Pub Date : 2024-10-08DOI: 10.1016/j.jpcs.2024.112374
Minyan Yan, He Zhang, Changwei Gong, Mingang Zhang, Qianru Gao
The influence of Mo doping on the formation enthalpy and electronic structure of Li2MgN2H2 material, as well as the specific improvement mechanism of its hydrogen storage properties, were investigated by employing the first-principles calculation method. The calculation results exhibit that when Mo is doped into the Li2MgN2H2 material, it is more inclined to take up Mg lattice site at the 8c position. For the Li2MgN2H2 material, Mo doping can effectively reduce its formation enthalpy by ca. 91.16 kJ/mol, thus resulting in the reduction of its structural stability. Moreover, when the Li2MgN2H2 material is doped with Mo, its cell volume increases, and its band gap narrows obviously. Meanwhile, the strong force between Mo and N causes the bond strengths of N–H and Li–N to weaken significantly. The aforementioned factors are beneficial to the improvement of its hydrogen sorption kinetics. This work aims to provide theoretical guidance for further development of new efficient catalysts to promote the Li–Mg–N–H material's application.
通过第一性原理计算方法，研究了掺杂钼对 Li2MgN2H2 材料的形成焓和电子结构的影响，以及其储氢性能的具体改善机制。计算结果表明，当 Mo 掺杂到 Li2MgN2H2 材料中时，它更倾向于占据 8c 位置的 Mg 晶格位点。对于锂2MgN2H2 材料来说，掺杂钼能有效降低其形成焓约 91.16 kJ/mol，从而导致其结构稳定性降低。此外，掺杂 Mo 后，Li2MgN2H2 材料的电池体积增大，带隙明显变窄。同时，Mo 和 N 之间的强作用力导致 N-H 和 Li-N 的键强度明显减弱。上述因素有利于改善其吸氢动力学。这项工作旨在为进一步开发新型高效催化剂提供理论指导，以促进锂-镁-氮-氢材料的应用。
{"title":"First-principles study on impact of Mo doping on the formation enthalpy and electronic structure of Li2MgN2H2 material","authors":"Minyan Yan, He Zhang, Changwei Gong, Mingang Zhang, Qianru Gao","doi":"10.1016/j.jpcs.2024.112374","DOIUrl":"10.1016/j.jpcs.2024.112374","url":null,"abstract":"<div><div>The influence of Mo doping on the formation enthalpy and electronic structure of Li<sub>2</sub>MgN<sub>2</sub>H<sub>2</sub> material, as well as the specific improvement mechanism of its hydrogen storage properties, were investigated by employing the first-principles calculation method. The calculation results exhibit that when Mo is doped into the Li<sub>2</sub>MgN<sub>2</sub>H<sub>2</sub> material, it is more inclined to take up Mg lattice site at the 8c position. For the Li<sub>2</sub>MgN<sub>2</sub>H<sub>2</sub> material, Mo doping can effectively reduce its formation enthalpy by ca. 91.16 kJ/mol, thus resulting in the reduction of its structural stability. Moreover, when the Li<sub>2</sub>MgN<sub>2</sub>H<sub>2</sub> material is doped with Mo, its cell volume increases, and its band gap narrows obviously. Meanwhile, the strong force between Mo and N causes the bond strengths of N–H and Li–N to weaken significantly. The aforementioned factors are beneficial to the improvement of its hydrogen sorption kinetics. This work aims to provide theoretical guidance for further development of new efficient catalysts to promote the Li–Mg–N–H material's application.</div></div>","PeriodicalId":16811,"journal":{"name":"Journal of Physics and Chemistry of Solids","volume":"196 ","pages":"Article 112374"},"PeriodicalIF":4.3,"publicationDate":"2024-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142438253","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 : 2024-10-08DOI: 10.1016/j.jpcs.2024.112375
Ayesha Masoud , Sidra Sarfraz , Muhammad Yaseen , Shatha A. Aldaghfag , Mudassir Ishfaq , Abdulaziz A. Alshihri , Umer Younis
Lead free halide double perovskites (HDPs) have attracted significant interest of the scientific community owing to their better stability, low cost, and eco-friendly nature, and high power conversion efficiency for optoelectronic, and thermoelectric usages. Herein, the physical properties of two novel Rb2NaInCl6 and Rb2NaTlCl6 HDPs are reported via first principles methods. Both HDPs are found to be stable thermodynamically and geometrically, supported by negative formation enthalpies, and structural optimization. Electronic properties analysis revealed direct band gap values of 4.88 and 3.13 eV for respective Rb2NaInCl6 and Rb2NaTlCl6 structures. Corresponding to these band gap values, both HDPs are optically active in the ultraviolet (UV) region of light. Static dielectric constant (Ɛ1 (0)) is consistent with Penn's model. Maximum polarization is achieved at 7.1/5.16 eV for Rb2Na(In/Tl)Cl6, respectively. Maximum absorption peaks occurred in UV region, predicting their suitability for high energy optoelectronic applications. The optical conductivity revealed the highest intensity of 3049.72 (at 5.4 eV) for Rb2NaTlCl6 and 2632.08 (at 7.4 eV) for Rb2NaInCl6. Moreover, our analysis of thermoelectric parameters revealed that Rb2NaInCl6 and Rb2NaTlCl6 have figure of merit (ZT) values of 0.73/0.75, respectively. High ZT values and greater absorption in the UV region suggest that Rb2Na(In/Tl)Cl6 are suitable for TE and optoelectronic usages.
