Search Results (23)

This study enhanced germanium (Ge) enrichment in the liquid fermentation of the edible fungus Lyophyllum decastes in order to boost its biological activity, particularly its antioxidant and immunomodulatory properties. Through the use of single-factor and Plackett–Burman designs, the experiments revealed critical parameters affecting Ge enrichment, including Ge oxide concentration, potato powder concentration, and peptone levels. The optimization of the Box–Behnken response surface methodology resulted in a Ge concentration of 3.61 mg/L, significantly enhancing the biomass, protein, polysaccharide, and flavonoid content in the mycelium. In contrast to traditional fermentation, Ge-rich fermentation enhanced the mycelial biomass by 30.97% and elevated the organic Ge content 50.19-fold. An analysis of the antioxidants revealed that the Ge-enriched mycelial water extract exhibited heightened activity, augmenting TNF-α production in RAW264.7 cells by 73.29% at a concentration of 200 μg/g. These findings indicate that the Ge-enriched fermentation of L. decastes holds promise for functional applications in health-supportive products due to its robust antioxidant and immune-enhancing capabilities. Full article

Germanium offers attractive optical properties despite being an indirect bandgap semiconductor, and new Ge-based devices are being optimized for sensing and photonics applications. In particular, considering the use of Ge as a sensor, improving its selectivity via organic grafting offers new alternatives that are still under investigation. In this work, we focus on the selective functionalization of germanium in SiGe-patterned alloys using a custom thiol-based luminescent molecule, namely 6-[2,7-bis[5-(5-hexyl-2-thienyl)-2-thienyl]-9-(6-sulfanylhexyl)fluoren-9-yl]hexane-1-thiol. The process selectively targets regions with Ge, while leaving Si-rich areas uncovered. Moreover, this study emphasizes the importance of an oxygen-free environment, as performing the functionalization in an inert atmosphere significantly improves surface coverage. Full article

Arbuscular mycorrhizal fungi (AMF) and the antioxidant germanium (Ge) are promising tools for boosting bioactive compound synthesis and producing healthier foods. However, their combined effect remains unexplored. This study demonstrates the synergistic impact of AMF and Ge on the growth, metabolite accumulation, biological activities, and nutritional qualities of Spinacia oleracea L. (spinach), a globally significant leafy vegetable. Individually, Ge and AMF increased biomass by 68.1% and 22.7%, respectively, while their combined effect led to an 86.3% increase. AMF and Ge also improved proximate composition, with AMF–Ge interaction enhancing crude fiber and mineral content (p < 0.05). Interestingly, AMF enhanced photosynthesis-related parameters (e.g., total chlorophyll) in Ge treated plants, which in turn increased carbohydrate accumulation. This accumulation could provide a route for the biosynthesis of amino acids, organic acids, and fatty acids, as evidenced by increased essential amino acid and organic acid levels. Consistently, the activity of key enzymes involved in amino acids biosynthesis (e.g., glutamine synthase (GS), methionine biosynthase (MS), lysine biosynthase (LS)) showed significant increments. Furthermore, AMF improved fatty acid levels, particularly unsaturated fatty acids in Ge-treated plants compared to the control. In addition, increased phenylalanine provided a precursor for the production of antioxidants (e.g., phenols and flavonoids), through the action of the enzyme phenylalanine ammonia-lyase (PAL), resulting in improved antioxidant activity gains as indicated by FRAP, ABTS, and DPPH assays. This study is the first to show that Ge enhances the beneficial effect of AMF on spinach, improving growth and nutritional quality, with promising implications for agricultural practices. Full article

