Pub Date : 2025-02-25DOI: 10.1016/j.matchemphys.2025.130602
Manish Yadav, Lekshmi S. Kumar, Gaurav C. Pandey, Chandana Rath
Here, we have investigated structural, optical and magnetic properties of CeCr1-xFexO3 (0.2 ≤ x ≤ 0.5) nanoparticles synthesized through combustion technique. Structural parameters determined from refinement shows that with increase in x from 0.2 to 0.5, both lattice parameters and volume increase. In addition to Fe3+ and Cr3+, we observe Fe2+ and Cr6+ from XPS (X-ray photoelectron spectroscopy) spectra and the concentration of Fe2+ increases more than that of Cr6+, showing an increase in lattice parameters. Band gap varies from 2.56 to 1.15 eV with increasing x from 0.2 to 0.5 which is ascribed to an increase in the ratio of Fe2+ to Fe3+ along with the increase in particle size. Surprisingly, the spin reorientation temperature, TSR increases from 62 K to 138 K with increase in x from 0.2 to 0.5 respectively. The increase in TSR is attributed to the enhanced Ce3+-Fe3+ interaction at the expense of Ce3+-Cr3+ interaction. Besides, an anomalous increase in HC has been observed at the vicinity of TSR irrespective of composition. With increasing x, the increase in Fe2+ concentration introduces double exchange interaction (Cr3+/Fe3+-Fe2+) and results in transition from complex antiferromagnetic (AFM) behavior to ferromagnetic (FM) one when x = 0.5. The enhancement in TSR along with tunable coercivity make these materials a potential candidate for spintronics, and magnetic switching devices.
{"title":"Tuning of band gap, spin reorientation transition along with unusual coercivity in CeCr1-xFexO3 (0.2 ≤ x ≤0.5) perovskite nanoparticles","authors":"Manish Yadav, Lekshmi S. Kumar, Gaurav C. Pandey, Chandana Rath","doi":"10.1016/j.matchemphys.2025.130602","DOIUrl":"10.1016/j.matchemphys.2025.130602","url":null,"abstract":"<div><div>Here, we have investigated structural, optical and magnetic properties of CeCr<sub>1-<em>x</em></sub>Fe<sub><em>x</em></sub>O<sub>3</sub> (0.2 ≤ <em>x</em> ≤ 0.5) nanoparticles synthesized through combustion technique. Structural parameters determined from refinement shows that with increase in <em>x</em> from 0.2 to 0.5, both lattice parameters and volume increase. In addition to Fe<sup>3+</sup> and Cr<sup>3+</sup>, we observe Fe<sup>2+</sup> and Cr<sup>6+</sup> from XPS (X-ray photoelectron spectroscopy) spectra and the concentration of Fe<sup>2+</sup> increases more than that of Cr<sup>6+</sup>, showing an increase in lattice parameters. Band gap varies from 2.56 to 1.15 eV with increasing <em>x</em> from 0.2 to 0.5 which is ascribed to an increase in the ratio of Fe<sup>2+</sup> to Fe<sup>3+</sup> along with the increase in particle size. Surprisingly, the spin reorientation temperature, <em>T</em><sub>SR</sub> increases from 62 K to 138 K with increase in <em>x</em> from 0.2 to 0.5 respectively. The increase in <em>T</em><sub>SR</sub> is attributed to the enhanced Ce<sup>3+</sup>-Fe<sup>3+</sup> interaction at the expense of Ce<sup>3+</sup>-Cr<sup>3+</sup> interaction. Besides, an anomalous increase in <em>H</em><sub>C</sub> has been observed at the vicinity of <em>T</em><sub>SR</sub> irrespective of composition. With increasing <em>x</em>, the increase in Fe<sup>2+</sup> concentration introduces double exchange interaction (Cr<sup>3+</sup>/Fe<sup>3+</sup>-Fe<sup>2+</sup>) and results in transition from complex antiferromagnetic (AFM) behavior to ferromagnetic (FM) one when <em>x</em> = 0.5. The enhancement in <em>T</em><sub>SR</sub> along with tunable coercivity make these materials a potential candidate for spintronics, and magnetic switching devices.</div></div>","PeriodicalId":18227,"journal":{"name":"Materials Chemistry and Physics","volume":"337 ","pages":"Article 130602"},"PeriodicalIF":4.3,"publicationDate":"2025-02-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143529633","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-25DOI: 10.1016/j.matchemphys.2025.130597
Mohsen Saremi Ghareh Gol, Abolfazl Malti, Farshad Akhlaghi
This research investigates the characteristics of a newly developed Al-WC-graphene nanocomposite, fabricated via flake powder metallurgy (FPM) technique. For exploring the best root for a successful graphene nanosheets (GNSs) dispersion, two distinct mixing procedure examined. The effects of GNS concentration and FPM processing parameters on the microstructure, porosity, hardness, fracture and dry sliding wear behavior of the produced nanocomposites were studied by XRD, FESEM, OM, density measurement, hardness measurement and pin-on-disk wearing test techniques. Findings revealed that 6 h of concurrent milling produced optimal porosity and hardness. While increasing GNSs content led to decreased density, addition of 0.5 vol% of GNSs improved the microhardness by up to 105 % as compared to that of the reference sample. Analysis of the fracture surfaces indicated diminishing of the composite's ductility by graphene addition. The nanocomposite containing 0.5 vol% of GNSs demonstrated superior wear resistance (up to 38 % improvement) under low loads and distances, whereas 1 vol% GNSs addition enhanced tribological performance (up to 33 % improvement) at higher loads and distances. These results attributed to formation of a protective tribo-layer that provided insights into the underlying wear mechanisms.
