In this study, we use molecular dynamics (MD) simulation to explore how Fe–Cr–Ni alloys change their structure when stretched or compressed from two directions at a steady rate and at room temperature. Bi-axial tensile deformation causes changes in stress, creates stacking faults and dislocations, and leads to a change from FCC-to-BCC phase, forming networks of stacking faults that are rectangular and square-shaped. In contrast, when materials are squeezed from two sides, they quickly become unstable, leading to a fast increase in dislocations, which then disappear and rearrange. The FCC-to-BCC transformation starts sooner during compression, creating a mix of FCC and BCC structures with a lot of twinning and honeycomb-like dislocation patterns close to failure. These results highlight the distinct deformation mechanisms under bi-axial loading, emphasizing phase transformation and dislocation dynamics in mechanical behavior. Understanding atomic-level interactions between deformation and phase change is crucial for designing high-strength Fe–Cr–Ni alloys, addressing a key challenge in materials research.

Binder-free Nickel Cobaltite (NiCo 2 O 4 ) nanosheet-like nanostructures assembled into flower-like microarchitectures were successfully grown on conducting nickel foam through a simple hydrothermal approach for supercapacitor applications. Structural and morphological analyses using X-ray diffraction (XRD) and field emission scanning electron microscopy (FESEM) confirmed the formation of cubic spinel NiCo 2 O 2 with uniform nanosheets growth over the nickel foam substrate. Electrochemical investigations performed using cyclic voltammetry (CV), Galvanostatic charge-discharge (GCD), and electrochemical impedance spectroscopy (EIS) demonstrated excellent capacitive performance of the fabricated electrode. The NiCo 2 O 2 /NF electrode exhibited a high specific capacitance of 1240 Fg -1 at a current density of 5 Ag -1 along with an excellent capacitance retention of 93% after 2000 charge. discharge cycles at 50 Ag -1 . The enhanced electrochemical performance is attributed to the unique nanosheets-like architecture and effective binder-free conductive network, making the fabricated electrode a promising candidate for high-performance supercapacitor applications.

Ni-doped ZnO nanoparticles (Zn1-xNixO; x = 0-4 %) were synthesized via a co-precipitation route to investigate the influence of Ni incorporation on structural, optical, magnetic, and UV photodetector properties. XRD and Rietveld refinement confirmed phase-pure wurtzite ZnO with minimal lattice distortion due to substitutional Ni2+ incorporation. The crystallite size increased from 18.5 nm (N0) to 27.5 nm (N4), accompanied by a reduction in microstrain as determined from Williamson-Hall analysis. UV-vis spectroscopy revealed a controlled bandgap narrowing from 3.29 eV (N0) to 3.24 eV (N4), while photoluminescence results showed suppressed deep-level emission and enhanced near-band-edge recombination, indicating reduced defect density. Magnetic measurements demonstrated room-temperature ferromagnetism with saturation magnetization increasing from 1.94 x 10-5 to 2.99 x 10-5 emu/mg as Ni content increased. When integrated into ZnO/p-Si heterojunctions, Ni doping yielded measurable improvements in UV photodetector performance: responsivity increased from 0.00235 to 0.01170 mA/W, sensitivity from 23.49 to 247.92, and detectivity from 0.010 x 10 1 0 to 0.098 x 10 1 0 Jones. These enhancements arise from increased UV absorption, defect passivation, and reduced Schottky barrier height. The results highlight that controlled Ni incorporation enables simultaneous tuning of optical, magnetic, and UV-sensing characteristics, making Ni-doped ZnO a promising candidate for multifunctional optoelectronic applications.

In this review, various key parameters are highlighted keeping in mind the journey of bio-electrochemical systems (BESs), starting from the electrochemical abiotic field, first toward the battery and fuel cells, and then toward the fully biotic approach of BESs. To start with, the development of abiotic electrochemical systems and the transition to battery and fuel cells are discussed. Then, the broader range of BESs are discussed, which have a similar as well as multifunctional approach for changing chemical energy into electrical energy or vice versa by using microbes as bio-catalysts. For example, in microbial fuel cells (MFCs) or enzymatic fuel cells (EFCs), organic wastes and biomass can be converted into electricity, but in microbial electrolysis cells (MECs), electrical energy is used to produce hydrogen or other products. Recovery of nutrients, metals or removal of recalcitrant compounds can also be done by shaping BESs as per our desired motive. In recent times, the discovery of microbial electrosynthesis (MES) has widely enhanced the spectrum of BESs. For electricity generation, solar energy can also be used in the case of photosynthetic microorganisms, leading to a concept of microbial solar cells (MSCs). Plant microbial fuel cells (PMFCs) are also gaining attention because of the use of rhizodeposits. Microbial desalination cells (MDCs) are also discussed, which utilize the electric potential difference via MFC technology for making water desalination systems. The role of nanomaterials in MFC/EFC technology is also discussed in terms of bio-compatibility, electrocatalytic activity, conductivity, reaction activity, bulk resistance, corrosion resistance and stability.