Gallium (Ga) and germanium (Ge) critical elements have a wide range of applications and market value. Extracting critical elements from coal gangue and combustion products can alleviate pressures on primary mining resources. Understanding the transformation behavior of Ga and Ge during coal gangue combustion processes is significant for resource utilization and environmental protection. Coal gangue from Xing’an League, Inner Mongolia, was chosen to explore how combustion temperatures (600 °C to 1000 °C) and particle sizes (50, 80, 10, 140, and 200 mesh) influence Ga and Ge migration during combustion. Techniques such as ICP-MS, XRD, XRF, SEM, TG-DSC, and sequential chemical extraction were employed to analyze the transformation of minerals and to quantify the contents and occurrence forms of Ga and Ge. Smaller gangue particle sizes were associated with higher concentrations of Ga and Ge. Approximately 99.19% of Ga and Ge in coal gangue were found in the residual, organic/sulfide-bound, and metal-oxide-bound modes. High temperatures promoted element volatilization and changed the reactions and interactions between elements and minerals. As combustion temperatures rose from 600 °C to 1000 °C, Ga and Ge contents in the products declined progressively. Under high temperatures, minerals like kaolinite, illite, and pyrite in gangue converted to silicate glass phases, mullite, and hematite. Minerals like kaolinite, calcite, and pyrite melted, leading to increased cohesion and agglomeration in the products. Over 90% of Ga and Ge in the combustion products existed in the residual, organic/sulfide-bound, and metal-oxide-bound forms. Moreover, Ga was enriched in combustion products, with its content exceeding critical extraction levels. The results may provide a useful reference for developing critical elements enrichment, extraction, and separation technologies from coal gangue. Full article

Gel electrolytes for lithium-ion batteries continue to replace the organic liquid electrolytes in conventional batteries due to their advantages of being less prone to leakage and non-explosive and possessing a high modulus of elasticity. However, the development of gel electrolytes has been hindered by their generally low ionic conductivity at room temperature and high interfacial impedance with electrodes. In this paper, a poly (vinylidene fluoride)-hexafluoropropylene copolymer (PVdF-HFP) with a flexible structure, Li₆PS₅Cl (LPSCl) powder of the sulfur–silver–germanium ore type, and lithium perchlorate salt (LiClO₄) were prepared into sulfide gel composite electrolyte films (GCEs) via a thermosetting process. The experimental results showed that the gel composite electrolyte with 1% LPSCl in the PVdF-HFP matrix exhibited an ionic conductivity as high as 1.27 × 10⁻³ S·cm⁻¹ at 25 °C and a lithium ion transference number of 0.63. The assembled LiFePO₄||GCEs||Li batteries have excellent rate (130 mAh·g⁻¹ at 1 C and 54 mAh·g⁻¹ at 5 C) and cycling (capacity retention was 93% after 100 cycles at 0.1 C and 80% after 150 cycles at 0.2 C) performance. This work provides new methods and strategies for the design and fabrication of solid-state batteries with high ionic conductivity and high specific energy. Full article

Gamma-ray spectroscopy is an effective technique for radioactive material characterization, routine inventory verification, nuclear safeguards, health physics, and source search scenarios. Gamma-ray spectrometers typically cannot be operated in the immediate vicinity of nuclear reactors due to their high flux fields and their resulting inability to resolve individual pulses. Low-power reactor facilities offer the possibility to study reactor gamma-ray fields, a domain of experiments hitherto poorly explored. In this work, we present gamma-ray spectroscopy experiments performed with various detectors in two reactors: The EPFL zero-power research reactor CROCUS, and the neutron beam facility at the Ohio State University Research Reactor (OSURR). We employed inorganic scintillators (CeBr₃), organic scintillators (trans-stilbene and organic glass), and high-purity germanium semiconductors (HPGe) to cover a range of typical—and new—instruments used in gamma-ray spectroscopy. The aim of this study is to provide a guideline for reactor users regarding detector performance, observed responses, and therefore available information in the reactor photon fields up to 2 MeV. The results indicate several future prospects, such as the online (at criticality) monitoring of fission products (like Xe, I, and La), dual-particle sensitive experiments, and code validation opportunities. Full article

We report ab initio molecular dynamic simulations of the organic structure-directing agent (OSDA) in the channels of SCM-14 and SCM-15 germanosilicates for models with different germanium distribution. Since OSDA was free to move inside the channels, independent of its initial orientation after the simulations in all structures the OSDA, protonated 4-pyrrolidinopyridine, is positioned almost perpendicular to the large channels of SCM-14. The structures obtained from the dynamic simulation are more stable by 157 to 331 kJ/mol than the structures obtained by initial geometry optimization. After simulations, the average distance between the N atom of the pyridine moiety of the OSDA and O from Ge-O-Ge is shorter by 0.2 Å than the same distance obtained from initial optimization. The stretching N-H frequencies in the IR spectra of the OSDA and other calculated vibrational frequencies are not characteristic of the orientation of the molecule and cannot be used to detect it. Full article