{"title":"First-principles investigation of Rb2NaXCl6 (X = In, Tl) compounds for energy harvesting applications","authors":"Ayesha Masoud , Sidra Sarfraz , Muhammad Yaseen , Shatha A. Aldaghfag , Mudassir Ishfaq , Abdulaziz A. Alshihri , Umer Younis","doi":"10.1016/j.jpcs.2024.112375","DOIUrl":"10.1016/j.jpcs.2024.112375","url":null,"abstract":"<div><div>Lead free halide double perovskites (HDPs) have attracted significant interest of the scientific community owing to their better stability, low cost, and eco-friendly nature, and high power conversion efficiency for optoelectronic, and thermoelectric usages. Herein, the physical properties of two novel Rb<sub>2</sub>NaInCl<sub>6</sub> and Rb<sub>2</sub>NaTlCl<sub>6</sub> HDPs are reported via first principles methods. Both HDPs are found to be stable thermodynamically and geometrically, supported by negative formation enthalpies, and structural optimization. Electronic properties analysis revealed direct band gap values of 4.88 and 3.13 eV for respective Rb<sub>2</sub>NaInCl<sub>6</sub> and Rb<sub>2</sub>NaTlCl<sub>6</sub> structures. Corresponding to these band gap values, both HDPs are optically active in the ultraviolet (UV) region of light. Static dielectric constant (Ɛ<sub>1</sub> (0)) is consistent with Penn's model. Maximum polarization is achieved at 7.1/5.16 eV for Rb<sub>2</sub>Na(In/Tl)Cl<sub>6</sub>, respectively. Maximum absorption peaks occurred in UV region, predicting their suitability for high energy optoelectronic applications. The optical conductivity revealed the highest intensity of 3049.72 (at 5.4 eV) for Rb<sub>2</sub>NaTlCl<sub>6</sub> and 2632.08 <span><math><mrow><msup><mi>Ω</mi><mrow><mo>−</mo><mn>1</mn></mrow></msup><msup><mtext>cm</mtext><mrow><mo>−</mo><mn>1</mn></mrow></msup></mrow></math></span> (at 7.4 eV) for Rb<sub>2</sub>NaInCl<sub>6</sub>. Moreover, our analysis of thermoelectric parameters revealed that Rb<sub>2</sub>NaInCl<sub>6</sub> and Rb<sub>2</sub>NaTlCl<sub>6</sub> have figure of merit (ZT) values of 0.73/0.75, respectively. High ZT values and greater absorption in the UV region suggest that Rb<sub>2</sub>Na(In/Tl)Cl<sub>6</sub> are suitable for TE and optoelectronic usages.</div></div>","PeriodicalId":16811,"journal":{"name":"Journal of Physics and Chemistry of Solids","volume":"196 ","pages":"Article 112375"},"PeriodicalIF":4.3,"publicationDate":"2024-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142427029","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 : 2024-10-05DOI: 10.1016/j.jpcs.2024.112373
Qian Zhang , Ruo Yu Yin , Zhi Huang , Yan-ying Liu , Jun-ming Hong
The development of high-efficiency catalysts for peroxymonosulfate (PMS) activation is critical for pollutant treatment in environmental applications. In this research, a Co organic framework (CoHHTP) combined with graphene oxide (GO) (CoHHTP/GO) with a 2D structure was prepared for PMS activation to treat the azo dye Reactive Black 5 (RBK5). The combination of CoHHTP and GO via oxygen groups resulted in the high activity of CoHHTP/GO, and almost 100 % performance was achieved within 30 min under various pH, temperature, PMS loading, and catalyst loading conditions. The maximum RBK5 removal efficiency was obtained with a catalyst loading of 3.0 g L−1, PMS loading of 0.5 mM, temperature of 25 °C, and pH of 6 with a pseudo-first-order kinetics k value of 0.1903 min−1. The activation energy of the CoHHTP/GO/PMS/RBK5 system was calculated to be 14.34 kJ mol−1. Meanwhile, radicals and nonradicals, including SO4·−, ·OH, ·O2−, and 1O2, were proven to be generated and involved in RBK5 degradation. Moreover, RBK5 degradation pathways were identified through experimental research and density functional theory calculation.
