Due to the unregulated and extremely exothermic nature of the reaction between oxidizing reagents and graphitic carbons, converting graphite to graphene oxide (GO) is a major difficulty. As a result, there is a significant difference in its oxidation level. We have reported for the first time an indepth analysis of distinct oxidation levels of various GO samples through the investigation of 'X'-ray photoelectron spectroscopy to clearly understand the GO oxidation level. The anomaly in GO oxidation level is confirmed by the change of C1s and O1s core level spectra towards higher binding energy (HBE) in highly oxidized materials. Based on the quantity of edge side and basal plane functionalities, we investigated and emphasized the inconsistency in oxidation levels of different GO samples. The new method to determine GO oxidation levels is more accurate and convenient than Boehm titration, and it has been further confirmed using Raman spectroscopy and PXRD techniques.

In two-dimensional (2D) materials, selective facet exposure is highly sought after but can be typically achieved only through sophisticated methods like chemical vapour deposition (CVD) or molecular beam epitaxy (MBE). Existing wet-chemical methods, whether diffusion-controlled or ligand-assisted, mostly concentrate on morphology control or facet tuning through shape regulation, but they hardly ever achieve both at the same time. Herein, we report a distinctive hard-templating approach that permits simultaneous facet engineering and 2D structure formation in non-van der Waals CuInS2 (CIS). In this method, an in-situ formed 2D van der Waals CuInP2S6 (CIPS) with a hexagonal atomic arrangement acts as the template. Importantly, the use of highly reactive white phosphorus permits the formation of CIPS within the wet-chemical temperature limit of 225 degrees C, whereas red phosphorus-based solid state synthesis requires 14 days of continuous heating at an elevated temperature of 600 degrees C. As a result, this straightforward method facilitates an energy-efficient, one-pot, greener conversion to non-vdW CIS with superior control over crystal facet exposure, replacing conventional multi-step complex procedures. The resulting 2D CIS possesses a cubic zincblende structure yet preserves the hexagonal atomic arrangement of the template, yielding dominant (111) facet exposure. Additionally, the template determines the flake thickness. Owing to both facet exposure and intrinsic phosphorus doping, this catalyst delivers significantly enhanced formate selectivity in the electrochemical CO2 reduction reaction compared with its non-2D or non-faceted counterparts with similar electrochemically active surface areas (ECSAs).

Stronger metallic alloys are always sought as structural materials to enable efficient, safe, and sustainable operations across various aerospace, automotive, energy, and defence sectors. Among these, single-phase, multicomponent alloys show exceptional tensile strength up to similar to 0.8-1.2 GPa. However, they possess a very low 0.2% yield strength (YS), i.e., they can be permanently deformed at very low stress levels of similar to 300 to 600 MPa. In this study, an ultra-high YS was achieved by controlled thermomechanical processing (rolling at room and cryo temperatures) that introduced stacking faults (SFs), nanotwins (NTs), and nanomartensite epsilon-laths (NMLs) during cold deformation, followed by facilitating solute segregation/partitioning to them through tempering at an intermediate temperature. We also reveal that, by exploiting atomic-scale solute interactions with deformationinduced structures, we can design ultra-strong alloys with YS > 2 GPa with elongation to fracture (El) similar to 7%. We demonstrate the phenomena in a low stacking fault energy multi-component (face-centered-cubic, fcc structured) Co-32Ni-24Cr alloy (all in at.%) containing 5-6 at.% Mo as a solute. The alloy microstructure also remains stable at 600 degrees C for up to 100 h and retains a YS of similar to 1.5 GPa with a %El of similar to 18% during the tensile test at 600 degrees C. The derived high YS and high-temperature stability are critically a consequence of solute segregation to the SF/NT boundaries and partitioning into NMLs, which we termed Solute-Partitioned NMLs (SP-NMLs) in the microstructure. Based on the exploration and revelation of structure-dependent segregation/partitioning of deformation-induced planar defects and NMLs in the alloy, we propose that this strategy is not limited to the present alloy composition and can be effective in other low SFE alloys with suitable solutes, opening avenues for designing ultra-strong materials.

