Department of Chemistry

Inducing post-transition metals in an oxide semiconductor system has a high potential for use in storage for neuromorphic computing. It is challenging to find a material that can be switched stably between multiple resistance states. This research explores the memristive properties of Sn (post-transition metal)-doped ZnO (SZO) thin films, emphasizing their application in memristor devices. The (magnetron sputtered) synthesized SZO thin films in the form of Ag/SZO/Au/Ti/SiO? device demonstrated a clear bipolar resistive switching (BRS) behavior with VSET and VRESET of 1.0 V and ?0.75 V, respectively. The memristor could change between a high resistance state and a low resistance state with a high RON/OFF rate of 104, mimicking synaptic behaviors such as potentiation and depression. This switching is attributed to the formation and dissolution of Ag filaments within the SZO layer, influenced by the migration of Ag? ions and the presence of oxygen vacancies. These vacancies facilitate the formation of conductive filaments under positive bias and their dissolution under negative bias. The endurance and retention tests showed stable switching characteristics, with the memristor maintaining distinct HRS and LRS over 100 cycles and retaining these states for over 5K seconds without significant degradation. Finally, the nonlinearity values for potentiation and depression were ?p?1.6 and ?d ? -0.14, suggesting that the memristor may be more responsive to increasing synaptic weights in biological systems. The linearity response at a very small pulse width showed the device is more applicable for neuromorphic applications. The observed memristor combined with stable endurance and retention performance, suggests that this memristor structure could play a crucial role in the development of artificial synapses and memory technologies. © 2024 Elsevier Ltd

Herein, we synthesized a Cu2O and Co3O4 incorporation with MoS2 to produce MoS2/Co3O4/Cu2O nanocomposites by facile sonication assisted hydrothermal methods. The phase structure and elemental composition of MoS2/Co3O4/Cu2O nanocomposites were investigated using X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) techniques. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) morphology studies confirm that MoS2/Co3O4 nanostructure self-assembles in a mixed nanosheet configuration after the introduction of Cu2O. The synthesized samples were used as new types of Pt-free counter electrodes (CE) for DSSCs. Among all, the DSSCs based on the MoS2/Co3O4/Cu2O CE yields a maximum power conversion efficiency of 3.68 % (Jsc = 8.2 mA cm?2, Voc = 0.71 mV and FF = 0.629 %) under the standard AM 1.5 G illumination, which is 2.5 times higher than that of pure MoS2. To assess the photocatalytic activity, prepared samples were used to suppress methylene blue (MB) and rhodamine B (RhB) dye under UV–visible light irradiation. The MoS2/Co3O4/Cu2O nanocomposites had the highest photocatalytic degradation efficiency of all the samples. It increased degradation efficiency from 43 % to 91 % for MB dye after 100 minutes, and from 47 % to 92 % for RhB dye after 90 minutes. Scavengers test analysis proved that the superoxide radical (•O2?) play a major role in the MoS2/Co3O4/Cu2O photocatalytic system. After four consecutive photocatalytic cycles, the crystal structure and surface morphology of the MoS2/Co3O4/Cu2O nanocomposites used in the 4th cycle were more stable, and this was confirmed by SEM, EDAX and XRD studies. The broader significance of these findings provides a straightforward approach for synthesizing a low-cost and high-efficiency MoS2/Co3O4/Cu2O nanocomposite for CE in DSSC photovoltaic cells and facilitates organic pollutant removal through photocatalytic applications. © 2024 Elsevier B.V.

In the past decade nanoscience, nanotechnology, and associated applications have witnessed significant upgradation from the perspective of fundamental, applied, and translational research. The art of nanoengineering has opened up prevailing prospects for a variety of applications, where numerous innovations and discoveries have followed the scientific research in this domain. To present a broad understanding of the subject matter, in this chapter, we provide a comprehensive introduction to the book by elaborating on the synthesis, classification, characterization, functionality, and applications of nanoengineered materials. Efforts are made to present integrated scientific approaches that would benefit chemists, physicists, and biologists working with basic as well as advanced functional materials with unique optoelectronic assets and biophysicochemical interfaces. We believe that such an exhaustive capture of the fundamentals of nanoengineering would lay a strong foundation for students, researchers, academicians as well as industry-based scientists.

