Pub Date : 2024-09-13DOI: 10.1007/s10971-024-06529-z
Ihtisham-ul-haq, M. I. Khan, lamia ben farhat
The lead-free halide double perovskite solar cell (LFHDPs) (C{s}_{2}AgBiB{r}_{6}) has emerged as a compelling alternative to conventional lead-based perovskites (LBPs) owing to its notable advantages in chemical stability and non-toxicity. However, due to their large indirect bandgap (Eg), (C{s}_{2}AgBiB{r}_{6}) solar cells exhibit low efficiency (η). To address these challenges, this study explores the doping of (C{s}_{2}AgBiB{r}_{6}) double perovskite with Magnesium (Mg), resulting in a reduced Eg and improved η. Mg doping not only mitigates recombination losses but also enhances charge carrier mobility and stability. Additionally, the incorporation of a (Z{n}_{2}Sn{O}_{4}) (ZTO) electron transport layer (ETL) enhances η and stability by facilitating rapid charge injection and electron diffusion. Excellent optical and electrical characteristics of the ZTO-based ETL make it suitable for improving the η of charge collection and light harvesting in solar cells. Importantly, the (C{s}_{2}A{g}_{0.95}M{g}_{0.05}BiB{r}_{6}) solar cell exhibits enhanced performance, significantly, the fabricated solar cells exhibit improved performance. The measured values include an open circuit voltage (Voc) of 0.9 V, a short circuit current density (Jsc) of 5.77 mA-cm−2, a fill factor of 0.76, and a η of 3.98%. This study not only helps to overcome film formation issues but also validates stable (C{s}_{2}A{g}_{0.95}M{g}_{0.05}BiB{r}_{6}) as an efficient material for solar applications. Overall, our study improves solar technologies that are friendly to the environment.
{"title":"Enhancing solar cell efficiency: lead-free double perovskite solar cells Cs2AgBiBr6 with magnesium-doped and Zn2SnO4 electron transport layer","authors":"Ihtisham-ul-haq, M. I. Khan, lamia ben farhat","doi":"10.1007/s10971-024-06529-z","DOIUrl":"https://doi.org/10.1007/s10971-024-06529-z","url":null,"abstract":"<p>The lead-free halide double perovskite solar cell (LFHDPs) <span>(C{s}_{2}AgBiB{r}_{6})</span> has emerged as a compelling alternative to conventional lead-based perovskites (LBPs) owing to its notable advantages in chemical stability and non-toxicity. However, due to their large indirect bandgap (E<sub>g</sub>), <span>(C{s}_{2}AgBiB{r}_{6})</span> solar cells exhibit low efficiency (η). To address these challenges, this study explores the doping of <span>(C{s}_{2}AgBiB{r}_{6})</span> double perovskite with Magnesium (Mg), resulting in a reduced E<sub>g</sub> and improved η. Mg doping not only mitigates recombination losses but also enhances charge carrier mobility and stability. Additionally, the incorporation of a <span>(Z{n}_{2}Sn{O}_{4})</span> (ZTO) electron transport layer (ETL) enhances η and stability by facilitating rapid charge injection and electron diffusion. Excellent optical and electrical characteristics of the ZTO-based ETL make it suitable for improving the η of charge collection and light harvesting in solar cells. Importantly, the <span>(C{s}_{2}A{g}_{0.95}M{g}_{0.05}BiB{r}_{6})</span> solar cell exhibits enhanced performance, significantly, the fabricated solar cells exhibit improved performance. The measured values include an open circuit voltage (V<sub>oc</sub>) of 0.9 V, a short circuit current density (J<sub>sc</sub>) of 5.77 mA-cm<sup>−2</sup>, a fill factor of 0.76, and a η of 3.98%. This study not only helps to overcome film formation issues but also validates stable <span>(C{s}_{2}A{g}_{0.95}M{g}_{0.05}BiB{r}_{6})</span> as an efficient material for solar applications. Overall, our study improves solar technologies that are friendly to the environment.</p><h3 data-test=\"abstract-sub-heading\">Graphical Abstract</h3>","PeriodicalId":664,"journal":{"name":"Journal of Sol-Gel Science and Technology","volume":null,"pages":null},"PeriodicalIF":2.5,"publicationDate":"2024-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142195891","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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 : 2024-09-13DOI: 10.1007/s10971-024-06524-4
L. C. Klein, Andrei Jitianu
Ever since the observation in 2001 that some organic-inorganic silica hybrid gels are rigid at room temperature but soften and flow around 100 °C, there has been interest in so-called melting gels. Following heating to 150 °C or higher, the gels no longer soften and are considered consolidated hybrid glasses. The catalog of melting gels has grown over the past 20 years. Longer chain substitutions and other functional groups have been attached to the ≡Si-O-Si≡ molecular species. The substitutions make it possible to adjust the glass transition, the viscosity, and the temperature range of their usefulness.