This study presents a comprehensive atomistic investigation into the vitrification and devitrification behavior of mono-atomic copper using molecular dynamics simulations. By systematically varying thermal and mechanical processing, we identify critical processing conditions for the vitrification and subsequently devitrification. During thermal processing, slow cooling facilitates the formation of a stable FCC phase, while rapid quenching suppresses crystallization, yielding an amorphous structure. Thermal devitrification reveals a pronounced crystallization onset near temperature T = 875 +/- 50 K, driven predominantly by FCC phase formation. Further, during mechanical processing, under uniaxial tensile deformation, devitrification process is observed as amorphous matrix progressively transforms through nucleation and coalescence of crystalline domains, with FCC regions dominating and minor emergence of BCC and HCP phases. Cyclic mechanical loading both uniaxial and triaxial further accelerates de-vitrification, promoting long-range atomic ordering and substantial reduction in amorphous content. Notably, triaxial cyclic loading induces extensive FCC ordering while transient BCC and icosahedral (ICO) structures diminish over time, underscoring their metastable nature. These results offer new insights into the thermomechanical processing of structural evolutions in metallic glasses and advance the understanding of phase stability, metastability, and crystallization kinetics in amorphous metals.

Aluminium-doped zinc oxide (ZnO:Al (0%, 1%, 2%, 3%)) nanoparticles were synthesised via a low-cost and scalable chemical co-precipitation method and systematically investigated for ultraviolet (UV) photodetection applications in n-ZnO:Al (0%, 1%, 2%, 3%)/p-Silicon (Si) heterojunction devices. Precisely controlled Al-doping concentrations enabled direct correlation between dopant incorporation, structural and optical properties, and device-level UV photo-response. X-ray diffraction confirmed retention of single-phase hexagonal wurtzite ZnO structure for all doping levels, with no secondary phases detected. Microstructure fitting revealed increase in crystallite size from 15.6nm for pristine ZnO to ~ 26nm for ZnO:Al (1%, 2%), followed by a slight reduction to 24.6nm for ZnO:Al (3%). Small-angle X-ray scattering analysis and electron microscopy suggested Al-doping induced morphology evolution from petal-like lamellae to mixed lamellar, rod-like, and spherical nanostructures, while preserving high crystallinity. Energy dispersive X-ray spectroscopy, in conjunction with electron microscopy, indicated successful incorporation of the Al-dopant atoms in the host ZnO lattice. Fourier-transform infrared spectroscopy indicated retention of the hexagonal wurtzite ZnO phase even with the successful incorporation of increasing Al-dopant atoms. All samples exhibited characteristic stretching bond of Zn-O at ~ 420cm-1, and ZnO:Al nanoparticles exhibited Al-O-Al stretching peaks at ~ 690cm-1, 745cm-1, and ~ 878cm-1. X-ray photoelectron spectroscopy indicated spin-orbit separation of 23.1eV between the Zn2p3/2 and Zn2p1/2 peaks, consistent with Zn2+ bound in hexagonal wurtzite ZnO matrix and indicated contribution from three distinct O-atom-environment components upon deconvolution of the O1s peak. Optical characterisation indicated systematic blue shift in absorption edge from 378nm for pristine ZnO to 373nm for ZnO:Al (3%), and increase in optical band gap from ~ 3.18eV for pristine ZnO to ~ 3.25eV for ZnO:Al (3%). Photoluminescence studies showed strong quenching of zinc defect-related (~ 400-450nm), oxygen defect-related (~ 460-520nm), and surface dangling bonds mediated (~ 566nm) deep-level emissions, and enhancement of near-band-edge emission (~ 397nm) with Al-doping. Chromaticity diagrams revealed a transition from cyan colour for pristine ZnO to emission deeper in the blue region for ZnO:Al (3%). ZnO:Al (0%, 1%, 2%, 3%) thin films were drop-cast on p-Si substrates to fabricate heterojunction UV photodetectors with silver electrodes. Devices exhibited rectifying behaviour and enhanced photo-response under UV light illumination. Increasing Al-doping reduced Schottky barrier height from 0.875eV to 0.829eV, and significantly improved photodetector performance, with responsivity increasing from 0.006mA/W to 0.985mA/W, specific detectivity reaching 2.728 × 1010 Jones, and external quantum efficiency rising from 0.002% to 0.334%. ZnO:Al (3%)/p-Si device demonstrated fast and stable photo-response with response and recovery times of ~ 0.38s. These results establish Al-doping as an effective strategy to enhance UV photodetection performance in ZnO-based heterojunction devices and highlight the potential of solution-processed ZnO:Al nanomaterials for low-cost high-performance UV optoelectronics.