Two-dimensional (2D) transition metal dichalcogenides (TMDs), particularly molybdenum diselenide (MoSe2), have emerged as promising semiconductors for next-generation energy harvesting due to their tunable bandgap, strong light-matter interactions, excellent carrier transport, and intrinsic mechanical flexibility. Herein, high-quality, large-area 2D MoSe2 layers were synthesized CMOS compatible SiO2/Si substrates via chemical vapor deposition (CVD), and subsequently transferred onto flexible indium tin oxide (ITO)-coated polyethylene terephthalate (PET) substrates via a polymer-assisted wet-transfer process for the fabrication of flexible piezoelectric nanogenerator (PENG) devices. Structural, morphological, and spectroscopic analysis confirmed the uniform growth, layered crystallinity, high optical quality, and excellent film continuity of the synthesized 2D MoSe2 films. The fabricated MoSe2-based PENG devices exhibited stable and reproducible piezoelectric output under various mechanical stimuli, including periodic bending, tapping, stretching, and vibration, demonstrating efficient mechanical-to-electrical energy conversion via the piezoelectric response of the layered MoSe2. The device generated a maximum output voltage of ~20 V, current density of 186 nA/cm2, and power density of 3.72 μW/cm2, under an applied force of 16N and an operating frequency of 4 Hz. Importantly, the device demonstrates practical applicability in real-world scenarios, including direct LED illumination, acoustic sensing, wind energy harvesting, and biomechanical motion monitoring. In addition, the device maintains excellent operational stability under repeated mechanical loading cycles, highlighting its robustness for long-term durability. This work establishes scalable CVD-grown 2D MoSe2 layers as a viable platform for high-performance, flexible nanogenerators, self-powered wearable electronics, and low-power sensors, paving the way toward sustainable micro-energy-harvesting technologies.

This study presents a novel method for creating patterned cuts into metallic foils by harnessing mixed-mode fracture, induced by the simultaneous application of electric current pulses and mechanical loading. Building on the principles of fracture under electromagnetic forces, i.e., passage of electric current pulses of moderately high densities through a pre-cracked metallic foil, with or without a mechanical stress, can lead to propagation of sharp crack in mode I, and crack deflection under mixed-mode loading, i.e., propagation of the crack along an angle relative to original configuration when a mechanical load is applied under mixed-mode during the application of electric current pulse through the foil, a specialized setup was developed to induce and control mixed-mode crack propagation through the coordinated application of mechanical loads at an angle and a series of electric current pulses. Conjugate finite element analysis provided the selection of optimal electric current pulsing and mechanical loading parameters to propagate the crack at the precise deflection angle under mixed-mode fracture by a predetermined incremental length. The working of the system was demonstrated by creating a predefined sinusoidal cut in a 25 μm-thick Al foil, confirming directional control over crack propagation. The combined experimental and computational approach offers distinct advantages, including high-resolution, tool-free patterned cutting of thin metallic sheets with sub-3 μm precision, representing a significant advancement in microfabrication technologies.

Lightweight, high-strength structural materials are component enablers in transportation and aerospace, reducing carbon footprints and enhancing fuel efficiency. Cast aluminium alloys, mainly based on eutectic compositions, make up ∼ 85% of these materials but often fail catastrophically due to inefficient load transfer across the interfaces between the brittle eutectic phase and the ductile matrix. Here, we discovered that promoting a superlattice nano-layer (SNL) around the eutectic fibres, achieved by adding Zr to an Al-Gd near-eutectic alloy, enables excellent load transfer capabilities, resulting in a ∼ 400% increase in tensile ductility. The primary α-Al matrix also contains a high number density of superlattice core-shell nano-particles. This exceptional increase in formability is attributed to the ability of the SNL to prevent dislocations from accumulating at the weak and brittle eutectic fibre/matrix interfaces, thereby avoiding stress concentrations that would otherwise initiate fibre breakage and debonding. The core-shell nano-particles in α-Al cause a large number of dislocation cross/multiple-slips on {111} planes, forming ultra-fine (∼ 12 nm) dislocation networks that leverage substantial plastic strain accumulation. This atomic interface design overcomes the ductility limitations of cast-eutectic alloys, enabling them for structural applications.