{"title":"Hybrid organic-inorganic gels that are melting gels","authors":"L. C. Klein, Andrei Jitianu","doi":"10.1007/s10971-024-06524-4","DOIUrl":"https://doi.org/10.1007/s10971-024-06524-4","url":null,"abstract":"<p>Ever since the observation in 2001 that some organic-inorganic silica hybrid gels are rigid at room temperature but soften and flow around 100 °C, there has been interest in so-called melting gels. Following heating to 150 °C or higher, the gels no longer soften and are considered consolidated hybrid glasses. The catalog of melting gels has grown over the past 20 years. Longer chain substitutions and other functional groups have been attached to the ≡Si-O-Si≡ molecular species. The substitutions make it possible to adjust the glass transition, the viscosity, and the temperature range of their usefulness.</p><h3 data-test=\"abstract-sub-heading\">Graphical Abstract</h3>","PeriodicalId":664,"journal":{"name":"Journal of Sol-Gel Science and Technology","volume":null,"pages":null},"PeriodicalIF":2.5,"publicationDate":"2024-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142195892","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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 : 2024-09-13DOI: 10.1007/s10971-024-06527-1
Najla AlMasoud, Mahmood Ali, Taghrid S. Alomar, Amal A. Al-wallan, Hafiz Muhammad Tahir Farid, Zeinhom M. El-Bahy
The demand of reduced graphene oxide-based nanosheets decorated with metal oxides in electrochemical energy storage devices has increased in recent years. The hydrothermal preparation of MnNiO3 and MnNiO3@rGO nanohybrid has been described in the current work. The prepared samples were evaluated structurally, morphologically and electrochemically using a variety of analytical instruments. The MnNiO3@rGO nanohybrid showed specific capacitance 1507 F/g calculated from the GCD plot with the exceptional cyclic stability of 5000th cycles at 1 A/g with a lower charge transfer resistance of 0.18 Ω. The exceptional performance of the MnNiO3@rGO nanohybrid can be due to the hierarchical structure and improvement in charge transfer capability. During redox process MnNiO3@rGO nanohybrid provides more active sites and a shorter channel for ion transport. As a result, the MnNiO3@rGO nanohybrid electrochemical performance can be significantly improved and its potential in energy storage systems.
{"title":"Recent developments in MnNiO3@rGO nanohybrid for advanced energy storage devices","authors":"Najla AlMasoud, Mahmood Ali, Taghrid S. Alomar, Amal A. Al-wallan, Hafiz Muhammad Tahir Farid, Zeinhom M. El-Bahy","doi":"10.1007/s10971-024-06527-1","DOIUrl":"https://doi.org/10.1007/s10971-024-06527-1","url":null,"abstract":"<p>The demand of reduced graphene oxide-based nanosheets decorated with metal oxides in electrochemical energy storage devices has increased in recent years. The hydrothermal preparation of MnNiO<sub>3</sub> and MnNiO<sub>3</sub>@rGO nanohybrid has been described in the current work. The prepared samples were evaluated structurally, morphologically and electrochemically using a variety of analytical instruments. The MnNiO<sub>3</sub>@rGO nanohybrid showed specific capacitance 1507 F/g calculated from the GCD plot with the exceptional cyclic stability of 5000th cycles at 1 A/g with a lower charge transfer resistance of 0.18 Ω. The exceptional performance of the MnNiO<sub>3</sub>@rGO nanohybrid can be due to the hierarchical structure and improvement in charge transfer capability. During redox process MnNiO<sub>3</sub>@rGO nanohybrid provides more active sites and a shorter channel for ion transport. As a result, the MnNiO<sub>3</sub>@rGO nanohybrid electrochemical performance can be significantly improved and its potential in energy storage systems.</p><h3 data-test=\"abstract-sub-heading\">Graphical Abstract</h3>","PeriodicalId":664,"journal":{"name":"Journal of Sol-Gel Science and Technology","volume":null,"pages":null},"PeriodicalIF":2.5,"publicationDate":"2024-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142256239","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pure ZnO nanoparticles and ZnO-Al2O3 nanocomposites prepared with Al2O3 content of 10, 20 and 30 atomic ratios were synthetized via Sol–gel method and then calcined for 2 h at different temperature 450, 700 and 900 °C. The structural, morphological and optical properties of the powder as-synthetized are investigated. Photocatalytic activity was assessed using methylene blue degradation. In the present work, the high purity of the nanoparticles was confirmed by EDS spectra. The XRD results show that ZnO powder has a wurtzite structure. The aluminum in composite powders leads to the appearance of the ZnAl2O4 spinel phase and it shows that this phase is appeared in the ZnO-30% at Al (Z30A) nanocomposite from an annealing temperature 450 °C as well as increasing the annealing temperature reduces the crystallite size. The flower-like morphology was well defined in these nanocomposites with an average size in the nanometer range. Photoluminescence reveals the incorporation of aluminum into the as-synthetized nanocomposites compared with XRD results.The optical absorption spectra have been presented the relationship between the band gap, particle size, annealing temperature, Al concentration and Urbach energy. Our result suggests that the annealing temperature 700 °C can be considered as an order-disorder transition temperature. The photo-catalytic application of pure ZnO and their composites nanoparticles shows that the best photocatalytic activity is obtained for the Z30A nanocomposite in the presence of MB dye, under UV light. This sample has the smallest crystal size and a high content of the ZnAl2O4 phase. A small particle size ensures high photoactivity.
