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Climatic changes are reaching alarming levels globally, seriously impacting the environment. To address this environmental crisis and achieve carbon neutrality, transitioning to hydrogen energy is crucial. Hydrogen is a clean energy source that produces no carbon emissions, making it essential in the technological era for meeting energy needs while reducing environmental pollution. Abundant in nature as water and hydrocarbons, hydrogen must be converted into a usable form for practical applications. Various techniques are employed to generate hydrogen from water, with solar hydrogen production—using solar light to split water—standing out as a cost-effective and environmentally friendly approach. However, the widespread adoption of hydrogen energy is challenged by transportation and storage issues, as it requires compressed and liquefied gas storage tanks. Solid hydrogen storage offers a promising solution, providing an effective and low-cost method for storing and releasing hydrogen. Solar hydrogen generation by water splitting is more efficient than other methods, as it uses self-generated power. Similarly, solid storage of hydrogen is also attractive in many ways, including efficiency and cost-effectiveness. This can be achieved through chemical adsorption in materials such as hydrides and other forms. These methods seem to be costly initially, but once the materials and methods are established, they will become more attractive considering rising fuel prices, depletion of fossil fuel resources, and advancements in science and technology. Solid oxide fuel cells (SOFCs) are highly efficient for converting hydrogen into electrical energy, producing clean electricity with no emissions. If proper materials and methods are established for solar hydrogen generation and solid hydrogen storage under ambient conditions, solar light used for hydrogen generation and utilization via solid oxide fuel cells (SOFCs) will be an efficient, safe, and cost-effective technique. With the ongoing development in materials for solar hydrogen generation and solid storage techniques, this method is expected to soon become more feasible and cost-effective. This review comprehensively consolidates research on solar hydrogen generation and solid hydrogen storage, focusing on global standards such as 6.5 wt% gravimetric capacity at temperatures between −40 and 60 °C. It summarizes various materials used for efficient hydrogen generation through water splitting and solid storage, and discusses current challenges in hydrogen generation and storage. This includes material selection, and the structural and chemical modifications needed for optimal performance and potential applications.

The reuse of waste materials has recently become appealing due to pollution and cost reduction factors. Using waste materials can reduce environmental pollution and product costs, thus promoting sustainability. Approximately 95% of calcium carbonate-containing waste eggshells end up in landfills, unused. These eggshells, a form of bio-waste, can be repurposed as catalytic electrode material for various applications, including supercapacitors, after being converted into CaO. Similarly, used waste battery electrode materials pose environmental hazards if not properly recycled. Various types of batteries, particularly lithium-ion batteries, are extensively used worldwide. The recycling of used lithium-ion batteries has become less important considering its low economic benefits. This necessitates finding alternative methods to recover and reuse the graphite rods of spent batteries. Therefore, this study reports the conversion of waste eggshell into calcium oxide by high-temperature calcination and extraction of nanographite from spent batteries for application in energy storage fields. Both CaO and CaO/graphite were characterized for their structural, morphological, and chemical compositions using XRD, SEM, TEM, and XPS techniques. The prepared CaO/graphite nanocomposite material was evaluated for its efficiency in electrochemical supercapacitor applications. CaO and its composite with graphite powder obtained from used lithium-ion batteries demonstrated improved performance compared to CaO alone for energy storage applications. Using these waste materials for electrochemical energy storage and conversion devices results in cheaper, greener, and sustainable processes. This approach not only aids in energy storage but also promotes sustainability through waste management by reducing landfills.

Abstract Type III beta phosphatidylinositol 4-kinase (PI4KIIIβ) is the only clinically validated drug target in Plasmodium kinases and therefore a critical target in developing novel drugs for malaria. Current PI4KIIIβ inhibitors have solubility and off-target problems. Here we set out to identify new Plasmodium PI4K ligands that could serve as leads for the development of new antimalarial drugs by building a PPI4K homology model since there was no available three-dimensional structure of PfPI4K and virtually screened a small library of ~ 22 000 fragments against it. Sixteen compounds from the fragment-based virtual screening (FBVS) were selected based on ≤ − 9.0 kcal/mol binding free energy cut-off value. These were subjected to similarity and sub-structure searching after they had passed PAINS screening and the obtained derivatives showed improved binding affinity for PfPI4K (− 10.00 to − 13.80 kcal/mol). Moreover, binding hypothesis of the top-scoring compound (31) was confirmed in a 100 ns molecular dynamics simulation and its binding pose retrieved after the system had converged at about 10 ns into the evolution was described to lay foundation for a rationale chemical-modification to optimize binding to PfPI4K. Overall, compound 31 appears to be a viable starting point for the development of PPI4K inhibitors with antimalarial activity.