{"title":"Catalytic degradation of Reactive Black 5 through peroxymonosulfate activation with Co organic frameworks combined with graphite oxide","authors":"Qian Zhang , Ruo Yu Yin , Zhi Huang , Yan-ying Liu , Jun-ming Hong","doi":"10.1016/j.jpcs.2024.112373","DOIUrl":"10.1016/j.jpcs.2024.112373","url":null,"abstract":"<div><div>The development of high-efficiency catalysts for peroxymonosulfate (PMS) activation is critical for pollutant treatment in environmental applications. In this research, a Co organic framework (CoHHTP) combined with graphene oxide (GO) (CoHHTP/GO) with a 2D structure was prepared for PMS activation to treat the azo dye Reactive Black 5 (RBK5). The combination of CoHHTP and GO via oxygen groups resulted in the high activity of CoHHTP/GO, and almost 100 % performance was achieved within 30 min under various pH, temperature, PMS loading, and catalyst loading conditions. The maximum RBK5 removal efficiency was obtained with a catalyst loading of 3.0 g L<sup>−1</sup>, PMS loading of 0.5 mM, temperature of 25 °C, and pH of 6 with a pseudo-first-order kinetics k value of 0.1903 min<sup>−1</sup>. The activation energy of the CoHHTP/GO/PMS/RBK5 system was calculated to be 14.34 kJ mol<sup>−1</sup>. Meanwhile, radicals and nonradicals, including SO<sub>4</sub><sup>·−</sup>, ·OH, ·O<sub>2</sub><sup>−</sup>, and <sup>1</sup>O<sub>2</sub>, were proven to be generated and involved in RBK5 degradation. Moreover, RBK5 degradation pathways were identified through experimental research and density functional theory calculation.</div></div>","PeriodicalId":16811,"journal":{"name":"Journal of Physics and Chemistry of Solids","volume":"196 ","pages":"Article 112373"},"PeriodicalIF":4.3,"publicationDate":"2024-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142427026","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}
A visible light active Co3O4-quantum dots (QDs)/Mn3O4 nanocomposite was successfully synthesized by a straightforward precipitation approach. Notably, the formation of Mn3O4 nanosheets in composite structure was evidenced by different physicochemical techniques especially transmission electron microscopy (TEM), energy dispersive X-ray (EDX) and N2 sorption analyses, which indicated the uniform distribution of Co3O4-QDs with small size of around 5 nm on the surface of Mn3O4 nanosheets along with the enhancement of specific surface area for final composite. Also, the persistence of Co3O4-QDs during nanocomposite synthesis was analyzed by X-ray diffraction (XRD), FT-IR and TEM techniques. The diffuse reflectance UV–Vis and electrochemical impedance spectroscopies revealed the reduction of band gap energy and enhanced charge separation efficiency for Co3O4-QDs/Mn3O4 nanocomposite, respectively, which consequently led to improved photocatalytic response in comparison with bare Co3O4-QDs and Mn3O4 nanosheets. The as-prepared nanocomposite exhibited excellent photocatalytic activity in the reduction of a wide range of substituted nitroarenes with the yields of higher than 80 % relative to the corresponding arylamines, using N2H4·H2O as the hydrogen source and ethanol as green solvent at 25 °C and ambient pressure under visible light illumination. The synergistic effect could improve the production of active hydrogen atoms, therefore, the reasons for this transformation over the prepared nanocomposite under benign conditions are fully discussed. Furthermore, the nanocomposite could be easily recycled without decay in photocatalytic activity for at least five successive cycles.
{"title":"Photocatalytic reduction of nitroarene derivatives by impressive visible-light active Co3O4-QDs/Mn3O4 nanocomposite","authors":"Melika Okhovatkar, Majid Masteri-Farahani, Mahsa Niakan, Mahdiyeh-Sadat Hosseini","doi":"10.1016/j.jpcs.2024.112371","DOIUrl":"10.1016/j.jpcs.2024.112371","url":null,"abstract":"<div><div>A visible light active Co<sub>3</sub>O<sub>4</sub>-quantum dots (QDs)/Mn<sub>3</sub>O<sub>4</sub> nanocomposite was successfully synthesized by a straightforward precipitation approach. Notably, the formation of Mn<sub>3</sub>O<sub>4</sub> nanosheets in composite structure was evidenced by different physicochemical techniques especially transmission electron microscopy (TEM), energy dispersive X-ray (EDX) and N<sub>2</sub> sorption analyses, which indicated the uniform distribution of Co<sub>3</sub>O<sub>4</sub>-QDs with small size of around 5 nm on the surface of Mn<sub>3</sub>O<sub>4</sub> nanosheets along with the enhancement of specific surface area for final composite. Also, the persistence of Co<sub>3</sub>O<sub>4</sub>-QDs during nanocomposite synthesis was analyzed by X-ray diffraction (XRD), FT-IR and TEM techniques. The diffuse reflectance UV–Vis and electrochemical impedance spectroscopies revealed the reduction of band gap energy and enhanced charge separation efficiency for Co<sub>3</sub>O<sub>4</sub>-QDs/Mn<sub>3</sub>O<sub>4</sub> nanocomposite, respectively, which consequently