Improving and reducing the cost of electrochemical performance is critical to developing energy storage technology. In this study, we investigated the effects of incorporating NiSe2 into the MoSe2, then the electrochemical behaviour of MoSe2@NiSe2 (0D/1D) hybrid-nanostructure prepared using a hydrothermal method. The Scanning electron microscopy (SEM) images confirmed that MoSe2, MoSe2@NiSe2 (0D/1D) hybrid-nanostructure in composites with surface enhancement. The MoSe2@NiSe2 (0D/1D) hybrid-nanostructure exhibits enhanced specific capacitance of 802 F g?1 compared to MoSe2 and shows extended cycle life up to 5000 cycles with 92.7 % of capacity retention. In addition, the active electrode consisting of MoSe2@NiSe2 (0D/1D) hybrid-nanostructure exhibits high ionic affinity due to the presence of abundant electrochemically active sites, which can reduce the internal resistance and lead to accelerated ion transport. Our results demonstrate that a simple and scalable approach can significantly improve the electrochemical performance of the MoSe2@NiSe2 (0D/1D) hybrid nanostructure

This chapter will emphasize the recent advancements focusing on (i) transition-metal-based organic transformations of 1,2,3-benzotriazin-4(3 H)-ones, (ii) reactions of 1,2,3-benzotriazin-4(3 H)-ones under thermal and photolytic conditions, as well as (iii) acid mediated or metal-free reactions of 1,2,3-benzotriazin-4(3 H)-ones to fabricate highly functionalized five, six-membered N-heterocycles and ortho -functionalized benzamides. Further, this book chapter also discusses the denitrogenative reactions of 1,2,3,4-benzothiatriazine-1,1(2 H)-dioxides with suitable reaction mechanisms of the developed protocols.

Water pollution is a critical environmental issue affecting ecosystems and human health worldwide. Contaminants such as heavy metals, dyes, antibiotics, and microplastics enter water bodies from the disposals of industrial, agricultural, and domestic waste. The development of new and advanced technologies for addressing water remediation has turned out to be a dire need. Protein?inorganic hybrid materials have emerged as innovative solutions for water remediation, leveraging the unique properties of both the proteins and the inorganic components. These hybrid materials connect the biocompatibility and specificity of proteins with that of the structural stability and catalytic capability of the inorganic frameworks. In recent times, protein inorganic hybrids are gaining importance in water remediation due to their ease of synthesis and chemical modification, stability, biocompatibility and biodegradability. This article brings out the recent advancements in the development of two major kinds of protein inorganic hybrid materials, viz., metal phosphate nanoflowers and gels in the context of water purification. The effect of major factors, like, morphology, porosity, pore size and nature, surface area, and the nature of the composite were systematically compared and analyzed to make it beneficial for future researchers in the development of such hybrid materials for water remediation in a sustainable manner. For this, the article addresses the current trends and draws conclusions on future perspectives to support the topic on providing clean and potable water for everyone on the globe

Diarylethene photoswitches featuring azole-based diaryl units combined with benzoheteroarene ?-linkers have gained significant research interest in recent years due to their potential to achieve higher photocyclization efficiencies compared to conventional dithienylethene switches. In this work, we investigate the suitability of these photoswitches for molecular solar thermal energy storage (MOST) applications through computational modeling of their electrocyclization and cycloreversion reactions. Our calculations demonstrate that it is possible to achieve simultaneously both large energy-storage densities (0.29–0.35 MJ kg–1) and prolonged energy-storage times (half-lives of up to 124 days) under ambient conditions in dithiazolyl and dioxazolyl switches containing six distinct benzoheteroarene ?-linkers. Furthermore, isomerization stabilization energy calculations and noncovalent interaction analysis reveal that the variations in energy-storage densities and times between the azole-based and dithienylethene switches stem from differences in aromaticities of the diaryl core and ?-linker, as well as changes in noncovalent interactions. Notably, we demonstrate that the relative populations of photoreactive anti-parallel and non-photoreactive parallel conformers of the ring-open form of these switches are governed by weak intramolecular C C interactions between the two aryl rings. These findings highlight the importance of optimizing such interactions to enhance energy-storage efficiencies in MOST systems

An efficient metal-free approach for synthesizing N-aryl- and N-alkyl phthalimide derivatives from 1,2,3-benzotriazin-4(3H)-ones is described. The reaction likely proceeds via a denitrogenative cyanation pathway, utilizing TMSCN as the cyanide source. This method is straightforward as well as scalable and supports a wide range of substrates with high functional group tolerance, yielding diverse phthalimide derivatives in good to excellent yields. The utility of this method is further highlighted by the successful synthesis of a tyrosinase inhibitor analogue in good yield