The increasing need for electrochemical energy storage systems with high power density and long-term stability has driven intensive efforts to develop next-generation electrode materials that surpass the limitations of conventional carbonaceous and transition metal-based architectures. In this context, bismuth ferrite (BiFeO3; BFO), which is also known as perovskite oxide, has been employed as a promising electrode material for energy storage applications. In the past few years, BFO and its hybrid materials have emerged as promising candidates for the fabrication of supercapacitors. However, their practical development is constrained by limited intrinsic electrical conductivity, sluggish charge-transfer kinetics, and structural instability under repeated cycling. This review critically examines recent progress in BFO-based electrode materials for supercapacitor applications. The synthesis methods for BFO-based materials have been discussed, and their advantages and limitations have been compared. Furthermore, the electrochemical performance of BFO-based hybrid materials for supercapacitor application has been critically examined. The energy storage mechanism and limitations of BFO-based supercapacitors have been discussed. Future perspectives for BFO-based materials for energy storage applications have been discussed.

Application of high-density electric current pulses to pre-cracked metallic conductors can induce rapid crack propagation through electromagnetic body forces generated by current reversal across the crack tip. While this phenomenon has been demonstrated, its associated microstructural characteristics and fracture mechanisms remain insufficiently understood. In this study, we examine the fracture surfaces of thin metallic foils subjected to pulsed electric currents, with and without superimposed mechanical loading. The results reveal pronounced local thinning consistent with plane-stress conditions, the formation of diamond-shaped surface features corresponding to incremental crack advance per pulse, and predominantly transgranular fracture with limited plastic zone development near the crack tip. Notably, these microstructural features remain largely unchanged under combined electromagnetic and mechanical loading. These findings provide direct microstructural evidence of electric current-induced fracture mechanisms and clarify the role of electromagnetic forces in governing incremental crack growth in thin conductors.

Nickel oxide (NiO), a wide bandgap p-type semiconductor, has emerged as a promising material for electrochemical sensing owing to its excellent redox properties, chemical stability, and facile synthesis. Its strong electrocatalytic activity enables effective detection of diverse analytes, including glucose, hydrogen peroxide, environmental pollutants, and biomolecules. Advances in nanotechnology have enabled the development of NiO-based nanostructures such as nanoparticles, nanowires, and nanoflakes, which offer enhanced surface area and improved electron transfer. Integration with conductive materials like graphene, carbon nanotubes, and metal–organic frameworks (MOFs) further enhance sensor performance through synergistic effects. Innovations in synthesis techniques, including hydrothermal, sol–gel, and green approaches, have expanded the applicability of NiO in next-generation sensing platforms. This review summarizes recent progress in the structural engineering, composite formation, and electrochemical mechanisms of NiO-based materials for advanced electrochemical sensing applications.

This research paper presented a review of different types of hydrogen storage technologies, current gaps and challenges of the hydrogen storage system. Transportation of hydrogen is the biggest task that has been involved in adoption of hydrogen as an import and export of clean energy. It has been categorized into three different approaches to describe the current hydrogen storage technologies i.e. compressed gas storage, solid-state storage and liquid hydrogen storage, and while liquid hydrogen storage relies on freezing temperatures to preserve hydrogen in liquid form, compressed gas storage involves large concentrations of pressurized hydrogen. Higher energy densities and lower operating pressures are potential benefits of solid-state storage, which is made up of metal hydrides, chemical hydrides, and porous materials. This review paper combines a comprehensive study of hydrogen storage technologies and approaches from various research studies. Furthermore, discuss on current gaps, challenges in hydrogen storage and comparing the results, methodologies, and conclusions of several significant papers related to Hydrogen Storage Technologies.