{"title":"Temperature annealing and aluminum atomic concentration effect on structural, morphological and optical properties of ZnO-Al2O3 nanocomposites powders and photocatalytic performances","authors":"Ferial Benmammar, Aicha Ayadi, Lyes Maifi, Abdelhamid Chari, Kamel Agroui","doi":"10.1007/s10971-024-06514-6","DOIUrl":"https://doi.org/10.1007/s10971-024-06514-6","url":null,"abstract":"<p>Pure ZnO nanoparticles and ZnO-Al<sub>2</sub>O<sub>3</sub> nanocomposites prepared with Al<sub>2</sub>O<sub>3</sub> content of 10, 20 and 30 atomic ratios were synthetized via Sol–gel method and then calcined for 2 h at different temperature 450, 700 and 900 °C. The structural, morphological and optical properties of the powder as-synthetized are investigated. Photocatalytic activity was assessed using methylene blue degradation. In the present work, the high purity of the nanoparticles was confirmed by EDS spectra. The XRD results show that ZnO powder has a wurtzite structure. The aluminum in composite powders leads to the appearance of the ZnAl<sub>2</sub>O<sub>4</sub> spinel phase and it shows that this phase is appeared in the ZnO-30% at Al (Z30A) nanocomposite from an annealing temperature 450 °C as well as increasing the annealing temperature reduces the crystallite size. The flower-like morphology was well defined in these nanocomposites with an average size in the nanometer range. Photoluminescence reveals the incorporation of aluminum into the as-synthetized nanocomposites compared with XRD results.The optical absorption spectra have been presented the relationship between the band gap, particle size, annealing temperature, Al concentration and Urbach energy. Our result suggests that the annealing temperature 700 °C can be considered as an order-disorder transition temperature. The photo-catalytic application of pure ZnO and their composites nanoparticles shows that the best photocatalytic activity is obtained for the Z30A nanocomposite in the presence of MB dye, under UV light. This sample has the smallest crystal size and a high content of the ZnAl<sub>2</sub>O<sub>4</sub> phase. A small particle size ensures high photoactivity.</p><h3 data-test=\"abstract-sub-heading\">Graphical Abstract</h3>","PeriodicalId":664,"journal":{"name":"Journal of Sol-Gel Science and Technology","volume":null,"pages":null},"PeriodicalIF":2.5,"publicationDate":"2024-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142195893","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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 : 2024-09-11DOI: 10.1007/s10971-024-06532-4
Aboud Ahmed Awadh Bahajjaj, Abdul Ghafoor Abid, Zobia Siddique, Farah Sajjad, Iram Manzoor, Ome Parkash Kumar, Tauseef Munawar, Mika Sillanpää, Jafar Hussain Shah
Electrochemical water splitting is a viable strategy to produce renewable fuels such as hydrogen. Oxygen evolution reaction (OER) at the anode is getting more attention than hydrogen evolution reaction (HER) because of its higher overpotential and slower electron transfer process. Many advancements in the construction of an effective electrocatalyst have been made recently in an effort to boost OER activity. Additionally, the commercial RuO2 and Pt-derived catalysts are the most fascinating and active electrocatalysts used in the OER and HER kinetics procedure. They show good activity but the massive price and insufficiency are the main obstacles to their widespread usage in the production of hydrogen and oxygen gas. In this case, SnS2_multi walled carbon nanotubes (MWCNTSs) are directly produced on nickel foam (NF) using hydrothermal synthesis. All the catalysts like SnS2, MWCNTSs, and SnS2_MWCNTSs have been developed, and then they are characterized for structural, morphological, compositional, and electrochemical characterization. The fabricated nanocomposite shows OER onset potential of 1.33 V, 116 mV overpotential at 10 mAcm−2, and has a Tafel slope of 47 mVdec−1. In contrast, its HER onset potential is −0.3 V having 209 mV overpotential at 10 mAcm−2 current density and a Tafel slope of 135 mVdec−1. The presence of more electroactive sites, the lowest charge transfer resistance at the electrode-electrolyte interface, the distinct and uniform nanocrystal-like morphology, and the synergistic interaction between SnS2 and MWCNTS are some of the factors that contribute to the low value of overpotential of SnS2_MWCNTSs. The resultant electrocatalyst worked well for the very effective oxidation of water and has a variety of possible applications.