led to improved photocatalytic response in comparison with bare Co<sub>3</sub>O<sub>4</sub>-QDs and Mn<sub>3</sub>O<sub>4</sub> nanosheets. The as-prepared nanocomposite exhibited excellent photocatalytic activity in the reduction of a wide range of substituted nitroarenes with the yields of higher than 80 % relative to the corresponding arylamines, using N<sub>2</sub>H<sub>4</sub>·H<sub>2</sub>O as the hydrogen source and ethanol as green solvent at 25 °C and ambient pressure under visible light illumination. The synergistic effect could improve the production of active hydrogen atoms, therefore, the reasons for this transformation over the prepared nanocomposite under benign conditions are fully discussed. Furthermore, the nanocomposite could be easily recycled without decay in photocatalytic activity for at least five successive cycles.</div></div>","PeriodicalId":16811,"journal":{"name":"Journal of Physics and Chemistry of Solids","volume":"196 ","pages":"Article 112371"},"PeriodicalIF":4.3,"publicationDate":"2024-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142427027","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 : 2024-10-03DOI: 10.1016/j.jpcs.2024.112372
Na Li, Ji Hua , Fangyan Chen, Wenqian Sun, Yubin Tang
Coupling two different photocatalytic materials to construct a heterojunction is a preferable strategy for obtaining the composite photocatalyst with high activity. Herein, a novel 0D/3D Z-scheme heterostructure ZnS/MIL-88(A) was constructed by anchoring 0D ZnS nanoparticles on the surface of the 3D MIL-88(A). The prepared ZnS/MIL-88(A) was characterized by using FT-IR, XRD, SEM, UV–vis and XPS. The photodegradation of tetracycline (TC) was conducted under the irradiation of visible light to evaluate the photocatalytic performance of ZnS/MIL-88(A). The creation of the Z-scheme heterostructure between ZnS and MIL-88(A) enables ZnS/MIL-88(A) to exhibit excellent visible-light absorption ability and dramatically boost separation and transfer of the photo-induced charge carriers. Compared with MIL-88(A), ZnS/MIL-88(A) shows prominently enhanced photocatalytic activity toward tetracycline, achieving a TC degradation rate of 94 %. The highest photodegradation rate constant (0.02083 min−1) of TC by ZnS/MIL-88(A) is 7.77 and 12.33 folds as large as those by MIL-88(A) and ZnS, respectively. After five cycles of reuse, ZnS/MIL-88(A) shows only a slightly decreased TC removal rate, presenting excellent photo-stability. Furthermore, the Z-scheme interfacial charge migration mode and the photocatalytic mechanism of ZnS/MIL-88(A) were discussed according to the band position as well as the identification result of the active species. The radicals ·O2− and ·OH generated in photocatalysis serve as major reactive species to decompose TC. This work provides a new way for designing efficient composite photocatalysts.
{"title":"A novel 0D/3D Z-Scheme heterojunction ZnS/MIL-88(A) with significantly boosted photocatalytic activity toward tetracycline","authors":"Na Li, Ji Hua , Fangyan Chen, Wenqian Sun, Yubin Tang","doi":"10.1016/j.jpcs.2024.112372","DOIUrl":"10.1016/j.jpcs.2024.112372","url":null,"abstract":"<div><div>Coupling two different photocatalytic materials to construct a heterojunction is a preferable strategy for obtaining the composite photocatalyst with high activity. Herein, a novel 0D/3D Z-scheme heterostructure ZnS/MIL-88(A) was constructed by anchoring 0D ZnS nanoparticles on the surface of the 3D MIL-88(A). The prepared ZnS/MIL-88(A) was characterized by using FT-IR, XRD, SEM, UV–vis and XPS. The photodegradation of tetracycline (TC) was conducted under the irradiation of visible light to evaluate the photocatalytic performance of ZnS/MIL-88(A). The creation of the Z-scheme heterostructure between ZnS and MIL-88(A) enables ZnS/MIL-88(A) to exhibit excellent visible-light absorption ability and dramatically boost separation and transfer of the photo-induced charge carriers. Compared with MIL-88(A), ZnS/MIL-88(A) shows prominently enhanced photocatalytic activity toward tetracycline, achieving a TC degradation rate of 94 %. The highest photodegradation rate constant (0.02083 min<sup>−1</sup>) of TC by ZnS/MIL-88(A) is 7.77 and 12.33 folds as large as those by MIL-88(A) and ZnS, respectively. After five cycles of reuse, ZnS/MIL-88(A) shows only a slightly decreased TC removal rate, presenting excellent photo-stability. Furthermore, the Z-scheme interfacial charge migration mode and the photocatalytic mechanism of ZnS/MIL-88(A) were discussed according to the band position as well as the identification result of the active species. The radicals ·O<sub>2</sub><sup>−</sup> and ·OH generated in photocatalysis serve as major reactive species to decompose TC. This work provides a new way for designing efficient composite photocatalysts.</div></div>","PeriodicalId":16811,"journal":{"name":"Journal of Physics and Chemistry of Solids","volume":"196 ","pages":"Article 112372"},"PeriodicalIF":4.3,"publicationDate":"2024-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142427083","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}
