Journal of Physics and Chemistry of Solids最新文献

{"title":"DFT and experimental study of Mg substituted strontium oxide for optoelectronic applications","authors":"Hibba Tu Rouf ,&nbsp;Talat Zeeshan ,&nbsp;Maria Khalil ,&nbsp;Farman Ullah ,&nbsp;Shahid M. Ramay ,&nbsp;Murtaza Saleem","doi":"10.1016/j.jpcs.2025.112656","DOIUrl":"10.1016/j.jpcs.2025.112656","url":null,"abstract":"<div><div>Strontium oxide and magnesium-doped compositions were analyzed using density functional theory to explore their electronic, thermoelectric, and optical properties. Magnesium-doped SrO thin films with various concentrations were experimentally prepared on silicon substrates using the sol-gel spin-coating technique. Structural analyses confirmed the stable single-phase cubic crystalline structure, unaffected by doping. Electronic studies revealed a reduced band gap and the formation of states near the Fermi level, improving charge carrier transport. The thermoelectric evaluation indicated enhanced electrical conductivity that observed for pure SrO as 4.42 × 10¹⁹ (Ω m s)⁻¹, whereas 9.43 × 10¹⁹ (Ω m s)⁻¹ for maximum Mg containing composition. The lowered thermal conductivity is contributing to superior thermoelectric performance. Optical analyses demonstrated improved absorption and reduced optical band gap, affirming enhanced light interaction capabilities. The highest refractive index and real epsilon values were recorded at the higher energy regimes approximately 2.94 and 12.89, respectively, for composition containing maximum dopant content. The optical band gap of SrO was calculated as 2.50 eV and found to decrease with increment of Mg substituting concentration. Experimental results showed strong alignment with theoretical predictions, underscoring the potential of Mg-doped SrO thin films as promising candidates for advanced optoelectronic and thermoelectric applications.</div></div>","PeriodicalId":16811,"journal":{"name":"Journal of Physics and Chemistry of Solids","volume":"201 ","pages":"Article 112656"},"PeriodicalIF":4.3,"publicationDate":"2025-02-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143526596","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}

{"title":"Comprehensive analysis of structural, dielectric, magnetic properties in self-propagating high-temperature (SHS) prepared lead iron niobate","authors":"Tanveer Quazi ,&nbsp;Shahin Sayyad ,&nbsp;Vishwajit M. Gaikwad","doi":"10.1016/j.jpcs.2025.112657","DOIUrl":"10.1016/j.jpcs.2025.112657","url":null,"abstract":"<div><div>Lead iron niobate, Pb(Fe_1/2Nb_1/2)O₃ (PFN), was synthesized via a self-propagating high-temperature synthesis (SHS) technique. The SHS process achieved pyrochlore-free monoclinic perovskite (space group Cm) at room temperature, transitioning to cubic symmetry (Pm3 m) above 380 °C, as confirmed by high-temperature XRD (HT-XRD). Lattice contraction with rising temperature revealed negative thermal expansion (NTE), driven by Pb²⁺ vibrational modes and octahedral tilting. Sintering at 800 °C (PFN-8-3) eliminated residual pyrochlore phases (Pb₂Fe₄Nb₄O₂₁) and enhanced relative density to 98 %, compared to 80 % for samples sintered at 700 °C (PFN-7-2). Dielectric studies identified a diffuse phase transition (DPT) near 105–115 °C, with permittivity reaching ∼18,600 (1 kHz) for PFN-8-3, attributed to grain densification and reduced porosity. Frequency-independent T_m and Debye-like relaxation confirmed non-relaxor behavior, linked to ordered Fe³⁺/Nb⁵⁺ B-site cation distribution. Electron density mapping via Fourier analysis highlighted Pb-dominated charge density (∼69 e/ų), with Fe/Nb contributions (∼29–32 e/ų), aligning with X-ray scattering trends. Magnetic hysteresis loops revealed weak room-temperature ferromagnetism, intensifying at higher sintering temperatures (coercivity ∼80 Oe, remnant magnetization ∼0.12 emu/g for PFN-8-3). The coexistence of ferroelectricity and ferromagnetism underscores PFN's potential in multifunctional devices, while the SHS route offers a rapid, energy-efficient pathway to phase-pure perovskites. This work bridges synthesis optimization, structural dynamics, and functional performance, advancing PFN's applicability in high-density capacitors, magnetoelectric sensors, and thermal management systems.</div></div>","PeriodicalId":16811,"journal":{"name":"Journal of Physics and Chemistry of Solids","volume":"201 ","pages":"Article 112657"},"PeriodicalIF":4.3,"publicationDate":"2025-02-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143528725","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}