Graphical Abstract
电化学水分离是生产氢气等可再生燃料的一种可行策略。阳极氧进化反应（OER）比氢进化反应（HER）更受关注，因为其过电位更高，电子转移过程更慢。为了提高 OER 的活性，最近在构建有效的电催化剂方面取得了许多进展。此外，商业化的 RuO2 和 Pt 衍生催化剂是在 OER 和 HER 动力学过程中使用的最有吸引力和最活跃的电催化剂。它们显示出良好的活性，但昂贵的价格和不足是其广泛用于氢气和氧气生产的主要障碍。在这种情况下，采用水热合成法在泡沫镍（NF）上直接生产 SnS2_多壁碳纳米管（MWCNTSs）。所有催化剂（如 SnS2、MWCNTSs 和 SnS2_MWCNTSs）均已开发完成，然后对它们进行了结构、形态、成分和电化学表征。所制备的纳米复合材料的 OER 起始电位为 1.33 V，在 10 mAcm-2 条件下的过电位为 116 mV，Tafel 斜率为 47 mVdec-1。相比之下，其 HER 起始电位为-0.3 V，在 10 mAcm-2 电流密度下有 209 mV 的过电位，塔菲尔斜率为 135 mVdec-1。SnS2_MWCNTS具有更多的电活性位点、在电极-电解质界面上具有最低的电荷转移电阻、独特而均匀的纳米晶体状形态以及SnS2和MWCNTS之间的协同作用，这些都是导致SnS2_MWCNTS过电位值较低的部分原因。所制备的电催化剂能有效地氧化水，具有多种应用前景。
{"title":"Facile construction of SnS2-MWCNTSs decorated nanoparticles for effective water splitting","authors":"Aboud Ahmed Awadh Bahajjaj, Abdul Ghafoor Abid, Zobia Siddique, Farah Sajjad, Iram Manzoor, Ome Parkash Kumar, Tauseef Munawar, Mika Sillanpää, Jafar Hussain Shah","doi":"10.1007/s10971-024-06532-4","DOIUrl":"https://doi.org/10.1007/s10971-024-06532-4","url":null,"abstract":"<p>Electrochemical water splitting is a viable strategy to produce renewable fuels such as hydrogen. Oxygen evolution reaction (OER) at the anode is getting more attention than hydrogen evolution reaction (HER) because of its higher overpotential and slower electron transfer process. Many advancements in the construction of an effective electrocatalyst have been made recently in an effort to boost OER activity. Additionally, the commercial RuO<sub>2</sub> and Pt-derived catalysts are the most fascinating and active electrocatalysts used in the OER and HER kinetics procedure. They show good activity but the massive price and insufficiency are the main obstacles to their widespread usage in the production of hydrogen and oxygen gas. In this case, SnS<sub>2</sub>_multi walled carbon nanotubes (MWCNTSs) are directly produced on nickel foam (NF) using hydrothermal synthesis. All the catalysts like SnS<sub>2</sub>, MWCNTSs, and SnS<sub>2</sub>_MWCNTSs have been developed, and then they are characterized for structural, morphological, compositional, and electrochemical characterization. The fabricated nanocomposite shows OER onset potential of 1.33 V, 116 mV overpotential at 10 mAcm<sup>−2,</sup> and has a Tafel slope of 47 mVdec<sup>−1</sup>. In contrast, its HER onset potential is −0.3 V having 209 mV overpotential at 10 mAcm<sup>−2</sup> current density and a Tafel slope of 135 mVdec<sup>−1</sup>. The presence of more electroactive sites, the lowest charge transfer resistance at the electrode-electrolyte interface, the distinct and uniform nanocrystal-like morphology, and the synergistic interaction between SnS<sub>2</sub> and MWCNTS are some of the factors that contribute to the low value of overpotential of SnS<sub>2</sub>_MWCNTSs. The resultant electrocatalyst worked well for the very effective oxidation of water and has a variety of possible applications.</p><h3 data-test=\"abstract-sub-heading\">Graphical Abstract</h3>","PeriodicalId":664,"journal":{"name":"Journal of Sol-Gel Science and Technology","volume":null,"pages":null},"PeriodicalIF":2.5,"publicationDate":"2024-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142195894","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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 : 2024-09-10DOI: 10.1007/s10971-024-06538-y
Andreas Tiron-Stathopoulos, Konstantinos Dimos
The unique properties that aerogels exhibit have been the main reason for the intense research around new synthesis routes and new applications in various fields in recent years. Composite aerogels combine the properties of both the aerogel matrix and the inclusions, where the latter can be several materials in various forms. Carbon dots are suitable candidates to use as inclusion for the development of composite aerogels and that is due to their low-cost production, low toxicity, biocompatibility, and tunable fluorescence. Here we report the synthesis of a composite silica matrix aerogel with boron-doped carbon dots inclusions, and we focus on the optical response of the material. The method we use to prepare the composite aerogel is the classical sol-gel process using tetraethyl orthosilicate as silica precursor, followed by CO2 supercritical drying. The resulting aerogel is crack-free, exhibiting a surface area of 518 m2/g and diverse optoelectronic