A comparative study of the crystal structures and electrochemical characteristics of bulk and nanoscale La1-xPrxCoO3 (x = 0, 0.3 and 0.6) perovskites is made using synchrotron x-ray diffraction, cyclic voltammetry, and galvanostatic charge/discharge methods. It is shown that the sol-gel synthesized nano structures and bulk LaCoO3 exhibit different crystal structures, viz., rhombohedral [a = b = 5.4401 Å, c = 13.134 Å (on hexagonal axes), Z = 6, Rc] and monoclinic [am = 5.3865 Å, bm = 5.4482 Å, cm = 7.6365 Å, βm = 89.010°, Z = 4, I2/a], respectively. The evidence for CoO6 octahedra distortion in bulk LaCoO3 is also gathered from the three distinct Raman active modes at 518, 646, and 688 cm−1 emerging due to the Jahn-Teller effect, which, in-turn, reduces the crystal symmetry for achieving structure stabilization. This amounts to changes in Co–O bond lengths and Co–O–Co bond angles with promotion of t2g electron to eg level simultaneously for Co3+(3d6) to attain an intermediate spin state (S = 1) or higher. However, Pr-insertion induces phase transition to orthorhombic in both but with space group Pnma in nanostructures and equivalent Pbnm in bulk. The substitution effect on the specific capacitance (C) is opposite in nature, i.e., while ‘C’ decreases from 149 to 12 F/g in nano structures, it increases from 0.4 to 4 F/g in bulk with increase in Pr-content from x=0 to 0.6. A galvanostatic charge-discharge test of pristine nano LaCoO3 performed at a constant scan rate of 50 mVs−1 reveals electrode electrochemical stability by retaining 96 % of specific capacitance ∼82.5 F/g for 2000 cycles at least. The variation in the crystal structure and bond length and/or angle plays a key role in controlling the electrochemical performance of Pr-substituted LaCoO3 perovskites.
{"title":"Praseodymium induced symmetry switching and electrochemical characteristics of LaCoO3 nanostructures","authors":"Priyanka Tiwari , Deepti Gangwar , Jayjit Kumar Dey , Fernando Igoa Saldaña , Jitendra Kumar , Subhash Thota","doi":"10.1016/j.jpcs.2024.112366","DOIUrl":"10.1016/j.jpcs.2024.112366","url":null,"abstract":"<div><div>A comparative study of the crystal structures and electrochemical characteristics of bulk and nanoscale La<sub>1-<em>x</em></sub>Pr<sub><em>x</em></sub>CoO<sub>3</sub> (<em>x</em> = 0, 0.3 and 0.6) perovskites is made using synchrotron <em>x</em>-ray diffraction, cyclic voltammetry, and galvanostatic charge/discharge methods. It is shown that the sol-gel synthesized nano structures and bulk LaCoO<sub>3</sub> exhibit different crystal structures, viz., rhombohedral [<em>a</em> = <em>b</em> = 5.4401 Å, <em>c</em> = 13.134 Å (on hexagonal axes), <em>Z</em> = 6, <em>R</em> <span><math><mrow><mover><mn>3</mn><mo>‾</mo></mover></mrow></math></span> <em>c</em>] and monoclinic [<em>a</em><sub><em>m</em></sub> = 5.3865 Å, <em>b</em><sub><em>m</em></sub> = 5.4482 Å, <em>c</em><sub><em>m</em></sub> = 7.6365 Å, <em>β</em><sub><em>m</em></sub> = 89.010°, Z = 4, <em>I2/a</em>], respectively. The evidence for CoO<sub>6</sub> octahedra distortion in bulk LaCoO<sub>3</sub> is also gathered from the three distinct Raman active modes at 518, 646, and 688 cm<sup>−1</sup> emerging due to the Jahn-Teller effect, which, in-turn, reduces the crystal symmetry for achieving structure stabilization. This amounts to changes in Co–O bond lengths and Co–<em>O</em>–Co bond angles with promotion of <em>t</em><sub>2g</sub> electron to <em>e</em><sub>g</sub> level simultaneously for Co<sup>3+</sup>(3<em>d</em><sup>6</sup>) to attain an intermediate spin state (<em>S</em> = 1) or higher. However, Pr-insertion induces phase transition to orthorhombic in both but with space group <em>Pnma</em> in nanostructures and equivalent <em>Pbnm</em> in bulk. The substitution effect on the specific capacitance (C) is opposite in nature, <em>i.e</em>., while ‘C’ decreases from 149 to 12 F/g in nano structures, it increases from 0.4 to 4 F/g in bulk with increase in Pr-content from <em>x=</em>0 to 0.6. A galvanostatic charge-discharge test of pristine nano LaCoO<sub>3</sub> performed at a constant scan rate of 50 mVs<sup>−1</sup> reveals electrode electrochemical stability by retaining 96 % of specific capacitance ∼82.5 F/g for 2000 cycles at least. The variation in the crystal structure and bond length and/or angle plays a key role in controlling the electrochemical performance of Pr-substituted LaCoO<sub>3</sub> perovskites.</div></div>","PeriodicalId":16811,"journal":{"name":"Journal of Physics and Chemistry of Solids","volume":"196 ","pages":"Article 112366"},"PeriodicalIF":4.3,"publicationDate":"2024-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142538709","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 : 2024-10-03DOI: 10.1016/j.jpcs.2024.112364