Antimony chalcogenides (Sb₂S₃ and Sb₂Se₃) have emerged as promising materials for solar energy conversion due to their exceptional optical and physicochemical properties. These materials are widely utilized as absorber layers in thin-film solar cells, offering a cost-effective and sustainable alternative for photovoltaic applications. In recent years, the solar cell capacitance simulator (SCAPS-1D) has become an indispensable tool for predicting and optimizing solar cell performance, bridging the gap between theoretical modelling and experimental design. This article reviews the key insights from both experimental studies and SCAPS-1D-based simulations on Sb₂S₃ and Sb₂Se₃ solar cells. Despite significant progress, a notable disparity persists between theoretical predictions and experimental efficiencies, underscoring the need for further experimental advancements. This review also addresses current challenges and outlines future research directions to enhance the performance and scalability of Sb₂S₃ and Sb₂Se₃ solar cells. By offering a comprehensive overview, this work aims to benefit the researchers in advancing the development of high-efficiency antimony chalcogenide-based solar technologies.

In this work, the researcher concentrated on the synthesis and analysis of the properties of Si-doped nanostructured hematite ([Formula: see text]-Fe 2 O[Formula: see text] thin films, aiming to use them as photoelectrodes in photoelectrochemical (PEC) cells for the production of hydrogen. Spray pyrolysis, deposition method is used for thin-film synthesis to achieve uniform, nanostructured layers with controllable doping levels. The confirmation of the hematite phase by XRD ensures that the desired [Formula: see text]-Fe 2 O 3 structure was achieved in both doped and undoped films. Scanning Electron Microscopy (SEM) analysis, revealing surface morphology and nanoscale structures, provided insights into how Si-doping affected factors like grain size, porosity, etc. The significant visible light absorption observed ([Formula: see text]2.1[Formula: see text]eV) aligns well with the band gap of hematite, which is promising for PEC applications. Furthermore, the marked improvement in photocurrent — specifically, a threefold increase ([Formula: see text]680[Formula: see text] [Formula: see text]A/cm 2 at 0.7[Formula: see text]V/SCE) at a 0.002 M Si-doping concentration highlights the effectiveness of Si doping by introducing favorable electronic changes, potentially increasing the conductivity of the hematite. The substitution of Fe[Formula: see text] ions by Si[Formula: see text] in the [Formula: see text]-Fe 2 O 3 lattice likely contributes to enhanced charge separation and reduced recombination rates that are the critical factors in sustaining higher photocurrents.

Paper-based microchemical systems have emerged as transformative and sustainable technologies for biological studies, offering affordability, biodegradability, and portability. Paper, with its multiscale porous structure and tunable properties, provides an ideal platform for replicating cellular microenvironments and facilitating biointerfaces for cell-related applications. Recent innovations have successfully integrated cellular analysis with paper-based platforms, enhancing functionality and expanding their potential. This review explores advances in paper-based platforms, emphasizing their role in enabling precise and accessible cellular analyses for both fundamental and applied research. These innovations broaden the potential of paper-based platforms for healthcare applications, including diagnostics, drug screening, and point-of-care testing, particularly in resource-limited settings. The review also discusses advances in fabrication techniques, material modifications, and surface functionalization to enhance cell adhesion, proliferation, and viability. Integration with image processing techniques is highlighted as a powerful tool for gaining insights into cellular behavior. Additionally, the versatile applications of paper-based platforms in various cellular studies are presented. Sustainable solutions, including hybrid platforms and automated systems, are examined to address challenges such as maintaining cellular microenvironments, enhancing assay sensitivity, and ensuring clinical reliability. This review underscores the potential of paper-based platforms to revolutionize clinical and biomedical analysis through sustainable and innovative technologies.