{"title":"Synergistic effects of graphene nanosheets on the microstructure, hardness and tribological performance of Al/WC nanocomposites fabricated by flake powder metallurgy","authors":"Mohsen Saremi Ghareh Gol, Abolfazl Malti, Farshad Akhlaghi","doi":"10.1016/j.matchemphys.2025.130597","DOIUrl":"10.1016/j.matchemphys.2025.130597","url":null,"abstract":"<div><div>This research investigates the characteristics of a newly developed Al-WC-graphene nanocomposite, fabricated via flake powder metallurgy (FPM) technique. For exploring the best root for a successful graphene nanosheets (GNSs) dispersion, two distinct mixing procedure examined. The effects of GNS concentration and FPM processing parameters on the microstructure, porosity, hardness, fracture and dry sliding wear behavior of the produced nanocomposites were studied by XRD, FESEM, OM, density measurement, hardness measurement and pin-on-disk wearing test techniques. Findings revealed that 6 h of concurrent milling produced optimal porosity and hardness. While increasing GNSs content led to decreased density, addition of 0.5 vol% of GNSs improved the microhardness by up to 105 % as compared to that of the reference sample. Analysis of the fracture surfaces indicated diminishing of the composite's ductility by graphene addition. The nanocomposite containing 0.5 vol% of GNSs demonstrated superior wear resistance (up to 38 % improvement) under low loads and distances, whereas 1 vol% GNSs addition enhanced tribological performance (up to 33 % improvement) at higher loads and distances. These results attributed to formation of a protective tribo-layer that provided insights into the underlying wear mechanisms.</div></div>","PeriodicalId":18227,"journal":{"name":"Materials Chemistry and Physics","volume":"337 ","pages":"Article 130597"},"PeriodicalIF":4.3,"publicationDate":"2025-02-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143510969","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-25DOI: 10.1016/j.matchemphys.2025.130604
Mohanram Murugan, Jayakrishna Kandasamy, S. Arulvel
During electrophoretic deposition (EPD), the deposition rate is crucial for preventing particle aggregation, which can lead to uneven distribution of nanoparticles on the SS316L surface. In this study, the deposition rate was optimized by analyzing the physical and surface properties of ZHP (ZnO (Zinc Oxide)/HAp (Hydroxyapatite)/PMEA (Polymethoxyethylacrylate)) nanocomposite coatings. The primary factors controlling the deposition rate with varied applied voltages (50 and 60 V) are temperature and current. At 60 V, the increased temperature reduces viscosity and improves the mobility of ZHP nanocomposites. Additionally, the increased current ensures a denser coating with fewer defects. To verify these effects, the physical properties of the ZHP nanocomposite coatings were characterized by surface analysis, X-ray diffraction, vibrational spectroscopy, and surface energy analysis. Among the ZHP nanocomposite coatings, ZHP-2 (0.115 % (w/V)–ZnO, 0.115 % (w/V)-HAp, 15.39 % (v/V)-PMEA, at 60V) showed a crack-free, less porous, and evenly distributed surface. X-ray diffraction analysis revealed that ZHP-2 had a reduced crystal diameter, increased micro-strain, decreased lattice constant, and increased dislocation density compared to ZHP-1 (0.115 % (w/V)–ZnO, 0.115 % (w/V)-HAp, 15.39 % (v/V)-PMEA, at 50V). Vibrational spectroscopy results confirmed the higher functionalization of the functional groups of additives and nanoparticles (ZnO and HAp) in ZHP-2. Lower surface energy indicated that hydrophobicity was present on the ZHP-2 coating. Further, the ZHP-2 showed significant improvements in surface properties such as general shear failure, higher hardness, lower roughness, higher bonding strength, higher scratch hardness, and shallower scratch depth. Therefore, the ZHP-2 nanocomposite coating exhibited a controlled deposition rate by reducing particle aggregation during EPD.