In this work, an Ag/Cu:ZnS/p-Si/Ag heterojunction UV photodetector was successfully fabricated using a cost-effective chemical bath deposition (CBD) technique. Cu-doped ZnS thin films with a thickness of similar to 390 nm were deposited onto p-Si substrates to tailor the optical and electronic properties. Structural analysis confirmed a cubic zinc blende phase with a slight reduction in lattice parameter (from 5.461 & Aring; to 5.293 & Aring;) upon Cu incorporation, indicating lattice distortion and defect engineering. Optical studies revealed a red shift in the absorption edge with a reduction in bandgap from 3.71 eV (ZnS) to 3.55 eV (Cu:ZnS). The fabricated heterojunction device exhibited a significant enhancement in photodetection performance under UV illumination (50 mu W/cm(2)), with photocurrent increasing from similar to 0.69 mu A (ZnS) to similar to 85.31 mu A (Cu:ZnS). The responsivity and specific detectivity improved remarkably from similar to 33.23 mA/W to similar to 4062.49 mA/W and from similar to 3.02 & times; 10(12) to similar to 18.2 & times; 10(12) Jones, respectively. Additionally, the device demonstrated faster response and recovery times of 0.30 s and 0.36 s, compared to 0.77 s and 0.75 s for the undoped device. The enhanced performance is attributed to Cu-induced defect states, improved charge carrier separation, and reduced barrier height (from 0.095 eV to 0.081 eV) at the heterojunction interface. The device also exhibited stable and reproducible behavior over 185 ON/OFF switching cycles. These results demonstrate that Cu incorporation is an effective strategy for optimizing ZnS-based heterojunctions, making the Ag/Cu:ZnS/p-Si/Ag structure a promising candidate for low-cost, high-performance UV photodetector applications.

In this present work, nanoparticles of Zn-doped SnO2 nanostructures were synthesized using a low-cost solution combustion synthesis method. The structural analysis and morphological properties with elemental composition of synthesized samples were characterized via X-ray diffraction (XRD) and field emission scanning electron microscopy (FESEM) with energy dispersive spectroscopy (EDS) respectively. XRD investigations confirm the tetragonal rutile structure with a reduction in average crystallite size from 8.63 nm to 7.06 nm with an increase of Zn2+concentration. FESEM with energy dispersive X-ray spectroscopy (EDS) confirms the formation of nanoparticles without any impurity. UV–Visible studies show a reduction in band gap energy values from 3.71 eV to 3.38 eV with an increment in concentration of Zn. Fourier transform infrared spectroscopy (FTIR) corresponds to O–H, C–H, Sn–OH, and Sn–O–Sn functional groups and confirms the creation of pure phase SnO2. Photoluminescence spectra (PL) of Zn-doped SnO2 nanostructures analyze the near band edge emission or UV emission at 454 nm and a green emission at 524 nm, confirming the excess of oxygen vacancies within the host structure. Raman spectra also confirm the abatement of crystallite size and existence of flaws like oxygen vacancies. These defects significantly influence the interaction of gas molecules with the surface of the sensing layer. The I–V (current–voltage) characteristics of the paper-based sensing device fabricated using Zn-doped SnO2 nanostructures were examined to investigate its response in the ammonia environment with regard to varying exposure time. An increase in electric current was observed at a specific applied voltage when the Zn-doped SnO2 nanostructured layer on Whatman paper was exposed to ammonia fumes, demonstrating its oxidizing nature. Only qualitative mode is used in these sensing studies.

