dispersion in the solution. The possibility of coating a material with a photoactive molecule with an easy and inexpensive method leads to the use of photocatalysis in the real world. The structural, optical, and textural characterizations of these materials were carried out using UV-vis. Diffuse Reflectance Spectroscopy (DRS) was used to calculate the energy band gap with the Kubelka-Munk method, and N₂ absorption-desorption measurements were used to study the exposed surface area (S_BET). The photocatalytic activity was evaluated in nanocomposites containing 0.1/0.2/0.3/0.5 wt.% of Fe₂O₃ or WO₃ or both Fe₂O₃ and WO₃. An enhancement of about 60% was achieved by adding 0.2% wt. of WO₃ after 2 h of exposure to UV light. The TiO₂@Fe₂O₃ and TiO₂@WO₃/Fe₂O₃ mixtures showed the same behavior as the TiO₂@WO₃ mixture. Therefore, the photoactivity of these photocatalysts is not related to the oxide itself. These solid results are due to the energy band structure of the materials. In fact, there is an important band matching among TiO₂, WO₃, and Fe₂O₃, which gives these nanocomposites a substantial improvement in photodegradation. The pH evaluated was neutral pH both at the beginning and at the end of the experiment, which is consistent with the well-known photodegradation pathway of methylene blue. Full article

(This article belongs to the Special Issue Advanced Nanomaterials for Photocatalytic Technologies)

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12 pages, 2125 KiB

Open AccessArticle

The Effect of Titanium Oxyfluoride Morphology on Photocatalytic Activity of Fluorine-Doped Titanium(IV) Oxide

by Marta Kowalkińska, Jakub Karczewski and Anna Zielińska-Jurek

Crystals 2023, 13(2), 356; https://doi.org/10.3390/cryst13020356 - 19 Feb 2023

Cited by 2 | Viewed by 2084

Abstract

Titanium oxyfluoride (TiOF₂) is a metastable product that can be obtained in a fluorine-rich environment. This material can also be a valuable precursor in the synthesis of titanium(IV) oxide (TiO₂). However, the effect of TiOF₂ morphology on the [...] Read more.

Titanium oxyfluoride (TiOF₂) is a metastable product that can be obtained in a fluorine-rich environment. This material can also be a valuable precursor in the synthesis of titanium(IV) oxide (TiO₂). However, the effect of TiOF₂ morphology on the physicochemical properties of TiO₂ has not been studied so far. In this work, single-phase TiOF₂ was prepared by a solvothermal method. The as-synthesized samples exhibited a variety of morphologies, including different shapes and crystallite sizes. These materials were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) combined with energy-dispersive X-ray spectroscopy (EDS), surface area measurements, thermal gravimetric analysis (TGA) and UV–vis diffuse reflectance spectroscopy (DR/UV–vis). Furthermore, TiOF₂ samples were used as precursors in the synthesis of fluorine-doped titanium(IV) oxide and applied in photocatalytic phenol degradation under UV-vis light. The experiments showed that the crystallite size of the precursor, as well as the number of fluoride ions used in the synthesis, were the predominant factors that affected the photocatalytic activity of the final photocatalyst. Full article

(This article belongs to the Special Issue Advanced Nanomaterials for Photocatalytic Technologies)

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12 pages, 4400 KiB

Open AccessArticle

Photocatalytic Degradation of Textile Orange 16 Reactive Dye by ZnO Nanoparticles Synthesized via Green Route Using Punica Granatum Leaf Extract

by Salma A. Al-Zahrani, Mallikarjunagouda B. Patil, Shridhar N. Mathad, Arun Y. Patil, Ahmed A. Otaibi, Najat Masood, Dorsaf Mansour, Anish Khan, A. Manikandan and Edi Syafri

Crystals 2023, 13(2), 172; https://doi.org/10.3390/cryst13020172 - 18 Jan 2023

Cited by 14 | Viewed by 2837 | Correction

Abstract

Since it does not use any dangerous chemicals and is a simple, low-cost process, the green synthesis approach for nanoparticle creation has several benefits compared to the physical and chemical synthesis routes. The current study describes an environmentally friendly synthesis of zinc oxide [...] Read more.