{"title":"Effect of applied voltage on surface properties of electrophoretic hybrid ZnO/HAp/PMEA coated stainless steel 316L","authors":"Mohanram Murugan, Jayakrishna Kandasamy, S. Arulvel","doi":"10.1016/j.matchemphys.2025.130604","DOIUrl":"10.1016/j.matchemphys.2025.130604","url":null,"abstract":"<div><div>During electrophoretic deposition (EPD), the deposition rate is crucial for preventing particle aggregation, which can lead to uneven distribution of nanoparticles on the SS316L surface. In this study, the deposition rate was optimized by analyzing the physical and surface properties of ZHP (ZnO (Zinc Oxide)/HAp (Hydroxyapatite)/PMEA (Polymethoxyethylacrylate)) nanocomposite coatings. The primary factors controlling the deposition rate with varied applied voltages (50 and 60 V) are temperature and current. At 60 V, the increased temperature reduces viscosity and improves the mobility of ZHP nanocomposites. Additionally, the increased current ensures a denser coating with fewer defects. To verify these effects, the physical properties of the ZHP nanocomposite coatings were characterized by surface analysis, X-ray diffraction, vibrational spectroscopy, and surface energy analysis. Among the ZHP nanocomposite coatings, ZHP-2 (0.115 % (w/V)–ZnO, 0.115 % (w/V)-HAp, 15.39 % (v/V)-PMEA, at 60V) showed a crack-free, less porous, and evenly distributed surface. X-ray diffraction analysis revealed that ZHP-2 had a reduced crystal diameter, increased micro-strain, decreased lattice constant, and increased dislocation density compared to ZHP-1 (0.115 % (w/V)–ZnO, 0.115 % (w/V)-HAp, 15.39 % (v/V)-PMEA, at 50V). Vibrational spectroscopy results confirmed the higher functionalization of the functional groups of additives and nanoparticles (ZnO and HAp) in ZHP-2. Lower surface energy indicated that hydrophobicity was present on the ZHP-2 coating. Further, the ZHP-2 showed significant improvements in surface properties such as general shear failure, higher hardness, lower roughness, higher bonding strength, higher scratch hardness, and shallower scratch depth. Therefore, the ZHP-2 nanocomposite coating exhibited a controlled deposition rate by reducing particle aggregation during EPD.</div></div>","PeriodicalId":18227,"journal":{"name":"Materials Chemistry and Physics","volume":"337 ","pages":"Article 130604"},"PeriodicalIF":4.3,"publicationDate":"2025-02-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143529576","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-25DOI: 10.1016/j.matchemphys.2025.130617
Ehsan Heidari, Shima Moazami, Abbas Bahrami, Sima Torkian
This study investigates the microstructure, corrosion behavior, biocompatibility, and cytotoxicity of TiAlFeCoNi and TiAlFeCoCu high-entropy alloy thin films, deposited on AISI 316L stainless steel by direct current magnetron sputtering. Grazing incidence X-ray diffraction (GIXRD), electron microscope, potentiodynamic polarization, and electrochemical impedance spectroscopy (EIS) were used to investigate microstructural and electrochemical properties of deposited thin films. GIXRD and FE-SEM results showed that elements are homogenously distributed in the coating layers and that the coatings have amorphous structure. The potentiodynamic polarization results suggests that both compositions have improved the corrosion resistance of the base alloy. In vitro biomineralization test showed that both compositions are indeed bioactive, given that crystals of hydroxyapatite were formed on both coatings after 7 days of immersion in the simulated body fluid (SBF), as opposed to the stainless-steel substrate which did not show any noticeable bioactivity. Cytotoxicity assessments showed that the TiAlFeCoNi coating has comparatively much higher cell viability. Overall, TiAlFeCoNi appears to be a very promising coating for biomedical applications.