A novel approach for the synthesis of diverse substituted imidazoles and quinoxalines via an iodine-promoted cyclization reaction is described. The methodology showcases a broad substrate scope, achieving moderate to very good yields for biologically relevant imidazoles and quinoxalines. Notably, iodine serves as both an iodinating agent and an oxidizing agent, as shown by a mechanistic study. The current methodology is capable of being scaled up to gram quantities, operates in a metal-free environment under mild reaction conditions, and utilizes readily available substrates

A popular approach to developing molecular solutions for solar?energy storage is based on exploiting the reactions of molecular photoswitches. However, given that the reactions in question are usually the reverse of one another, it becomes imperative to handle conflicting performance criteria when optimizing the reactions. Here, studying diarylethene switches operated by electrocyclization (for storing the solar energy) and cycloreversion (for releasing the solar energy) reactions, we show that these processes can be made to simultaneously exhibit the desired characteristics by introducing a tricyclic rather than monocyclic ??linker as the bridge between the two aryl units. Specifically, we perform quantum chemical calculations to demonstrate that such a scenario is realizable by tailoring, using aromaticity, certain parts of the tricyclic structure for electrocyclization and other parts for cycloreversion. Furthermore, employing this strategy, we identify several diarylethene switches, each with their own unique tricyclic ??linker, that concurrently meet key performance criteria like large energy?storage densities and long energy?storage times. Accordingly, we conclude that there appears to be considerable structural flexibility in implementing the ideas for efficient diarylethene?based solar?energy storage put forth in this work

Two tungsten-based oxides, Li2WO4 and h-WO3, were investigated as anode materials for lithium-ion batteries in half-cell configuration (vs. Li) within the voltage window of 3.0–0.05 V. The initial lithiation process in both materials involves Li intercalation into the lattice, followed by a conversion reaction. The Li2WO4 anode exhibited outstanding electrochemical performance, delivering a high reversible capacity of 547 mAh g?1 at 0.1C and 355 mAh g?1 at 1C after 70 cycles. Furthermore, it demonstrated fast charging capability and exceptional cycling stability, maintaining a discharge capacity of 280 mAh g?1 at 5C even after 1500 cycles. In comparison, the h-WO3 anode displayed significantly lower performance under similar conditions. These results highlight that the presence of pre-existing lithium ions in the host lattice of Li2WO4 facilitates efficient lithiation and delithiation, contributing to its superior capacity and extended cycle life. This study underscores the potential of Li2WO4 as a promising anode material for next-generation lithium-ion batteries

Indazoles are high value chemical building blocks used in medicinal chemistry and materials science for their distinct structural and functional features. This study details a [3+2]?cycloaddition reaction between various aryl?ketodiazoesters and ortho?(trimethylsilyl)aryl triflates under mild conditions, leading predominantly to 1?acyl?1H?indazoles. N?aryl?1H?indazoles and aryl benzoates were also observed as other products. The reaction exhibits broad functional group tolerance and scalability, making it a valuable synthetic approach. Mechanistic insights, derived from control experiments and density functional theory (DFT) calculations, elucidate the cycloaddition pathway and rationalize the formation of the products. Collectively, these findings underscore the method’s potential for synthesizing complex indazole derivatives, which hold significant promises for applications in pharmaceutical development and advanced materials research

Molecular photoswitches that absorb sunlight and store it in the form of chemical energy are attractive for applications in molecular solar thermal energy storage (MOST) systems. Typically, these systems utilize the absorbed energy to photoisomerize into a metastable form, which acts as an energy reservoir. Diarylethenes featuring aromatic ethene ?-linkers have garnered research interest in recent years as a promising class of T-type photoswitches, which undergo photocyclization from an aromatic ring-open form into a less aromatic or non-aromatic ring-closed form. Based on several recent computational and experimental studies, this perspective analyzes the potential of these switches for MOST applications. Specifically, we discuss how they can be made to simultaneously achieve high energy-storage densities, long energy-storage times, and high photocyclization quantum yields by tuning the aromatic character of the ethene ?-linker