Food safety is one of the major challenges around the globe due to the contamination of food from chemicals, biological and environmental pollutants, heavy metals, and organic pollutants. Most of the pollutants are non-degradable or their degradation process is difficult. The toxicity of the environmental pollutants affects the human health as well as aquatic life. This motivated the researchers towards the development of sensitive, cost-effective and selective sensing technologies for pollutants' detection and clinical diagnostic applications. In particular, electrochemical sensors offer significant advantages such as low detection limit, portability, simplicity, benign fabrication process, selectivity and recovery in real samples. Numerous electrode materials were explored for the construction of electrochemical sensors and nanostructured tin dioxide (SnO2) based materials exhibited excellent electrochemical performance for the detection of environmental pollutants and biomolecules. This review highlights the recent developments in the preparation of SnO2 based electrode modifiers towards the fabrication of electrochemical sensors and their applications in the monitoring pollutants' detection. The limitations of the SnO2 based materials and their future perspectives have been discussed.

Phononic frequency combs are the mechanical counterparts of optical frequency combs, representing a pivotal progression in nonlinear studies of micro-electromechanical systems. This work presents the generation of tunable frequency combs based on three-mode interaction through combination internal resonance and a ferroelectric thin film in curved piezoelectric micromachined ultrasonic transducer. The experimental results demonstrate rich three-mode coupled nonlinear dynamics and how this coupling leads to frequency comb generation under specific input actuation parameters. The comb spacing and the number of spectral lines can be tuned by modulating the applied DC voltage, as well as the AC input voltage and frequency. Unlike previous studies on three-mode comb analysis, a theoretical model is systematically developed using nonlinear von Kármán plate theory to elucidate the experimentally observed dynamics of nonlinear three-mode intermodal coupling through combination internal resonance and its role in comb generation. Our findings demonstrate resonance coupling between the first and third asymmetric modes and the second symmetric modes, underscoring the generation of tunable multimode phononic frequency combs. This advancement paves the way for further progress in nonlinear phononics, enabling diverse applications in sensors, acoustic imaging, and phonon computation.

In the past few years, metal chalcogenides have received extensive consideration because of their excellent physicochemical belongings. Particularly, molybdenum selenide (MoSe2) is a promising metal dichalcogenide which possesses decent optical, electrical, and chemical properties and can be explored for a variety of applications. MoSe2 has been extensively used for several applications such as energy storage and sensing. Since the energy crisis is one of the major challenges of today’s world, super-capacitors and hydrogen evolution are promising energy technologies that may benefit the global world in the future. Thus, researchers have been motivated towards the strategy and fabrication of electrode materials for super-capacitors and hydrogen evolution applications. MoSe2 is a multifunctional material, and previous years have witnessed the rapid growth in the publication of MoSe2-based electrode materials for super-capacitors, hydrogen evolution, and electrochemical sensing applications. Thus, it is of great significance to merge the previous reports into a single review article on MoSe2-based modified electrode materials for super-capacitors, hydrogen evolution, and electrochemical sensing applications. Therefore, we have compiled the previous reports on the design and fabrication of MoSe2 and electrodes based on its composites for super-capacitors, hydrogen evolution, and electrochemical sensing applications. It is believed that this article may benefit the researchers working in the research field of super-capacitors, hydrogen evolution, and electrochemical sensing applications.