{"title":"On the microstructure, electrochemical properties, biocompatibility, and cytotoxicity of TiAlFeCoX (X=Ni, Cu) high-entropy alloy thin films, deposited by DC magnetron sputtering","authors":"Ehsan Heidari, Shima Moazami, Abbas Bahrami, Sima Torkian","doi":"10.1016/j.matchemphys.2025.130617","DOIUrl":"10.1016/j.matchemphys.2025.130617","url":null,"abstract":"<div><div>This study investigates the microstructure, corrosion behavior, biocompatibility, and cytotoxicity of TiAlFeCoNi and TiAlFeCoCu high-entropy alloy thin films, deposited on AISI 316L stainless steel by direct current magnetron sputtering. Grazing incidence X-ray diffraction (GIXRD), electron microscope, potentiodynamic polarization, and electrochemical impedance spectroscopy (EIS) were used to investigate microstructural and electrochemical properties of deposited thin films. GIXRD and FE-SEM results showed that elements are homogenously distributed in the coating layers and that the coatings have amorphous structure. The potentiodynamic polarization results suggests that both compositions have improved the corrosion resistance of the base alloy. <em>In vitro</em> biomineralization test showed that both compositions are indeed bioactive, given that crystals of hydroxyapatite were formed on both coatings after 7 days of immersion in the simulated body fluid (SBF), as opposed to the stainless-steel substrate which did not show any noticeable bioactivity. Cytotoxicity assessments showed that the TiAlFeCoNi coating has comparatively much higher cell viability. Overall, TiAlFeCoNi appears to be a very promising coating for biomedical applications.</div></div>","PeriodicalId":18227,"journal":{"name":"Materials Chemistry and Physics","volume":"337 ","pages":"Article 130617"},"PeriodicalIF":4.3,"publicationDate":"2025-02-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143519308","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-25DOI: 10.1016/j.matchemphys.2025.130615
T. García-Mendoza , J.B. Martinez Enriquez , D. Ordaz Rosado , J. Zamora , M.A. Peña-Rico , A.K. Navarro-Mtz , A. Cruz-Nolasco , A. Martinez-Garcia , C.G. Garay-Reyes , G. Vásquez-Victorio , A.J. Cortés-López , F. Chiñas Castillo , E.A. Juarez-Arellano
This study investigates the synthesis and characterization of non-equiatomic high-entropy alloys (HEAs) within the Al10+xM12-xFe35Mn23Ni20 system (where M = Cr, Mo; x = 0, 0.2). Empirical mathematical models were employed to predict the formation of single-phase structures, which were then verified experimentally. The HEAs were synthesized via mechanosynthesis. The influence of ethanol as a process control agent (PCA) was also evaluated. High-energy ball milling for 120 min yielded the desired HEAs. A single-phase structure was observed for the system with Cr, whereas multiphase structures were observed when Cr was substituted for Mo. The synthesized materials were characterized structurally, microstructurally, elementally, thermally, and magnetically. The use of PCA significantly influences various properties, including particle size, phase formation, thermal-magnetic behavior, and cytotoxicity. While PCA generally improves the particle size distribution, it also promotes the formation of multiphase structures in some cases. Notably, PCA treatment led to a significant increase in the saturation magnetization. Unexpectedly, PCA diminished the cytotoxicity of HEAs. All the products exhibited thermal stability up to 1100 K and showed a tendency for nitrogen absorption. The cytotoxic effects of the synthesized HEAs were evaluated for the first time in healthy human kidney cells (HEK 293T cell line) and tumor cells (C6 glioma cell line). Notably, HEAs synthesized without PCA exhibited significant cytotoxicity, significantly reducing the viability of tumor cells (∼70-40 %), while maintaining good biocompatibility with healthy kidney cells. These findings suggest potential biomedical applications for these HEAs.
{"title":"Mechanosynthesis, characterization, and cytotoxic evaluation of soft ferromagnetic non-equiatomic high entropy alloys in the system Al10+xM12-xFe35Mn23Ni20 (M = Cr, Mo; x = 0, 0.2)","authors":"T. García-Mendoza , J.B. Martinez Enriquez , D. Ordaz Rosado , J. Zamora , M.A. Peña-Rico , A.K. Navarro-Mtz , A. Cruz-Nolasco , A. Martinez-Garcia , C.G. Garay-Reyes , G. Vásquez-Victorio , A.J. Cortés-López , F. Chiñas Castillo , E.A. Juarez-Arellano","doi":"10.1016/j.matchemphys.2025.130615","DOIUrl":"10.1016/j.matchemphys.2025.130615","url":null,"abstract":"<div><div>This study investigates the synthesis and characterization of non-equiatomic high-entropy alloys (HEAs) within the Al<sub>10+x</sub>M<sub>12-x</sub>Fe<sub>35</sub>Mn<sub>23</sub>Ni<sub>20</sub> system (where M = Cr, Mo; x = 0, 0.2). Empirical mathematical models were employed to predict the formation of single-phase structures, which were then verified experimentally. The HEAs were synthesized via mechanosynthesis. The influence of ethanol as a process control agent (PCA) was also evaluated. High-energy ball milling for 120 min yielded the desired HEAs. A single-phase structure was observed for the system with Cr, whereas multiphase structures were observed when Cr was substituted for Mo. The synthesized materials were characterized structurally, microstructurally, elementally, thermally, and magnetically. The use of PCA significantly influences various properties, including particle size, phase formation, thermal-magnetic behavior, and cytotoxicity. While PCA generally improves the particle size distribution, it also promotes the formation of multiphase structures in some cases. Notably, PCA treatment led to a significant increase in the saturation magnetization. Unexpectedly, PCA diminished the cytotoxicity of HEAs. All the products exhibited thermal stability up to 1100 K and showed a tendency for nitrogen absorption. The cytotoxic effects of the synthesized HEAs were evaluated for the first time in healthy human kidney cells (HEK 293T cell line) and tumor cells (C6 glioma cell line). Notably, HEAs synthesized without PCA exhibited significant cytotoxicity, significantly reducing the viability of tumor cells (∼70-40 %), while maintaining good biocompatibility with healthy kidney cells. These findings suggest potential biomedical applications for these HEAs.</div></div>","PeriodicalId":18227,"journal":{"name":"Materials Chemistry and Physics","volume":"337 ","pages":"Article 130615"},"PeriodicalIF":4.3,"publicationDate":"2025-02-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143519184","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-25DOI: 10.1016/j.matchemphys.2025.130600