Duchenne muscular dystrophy (DMD) is a neuro-muscular disease that affects males in the pediatric age group.Currently, there is no painless, cost-effective prognostic methodavailable to monitor DMD progression. The main hypothesis ofthis study was that the biochemical composition of extracellularvesicles (EVs) isolated from the urine of DMD patients can bedistinctly differentiated from that of healthy controls using surface-enhanced Raman Spectroscopy (SERS) combined with machinelearning models. This differentiation is expected to provide anoninvasive, rapid, and accurate diagnostic tool for the earlydetection, staging, and monitoring of DMD by identifying themolecular signatures captured by SERS and leveraging theanalytical power of machine learning algorithms. We collectedfasting morning urine samples from 52 DMD patients and 17 healthy controls and isolated EVs using a Total Exosome Isolation kit.The SERS substrates are prepared using silver nanoparticles, which were employed to capture the molecular fingerprints of the EVswith uniformity and reproducibility, achieving relative standard deviation values of 7.3% and 8.9%. We observed alterations inphenylalanine and ?-helical proteins in patients with DMD compared to controls. These spectral data were analyzed using PCA,Support Vector Machines, and k-Nearest Neighbor (KNN) algorithms to identify distinct patterns and stage DMD based onbiochemical composition. Our integrated approach demonstrated 60% sensitivity and 100% specificity in distinguishing DMDpatients from healthy controls, highlighting the potential of SERS and KNN for noninvasive, accurate, and rapid diagnosis of DMD.This method offers a promising avenue for early detection and personalized treatment strategies, ultimately improving patientoutcomes and quality of life

Renewable energy has gained widespread recognition for its potential to drive sustainable power generation and mitigate climate change. However, the rapid expansion of these resources highlights inherent challenges arising from their non?dispatchable, intermittent, and asynchronous nature, underscoring the critical need for grid?scale energy storage. Although numerous storage technologies exist, cohesive insights into commercially available or nearing commercialization remain limited. The review addresses that gap by presenting a comprehensive analysis of marketable grid?scale energy?storage solutions. The discussion begins with an examination of growth dynamics and regional trends in energy?storage capacities worldwide. By using California and Saudi Arabia as representative samples of the Mediterranean and hot desert regions under the Köppen classification, the review illustrates how climatic zones influence energy?storage requirements. After highlighting recyclability challenges associated with lithium?ion batteries, the study explores emerging electrochemical and gravitational?storage technologies. It then articulates critical parameters for evaluating energy?storage solutions and provides a comparative performance analysis. The review concludes by identifying a range of commercialized innovations and recommending a holistic approach to strengthen reliance on renewable energy

The hybridization of biomolecules with gold nanoclusters (AuNCs) has emerged as a promising research direction in bioelectronics, extending multidimensional prospects for diverse applications, from wearable health monitoring to advanced medical devices and tissue engineering. Here, we report a hybrid of bovine serum albumin (BSA) protein and gold nanoclusters of various concentrations to harness the distinctive properties of gold nanoclusters and enhance the electronic functionalities of biomolecules. Self-assembled monolayers (SAMs) of hybrid materials demonstrate enhanced electrical conduction with a film thickness of 10–15 nm as obtained from atomic force microscopy topographical images, revealing minimal aggregation. Current–voltage (I–V) characteristics at ±0.5 V showed significantly higher current densities for optimized hybrid material (BSA-Au6) SAMs, reaching 150 A/cm2. Compared to prior studies on BSA and metal hybrid thin films, the observed 100-fold enhancement in electrical conductivity for AuNC-doped SAMs highlights the novelty of this work. Moreover, our study with different AuNC concentrations demonstrated that six equivalents of AuNCs significantly boosted conductivity due to efficient electron transport mechanisms, which was further investigated with electrical impedance measurements. Our findings provide valuable insights into the underlying electronic transport mechanisms across hybrid materials for applications in bioelectronics and molecular electronics, marking a breakthrough compared to conventional protein films.

Organic solar cells (OSCs) have achieved remarkable progress, with power conversion efficiencies (PCEs) surpassing 19–20%, driven by the development of polymeric electron donors and non-fullerene acceptors (NFAs) in bulk-heterojunction (BHJ) architectures. BHJ OSCs, which rely on physical blending of donor (D) and acceptor (A) materials, face significant challenges in maintaining long-term stability. This instability limits the commercial viability of BHJ OSCs despite advancements in optimizing their morphology and device architecture. Single-component organic solar cells (SCOSCs) have emerged as a promising alternative to address these stability challenges. By covalently linking D and A units into a single molecule these single-material devices combine the advantages of light absorption and charge transport within a unified structure, eliminating complex interfacial layers and mitigating phase-separation issues inherent in BHJ systems. To date, SCOSCs have reached a maximum power conversion efficiency (PCE) of 15%, marking notable progress toward bridging the performance gap with BHJ devices. This review highlights the structural advancements in SCOSCs, with a particular emphasis on molecular dyads, D–A double cable polymers and conjugated block copolymers, and their photovoltaic performance. Furthermore, it discusses potential strategies for future innovations to improve the efficiency and scalability of SCOSCs.