{"title":"Helical phosphorene nanoribbons: Electronic and magnetic properties","authors":"Rouhollah Farghadan","doi":"10.1016/j.jpcs.2025.112641","DOIUrl":"10.1016/j.jpcs.2025.112641","url":null,"abstract":"<div><div>This study systematically investigates the impact of mechanical deformation and edge structure on the electronic and magnetic properties of phosphorene nanoribbons (PNRs). By examining both armchair and zigzag edge configurations, as well as helicoidal and twisted PNRs, we assess changes in the energy gap, electron and hole effective masses, and magnetic behavior at zigzag edges using the tight-binding and mean-field Hubbard models. The geometry of a helical structure, characterized by its spiral pitch, plays a pivotal role in controlling the strain magnitude. Among the three analyzed nanoribbons — helicoidal armchair, twisted armchair, and twisted zigzag PNRs — nonmagnetic behavior predominantly occurs under helicene conditions. Interestingly, as the strain increases, the energy gap expands. In contrast, helicoidal zigzag PNRs exhibit striking spin-dependent behavior, with the energy gap showing distinct trends for majority and minority electrons. While the gap for one spin state remains unchanged, the other experiences a notable increase. Moreover, The effective mass exhibits a significant rise in armchair edges and varies markedly across spin states and carrier types for zigzag edges. These findings open new possibilities for engineering electronic and magnetic properties in PNRs through controlled mechanical deformation.</div></div>","PeriodicalId":16811,"journal":{"name":"Journal of Physics and Chemistry of Solids","volume":"201 ","pages":"Article 112641"},"PeriodicalIF":4.3,"publicationDate":"2025-02-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143528726","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}

{"title":"19F high-resolution NMR studies on cation distribution and F− dynamics in highly conductive BaF2–CaF2 composite prepared by thermal plasma processing","authors":"Miwa Murakami,&nbsp;Kazuyuki Sato,&nbsp;Kiyonori Takegoshi","doi":"10.1016/j.jpcs.2025.112653","DOIUrl":"10.1016/j.jpcs.2025.112653","url":null,"abstract":"<div><div>Mixing of immiscible BaF₂ and CaF₂ by mechanical milling or thermal plasma processing leads to a solid composite, whose ionic conductivity is much higher than those of BaF₂ and CaF₂. Distribution of Ba and Ca cations in the BaF₂–CaF₂ composite prepared by thermal plasma processing is examined by ¹⁹F NMR. Analysis of signal intensities of ¹⁹F high-resolution solid-state NMR shows that occupation ratios for the cations at four vertexes of a tetrahedron unit in a fluorite-type structure with one fluoride ion at its center are roughly given by binomial distribution. Further, ¹⁹F–¹⁹F dipolar correlation experiment shows that spatial distribution of both cations is random in a length scale of ca. 2 nm or less. These show that homogeneous mixing of vaporized BaF₂ and CaF₂ in thermal plasma is maintained in solids obtained by rapid cooling and leads to random distribution of both cations. Rearrangement of local configuration of both cations in a length scale less than a few nm occurs well below the decomposition temperature, which relaxes local strain associated with homogeneous mixing of different cations and lowers ionic conductivity. It is further shown that the fluoride ions in Ba-rich local environment are less mobile as compared to those in Ca-rich. The ionic conductivity evaluated using the fluoride-ion exchange rate estimated from ¹⁹F NMR spectra is consistent with the observed one, thus showing that exchange among the fluoride ions in different local environments is the fundamental step of the bulk ion conduction.</div></div>","PeriodicalId":16811,"journal":{"name":"Journal of Physics and Chemistry of Solids","volume":"201 ","pages":"Article 112653"},"PeriodicalIF":4.3,"publicationDate":"2025-02-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143526585","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}