Michele Vergari , Skerxho Osmani , Andrea Basagni , Enrico Scattolin , Martina Rea , Alberto Gasparotto , Gian Andrea Rizzi , Luca Gavioli
In the present work, composite films consisting of Bi24Fe2O39 nanocrystals and an amorphous iron oxide (FeOx) phase have been fabricated by a pulsed micro-plasma cluster source (PMCS) coupled with supersonic cluster beam deposition (SCBD) on a fluorine-doped tin oxide glass substrate, followed by air annealing. The use of BiFe targets with different composition allowed to tailor the Fe/Bi relative concentration from 6 % to 71 % in the resulting electrode materials, that were tested as photoanodes for the oxygen evolution reaction (OER), both in KOH aqueous solutions and in the presence of Na2SO3 as holes scavenger. The morphological characterization shows the presence of a crystalline Bi24Fe2O39 phase surrounded by a dominant amorphous FeOx matrix. Electrochemical tests on such FeOx/Bi24Fe2O39 phases reveals that the improvement of the charge transfer and charge injection constants, the shift of the flat band potential from 0.39 to 0.75 V vs. RHE and the increased photocurrent take place for an increased relative Fe content. The presence of FeOx amorphous phase is indeed responsible for the band gap reduction from 2.57 to 2.36 eV, enabling enhanced visible light absorption, and of the significantly improved charge injection efficiency in the electrolyte solution at high biases, confirming that Fe sites are better for hole injection compared to Bi centers.
{"title":"Influence of surface iron content on the photoelectrochemical properties of BiFeO films deposited via SCBD","authors":"Michele Vergari , Skerxho Osmani , Andrea Basagni , Enrico Scattolin , Martina Rea , Alberto Gasparotto , Gian Andrea Rizzi , Luca Gavioli","doi":"10.1016/j.matchemphys.2025.130600","DOIUrl":"10.1016/j.matchemphys.2025.130600","url":null,"abstract":"<div><div>In the present work, composite films consisting of Bi<sub>24</sub>Fe<sub>2</sub>O<sub>39</sub> nanocrystals and an amorphous iron oxide (FeO<sub>x</sub>) phase have been fabricated by a pulsed micro-plasma cluster source (PMCS) coupled with supersonic cluster beam deposition (SCBD) on a fluorine-doped tin oxide glass substrate, followed by air annealing. The use of BiFe targets with different composition allowed to tailor the Fe/Bi relative concentration from 6 % to 71 % in the resulting electrode materials, that were tested as photoanodes for the oxygen evolution reaction (OER), both in KOH aqueous solutions and in the presence of Na<sub>2</sub>SO<sub>3</sub> as holes scavenger. The morphological characterization shows the presence of a crystalline Bi<sub>24</sub>Fe<sub>2</sub>O<sub>39</sub> phase surrounded by a dominant amorphous FeO<sub>x</sub> matrix. Electrochemical tests on such FeO<sub>x</sub>/Bi<sub>24</sub>Fe<sub>2</sub>O<sub>39</sub> phases reveals that the improvement of the charge transfer and charge injection constants, the shift of the flat band potential from 0.39 to 0.75 V vs. RHE and the increased photocurrent take place for an increased relative Fe content. The presence of FeO<sub>x</sub> amorphous phase is indeed responsible for the band gap reduction from 2.57 to 2.36 eV, enabling enhanced visible light absorption, and of the significantly improved charge injection efficiency in the electrolyte solution at high biases, confirming that Fe sites are better for hole injection compared to Bi centers.</div></div>","PeriodicalId":18227,"journal":{"name":"Materials Chemistry and Physics","volume":"337 ","pages":"Article 130600"},"PeriodicalIF":4.3,"publicationDate":"2025-02-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143519182","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-25DOI: 10.1016/j.matchemphys.2025.130613
Yuan Zhong , Jinli Li , Huaiyou Wang , Min Wang
Sulfates exhibit high melting and decomposition temperatures, making them promising candidates for application in third-generation concentrated solar power systems. Sulfates in salt lakes typically crystallize as MgSO4·7H2O. This study investigates the thermal decomposition mechanism of MgSO4·7H2O through a combination of thermodynamic calculations and experimental characterization techniques, including thermogravimetry-differential scanning calorimetry (TG/DSC), X-ray diffraction (XRD), and thermogravimetry-Fourier transform infrared spectroscopy (TG/FTIR). The results reveal that the dehydration of MgSO4·7H2O proceeds through intermediate phases, yielding MgSO4·6H2O, MgSO4·H2O, and ultimately MgSO4, without the formation of hydrolysis products. Phase-pure MgSO4 can be effectively prepared through heating MgSO4·7H2O within the temperature range of 300 °C–850 °C. The decomposition of MgSO4 produces MgO along with gaseous SO3, SO2, and O2. The decomposition of MgSO4 in atmospheric environment was found to be a gradual process, with initial and complete decomposition temperatures of 875.21 °C and 1044.3 °C, respectively. This study provides a thermodynamic basis for comprehending the thermal decomposition behavior of MgSO4·7H2O, and offers fundamental data for the application of MgSO4·7H2O and MgSO4 as energy storage materials.