This study focuses on fabricating a dual-active photocatalytic cartridge material for degrading dyes and antibiotics. Hence, the in-situ uniform growth of MnO2/CuO on 3D porous high surface area carbonaceous matrix, not only efficiently degrades Eriochrome Black T (EBT - 95.40 %), Loffler’s Methylene Blue (MB - 98.06 %), and azithromycin (96.50 %) within 100 min of light illumination but also reusable and stable upto 6 cycles. The mechanistic understanding based on band structure analysis, electron paramagnetic resonance technique and scavenging experiments, cumulatively explains about the participation of hydroxyl radical (•OH) at valence band of MnO2 (VBMO) and superoxide radical (•O2–) at conduction band of CuO (CBCO) in redox reactions following a Z-scheme mechanism. The theoretical studies show that the charge redistribution creates a built-in electric field between CuO-CNT-MnO2 layers, driving photogenerated electrons and holes in opposite directions, forming •O2– at CBCO and •OH at VBMO, thus enhancing degradation kinetics. The toxicity study shows 100 % cell viability with 100 minutes of dye-degraded water, 100 % bacterial viability, and healthier plants when exposed to azithromycin-degraded water, overall indicating that the degraded products are bio-compatible. A sustainable and smart prototype filter technology is demonstrated, which effectively filters 5 litres of dye/antibiotic under continuous light irradiation.

Developing an efficient and durable electrocatalysts for oxygen electrolysis is crucial for advancing clean energy technologies. However, the sluggish kinetics of oxygen reduction reaction (ORR) and oxygen evolution reaction (OER), along with catalyst degradation, remain major obstacles. Here, we optimized the composition of composite nanocatalysts obtained by doping of an electron deficient, B-atoms into graphene quantum dots (GQD) attached with Cobalt Sulfide (CoS) nanostructures. Optimizing the surface structure and investigating the interfacial interactions, the catalyst demonstrated an exceptional oxygen electrode reaction performance. The faster electronic synergism between the defect engineering BGQD and CoS offers more catalytic active sites as well as faster electrical conductivity and higher adsorption/desorption rate of oxygenated intermediates at the electrode surface for the electrolysis processes. Among the optimized composite electrode material CSBGQD-13 (CoS/BGQD (1:3)) exhibited high positive onset (Eonset = 1.04 V vs. RHE) and half-wave potential (E1/2 = 0.84 V vs. RHE) with high limiting current density of 7.6 mA/cm2 at 1600 rpm and a reasonable resistance to the MeOH crossover effect during ORR. In addition, our electrocatalyst demonstrated long-term durability and effective OER activity with the lowest Tafel slope of 82 mV/dec among other CSBGQDs and a lower overpotential of 0.27 V vs. RHE at a current density of 10 mA/cm2. Furthermore, the CSBGQD-13 claims excellent dual function electrocatalytic performance towards ORR and OER with a very small ?E value (only 0.66 V vs. RHE), a higher catalytic current density. Henceforth, for possible fuel cell applications, we believe that this electrode material may provide an understanding of the principles of metal sulfide carbon dots hybrid catalysts

Reduced graphene oxide (rGO) has captivated the scientific community due to its exceptional electrical conductivity, high specific surface area, and excellent mechanical strength. The physical properties of reduced graphene oxide (rGO) are strongly dependent on the presence of different functional groups in its structural framework, along with surface roughness. In this study, laser annealing was employed by a nanosecond Nd:YAG laser to investigate the impact of varying laser energies on the wettability and conductivity of reduced graphene oxide (rGO) samples grown by the pulsed laser deposition (PLD) technique. The rGO films were annealed with different laser fluences, such as 10, 20, 30, 38, 48, 55, and 250 mJ/cm2. Our results reveal a notable transition in wettability, transforming the initially hydrophobic rGO samples into a hydrophilic state. Hydrophilic graphene oxide (GO) or reduced graphene oxide (rGO) surfaces have significant potential for use in biomedical applications due to their unique combination of properties, including biocompatibility, high surface area, and abundant oxygen-containing functional groups. Along with wettability properties, conductivity changes were also observed. The presented findings not only contribute to the understanding of laser-induced modifications in rGO but also highlight the potential applications of controlled laser annealing in tailoring the surface properties of graphene-based materials for diverse technological advancements