Yurii A. Aleshchenko , Andrey V. Muratov , Elena S. Zhukova , Lenar S. Kadyrov , Boris P. Gorshunov , Giovanni A. Ummarino , Ilya A. Shipulin
The uncertainty of the nature of the normal state and superconducting condensate of unconventional superconductors continues to stimulate considerable speculation about the mechanism of superconductivity in these materials. Of particular interest are the type of symmetry of the order parameter and the basic electronic characteristics of the superconducting and normal states. We report the derivation of temperature dependences of the superconducting condensate plasma frequency, superfluid density, and London penetration depth by measuring terahertz spectra of conductivity and dielectric permittivity of the Ba(FeNi)As thin films with different Ni concentrations. A comprehensive analysis of the experimental data was performed in the framework of the simple three-band Eliashberg model under the assumption that the superconducting coupling mechanism is mediated by antiferromagnetic spin fluctuations. The results of independent experiments support the choice of model parameters. Based on calculations of the temperature dependences of superconducting gaps, we may conclude that the obtained results are compatible with the scenario, in which Ba(FeNi)As is a multiband superconductor with s-wave pairing symmetry.
{"title":"THz optical response of Ba(Fe1−xNix)2As2 films analyzed within the three-band Eliashberg s±-wave model","authors":"Yurii A. Aleshchenko , Andrey V. Muratov , Elena S. Zhukova , Lenar S. Kadyrov , Boris P. Gorshunov , Giovanni A. Ummarino , Ilya A. Shipulin","doi":"10.1016/j.jpcs.2024.112364","DOIUrl":"10.1016/j.jpcs.2024.112364","url":null,"abstract":"<div><div>The uncertainty of the nature of the normal state and superconducting condensate of unconventional superconductors continues to stimulate considerable speculation about the mechanism of superconductivity in these materials. Of particular interest are the type of symmetry of the order parameter and the basic electronic characteristics of the superconducting and normal states. We report the derivation of temperature dependences of the superconducting condensate plasma frequency, superfluid density, and London penetration depth by measuring terahertz spectra of conductivity and dielectric permittivity of the Ba(Fe<span><math><msub><mrow></mrow><mrow><mn>1</mn><mo>−</mo><mi>x</mi></mrow></msub></math></span>Ni<span><math><msub><mrow></mrow><mrow><mi>x</mi></mrow></msub></math></span>)<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span>As<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span> thin films with different Ni concentrations. A comprehensive analysis of the experimental data was performed in the framework of the simple three-band Eliashberg model under the assumption that the superconducting coupling mechanism is mediated by antiferromagnetic spin fluctuations. The results of independent experiments support the choice of model parameters. Based on calculations of the temperature dependences of superconducting gaps, we may conclude that the obtained results are compatible with the scenario, in which Ba(Fe<span><math><msub><mrow></mrow><mrow><mn>1</mn><mo>−</mo><mi>x</mi></mrow></msub></math></span>Ni<span><math><msub><mrow></mrow><mrow><mi>x</mi></mrow></msub></math></span>)<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span>As<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span> is a multiband superconductor with s<span><math><msub><mrow></mrow><mrow><mo>±</mo></mrow></msub></math></span>-wave pairing symmetry.</div></div>","PeriodicalId":16811,"journal":{"name":"Journal of Physics and Chemistry of Solids","volume":"196 ","pages":"Article 112364"},"PeriodicalIF":4.3,"publicationDate":"2024-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142427032","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}
Recently, solar cells have appeared as a promising solution to meet the increasing energy demand. However, their large-scale commercial use is limited by issues such as toxicity (Cd, Pb, etc), high manufacturing costs, lower stability, and low efficiency. In this perspective, kusachiite solar cells (KSCs) are environmentally friendly, long-term stable, and easy to manufacture. Thus, in this work, kusachiite (CuBi2O4) is used as an absorber layer, with NiO and SrTiO3 serving as the hole transport material (HTM) and an electron transport layer (ETL), respectively. The KSCs, with a structure of FTO/SrTiO3/CuBi2O4/NiO/Au, are numerically simulated. Maximum power conversion efficiency is achieved by optimizing several photovoltaic parameters, such as the thickness and doping density of the ETL, absorber, and HTM. The optimized thicknesses for the HTL, absorber layer, and ETL are 1.5 μm, 2.28 μm, and 0.02 μm, respectively. The designed KSCs exhibit an efficiency eta (η) of 31.89 %, an open-circuit voltage (Voc) of 1.31 V, a short-circuit current (Jsc) of 28.58 mA/cm2, and a fill factor (FF) of 84.99 %.
