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The field of energy storage and conversion materials has witnessed transformative advancements owing to the integration of advanced in situ characterization techniques. Among them, numerous real-time characterization techniques, especially in situ transmission electron microscopy (TEM)/scanning TEM (STEM) have tremendously increased the atomic-level understanding of the minute transition states in energy materials during electrochemical processes. Advanced forms of in situ/operando TEM and STEM microscopic techniques also provide incredible insights into material phenomena at the finest scale and aid to monitor phase transformations and degradation mechanisms in lithium-ion batteries. Notably, the solid–electrolyte interface (SEI) is one the most significant factors that associated with the performance of rechargeable batteries. The SEI critically controls the electrochemical reactions occur at the electrode–electrolyte interface. Intricate chemical reactions in energy materials interfaces can be effectively monitored using temperature-sensitive in situ STEM techniques, deciphering the reaction mechanisms prevailing in the degradation pathways of energy materials with nano- to micrometer-scale spatial resolution. Further, the advent of cryogenic (Cryo)-TEM has enhanced these studies by preserving the native state of sensitive materials. Cryo-TEM also allows the observation of metastable phases and reaction intermediates that are otherwise challenging to capture. Along with these sophisticated techniques, Focused ion beam (FIB) induction has also been instrumental in preparing site-specific cross-sectional samples, facilitating the high-resolution analysis of interfaces and layers within energy devices. The holistic integration of these advanced characterization techniques provides a comprehensive understanding of the dynamic changes in energy materials. This review highlights the recent progress in employing state-of-the-art characterization techniques such as in situ TEM, STEM, Cryo-TEM, and FIB for detailed investigation into the structural and chemical dynamics of energy storage and conversion materials. [ABSTRACT FROM AUTHOR]

Diabetes mellitus is considered a serious medical issue that is the leading cause of mortality worldwide. Hence, there is a huge demand for developing efficient, reliable, and inexpensive non-enzymatic glucose sensors that can rapidly and accurately monitor glucose levels in physiological fluids. Herein, we developed an efficient and robust Ni/NiO@C composite as an electrocatalyst, which is synthesized via a simple co-precipitation method followed by a controlled annealing treatment. The resulting Ni/NiO@C composite has a spherical structure, yielding the salient features of large surface area, high structural void porosity, accessible surface-active edges, and redox-active centers of Ni2+/Ni3+ which could effectively improve the electrocatalytic oxidation for the detection of glucose. The detailed investigation revealed the electrochemical oxidation of glucose situated at 0.48 V with a wide linear range over the concentration from 0.5 μM to 2.0 mM. Based on the calibration plot, the limit of detection (LOD) and sensitivity were calculated to be 0.061 μM, and 9.73 μA cm−2 μM−1, respectively. The designed sensor's electroanalytical performance was effectively validated for the investigation of target species in actual samples. This work offers insights into the synergistic electrocatalytic activity of precious metal and enzyme-free catalysts for use in clinical diagnostics for the analysis of glucose molecules. [ABSTRACT FROM AUTHOR]

Anodized aluminum oxide (AAO) molds were used for the production of large-area and inexpensive superhydrophobic polymer films. A controlled anodization methodology was developed for the fabrication of hierarchical micro–nanoporous (HMN) AAO imprint molds (HMN-AAO), where phosphoric acid was used as both an electrolyte and a widening agent. Heat generated upon repetitive high-voltage (195 V) anodization steps is effectively dissipated by establishing a cooling channel. On the HMN-AAO, within the hemispherical micropores, arrays of hexagonal nanopores are formed. The diameter and depth of the micro- and nanopores are 18/8 and 0.3/1.25 µm, respectively. The gradual removal of micropatterns during etching in both the vertical and horizontal directions is crucial for fabricating HMN-AAO with a high aspect ratio. HMN-AAO rendered polycarbonate (PC) and polymethyl methacrylate (PMMA) films with respective water contact angles (WCAs) of 153° and 151°, respectively. The increase in the WCA is 80% for PC (85°) and 89% for PMMA (80°). On the PC and PMMA films, mechanically robust arrays of nanopillars are observed within the hemispherical micropillars. The micro–nanopillars on these polymer films are mechanically robust and durable. Regular nanoporous AAO molds resulted in only a hydrophobic polymer film (WCA = 113–118°). Collectively, the phosphoric acid-based controlled anodization strategy can be effectively utilized for the manufacturing of HMN-AAO molds and roll-to-roll production of durable superhydrophobic surfaces. [ABSTRACT FROM AUTHOR]

Metal sulfide-incorporated graphitic carbon nitride-based semiconductor catalysts have attracted considerable attention in the field of clean energy and environmental remediation because of their low cost, eco-friendliness, high efficiency, and ease of use. Herein, we demonstrate a facile one-pot synthesis of CuS nanoparticles in situ grown on the layered porous sulfur-doped graphitic carbon nitride nanosheets (CuS/S-g-C3N4), which act as a catalyst for the reduction of 4-nitrophenol. 4-Nitrophenol was reduced (converted into 4-aminophenol) by about 89.92% and 99.98% with S-g-C3N4 and CuS/S-g-C3N4 composites, respectively, within 3 min. The results demonstrate that the CuS/S-g-C3N4 nanohybrid composite showed superior catalytic performance compared to bare S-g-C3N4 due to the enhancement caused by increasing the affinity of accessible surface-active edge sites and interfacial contact allowing an effective modification of the electronic structure, high structural porosity, and richness in sulfur vacancy. Further, the fast electron transfer 4-NP reduction mechanism on CuS/S-g-C3N4 was explicated and discussed. Additionally, the CuS/S-g-C3N4 nanocomposite revealed good stability towards catalytic reduction even after repeated usage. Thus, the present study affords an in situ synthesis of CuS on the S-g-C3N4 nanocomposite for improving the catalytic conversion of the nitro group to the amine group. [ABSTRACT FROM AUTHOR]

Sodium-ion batteries (SIBs) have emerged as a promising alternative to lithium-ion batteries (LIBs) in sectors requiring extensive energy storage. The abundant availability of sodium at a low cost addresses concerns associated with lithium, such as environmental contamination and limited availability. However, SIBs exhibit lower energy density and cyclic stability compared to LIBs. One of the key challenges in improving the performance of SIBs lies in the electrochemical properties of the cathode materials. Among the various cathodes utilized in SIBs, sodium vanadium phosphates (NVPs) and sodium vanadium fluorophosphates (NVPFs) are particularly advantageous. These vanadium-based cathodes offer high theoretical capacity and are cost-effective. Commercialization of SIBs with NVPF cathodes has already begun. However, the poor conductivity of these cathode materials leads to a short cycle life and inferior rate performance. Various synthesis methods have been explored to enhance the conductivity, including heteroatom doping (N, S, and Co), surface modification, the fabrication of porous nanostructures, and composite formation with conductive carbon materials. In particular, cathodes with interconnected hierarchical micro- and nano-porous morphologies have shown promise. This review focuses on the diverse synthesis methods reported for preparing hierarchically porous cathodes. With increased attention, particular emphasis has been placed on carbon composites of NVPs and NVPFs. Additionally, the synthesis of vanadium pentoxide-based cathodes is also discussed. [ABSTRACT FROM AUTHOR]