properties compared to the pristine carbon dots in solution, as an excitation-dependent emission and an unusual blue-shift for excitation centered in the UVB region. The unfamiliar optoelectronic properties of the carbon dots in the aerogel are discussed and are attributed to the influence of the silica matrix. Hence, the induced carbon dots’ aggregation may lead to recombination de-excitation pathways, whereas the photoluminescence contribution by the core-related de-excitation pathway may shorten, as the penetration depth of radiation into the dots’ core may be affected by its intensity which drops drastically for high energies (for λexc. < 300 nm) due to strong absorption by the silica matrix.
{"title":"Carbon dots’ unusual optoelectronic properties in silica aerogels","authors":"Andreas Tiron-Stathopoulos, Konstantinos Dimos","doi":"10.1007/s10971-024-06538-y","DOIUrl":"https://doi.org/10.1007/s10971-024-06538-y","url":null,"abstract":"<p>The unique properties that aerogels exhibit have been the main reason for the intense research around new synthesis routes and new applications in various fields in recent years. Composite aerogels combine the properties of both the aerogel matrix and the inclusions, where the latter can be several materials in various forms. Carbon dots are suitable candidates to use as inclusion for the development of composite aerogels and that is due to their low-cost production, low toxicity, biocompatibility, and tunable fluorescence. Here we report the synthesis of a composite silica matrix aerogel with boron-doped carbon dots inclusions, and we focus on the optical response of the material. The method we use to prepare the composite aerogel is the classical sol-gel process using tetraethyl orthosilicate as silica precursor, followed by CO<sub>2</sub> supercritical drying. The resulting aerogel is crack-free, exhibiting a surface area of 518 m<sup>2</sup>/g and diverse optoelectronic properties compared to the pristine carbon dots in solution, as an excitation-dependent emission and an unusual blue-shift for excitation centered in the UVB region. The unfamiliar optoelectronic properties of the carbon dots in the aerogel are discussed and are attributed to the influence of the silica matrix. Hence, the induced carbon dots’ aggregation may lead to recombination de-excitation pathways, whereas the photoluminescence contribution by the core-related de-excitation pathway may shorten, as the penetration depth of radiation into the dots’ core may be affected by its intensity which drops drastically for high energies (for <i>λ</i><sub>exc.</sub> < 300 nm) due to strong absorption by the silica matrix.</p><h3 data-test=\"abstract-sub-heading\">Graphical Abstract</h3>","PeriodicalId":664,"journal":{"name":"Journal of Sol-Gel Science and Technology","volume":null,"pages":null},"PeriodicalIF":2.5,"publicationDate":"2024-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142195924","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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 : 2024-09-09DOI: 10.1007/s10971-024-06526-2
Mucahit Abdullah Sari, Enes Kilinc, Fatih Uysal, Huseyin Kurt, Erdal Celik
This research aims to produce and develop semiconducting thermoelectric materials for thermoelectric generators in aerospace applications. In this context, ZnAlGeO powders were synthesized via the sol-gel method using precursor materials and a 20% toluene solution in ethanol as the solvent. Glacial acetic acid was added to accelerate gel formation. The pH and turbidity values of prepared solutions were measured using a pH meter and turbidimeter. After gelation, the obtained xerogel was dried at 200 °C for 9 h to remove moisture and undesired gases. Dried powders were calcined at 600 °C for 4 h in air, resulting in final ZnAlGeO materials. The pellets underwent thermal processing for 36 h at a temperature of 1350 °C, targeting the production of bulk samples within the n-type semiconductor category. Extensive characterization, including thermal, structural, microstructural, and thermoelectric properties, was conducted using various techniques such as DTA-TG, FTIR, XRD, XPS, SEM, and thermoelectric measurement devices. The study concludes that the produced semiconducting ceramic materials exhibit efficiency for thermoelectric generator production.