{"title":"Tailoring nickel disulfide for energy applications: A hydrothermal approach to enhanced performance","authors":"Vaibhav B. Sankpal ,&nbsp;Umesh V. Shembade ,&nbsp;Sandeep B. Wategaonkar ,&nbsp;Tukaram D. Dongale ,&nbsp;Annasaheb V. Moholkar ,&nbsp;Mohammad Rafe Hatshan ,&nbsp;Kulurumotlakatla Dasha Kumar ,&nbsp;Rajkumar S. Pandav ,&nbsp;Gopinath S. Khansole","doi":"10.1016/j.jpcs.2025.112652","DOIUrl":"10.1016/j.jpcs.2025.112652","url":null,"abstract":"<div><div>This study focused on synthesizing the nickel disulfide (NiS₂) with a non-uniform microflower morphology via hydrothermal synthesis for supercapacitor and water-splitting applications. X-ray diffraction, Fourier transform infrared and Raman spectroscopy, Scanning electron microscopy, and Transmission electron microscopy confirmed the crystal structure, presence of various functional groups, stretching/bending vibration present in the prepared NiS₂ material, and surface morphology and interatomic illustration of the NiS₂ materials. As a result, the prepared materials were utilized for the electrochemical and electrocatalytic measurements using flexible steel mesh as a working electrode in 1 M KOH via a three-electrode cell system. Using a flexible steel mesh electrode, the optimized NiS₂ electrode exhibited a specific capacitance of 630 F/g at 5 mA/cm² with 92 % retention after 5000 cycles. An assembled asymmetric supercapacitor device achieved energy and power densities of 13 Wh/kg and 900 W/kg, respectively, with good cycling stability. For water splitting, the same electrode showed a low overpotential of 140 mV, a Tafel slope of 73 mV/dec, and a high electrochemically active surface area (46.50 cm²). These results demonstrate the potential of NiS₂ for dual applications in sustainable energy storage and conversion.</div></div>","PeriodicalId":16811,"journal":{"name":"Journal of Physics and Chemistry of Solids","volume":"201 ","pages":"Article 112652"},"PeriodicalIF":4.3,"publicationDate":"2025-02-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143551427","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}

{"title":"Solvent-free mechanochemical synthesis of photocatalytically active nanocomposite based on binary and ternary sulfides of zinc and indium","authors":"Lyazzat Mussapyrova ,&nbsp;Shuoping Ding ,&nbsp;Nina Daneu ,&nbsp;Róbert Džunda ,&nbsp;Zdenka Lukáčová Bujňáková ,&nbsp;Kairat Kenges ,&nbsp;Maximilian Wohlgemuth ,&nbsp;Erika Dutková ,&nbsp;Imelda Octa Tampubolon ,&nbsp;Halyna Bodnár Yankovych ,&nbsp;Rashid Nadirov ,&nbsp;Lars Borchardt ,&nbsp;Norbert Steinfeldt ,&nbsp;Matej Baláž","doi":"10.1016/j.jpcs.2025.112647","DOIUrl":"10.1016/j.jpcs.2025.112647","url":null,"abstract":"<div><div>A novel rapid solvent-free approach for the preparation of a nanocomposite containing the solid solution of zinc indium sulfide (ZIS), binary indium sulfide and a small amount of zinc sulfide is reported herein. In just 15 min of processing the elemental mixture of zinc, indium and sulfur in a planetary ball mill, a considerable amount of nanocrystalline ZIS, with an admixture of binary intermediates was obtained via mechanochemical synthesis (ZIS-15). The detailed investigation of lattice parameters via Rietveld refinement of the XRD data has shown the continuous shrinkage of unit cell upon incorporation of zinc into the lattice of indium sulfide, thus pointing to the formation of a solid solution. When milling was prolonged for a further 15 min (ZIS-30), the color changed from brown to orange and the amount of ZIS further increased, albeit it was not possible to completely transform binary intermediates into ZIS. The zeta potential values were documented to be −21.6 and −11.5 mV for ZIS-15 and ZIS-30, respectively, documenting different surface properties. The difference is most probably caused by the higher content of binary indium sulfide in ZIS-15. The obvious difference was evidenced also in the photocatalytic activity to decompose rhodamine B dye, which was 2.5 times higher in the case of ZIS-15, thus the