Since it does not use any dangerous chemicals and is a simple, low-cost process, the green synthesis approach for nanoparticle creation has several benefits compared to the physical and chemical synthesis routes. The current study describes an environmentally friendly synthesis of zinc oxide (ZnO) nanoparticles (NPs) using an extract of Punica granatum plant leaves. Fourier-transform infrared spectroscopy (FTIR), ultraviolet-visible spectrophotometer (UV-Vis), field-emission scanning electron microscopy (FESEM), energy-dispersive X-ray spectroscopy, and X-ray diffraction techniques were used to characterize the morphology, composition, and structural properties of the synthesized zinc oxide nanoparticles. The XRD pattern reveals that the ZnO nanoparticles are crystalline and have a diameter of 20 nm. According to the FESEM studies, the ZnO-NPs have sizes ranging from 50 to 100 nm on average and are almost spherical. When exposed to direct sunlight, the produced ZnO-NPs demonstrate impressive photocatalytic oxidation of textile Orange 16, a reactive dye. As a result, our research advances the development of a green photocatalyst for the removal of harmful dyes from water. Full article

(This article belongs to the Special Issue Advanced Nanomaterials for Photocatalytic Technologies)

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Review

Jump to: Research, Other

31 pages, 1544 KiB

Open AccessReview

Synthesis of Bimetallic Nanoparticles and Applications—An Updated Review

by Dahir Sagir Idris and Arpita Roy

Crystals 2023, 13(4), 637; https://doi.org/10.3390/cryst13040637 - 7 Apr 2023

Cited by 46 | Viewed by 11197

Abstract

The manipulation of matter at the atomic level (nanotechnology) has experienced an explosion in research interest in recent years. Bimetallic nanoparticles are vital due to their high biocompatibility, stability and comparatively less toxicity. The synthesis methods that include physical, chemical and biological methods [...] Read more.

The manipulation of matter at the atomic level (nanotechnology) has experienced an explosion in research interest in recent years. Bimetallic nanoparticles are vital due to their high biocompatibility, stability and comparatively less toxicity. The synthesis methods that include physical, chemical and biological methods are explored and explained in detail, along with their advantages. They have a wide range of applications due to their synergistic properties including biological applications (in medicine and agriculture), environmental application (in water treatment and removal of toxic contaminants), engineering application (in nanosensors, nanochips and nano-semiconductors) and chemical and physical application (in optics, catalysis and paints). The green synthesis approach is a promising method of synthesis that can give rise to more biocompatible and less toxic bimetallic nanoparticles due to increasing environmental pollution. However, despite these interesting attributes of bimetallic nanoparticle, there is still much work to be done to improve the biocompatibility of bimetallic nanoparticles because of their toxicity and potentially hazardous effects. Full article

(This article belongs to the Special Issue Advanced Nanomaterials for Photocatalytic Technologies)

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Other

Jump to: Research, Review

1 pages, 161 KiB

Open AccessCorrection

Correction: Al-Zahrani et al. Photocatalytic Degradation of Textile Orange 16 Reactive Dye by ZnO Nanoparticles Synthesized via Green Route Using Punica Granatum Leaf Extract. Crystals 2023, 13, 172

by Salma A. Al-Zahrani, Mallikarjunagouda B. Patil, Shridhar N. Mathad, Arun Y. Patil, Ahmed A. Otaibi, Najat Masood, Dorsaf Mansour, Anish Khan, A. Manikandan and Edi Syafri

Crystals 2023, 13(7), 1024; https://doi.org/10.3390/cryst13071024 - 28 Jun 2023

Cited by 1 | Viewed by 755

Abstract

In the original publication [...] Full article

(This article belongs to the Special Issue Advanced Nanomaterials for Photocatalytic Technologies)

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