{"title":"Production and development of ZnAlGeO semiconducting materials for thermoelectric generators in potential aerospace applications","authors":"Mucahit Abdullah Sari, Enes Kilinc, Fatih Uysal, Huseyin Kurt, Erdal Celik","doi":"10.1007/s10971-024-06526-2","DOIUrl":"https://doi.org/10.1007/s10971-024-06526-2","url":null,"abstract":"<p>This research aims to produce and develop semiconducting thermoelectric materials for thermoelectric generators in aerospace applications. In this context, ZnAlGeO powders were synthesized via the sol-gel method using precursor materials and a 20% toluene solution in ethanol as the solvent. Glacial acetic acid was added to accelerate gel formation. The pH and turbidity values of prepared solutions were measured using a pH meter and turbidimeter. After gelation, the obtained xerogel was dried at 200 °C for 9 h to remove moisture and undesired gases. Dried powders were calcined at 600 °C for 4 h in air, resulting in final ZnAlGeO materials. The pellets underwent thermal processing for 36 h at a temperature of 1350 °C, targeting the production of bulk samples within the n-type semiconductor category. Extensive characterization, including thermal, structural, microstructural, and thermoelectric properties, was conducted using various techniques such as DTA-TG, FTIR, XRD, XPS, SEM, and thermoelectric measurement devices. The study concludes that the produced semiconducting ceramic materials exhibit efficiency for thermoelectric generator production.</p><h3 data-test=\"abstract-sub-heading\">Graphical Abstract</h3>","PeriodicalId":664,"journal":{"name":"Journal of Sol-Gel Science and Technology","volume":null,"pages":null},"PeriodicalIF":2.5,"publicationDate":"2024-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142195895","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
So far, the sol-gel process has been available to prepare precursor gels of bioactive glasses with various compositions. In this report, we described a novel coating method of bioactive gels on a titanium substrate where the sol-gel transition is controlled by applying external electric fields. The application of a constant current of 10 mA/cm2 in an acidic sol containing pre-hydrolyzed tetraethoxysilane, calcium nitrate, and ammonium dihydrogen phosphate led to the deposition of gels on the titanium cathodes due to the generation of OH– by water electrolysis as a catalyst of the sol-gel transition. The obtained gels, which were characterized to be amorphous and consisted of Si, Ca, and P, covered the titanium substrates as a coating. The bioactivity of the gels deposited was confirmed by soaking in a simulated body fluid (SBF) up to 7 days, suggesting that the electrochemically assisted sol-gel process is promising for providing bioactive coatings on metallic implants.