Copper has several desirable characteristics, including being lightweight and having excellent mechanical, electrical, and thermal properties. Its remarkable resistance to corrosion and cheap cost make it essential for a wide range of industrial uses, such as electrical cables, switches, transformers, telephones, automobiles, and warship hull components. This study investigates the behavior of copper atoms under nano-indentation using a large-scale atomic/molecular massively parallel simulator. Nano-indentation simulations were performed at a velocity of 100 Å/ps. For the first time, this study reveals how the BCC crystal structure and dislocation evolve during indentation and demonstrates how hardness varies with changes in the radius of a spherical indenter tip. Crystal evolution and dislocation mechanisms were analyzed using several parameters, including indentation force–displacement curves, radial distribution function, atomic percentage change with indentation depth, dislocation density, total energy variation with penetration, and visualizations of dislocation during the nano-indentation process in copper. The outcomes of this work offer meaningful insights for researchers focused on material design and performance optimization in engineering applications.

The abundance of compost and its bio-circular economy, wherein bio-waste seamlessly transforms into compost, renders it a promising candidate for investigation as a new type of biomaterial for storing renewable energy; to that effect, in this work the capacitive and non-capacitive charge storage in a compost based symmetric device configuration have been investigated. Normally, capacitive charge storage aligns with the principles of dielectric or electrolytic capacitance, which is non-faradaic in nature; however, in the case of batteries, faradaic processes dominate for non-capacitive charge storage. Due to the complex nature of compost, the type of compost and the type of current collectors have been varied while using distilled water as an aqueous media, and the investigation in this work encompasses both capacitive and non-capacitive processes in a symmetric dual current collector device to delineate and discern the diverse charge storage mechanisms inherent to capacitors and batteries. Test cells have been optimised with respect to volume, distance between the current collector, and variation in applied current; following that, optimised test cells have been analysed using cyclic voltammetry (CV), galvanostatic charge-discharge (GCD) studies and electrochemical impedance spectroscopy (EIS) to study non-faradaic and faradaic processes in terms of charge storage capability, charging and discharging time, specific capacitance, and specific capacity. To observe the role of microorganisms in the compost, autoclave studies using the best compost sample (baked at 120 degrees C for 60min) have also been performed. In addition, chrono-amperometry studies have been performed to investigate the stability of the device. The results show a multifunctional charge storage behaviour in compost being used as a bio-media, and hence, this work lays a foundation for a new type of ecofriendly bio-media for charge storage.

Optimizing electrode efficiency and durability is essential for the progression of microbial fuel cell (MFC) technology. This study investigates the performance enhancement of a single-chamber soil-compost microbial fuel cell (MFC) using SnO₂ and SnO₂/PPy-coated copper electrodes. Electrodes were fabricated via electrodeposition using chronoamperometry, and their electrochemical properties were analyzed through cyclic voltammetry (CV), linear sweep voltammetry (LSV), electrochemical impedance spectroscopy (EIS), and linear polarization resistance (LPR). The deposition of SnO₂ and SnO₂-PPy shifted oxidation peaks from 0.295 V to 0.531 V and 0.512 V, respectively, with improved redox peak currents. Power density measurements revealed significant increases, reaching 5.4 mW/m² and 10 mW/m² with current densities of 152.68 mA/m² and 187.65 mA/m² for SnO₂ and SnO₂-PPy coatings—approximately 11-fold and 21-fold higher than uncoated electrodes in the MFC system. Corrosion resistance improved substantially, reducing corrosion rates by a factor of six. Structural and surface morphology analyses were conducted using energy dispersive X-ray spectroscopy with scanning electron microscope (EDXS-SEM) and X-ray diffraction (XRD), confirming successful deposition.

Dysprosium-doped Zinc silicate nanophosphors, synthesized via co-precipitation, were studied for their properties under varying annealing temperatures. Increasing annealing temperature improved crystallinity in 0.5 mol

This study investigates the rupture mechanism of layered Fe-Cr-Ni alloy under multiaxial tensile deformation using molecular dynamics simulations. The results found that the presence of layered orientation of Fe-Cr-Ni significantly impacts nanovoid formation, growth, and coalescence during multiaxial (uniaxial, biaxial, and triaxial) deformation. During triaxial deformation, nanovoids nucleate early and grow rapidly, leading to material failure, with body-centered cubic structure forming around void surfaces due to strain-induced phase transformations. Biaxial tensile deformation facilitates minor amount of face-centered cubic to body-centered cubic transformations with rectangular and square-shaped stacking faults. Uniaxial tensile deformation produces the highest degree of dislocation interactions, leading to complex defect structures. Our study highlights that the yield stress, dislocation density, surface area, and solid volume vary across different deformation modes. Layered or twin boundaries act as barriers for movement of dislocation, reducing the plasticity and enhancing void nucleation. Our findings provide critical insights into atomic-scale mechanisms driving void formation, phase transformation, and material failure in Fe-Cr-Ni alloys with twin boundaries, contributing to improved material design under multiaxial loading conditions.