{"title":"Exploring 32 % efficiency of eco-friendly kusachiite-based solar cells: A numerical study","authors":"Sumit Choudhary , Rahutosh Ranjan , Manish Nath Tripathi , Neelabh Srivastava , Arvind Kumar Sharma , Masamichi Yoshimura , Li Chang , Rajanish N. Tiwari","doi":"10.1016/j.jpcs.2024.112369","DOIUrl":"10.1016/j.jpcs.2024.112369","url":null,"abstract":"<div><div>Recently, solar cells have appeared as a promising solution to meet the increasing energy demand. However, their large-scale commercial use is limited by issues such as toxicity (Cd, Pb, etc), high manufacturing costs, lower stability, and low efficiency. In this perspective, kusachiite solar cells (KSCs) are environmentally friendly, long-term stable, and easy to manufacture. Thus, in this work, kusachiite (CuBi<sub>2</sub>O<sub>4</sub>) is used as an absorber layer, with NiO and SrTiO<sub>3</sub> serving as the hole transport material (HTM) and an electron transport layer (ETL), respectively. The KSCs, with a structure of FTO/SrTiO<sub>3</sub>/CuBi<sub>2</sub>O<sub>4</sub>/NiO/Au, are numerically simulated. Maximum power conversion efficiency is achieved by optimizing several photovoltaic parameters, such as the thickness and doping density of the ETL, absorber, and HTM. The optimized thicknesses for the HTL, absorber layer, and ETL are 1.5 μm, 2.28 μm, and 0.02 μm, respectively. The designed KSCs exhibit an efficiency eta (η) of 31.89 %, an open-circuit voltage (<em>V</em><sub><em>oc</em></sub>) of 1.31 V, a short-circuit current (<em>J</em><sub><em>sc</em></sub>) of 28.58 mA/cm<sup>2</sup>, and a fill factor (FF) of 84.99 %.</div></div>","PeriodicalId":16811,"journal":{"name":"Journal of Physics and Chemistry of Solids","volume":"196 ","pages":"Article 112369"},"PeriodicalIF":4.3,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142427081","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}
SCAPS-1D platform was used to simulate a solar cell with FTO/CdS/Sb2Se3/CuInSe2/Au structure which was recently fabricated by Liu et al. (2022) [1] [Journal of Energy Chemistry68 521–528 (2022)] and a very similar result was obtained. Reported parameters were Fill Factor (FF) = 53.60 %, short circuit current density (JSC) = 26.18 mA/cm2, open circuit voltage (VOC) = 0.37 V, and power conversion efficiency (PCE) = 5.19 %, while simulated parameters were FF of 54.68 %, JSC of 27.54 mA/cm2, VOC of 0.36 V, and PCE = 5.55 %. The advancements have been evaluated by analyzing FTO/CdS/Sb2Se3/CuInSe2/Au and FTO/C60/Sb2Se3/CuInSe2/Au configurations, serving as the reference cells. To improve the cell performance, the CdS layer was replaced with another layer (C60) which shows excellent electron transport properties. Replacing the CdS layer with C60 led to an increase in the power conversion efficiency by 65 % (from 5.55 % up to 9.20 %). In photovoltaic systems, the PCE constitutes a pivotal parameter that can be enhanced through the absorption of a broad spectrum of incident photons. Consequently, the implementation of two absorber layers within a solar cell, each characterized by a graded band gap energy, enables the capture of solar photons over a more extensive spectral range. Therefore, a perovskite containing a band gap of 1.5 eV, lead-free, and Sn-based was used as the second absorber layer in the device. Therefore, a solar cell with FTO/C60/CsSn0.5Ge0.5I3/Sb2Se3/CuInSe2/Au structure was simulated, and significant results were achieved. Results showed that inserting the CsSn0.5Ge0.5I3 layer led to an increase in PCE up to 11.42 %.