Inorganic semiconductors like silicon and germanium are the foundation of modern electronic devices. However, they have certain limitations, such as high production costs, limited flexibility, and heavy weight. Additionally, the depletion of natural resources required for inorganic semiconductor production raises concerns about sustainability. Therefore, the exploration and development of organic semiconductors offer a promising solution to overcome these challenges and pave the way for a new era of electronics. New applications for electronic and optoelectronic devices have been made possible by the recent emergence of organic semiconductors. Numerous innovative results on the performance of charge transport have been discovered with the growth of organic electronics. These discoveries have opened up new possibilities for the development of organic electronic devices, such as organic solar cells, organic light-emitting diodes, and organic field-effect transistors. The use of organic materials in these devices has the potential to revolutionise the electronics industry by providing low-cost, flexible, and lightweight alternatives to traditional inorganic materials. The understanding of charge carrier transport in organic semiconductors is crucial for the development of efficient organic electronic devices. This review offers a thorough overview of the charge carrier transport phenomenon in semiconductors with a focus on the underlying physical mechanisms and how it affects device performance. Additionally, the processes of carrier generation and recombination are given special attention. Furthermore, this review provides valuable insights into the fundamental principles that govern the behaviour of charge carriers in these materials, which can inform the design and optimisation of future devices. Full article

This research aims to optimize the efficiency of the device structures by introducing the novel double perovskite absorber layer (PAL). The perovskite solar cell (PSC) has higher efficiency with both lead perovskite (PVK), i.e., methylammonium tin iodide (MASnI₃) and Caseium tin germanium iodide (CsSnGeI₃). The current simulation uses Spiro-OMeTAD as the hole transport layer (HTL) and TiO₂ as an electron transport layer (ETL) to sandwich the PVK layers of MASnI₃ and CsSnGeI₃, which have precise bandgaps of 1.3 eV and 1.5 eV. The exclusive results of the precise modeling technique for organic/inorganic PVK-based photovoltaic solar cells under the illumination of AM1.5 for distinctive device architectures are shown in the present work. Influence of defect density (DD) is also considered during simulation that revealed the best PSC parameters with J_SC of 31.41 mA/cm², V_OC of 1.215 V, FF of nearly 82.62% and the highest efficiency of 31.53% at the combined DD of 1.0 × 10¹⁴ cm⁻³. The influence of temperature on device performance, which showed a reduction in PV parameters at elevated temperature, is also evaluated. A steeper temperature gradient with an average efficiency of −0.0265%/K for the optimized PSC is observed. The novel grading technique helps in achieving efficiency of more than 31% for the optimized device. As a result of the detailed examination of the total DD and temperature dependency of the simulated device, structures are also studied simultaneously. Full article

The use of quartz is critical to the electron spin resonance (ESR) dating of sediments and fault gouges. The germanium center (Ge center) in quartz is a commonly used color center employed in ESR signal measurement. Although Ge center signals in quartz can be detected using an ESR spectrometer, they are weak and sometimes undetectable. Impurities in quartz grains can further aggravate these deficiencies and may even invalidate any attempt to repeat ESR ages due to the deficiencies evident in the processes used in sample preparation. Using sieving, carbonate-organic matter removal, water flotation, magnetic separation, heavy liquid separation, and HF solution etching, we separated quartz, feldspar (plagioclase), mica, and the heavy minerals and measured the ESR signal in each of them to examine the impact of impurities within mineral grains on the ESR signals. From the ESR spectra, we observed intense ESR signals in feldspar and the heavy minerals and weak signals in mica at the same positions as the Ge center in the quartz. The ESR signals in the feldspar proved to be the most intense and overrode the peaks exhibited by the Ge center in the quartz. Feldspar is commonly associated with quartz in sediments, but it is difficult to separate it from quartz as their colors, specific gravities, and magnetic properties are similar. Any ESR signal in quartz containing foreign minerals would therefore be likely to be heavily disturbed by the signals from these foreign minerals, particularly from the feldspar and heavy minerals. ESR signals in the feldspar decreased similarly to those in the quartz when exposed to sunlight, declining by 70%–80% after being exposed for 50 h. Such declination was more obvious in high-altitude areas than in low-altitude areas. Our results indicate that highly pure quartz is required when dating; we would therefore strongly suggest that the procedures for the purification of quartz grains should include floating, heavy liquid separation, and HF solution etching to remove the feldspar, heavy minerals, and any remnant magnetite. Such a procedure would guarantee that the signal that is measured comes from the quartz alone, allowing repeatable measurements using the same spectrometer as well as valid comparisons between the spectrometries derived from different spectrometers. Full article