presence of higher number of binary sulfides seems to be beneficial. ZIS-15 was capable of degrading also non-colored diclofenac sodium. Thus, the actual inability to achieve a complete conversion to ZIS in 30 min is used as a benefit to obtain a photocatalyst with better activity here. The proposed study also highlights a great suitability of solvent-free mechanochemical synthesis for the sustainable production of nanocrystalline semiconductor photocatalysts, as the calculated E-factor of 22.9 is much lower than when using traditional hydrothermal synthesis. This also accounts for the atom economy, as we are using only the reactants forming the product, whereas the classical chemistry uses salts.</div></div>","PeriodicalId":16811,"journal":{"name":"Journal of Physics and Chemistry of Solids","volume":"201 ","pages":"Article 112647"},"PeriodicalIF":4.3,"publicationDate":"2025-02-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143551915","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}

{"title":"Photovoltaic potential of doped MgTiO3 (F, Br, I): prediction of optoelectronic and catalytic within ab initio approach","authors":"Abdellah Bouzaid ,&nbsp;Younes Ziat ,&nbsp;Hamza Belkhanchi","doi":"10.1016/j.jpcs.2025.112648","DOIUrl":"10.1016/j.jpcs.2025.112648","url":null,"abstract":"&lt;div&gt;&lt;div&gt;This study investigates the structural, electronic, optical, and photocatalytic properties of the perovskite MgTiO&lt;sub&gt;3&lt;/sub&gt;, for pure and doped with halogens F, Br, and I at x = 8.33 % and 16 % concentrations, using an ab initio FP-LAPW method within the DFT framework and employing the GGA-mBJ approximation. The results of structural optimization indicate that both compounds exhibit negative formation energies for pure and doped states, respectively, showing their thermodynamic stability, while doping MgTiO&lt;sub&gt;3&lt;/sub&gt; at oxygen sites with Y (F, Br, and I) significantly decreases the band gap energy compared to pure MgTiO&lt;sub&gt;3&lt;/sub&gt;, which has a band gap of 2.926 eV. Specifically, the band gaps for doped &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;M&lt;/mi&gt;&lt;mi&gt;g&lt;/mi&gt;&lt;/mrow&gt;&lt;mn&gt;4&lt;/mn&gt;&lt;/msub&gt;&lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;T&lt;/mi&gt;&lt;mi&gt;i&lt;/mi&gt;&lt;/mrow&gt;&lt;mn&gt;4&lt;/mn&gt;&lt;/msub&gt;&lt;msub&gt;&lt;mi&gt;O&lt;/mi&gt;&lt;mrow&gt;&lt;mo&gt;(&lt;/mo&gt;&lt;mrow&gt;&lt;mn&gt;12&lt;/mn&gt;&lt;mo&gt;−&lt;/mo&gt;&lt;msub&gt;&lt;mi&gt;n&lt;/mi&gt;&lt;mi&gt;i&lt;/mi&gt;&lt;/msub&gt;&lt;/mrow&gt;&lt;mo&gt;)&lt;/mo&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;msub&gt;&lt;mi&gt;Y&lt;/mi&gt;&lt;mrow&gt;&lt;mi&gt;n&lt;/mi&gt;&lt;mi&gt;i&lt;/mi&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt; where Y&lt;img&gt;F, Br, and I decrease as follows: at x = 8.33 %, the gaps are 2.61, 1.91, and 1.28 eV; at x = 16 %, they are approximately 2.82, 1.85, and 1.53 eV, respectively. This reduction results from introducing additional energy levels just below the conduction band, narrowing the band gap, and raising the Fermi level. Consequently, the material transitions into an n-type semiconductor. Additionally, doping &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;M&lt;/mi&gt;&lt;mi&gt;g&lt;/mi&gt;&lt;/mrow&gt;&lt;mn&gt;4&lt;/mn&gt;&lt;/msub&gt;&lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;T&lt;/mi&gt;&lt;mi&gt;i&lt;/mi&gt;&lt;/mrow&gt;&lt;mn&gt;4&lt;/mn&gt;&lt;/msub&gt;&lt;msub&gt;&lt;mi&gt;O&lt;/mi&gt;&lt;mn&gt;10&lt;/mn&gt;&lt;/msub&gt;&lt;msub&gt;&lt;mi&gt;Y&lt;/mi&gt;&lt;mn&gt;2&lt;/mn&gt;&lt;/msub&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt; (Y&lt;img&gt;Br, I) at x = 16 % reduces the bandgap, which enhances absorption and optical conductivity in the visible range, thus increasing the photocatalytic activity of the materials for hydrogen production. Our results indicate that Br and I doping at this level improves MgTiO&lt;sub&gt;3&lt;/sub&gt; performance in photocatalytic water splitting for hydrogen generation. Furthermore, regarding the impact on photocatalytic activity related to the redox zones (H&lt;sup&gt;+&lt;/sup&gt;/H&lt;sub&gt;2&lt;/sub&gt; and O&lt;sub&gt;2&lt;/sub&gt;/H&lt;sub&gt;2&lt;/sub&gt;O