{"title":"Numerical optimization of cesium tin-germanium triiodide/antimony selenide perovskite solar cell with fullerene nanolayer","authors":"Masood Mehrabian , Pourya Norouzzadeh , Omid Akhavan","doi":"10.1016/j.jpcs.2024.112370","DOIUrl":"10.1016/j.jpcs.2024.112370","url":null,"abstract":"<div><div>SCAPS-1D platform was used to simulate a solar cell with FTO/CdS/Sb<sub>2</sub>Se<sub>3</sub>/CuInSe<sub>2</sub>/Au structure which was recently fabricated by Liu et al. (2022) [1] [<em>Journal of Energy Chemistry</em> <strong>68</strong> 521–528 (2022)] and a very similar result was obtained. Reported parameters were Fill Factor (FF) = 53.60 %, short circuit current density (J<sub>SC</sub>) = 26.18 mA/cm<sup>2</sup>, open circuit voltage (V<sub>OC</sub>) = 0.37 V, and power conversion efficiency (PCE) = 5.19 %, while simulated parameters were FF of 54.68 %, J<sub>SC</sub> of 27.54 mA/cm<sup>2</sup>, V<sub>OC</sub> of 0.36 V, and PCE = 5.55 %. The advancements have been evaluated by analyzing FTO/CdS/Sb<sub>2</sub>Se<sub>3</sub>/CuInSe<sub>2</sub>/Au and FTO/C<sub>60</sub>/Sb<sub>2</sub>Se<sub>3</sub>/CuInSe<sub>2</sub>/Au configurations, serving as the reference cells. To improve the cell performance, the CdS layer was replaced with another layer (C<sub>60</sub>) which shows excellent electron transport properties. Replacing the CdS layer with C<sub>60</sub> led to an increase in the power conversion efficiency by 65 % (from 5.55 % up to 9.20 %). In photovoltaic systems, the PCE constitutes a pivotal parameter that can be enhanced through the absorption of a broad spectrum of incident photons. Consequently, the implementation of two absorber layers within a solar cell, each characterized by a graded band gap energy, enables the capture of solar photons over a more extensive spectral range. Therefore, a perovskite containing a band gap of 1.5 eV, lead-free, and Sn-based was used as the second absorber layer in the device. Therefore, a solar cell with FTO/C<sub>60</sub>/CsSn<sub>0.5</sub>Ge<sub>0.5</sub>I<sub>3</sub>/Sb<sub>2</sub>Se<sub>3</sub>/CuInSe<sub>2</sub>/Au structure was simulated, and significant results were achieved. Results showed that inserting the CsSn<sub>0.5</sub>Ge<sub>0.5</sub>I<sub>3</sub> layer led to an increase in PCE up to 11.42 %.</div></div>","PeriodicalId":16811,"journal":{"name":"Journal of Physics and Chemistry of Solids","volume":"196 ","pages":"Article 112370"},"PeriodicalIF":4.3,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142427084","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 : 2024-10-01DOI: 10.1016/j.jpcs.2024.112367
Jyoti Ahlawat, Suman Pawaria, Rinki Dahiya, Anil Ohlan, Sajjan Dahiya, Rajesh Punia, A.S. Maan
The fundamental understanding of electric charge (ion + polarons/electrons) transport and relaxation mechanism is essential for applications in solid state ionics. In present work, to study Na+ transport, the electrical conductivity of zinc phosphate glasses modified with Na2O has been investigated in temperature range 313K and 473K and frequency range of 100 mHz to 1 MHz. The experimental data of Nyquist plots is fitted with appropriate equivalent circuits at different temperatures which reveals presence of mixed conduction (polaronic + ionic) and Na+ diffusion (at 50 mol% Na2O) in studied glass samples. The values of frequency exponent (s) obtained from the fitting of experimental data of the real part of electrical conductivity with Almond–West equation (WAE) have been used to determine the conduction mechanism. The electric transport in studied glasses occurred via correlated barrier hopping and non-overlapping small polaron tunnelling conduction models depending on the glass composition and temperature range of investigation. Electric Modulus studies further supports the assertion of composition and temperature dependent conduction mechanisms. The activation energies determined from conductivity, electric modulus, and impedance measurements are found to be consistent, indicating a good correlation in the study.
{"title":"Broadband Dielectric Spectroscopy: Unraveling Na+diffusion and mixed conduction in Na₂O-modified zinc phosphate glasses for electrode material applications","authors":"Jyoti Ahlawat, Suman Pawaria, Rinki Dahiya, Anil Ohlan, Sajjan Dahiya, Rajesh Punia, A.S. Maan","doi":"10.1016/j.jpcs.2024.112367","DOIUrl":"10.1016/j.jpcs.2024.112367","url":null,"abstract":"<div><div>The fundamental understanding of electric charge (ion + polarons/electrons) transport and relaxation mechanism is essential for applications in solid state ionics. In present work, to study Na<sup>+</sup> transport, the electrical conductivity of zinc phosphate glasses modified with Na<sub>2</sub>O has been investigated in temperature range 313K and 473K and frequency range of 100 mHz to 1 MHz. The experimental data of Nyquist plots is fitted with appropriate equivalent circuits at different temperatures which reveals presence of mixed conduction (polaronic + ionic) and Na<sup>+</sup> diffusion (at 50 mol% Na<sub>2</sub>O) in studied glass samples. The values of frequency exponent (s) obtained from the fitting of experimental data of the real part of electrical conductivity with Almond–West equation (WAE) have been used to determine the conduction mechanism. The electric transport in studied glasses occurred via correlated barrier hopping and non-overlapping small polaron tunnelling conduction models depending on the glass composition and temperature range of investigation. Electric Modulus studies further supports the assertion of composition and temperature dependent conduction mechanisms. The activation energies determined from conductivity, electric modulus, and impedance measurements are found to be consistent, indicating a good correlation in the study.</div></div>","PeriodicalId":16811,"journal":{"name":"Journal of Physics and Chemistry of Solids","volume":"196 ","pages":"Article 112367"},"PeriodicalIF":4.3,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142427034","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}
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