The heartwood of Acacia catechu has been highly valued in both contemporary and ayurvedic medicine for its anti-bacterial, anti-oxidant, and anti-inflammatory properties. However, traditional applications face challenges such as low absorption, rapid degradation and limited bio availability. To overcome these limitations, this study aimed to synthesize and characterize the eco-friendly and sustainable A. catechu derived silver oxide nanoparticles (Ac-AgONPs) and assess their biological activities. Ac-AgONPs were prepared utilising the hydroalcoholic extract of A. catechu heartwood. The biosynthesized Ac-AgONPs exhibited a distinctive surface plasmon resonance peak at 590nm. A crystalline structure of Ag₂O/AgO with an average diameter of 24.7nm was identified through XRD analysis. Transmission electron microscopy imaging illustrated spherical nanoparticles with an average size of 13.2nm. HPLC analysis identified catechin, tannic acid and β-carotene as crucial phytochemicals which might be involved in bioreduction of nanoparticles. Ac-AgONPs showed significantly enhanced antibacterial properties compared to crude extract, achieving a 19 ± 0.57mm inhibition zone against Staphylococcus aureus and improved efficacy against Escherichia coli, Pseudomonas species and Bacillus subtilis. The nanoparticles also displayed outstanding free radical scavenging activity (IC₅₀: 3.65µg/mL), exceeding the antioxidant potential of plant extract by more than twenty times. Additionally, Ac-AgONPs facilitated the rapid photodegradation of methylene blue dyes with increasing efficiency in proportion to the concentration of nanoparticles used. Overall, this study concluded that green-synthesized Ac-AgONPs offer superior bioactivity, increased antimicrobial efficacy, efficient antioxidant and photocatalytic activity, positioning them as a promising candidate for biomedical applications.

In the present study, pristine and Li-doped ZnO nanoparticles were synthesized using a well-established, costeffective chemical co-precipitation method. The synthesized nanoparticles were used to fabricate Ag/ZnO/p-Si/ Ag heterojunction photodetectors through drop-casting technique, targeting UV and visible light detection applications. The Structural, optical, and morphological characterizations were performed using XRD, UV-Vis, FTIR, PL, XPS, FESEM, HRTEM, and ICP-MS. XRD confirmed the formation of the hexagonal wurtzite phase of ZnO while FTIR verified the presence of Zn-O functional groups. The PL spectra indicated defect-related emissions, whereas XPS/ICP-MS confirmed the presence of Zn2+ and O2- species and successful incorporation of Li. The morphology of the synthesized nanoparticles was analyzed using FESEM and HRTEM. The fabricated photodetectors showed efficient UV (50 mu W/cm2) and visible (30 mW/cm2) light response, with 2 % Li-doped ZnO exhibiting faster response/recovery, nearly double the quantum efficiency of pristine ZnO, and stable switching. The synthesized nanoparticles also displayed antibacterial activity against E. coli, highlighting potential applications in photodetection and biomedical fields.

This study investigates the influence of twin spacing and twin thickness on the tensile behavior of Fe-Cr-Ni alloys using molecular dynamics simulations. Microstructural features such as twin planes and stacking faults significantly impact the mechanical properties and deformation mechanisms of metals and alloys. The presence of twin planes guides the formation and evolution of stacking faults and dislocations during tensile deformation. Stress–strain analyses reveal distinct deformation stages, with twin spacing playing a crucial role in determining yield strength and plasticity. Alloys with nanotwins exhibit increased strength as twin spacing decreases, reaching a critical spacing at d = 1.25 nm. Additionally, the analysis indicates that larger stacking fault areas correlate with enhanced plastic flow. The study also explores the effects of twin thickness on mechanical properties and phase transitions, finding that greater twin thickness enhances yield strength but reduces ductility. These insights underscore the importance of strategically designing twin boundaries and controlling their spacing to develop advanced materials with optimized strength, ductility, and deformation resistance. This research provides a foundational understanding for tailoring the mechanical performance of Fe-Cr-Ni alloys through microstructural engineering.