{"title":"Electrochemically assisted sol-gel deposition of bioactive gels for biomedical applications","authors":"Tomohiko Yoshioka, Naoki Miyamoto, Satoshi Hayakawa","doi":"10.1007/s10971-024-06530-6","DOIUrl":"https://doi.org/10.1007/s10971-024-06530-6","url":null,"abstract":"<p>So far, the sol-gel process has been available to prepare precursor gels of bioactive glasses with various compositions. In this report, we described a novel coating method of bioactive gels on a titanium substrate where the sol-gel transition is controlled by applying external electric fields. The application of a constant current of 10 mA/cm<sup>2</sup> in an acidic sol containing pre-hydrolyzed tetraethoxysilane, calcium nitrate, and ammonium dihydrogen phosphate led to the deposition of gels on the titanium cathodes due to the generation of OH<sup>–</sup> by water electrolysis as a catalyst of the sol-gel transition. The obtained gels, which were characterized to be amorphous and consisted of Si, Ca, and P, covered the titanium substrates as a coating. The bioactivity of the gels deposited was confirmed by soaking in a simulated body fluid (SBF) up to 7 days, suggesting that the electrochemically assisted sol-gel process is promising for providing bioactive coatings on metallic implants.</p><h3 data-test=\"abstract-sub-heading\">Graphical Abstract</h3>","PeriodicalId":664,"journal":{"name":"Journal of Sol-Gel Science and Technology","volume":null,"pages":null},"PeriodicalIF":2.5,"publicationDate":"2024-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142195923","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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 : 2024-09-09DOI: 10.1007/s10971-024-06534-2
Gulsen Sahin, Abdullah Goktas, Esra Aslan
Water recycling is a convenient way to get around the water shortage and wastewater analysis. The water can be reused for domestic purposes by eliminating organic pollutants through a photocatalytic process. For this aim, the sol-gel dip coating process synthesized ZrO2 nanostructured thin films with tunable structural, morphological, and optical properties and photocatalytic activities. Zr sources (acetate, nitrate, and chloride), annealing temperature (TA), and thickness (d)-dependent structural, morphological, optical, and photocatalytic performances of the ZrO2 films were scrutinized by x-ray diffraction (XRD), scanning electron microscopy (SEM), electron dispersive x-ray spectroscopy (EDS), mapping technique, and UV–Vis spectroscopy. The XRD, SEM, EDS, and mapping analyses confirmed the formation of nanostructured ZrO2 thin film. The results revealed that ZrO2 film had a tetragonal phase with various crystallite sizes and different surface morphologies as the Zr sources, TA, and d varied. There were significant variations in the optical absorbance, band gap, refractive index, and absorption coefficient based on Zr sources, TA, and d. Among all ZrO2 films, the film sample synthesized by the Zr-acetate source annealed at TA of 500 °C and with d of 940 nm was found to be the most effective film in terms of optical and crystalline quality as well as photocatalytic performance (94% efficiency in 150 min) for the degradation of methylene blue dye. The enhanced light utilization capability suppressed charge recombination, surface morphology, grain size, defect concentration, and optical band gap values of the nanostructured zirconia thin films are the key factors corresponding to enhanced photocatalytic performance.
Graphical Abstract
水循环利用是解决水资源短缺和废水分析问题的便捷途径。通过光催化过程消除有机污染物，可将水回用于家庭用途。为此，采用溶胶-凝胶浸涂工艺合成了具有可调结构、形态、光学特性和光催化活性的 ZrO2 纳米结构薄膜。通过 X 射线衍射 (XRD)、扫描电子显微镜 (SEM)、电子色散 X 射线光谱 (EDS)、制图技术和紫外可见光谱，研究了 ZrO2 薄膜的 Zr 来源（醋酸盐、硝酸盐和氯化物）、退火温度 (TA) 和厚度 (d) 与结构、形态、光学和光催化性能的关系。X射线衍射、扫描电子显微镜、电子色散 X 射线光谱和绘图分析证实了纳米结构 ZrO2 薄膜的形成。结果表明，随着 Zr 源、TA 和 d 的变化，ZrO2 薄膜具有不同结晶尺寸和不同表面形态的四方相。在所有 ZrO2 薄膜中，由醋酸锆源合成的薄膜样品在 TA 值为 500 ℃、d 值为 940 nm 时退火，其光学质量、结晶质量和光催化性能（150 分钟内效率为 94%）对亚甲基蓝染料的降解效果最好。纳米结构氧化锆薄膜的光利用能力增强、电荷重组抑制、表面形貌、晶粒尺寸、缺陷浓度和光带隙值是光催化性能增强的关键因素。
{"title":"A new way to tune photocatalytic activity, surface morphology, and structural/optical parameters of ZrO2 thin films using different Zr sources along with annealing temperature and film thickness","authors":"Gulsen Sahin, Abdullah Goktas, Esra Aslan","doi":"10.1007/s10971-024-06534-2","DOIUrl":"https://doi.org/10.1007/s10971-024-06534-2","url":null,"abstract":"<p>Water recycling is a convenient way to get around the water shortage and wastewater analysis. The water can be reused for domestic purposes by eliminating organic pollutants through a photocatalytic process. For this aim, the sol-gel dip coating process synthesized ZrO2 nanostructured thin films with tunable structural, morphological, and optical properties and photocatalytic activities. Zr sources (acetate, nitrate, and chloride), annealing temperature (T<sub>A</sub>), and thickness (d)-dependent structural, morphological, optical, and photocatalytic performances of the ZrO<sub>2</sub> films were scrutinized by x-ray diffraction (XRD), scanning electron microscopy (SEM), electron dispersive