at pH = 7), &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;M&lt;/mi&gt;&lt;mi&gt;g&lt;/mi&gt;&lt;/mrow&gt;&lt;mn&gt;4&lt;/mn&gt;&lt;/msub&gt;&lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;T&lt;/mi&gt;&lt;mi&gt;i&lt;/mi&gt;&lt;/mrow&gt;&lt;mn&gt;4&lt;/mn&gt;&lt;/msub&gt;&lt;msub&gt;&lt;mi&gt;O&lt;/mi&gt;&lt;mn&gt;10&lt;/mn&gt;&lt;/msub&gt;&lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;B&lt;/mi&gt;&lt;mi&gt;r&lt;/mi&gt;&lt;/mrow&gt;&lt;mn&gt;2&lt;/mn&gt;&lt;/msub&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt; and &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;M&lt;/mi&gt;&lt;mi&gt;g&lt;/mi&gt;&lt;/mrow&gt;&lt;mn&gt;4&lt;/mn&gt;&lt;/msub&gt;&lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;T&lt;/mi&gt;&lt;mi&gt;i&lt;/mi&gt;&lt;/mrow&gt;&lt;mn&gt;4&lt;/mn&gt;&lt;/msub&gt;&lt;msub&gt;&lt;mi&gt;O&lt;/mi&gt;&lt;mn&gt;10&lt;/mn&gt;&lt;/msub&gt;&lt;msub&gt;&lt;mi&gt;I&lt;/mi&gt;&lt;mn&gt;2&lt;/mn&gt;&lt;/msub&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt; are optimally positioned within the redox potential range. These materials exhibit differences in the intensities of the redox couples, with increased activity observed in the O&lt;sub&gt;2&lt;/sub&gt;/H&lt;sub&gt;2&lt;/sub&gt;O redox zone. This theoretical foundation underscores the potential of halogen-doped MgTiO&lt;sub&gt;3&lt;/sub&gt; as an efficient","PeriodicalId":16811,"journal":{"name":"Journal of Physics and Chemistry of Solids","volume":"201 ","pages":"Article 112648"},"PeriodicalIF":4.3,"publicationDate":"2025-02-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143478732","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}

{"title":"Computational investigation of newly proposed double halide perovskites Cs2GaBiX6 (X = Cl, Br and I) with enhanced optoelectronic properties for green energy harvesting and photocatalytic applications","authors":"M. Shakil ,&nbsp;Farah Naz ,&nbsp;Saman Yasin ,&nbsp;Arslan Ali ,&nbsp;M. Muddassir ,&nbsp;S.S.A. Gillani ,&nbsp;I. Hussain ,&nbsp;N. Bano","doi":"10.1016/j.jpcs.2025.112638","DOIUrl":"10.1016/j.jpcs.2025.112638","url":null,"abstract":"<div><div>Double perovskites are considered very suitable candidates for opto-electronic and photovoltaic applications due to their stable crystal structures and tunable band gap required for solar energy harvesting. Therefore, in this work double perovskites Cs₂GaBiX₆ (X = Cl, Br and I) are investigated using DFT approach. Initially stable structural parameters are found through geometry optimization process using generalized gradient approximation (GGA) with Perdew–Burke–Ernzerhof (PBE) exchange correlational functional. Using stable structures, electronic behavior is analyzed through density of states (DOS) and energy band gaps calculated by both GGA-PBE and Heyd-Scuseria-Ernzerhof (HSE06) hybrid functional. The calculated band gaps are found to be increased when calculated by hybrid functional HSE06 as compared to the band gaps calculated by GGA-PBE method. Afterwards, optical parameters like absorption coefficient, loss function, optical conductivity, reflectivity, dielectric function and refractive index of these compounds are determined and analyzed. Mechanical stability of these considered compounds have been evaluated from elastic constants, bulk modulus, Young's modulus, shear modulus, Poisson's ratio, Pugh's ratio and anisotropy indexes parameters. Thermodynamic parameters like Debye temperature, longitudinal and transverse velocity, thermal conductivity, melting temperature, Grüneisen parameters, thermal expansion is also determined and explained to evaluate the thermal behavior of the materials. Furthermore, the photocatalytic behavior is also characterized to determine their feasibility for water splitting and other photocatalysis processes. The obtained results of electronic, optical, mechanical, thermodynamic and photocatalytic behavior revealed that these materials are very suitable candidates for opto-electronic, energy harvesting and photocatalysis applications.</div></div>","PeriodicalId":16811,"journal":{"name":"Journal of Physics and Chemistry of Solids","volume":"201 ","pages":"Article 112638"},"PeriodicalIF":4.3,"publicationDate":"2025-02-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143488936","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}