{"title":"Thermal decomposition mechanism of MgSO4·7H2O","authors":"Yuan Zhong , Jinli Li , Huaiyou Wang , Min Wang","doi":"10.1016/j.matchemphys.2025.130613","DOIUrl":"10.1016/j.matchemphys.2025.130613","url":null,"abstract":"<div><div>Sulfates exhibit high melting and decomposition temperatures, making them promising candidates for application in third-generation concentrated solar power systems. Sulfates in salt lakes typically crystallize as MgSO<sub>4</sub>·7H<sub>2</sub>O. This study investigates the thermal decomposition mechanism of MgSO<sub>4</sub>·7H<sub>2</sub>O through a combination of thermodynamic calculations and experimental characterization techniques, including thermogravimetry-differential scanning calorimetry (TG/DSC), X-ray diffraction (XRD), and thermogravimetry-Fourier transform infrared spectroscopy (TG/FTIR). The results reveal that the dehydration of MgSO<sub>4</sub>·7H<sub>2</sub>O proceeds through intermediate phases, yielding MgSO<sub>4</sub>·6H<sub>2</sub>O, MgSO<sub>4</sub>·H<sub>2</sub>O, and ultimately MgSO<sub>4</sub>, without the formation of hydrolysis products. Phase-pure MgSO<sub>4</sub> can be effectively prepared through heating MgSO<sub>4</sub>·7H<sub>2</sub>O within the temperature range of 300 °C–850 °C. The decomposition of MgSO<sub>4</sub> produces MgO along with gaseous SO<sub>3</sub>, SO<sub>2</sub>, and O<sub>2</sub>. The decomposition of MgSO<sub>4</sub> in atmospheric environment was found to be a gradual process, with initial and complete decomposition temperatures of 875.21 °C and 1044.3 °C, respectively. This study provides a thermodynamic basis for comprehending the thermal decomposition behavior of MgSO<sub>4</sub>·7H<sub>2</sub>O, and offers fundamental data for the application of MgSO<sub>4</sub>·7H<sub>2</sub>O and MgSO<sub>4</sub> as energy storage materials.</div></div>","PeriodicalId":18227,"journal":{"name":"Materials Chemistry and Physics","volume":"337 ","pages":"Article 130613"},"PeriodicalIF":4.3,"publicationDate":"2025-02-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143510968","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-24DOI: 10.1016/j.matchemphys.2025.130609
Rashid Fareed , Ambreen Bashir , Soumaya Gouadria , Sana Iqbal , Muhammad Rafaqat , Chang-Feng Yan , Said Mansour , Shoukat Alim Khan , Muammer Koc , Tauseef Munawar , Faisal Iqbal
Developing low-cost and efficient electrocatalysts to drive hydrogen and oxygen evolution reactions in electrochemical water splitting is a crucial demand on an industrial scale. In this work, the hydrothermal strategy is adopted to fabricate an electrocatalyst based on Sm2Se3 and Sm2Se3/g-C3N4 on stainless steel (SS) substrate and reported the OER/HER catalytic performance of both catalysts in an alkaline medium. The different characterization techniques confirm excellent physical properties like phase purity, chemical interaction, chemical composition, and porous sheet-like structure of composite material. Interestingly, this interconnected porous network showed excellent conductivity and abundant active sites, improving OER/HER. The composite catalyst required a low overpotential of 218 mV (for OER) and 277 mV (for HER) to obtain a 10 mA cm−2 current density. The values of Tafel slope and polarization resistance were reduced in the Sm2Se3/g-C3N4 electrocatalyst. In addition, the chronoamperometry test over 45 h confirmed the excellent stability of the composite. This work demonstrates that the strong coupling of metal chalcogenide with C-support opens a new avenue for designing an efficient electrocatalyst for water-splitting applications.