x-ray spectroscopy (EDS), mapping technique, and UV–Vis spectroscopy. The XRD, SEM, EDS, and mapping analyses confirmed the formation of nanostructured ZrO<sub>2</sub> thin film. The results revealed that ZrO<sub>2</sub> film had a tetragonal phase with various crystallite sizes and different surface morphologies as the Zr sources, T<sub>A</sub>, and d varied. There were significant variations in the optical absorbance, band gap, refractive index, and absorption coefficient based on Zr sources, TA, and d. Among all ZrO<sub>2</sub> films, the film sample synthesized by the Zr-acetate source annealed at T<sub>A</sub> of 500 °C and with d of 940 nm was found to be the most effective film in terms of optical and crystalline quality as well as photocatalytic performance (94% efficiency in 150 min) for the degradation of methylene blue dye. The enhanced light utilization capability suppressed charge recombination, surface morphology, grain size, defect concentration, and optical band gap values of the nanostructured zirconia thin films are the key factors corresponding to enhanced photocatalytic performance.</p><h3 data-test=\"abstract-sub-heading\">Graphical Abstract</h3>","PeriodicalId":664,"journal":{"name":"Journal of Sol-Gel Science and Technology","volume":null,"pages":null},"PeriodicalIF":2.5,"publicationDate":"2024-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142195925","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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 : 2024-09-09DOI: 10.1007/s10971-024-06539-x
K. M. S. Dawngliana, Lalruat Puia, A. L. Fanai, Ralte Lalrempuia, S. Rai
This article discusses our investigations into the structural and spectroscopic properties of Nd3+ co-doped alumino-silicate glass prepared by an in-situ sol-gel method. Structural characterization was carried out using X-ray powder diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM) techniques. The XRD analysis reveals that the material is still amorphous even after being heated to 900 °C. FTIR analysis was used to identify the functional groups of the produced sol-gel silicate glass. The optical absorption spectra from the ground state 4I9/2 show seven peaks in the UV-VIS and NIR regions. The optical absorption spectrum of Nd3+ co-doped alumino-silicate glass-ceramic was used to determine the Judd-Ofelt (JO) intensity parameters (Ω2, Ω4 and Ω6). The photoluminescence (PL) spectrum was recorded with a 2W diode laser source of 808 nm excitations. From the larger stimulated emission cross-section (3.80 x 10−20 cm2) of the 4F3/2 → 4I11/2 transition, it is concluded that the SiNdAl glasses could be highly useful for the development of solid state laser materials. From the observed refractive indices at three different wavelengths, non-linear parameters for the glass, such as the Abbe number (υAb) and non-linear refractive index (n2), are derived.
{"title":"Effect of Al on photoluminescence properties of Nd3+ in silicate glass prepared by in-situ sol-gel method","authors":"K. M. S. Dawngliana, Lalruat Puia, A. L. Fanai, Ralte Lalrempuia, S. Rai","doi":"10.1007/s10971-024-06539-x","DOIUrl":"https://doi.org/10.1007/s10971-024-06539-x","url":null,"abstract":"<p>This article discusses our investigations into the structural and spectroscopic properties of Nd<sup>3+</sup> co-doped alumino-silicate glass prepared by an in-situ sol-gel method. Structural characterization was carried out using X-ray powder diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM) techniques. The XRD analysis reveals that the material is still amorphous even after being heated to 900 °C. FTIR analysis was used to identify the functional groups of the produced sol-gel silicate glass. The optical absorption spectra from the ground state <sup>4</sup>I<sub>9/2</sub> show seven peaks in the UV-VIS and NIR regions. The optical absorption spectrum of Nd<sup>3+</sup> co-doped alumino-silicate glass-ceramic was used to determine the Judd-Ofelt (JO) intensity parameters (Ω<sub>2</sub>, Ω<sub>4</sub> and Ω<sub>6</sub>). The photoluminescence (PL) spectrum was recorded with a 2W diode laser source of 808 nm excitations. From the larger stimulated emission cross-section (3.80 x 10<sup>−20</sup> cm<sup>2</sup>) of the <sup>4</sup>F<sub>3/2</sub> → <sup>4</sup>I<sub>11/2</sub> transition, it is concluded that the SiNdAl glasses could be highly useful for the development of solid state laser materials. From the observed refractive indices at three different wavelengths, non-linear parameters for the glass, such as the Abbe number (υ<sub>Ab</sub>) and non-linear refractive index (n<sub>2</sub>), are derived.</p><h3 data-test=\"abstract-sub-heading\">Graphical Abstract</h3>","PeriodicalId":664,"journal":{"name":"Journal of Sol-Gel Science and Technology","volume":null,"pages":null},"PeriodicalIF":2.5,"publicationDate":"2024-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142195928","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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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