At present, lead halide PVSKSCs are promising photovoltaic cells but have some limitations, including their low stability in ambient conditions and the toxicity of lead. Thus, it will be of great significance to explore lead-free perovskite materials as an alternative absorber layer. In recent years, the numerical simulation of perovskite solar cells (PVSKSCs) via the solar cell capacitance simulation (SCAPS) method has attracted the attention of the scientific community. In this work, we adopted SCAPS for the theoretical study of lead (Pb)-free PVSKSCs. A cesium bismuth iodide (CsBi3I10; CBI) perovskite-like material was used as an absorber layer. The thickness of the CBI layer was optimized. In addition, different electron transport layers (ETLs), such as titanium dioxide (TiO2), tin oxide (SnO2), zinc oxide (ZnO), and zinc selenide (ZnSe), and different hole transport layers, such as spiro-OMeTAD (2,2,7,7-tetrakis(N,N-di(4-methoxyphenylamine)-9,9′-spirobifluorene), poly(3-hexylthiophene-2,5-diyl) (P3HT), poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine (PTAA), and copper oxide (Cu2O), were explored for the simulation of CBI-based PVSKSCs. A device structure of FTO/ETL/CBI/HTL/Au was adopted for simulation studies. The simulation studies showed the improved photovoltaic performance of CBI-based PVSKSCs using spiro-OMeTAD and TiO2 as the HTL and ETL, respectively. An acceptable PCE of 11.98% with a photocurrent density (Jsc) of 17.360258 mA/cm2, a fill factor (FF) of 67.10%, and an open-circuit voltage (Voc) of 1.0282 V were achieved under the optimized conditions. It is expected that the present study will be beneficial for researchers working towards the development of CBI-based PVSKSCs.

This study demonstrates the complete closure of a crack and subsequent materials healing via a solid-state process upon application of high-density electric current pulses. This novel method leverages the simultaneous generation of a high-temperature field near the crack tip, a compressive stress zone induced by temperature gradients, and a significant electromagnetic force acting in Mode I, all arising from the flow of electric current around the crack. Finite element-based analysis is employed to optimize the process parameters, ensuring the dominance of the compressive stress field over the tensile electromagnetic force near the crack tip. Conjugate experiments demonstrate that fatigue-induced edge cracks in a metallic material (e.g., SS 316) can be fully healed by applying electric current pulses with extended pulse-width (e.g., 200 ms) and high densities (e.g., 10(6-)10(8) A/m(2)). Detailed microstructural analysis of the healed region reveals micro-void-free complete bonding between the crack faces, characterized by a narrow strip (<100 mu m width) featuring small, recrystallized grains. The observed boundary migration, entrapment of cavities inside grains, and partial alignment of dislocation substructures across the original crack confirm the solid-state diffusion bonding responsible for the materials healing. The yield strength, ductility and fatigue life of the "healed" material are commendable and can be significantly improved to mimic those of as-received material after solutionizing heat treatment. Overall, this study introduces a novel method for controlled crack closure and materials healing in in-service components, offering the potential to extend their operational life significantly.

In the recent reports, it is clear that lead-free perovskite materials with low band gaps are desirable candidates for photovoltaic cells. In this regard, it was observed that germanium (Ge) is a less toxic lead-free metal that is significant for the preparation of Ge-based perovskite materials. Ge-based perovskite materials, for example, methyl ammonium germanium iodide (MAGeI3), cesium germanium iodide (CsGeI3), and/or formamidinium germanium iodide (FAGeI3) may be the suitable absorber materials and alternatives towards the fabrication of lead-free photovoltaic cells. In the past few years, few attempts were made to develop FAGeI3-based perovskite solar cells, but their photovoltaic performance is still under limitations. This is indicating that some significant and effective strategies should be designed and developed for the construction of Ge-based perovskite solar cells. It is believed that optimization of layer thickness, device structure, and selection of a suitable electron transport layer (ETL) may improve the photovoltaic performance of FAGeI3-based perovskite solar cells. Solar cell capacitance simulation, i.e., SCAPS is one of the promising software programs that can provide significant theoretical findings for the development of FAGeI3-based perovskite solar cells. The simulation studies via SCAPS may benefit researchers to save their energy and high cost for the optimization process in the laboratories. In this research article, SCAPS was adopted as a simulation tool for the theoretical investigations of FAGeI3-based perovskite solar cells. The simulation studies exhibited the excellent efficiency of 15.62% via SCAPS. This study proposed the optimized device structure of FTO/TiO2/FAGeI3/PTAA/Au with enhanced photovoltaic performance.