{"title":"Exploiting synergistic effects of graphitic carbon nitride-supported samarium selenide (Sm2Se3/g-C3N4) nanocomposite for efficient OER/HER in an alkaline medium","authors":"Rashid Fareed , Ambreen Bashir , Soumaya Gouadria , Sana Iqbal , Muhammad Rafaqat , Chang-Feng Yan , Said Mansour , Shoukat Alim Khan , Muammer Koc , Tauseef Munawar , Faisal Iqbal","doi":"10.1016/j.matchemphys.2025.130609","DOIUrl":"10.1016/j.matchemphys.2025.130609","url":null,"abstract":"<div><div>Developing low-cost and efficient electrocatalysts to drive hydrogen and oxygen evolution reactions in electrochemical water splitting is a crucial demand on an industrial scale. In this work, the hydrothermal strategy is adopted to fabricate an electrocatalyst based on Sm<sub>2</sub>Se<sub>3</sub> and Sm<sub>2</sub>Se<sub>3</sub>/g-C<sub>3</sub>N<sub>4</sub> on stainless steel (SS) substrate and reported the OER/HER catalytic performance of both catalysts in an alkaline medium. The different characterization techniques confirm excellent physical properties like phase purity, chemical interaction, chemical composition, and porous sheet-like structure of composite material. Interestingly, this interconnected porous network showed excellent conductivity and abundant active sites, improving OER/HER. The composite catalyst required a low overpotential of 218 mV (for OER) and 277 mV (for HER) to obtain a 10 mA cm<sup>−2</sup> current density. The values of Tafel slope and polarization resistance were reduced in the Sm<sub>2</sub>Se<sub>3</sub>/g-C<sub>3</sub>N<sub>4</sub> electrocatalyst. In addition, the chronoamperometry test over 45 h confirmed the excellent stability of the composite. This work demonstrates that the strong coupling of metal chalcogenide with C-support opens a new avenue for designing an efficient electrocatalyst for water-splitting applications.</div></div>","PeriodicalId":18227,"journal":{"name":"Materials Chemistry and Physics","volume":"337 ","pages":"Article 130609"},"PeriodicalIF":4.3,"publicationDate":"2025-02-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143526674","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-24DOI: 10.1016/j.matchemphys.2025.130568
W.A. Hammad , Fahad M. Alqahtani , M.A. Darweesh , M.H.A. Amr , Basant Eweida , Ahmed Bakr
Industrial wastewater often contains high levels of heavy metals, posing significant environmental and public health risks. This study investigates the adsorption efficiency of activated carbon derived from palm fronds treated with H3PO4 (ACTPFs) for the removal of copper ions (Cu (II)) from aqueous solutions. Batch experiments were conducted at room temperature (25 ± 1 °C) to examine the effects of pH, initial metal concentration, adsorbent dosage, and contact time on adsorption. Characterization of ACTPFs was performed using BET (surface area and porosity), SEM (surface morphology), FT-IR, and XRD techniques. The results showed that ACTPFs achieved a Cu (II) removal efficiency of 99.65 % within 90 min under neutral conditions. Thermodynamic studies indicated that the adsorption process is spontaneous and feasible, as evidenced by negative ΔG° values, while positive ΔH° and ΔS° values suggested endothermic and entropy-driven adsorption. Kinetic analysis revealed that the adsorption followed both Freundlich and Langmuir isotherm models, demonstrating favorable adsorption characteristics. The findings confirm that H3PO4-treated palm frond-derived activated carbon is a cost-effective, environmentally friendly, and highly efficient adsorbent for the removal of Cu (II) from industrial wastewater.