{"title":"Functionalized graphene quantum dots with distinctive solvent-driven emission and enhanced carbon monoxide sensing: A DFT study","authors":"Saswati Sarkar ,&nbsp;Aditi Sadhu ,&nbsp;Deep Mondal,&nbsp;Debnarayan Jana","doi":"10.1016/j.jpcs.2025.112629","DOIUrl":"10.1016/j.jpcs.2025.112629","url":null,"abstract":"<div><div>The widespread efficacy of graphene in nanotechnology has allowed researchers over the years to merge its unique features with quantum confinement effects to unlock newer possibilities in multiple domains. In this work, we have tailored a two-dimensional graphene sheet to 8 distinctive achiral quantum dots and systematically explored their tunable electro-optical responses through surface functionalization with consequent applicability in gas sensing. Emergent traces of spin-splitting in shape-dependent zigzag edges highlight the possibility of metal-free magnetic behavior of graphene in ambient conditions. Absorption and fluorescence spectra have been critically explored with a diverse range of oscillator strengths in the presence of water as a solvent (TD-DFT/CAM-B3LYP/PCM model) revealing the underlying alluring optical signatures. The introduced charge anisotropy through doping of III-V group elements caters to significant dipole moments that attract health-hazardous polar gas molecules like carbon monoxide (CO) with strengthened sensitivity.</div></div>","PeriodicalId":16811,"journal":{"name":"Journal of Physics and Chemistry of Solids","volume":"201 ","pages":"Article 112629"},"PeriodicalIF":4.3,"publicationDate":"2025-02-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143464040","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}

{"title":"Optimisation of the synthesis of spherical ZSM-5 for the dehydration of methanol to dimethyl ether","authors":"Małgorzata Rutkowska ,&nbsp;Wiktoria Dubiel ,&nbsp;Andrzej Kowalczyk ,&nbsp;Aleksandra Jankowska ,&nbsp;Zofia Piwowarska ,&nbsp;Krzysztof Maćkosz ,&nbsp;Jakub Kawałko ,&nbsp;Barbara Gil ,&nbsp;Lucjan Chmielarz","doi":"10.1016/j.jpcs.2025.112645","DOIUrl":"10.1016/j.jpcs.2025.112645","url":null,"abstract":"<div><div>In the presented work, spherical zeolite ZSM-5 was tested as a catalyst for the synthesis of a biofuel, dimethyl ether (DME) from methanol. Conventional zeolites with strong acid sites are very active in this reaction but are rapidly deactivated by coke deposits. To overcome this problem, spherical, hierarchical ZSM-5 was synthesised using mesoporous silica spheres (MSS) as a 'reactive' template, providing the source of silica templating the final morphology of the catalyst. A series of samples, subjected to hydrothermal treatment for 7–15 days, was prepared. At the beginning of the synthesis gel ageing, the MSS surface dissolute under basic conditions and, over time, crystallisation of ZSM-5 zeolite was observed on a spherical matrix. Prolonged crystallisation led to the complete ‘consumption’ of MSS and the formation of fully developed zeolite crystals. A 12-day hydrothermal treatment was found to be optimal to obtain a catalyst with very good characteristics of ZSM-5 zeolite (verified by X-ray diffraction and N₂-sorption) and a spherical grain shape (SEM microscopy). The activity of the samples was compared to the conventional commercially available ZSM-5 zeolite. The spherical shape of the zeolite grains was found to have a positive effect on catalytic activity. The spherical MSS@ZSM-5_12d sample was more stable in the long-term catalytic test compared to the commercial ZSM-5 (a methanol conversion of about 90 % remained unchanged for about 15 h). Furthermore, in conventional ZSM-5, a higher amount of coke deposit was detected after the stability test (8.9 %, vs 7.2 % for the spherical sample, TG analysis, FT-IR spectroscopy).</div></div>","PeriodicalId":16811,"journal":{"name":"Journal of Physics and Chemistry of Solids","volume":"201 ","pages":"Article 112645"},"PeriodicalIF":4.3,"publicationDate":"2025-02-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143464041","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}