In this study, a hybrid organic–inorganic perovskite solar cell (PSC) based on methylammonium germanium triiodide (MAGeI₃), which is composed of methylammonium ($\mathrm{C}{\mathrm{H}}_3\mathrm{N}{\mathrm{H}}_3^{+})$ cations and germanium triiodide ($\mathrm{G}\mathrm{e}{\mathrm{I}}_3^{-}$) anions, has been numerically studied using SCAPS-1d codes. An extensive investigation of various electron transport layers (ETLs) and hole transport layers (HTLs) was conducted to identify the most optimal device configuration. The FTO/ZnOS/MAGeI₃/PEDOT-WO₃ structure performed the highest efficiency of all combinations tested, with an impressive optimized efficiency of 15.84%. This configuration exhibited a V_oc of 1.38 V, J_sc of 13.79 mA/cm², and FF of 82.58%. J-V characteristics and external quantum efficiency (EQE) measurements indicate that this device offers superior performance, as it has reduced current leakage, improved electron and hole extraction characteristics, and reduced trap-assisted interfacial recombination. Optimum device performance was achieved at active layer thickness of 560 nm. These findings may also serve as a basis for developing lightweight and ultra-thin solar cells, in addition to improving overall efficiency. Furthermore, a comprehensive correlation study was conducted to evaluate the optimum thickness and doping level for both ZnOS-ETL and PEDOT-WO₃-HTL. The photovoltaic performance parameters of the FTO/ZnOS/MAGeI₃/PEDOT-WO₃ structure were analyzed over a wide temperature range (275 K to 450 K). The structure exhibited stable performance at elevated operating temperatures up to 385 K, with only minimal degradation in PCE of approximately 0.42%. Our study underscores the promise of utilizing cost-effective and long-term stability materials like ZnOS and PEDOT-WO₃ alongside the toxic-free MAGeI₃ perovskite. This combination exhibits significant potential for eco-friendly PSC, paving the way for the development of highly efficient ultra-thin PSC. Full article

Germanium is an essential microelement, and its deficiency can result in numerous diseases, particularly oncogenic conditions. Consequently, water-soluble germanium compounds, including inorganic and coordination compounds, have attracted significant attention due to their biological activity. The review analyzes the primary research from the last decade related to the anticancer activity of germanium compounds. Furthermore, the review clarifies their actual toxicity, identifies errors and misconceptions that have contributed to the discrediting of their biological activity, and briefly suggests a putative mechanism of germanium-mediated protection from oxidative stress. Finally, the review provides clarifications on the discovery history of water-soluble organic germanium compounds, which was distorted and suppressed for a long time. Full article