{"title":"Innovative methods using palm frond-derived activated carbon for Cu (II) adsorption","authors":"W.A. Hammad , Fahad M. Alqahtani , M.A. Darweesh , M.H.A. Amr , Basant Eweida , Ahmed Bakr","doi":"10.1016/j.matchemphys.2025.130568","DOIUrl":"10.1016/j.matchemphys.2025.130568","url":null,"abstract":"<div><div>Industrial wastewater often contains high levels of heavy metals, posing significant environmental and public health risks. This study investigates the adsorption efficiency of activated carbon derived from palm fronds treated with H<sub>3</sub>PO<sub>4</sub> (ACTPFs) for the removal of copper ions (Cu (II)) from aqueous solutions. Batch experiments were conducted at room temperature (25 ± 1 °C) to examine the effects of pH, initial metal concentration, adsorbent dosage, and contact time on adsorption. Characterization of ACTPFs was performed using BET (surface area and porosity), SEM (surface morphology), FT-IR, and XRD techniques. The results showed that ACTPFs achieved a Cu (II) removal efficiency of 99.65 % within 90 min under neutral conditions. Thermodynamic studies indicated that the adsorption process is spontaneous and feasible, as evidenced by negative ΔG° values, while positive ΔH° and ΔS° values suggested endothermic and entropy-driven adsorption. Kinetic analysis revealed that the adsorption followed both Freundlich and Langmuir isotherm models, demonstrating favorable adsorption characteristics. The findings confirm that H<sub>3</sub>PO<sub>4</sub>-treated palm frond-derived activated carbon is a cost-effective, environmentally friendly, and highly efficient adsorbent for the removal of Cu (II) from industrial wastewater.</div></div>","PeriodicalId":18227,"journal":{"name":"Materials Chemistry and Physics","volume":"339 ","pages":"Article 130568"},"PeriodicalIF":4.3,"publicationDate":"2025-02-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143642170","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-24DOI: 10.1016/j.matchemphys.2025.130612
Nhu Hoa Thi Tran , Tran T.T. Van , Hieu Van Le , Hanh Kieu Thi Ta , Dung Van Hoang
In the realm of biomedical applications, Surface-Enhanced Raman Spectroscopy (SERS) stands out as a potent analytical technique, offering swift analysis and unparalleled sensitivity. This study diverges from conventional single metallic nanoparticles, spotlighting the efficacy of composite materials, particularly the synergy of ZnO flowers (ZnO) and silver nanoparticles (Ag) in SERS biosensor applications. The resulting Ag NPs - decorated ZnO nanoflowers (ZnO–Ag) structure, acting as a SERS substrate, introduces a profusion of "hot spots" through Ag deposition on 3-D ZnO, facilitated by electron transfer between the noble metal and ZnO, ensuring super-stable SERS activity. Our research presents a cost-effective method for fabricating ZnO–Ag SERS substrates that simultaneously exhibit a high density of "hot spots" and exceptional stability in SERS performance. Investigating the enhancement potential, our investigation focuses on ZnO–Ag with thiram, revealing a meager limit of detection (LOD) at 1.14 × 10−11 M and an enhancement factor (EF) of 3.3 × 109. Moreover, considering the number of ZnO layers and optimizing the ZnO surface, an exploration into sensor performance yields compelling results for carbendazim with an LOD of 9.4 × 10−10 M and an EF of 4.9 × 108. This research unveils significant implications, offering a streamlined and remarkably effective solution for the precise detection of pesticide residues in the environment.
{"title":"Study of Ag NPs decorated - ZnO nanoflowers for the SERS - Based detection of pesticides: An experimental approach","authors":"Nhu Hoa Thi Tran , Tran T.T. Van , Hieu Van Le , Hanh Kieu Thi Ta , Dung Van Hoang","doi":"10.1016/j.matchemphys.2025.130612","DOIUrl":"10.1016/j.matchemphys.2025.130612","url":null,"abstract":"<div><div>In the realm of biomedical applications, Surface-Enhanced Raman Spectroscopy (SERS) stands out as a potent analytical technique, offering swift analysis and unparalleled sensitivity. This study diverges from conventional single metallic nanoparticles, spotlighting the efficacy of composite materials, particularly the synergy of ZnO flowers (ZnO) and silver nanoparticles (Ag) in SERS biosensor applications. The resulting Ag NPs - decorated ZnO nanoflowers (ZnO–Ag) structure, acting as a SERS substrate, introduces a profusion of \"hot spots\" through Ag deposition on 3-D ZnO, facilitated by electron transfer between the noble metal and ZnO, ensuring super-stable SERS activity. Our research presents a cost-effective method for fabricating ZnO–Ag SERS substrates that simultaneously exhibit a high density of \"hot spots\" and exceptional stability in SERS performance. Investigating the enhancement potential, our investigation focuses on ZnO–Ag with thiram, revealing a meager limit of detection (LOD) at 1.14 × 10<sup>−11</sup> M and an enhancement factor (EF) of 3.3 × 10<sup>9</sup>. Moreover, considering the number of ZnO layers and optimizing the ZnO surface, an exploration into sensor performance yields compelling results for carbendazim with an LOD of 9.4 × 10<sup>−10</sup> M and an EF of 4.9 × 10<sup>8</sup>. This research unveils significant implications, offering a streamlined and remarkably effective solution for the precise detection of pesticide residues in the environment.</div></div>","PeriodicalId":18227,"journal":{"name":"Materials Chemistry and Physics","volume":"337 ","pages":"Article 130612"},"PeriodicalIF":4.3,"publicationDate":"2025-02-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143519181","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}