Germanium-based multi-metallic-oxide materials have advantages of low activation energy, tunable output voltage, and high theoretical capacity. However, they also exhibit unsatisfactory electronic conductivity, sluggish cation kinetics, and severe volume change, resulting in inferior long-cycle stability and rate performance in lithium-ion batteries (LIBs). To solve these problems, we synthesize metal-organic frameworks derived from rice-like Zn₂GeO₄ nanowire bundles as the anode of LIBs via a microwave-assisted hydrothermal method, minimizing the particle size and enlarging the cation’s transmission channels, as well as, enhancing the electronic conductivity of the materials. The obtained Zn₂GeO₄ anode exhibits superior electrochemical performance. A high initial charge capacity of 730 mAhg⁻¹ is obtained and maintained at 661 mAhg⁻¹ after 500 cycles at 100 mA g⁻¹ with a small capacity degradation ratio of ~0.02% for each cycle. Moreover, Zn₂GeO₄ exhibits a good rate performance, delivering a high capacity of 503 mA h g⁻¹ at 5000 mA g⁻¹. The good electrochemical performance of the rice-like Zn₂GeO₄ electrode can be attributed to its unique wire-bundle structure, the buffering effect of the bimetallic reaction at different potentials, good electrical conductivity, and fast kinetic rate. Full article

Increasing concerns about the vulnerability of the world’s energy supply and the necessity to implement sustainable technologies have prompted researchers to develop high-performance electrocatalysts that are affordable and efficient for converting and storing renewable energy. This article reports a facile approach to fabricating two-dimensional (2D) Ge-decorated h-BN/MoS₂ heterostructure nanosheets by self-assembly for multiple electrochemical applications such as supercapacitor and hydrogen evolution reactions. The organization of the physical and chemical links between the germanium modulations on the heterostructure of boron nitride/molybdenum sulphide (Ge/h-BN/MoS₂) were facilitated to generate more active sites. Furthermore, the asymmetric supercapacitor of Ge-decorated h-BN/MoS₂ amplified the capacitance to 558.53 F g⁻¹ at 1 A g⁻¹ current density and 159.19 F g⁻¹ at 10 A g⁻¹, in addition to a retention rate of 85.69% after 2000 cycles. Moreover, the Ge-decorated h-BN/MoS₂ catalyst realized a low over-potential value, with an RHE of 0.57 (HER) at 5 mA/cm², a Tafel value of ∼204 mV/dec, and long-term electrolysis stability of 10 h. This work may open the door for further investigations on metal-decorated heterostructures, which have a significant potential for both supercapacitor and water-splitting applications. Full article

The use of lithium-ion batteries allows for a reliable and efficient storage of electricity. Commercial batteries use flammable liquid organic electrolytes, which have a low thermal and electrochemical stability. Replacing liquid electrolytes with solid ones would solve these problems. NASICON-structured electrolytes, in particular LATP (Li_1+yTi_2-yAl_y(PO₄)₃) and LAGP (Li_1+yGe_2-3yAl_y(PO₄)₃), are among the most promising electrolytes for all-solid-state batteries. The partial replacement of titanium ions with germanium ions can lead to materials that combine the high lithium-ion conductivity of LATP with the high chemical stability of LAGP. The aim of this work was to synthesize and study the ionic mobility of Li_1+yTi_2-x-yGe_xAl_y(PO₄)₃ (x = 0–2, y = 0–0.3) with the NASICON structure. Li_1+yTi_2-x-yGe_xAl_y(PO₄)₃ (x = 0–2, y = 0–0.3) electrolytes were synthesized with the solid-state method and investigated using X-ray diffraction and scanning electron microscopy, impedance spectroscopy, and NMR spectroscopy. The processes occurring during the solid-state synthesis of Li_1+yTi_2-x-yGe_xAl_y(PO₄)₃ were studied. An increase in conductivity from 10⁻⁷ S/cm to 4.6·10⁻⁶ S/cm at 25 °C was found when 10% of titanium ions were replaced with germanium. The additional introduction of aluminum resulted in an increase in lithium conductivity of up to 1.4·10⁻⁴ S/cm (25 °C). Since grain boundaries were of decisive importance for the overall ionic conductivity of the NASICON-structured phosphates, the influence of the precursor mechanical treatment on the microstructure and ionic conductivity of the prepared materials was studied. The use of the mechanical treatment led to a significant increase in grain size (reducing the grain boundaries and their resistance) and an increase in ionic conductivity (up to 6.4·10⁻⁴ S/cm at 25 °C). The obtained materials could be considered promising solid electrolytes for all-solid-state lithium batteries with high safety and stability. Full article