With an alarming increase in the number of cancer patients and a variety of tumors, it is high time for intensive investigation on more efficient and potent anti-tumor agents. Though numerous agents have enriched the literature, still there exist challenges, with the availability of different targets and possible cross-reactivity. Herein we have chosen the phosphoinositide 3-kinase (PI3K) as the target of interest and investigated the potential of pyrido fused imidazo[4,5-c]quinoline derivatives to bind strongly to the active site, thereby inhibiting the progression of various types of tumors. The AutoDock, Glide and the Prime-MM/GBSA analysis are used to execute the molecular docking investigation and validation for the designed compounds. The anti-tumor property evaluations were carried out by using PASS algorithm. Based on the GLIDE score, the binding affinity of the designed molecules towards the target PI3K was evaluated. The energetics associated with static interactions revealed 1j as the most potential candidate and the dynamic investigations including RMSD, RMSF, Rg, SASA and hydrogen bonding also supported the same through relative stabilization induced through ligand interactions. Subsequently, the binding free energy of the Wortmannin and 1j complex calculated using MM-PBSA analysis. Further evaluations with PASS prediction algorithm also supported the above results. The studies reveal that there is evidence for considering appropriate pyrido fused imidazo[4,5-c]quinoline compounds as potential anti-tumor agents.

Abstract Marine mussels contain an abundant catechol moiety, 3,4‐dihydroxyphenylalanine (DOPA), in their interfacial foot proteins. DOPA contributes to both surface adhesion and bridging between the surface and overhead proteins (surface priming) by taking advantage of the unique redox properties of catechol. Inspired by the mussel surface priming mechanism, herein we synthesized a series of DOPA‐mimetic analogs – a bifunctional group molecule, consisting of a catechol group and an acrylic group at the opposite ends. The surface primers with differently substituted (−COOH, −CH3) alkyl chains in the middle spacer were synthesized. Time‐dependent oxidation and redox potentials of the surface primers were studied in an oxidizing environment to gain a better understanding of the mussel‘s redox chemistry. The thickness and degree of priming of the surface primers on silicon‐based substrates were analyzed by ellipsometry and UV/Vis absorption spectroscopy. The post‐reactivity of the acrylic groups of the primed layer was first visualized through a reaction with an acrylic group‐reactive dye.

A novel electrochemical sensor based on iron tungstate doped tin oxide nanocomposite Nafion (FeWO4/SnO2/Nf) immobilized modified glassy carbon electrode (GCE) is fabricated to determine hydroquinone (HQ) in this present study. The structural morphology and phase of FeWO4/SnO2 nanocomposite are characterized by X-ray powder diffraction (XRD), energy dispersive X-ray analysis (EDX), Fourier transform infrared spectroscopy (FT-IR), high transmission electron microscopy (HR-TEM) and Field emission scanning electron microscopy (FE-SEM), Brunauer-Emmett-Teller (BET) and X-ray photoelectron spectroscopy (XPS) respectively. Electrochemical methods such as cyclic voltammetry (CV), difference pulse voltammetry (DPV) and amperometric (i-t curve) are used to describe the electrochemical performance of the surface modified electrode for HQ sensing studies. The FeWO4/SnO2/Nf immobilized GCE is exhibited excellent catalytic activity with the increasing current signal during HQ sensing. The linear range of response is obtained between 0.01 µM and 50 µM for HQ detection under optimized conditions and the low detection limit (LOD) is found to be 0.0013 µM. Moreover, the present modified electrode shows good reproducibility and excellent anti-interference behavior. In addition, the present electrochemical sensor is applied to the real samples of collected waters from various sources and the obtained experimental results are quite satisfactory. Keywords: Electrochemical methods, Anti-interference, Amperometric method, HQ sensor

Improper disposal of pharmaceutical drugs, including antibiotics, can affect the ecological system and generate serious health problems for living organisms. In this work, we have developed an electrochemical sensor based on a strontium manganese oxide/functionalized hexagonal boron nitride (SrMnO3/f-BN) electrocatalyst for the detection of the antibiotic drug furaltadone (FLD). Various analytical techniques were used to characterize the physicochemical properties of the as-prepared SrMnO3/f-BN composite. The as-fabricated SrMnO3/f-BN composite electrode showed excellent sensing activity towards FLD, with a wide linear range (0.01–152.11 µM) and low detection limit (2.0 nM). The sensor exhibited good selectivity towards FLD for detection in the presence of various interfering species (nitro compounds, metal ions, and biological compounds). Interestingly, real-time analysis using the proposed SrMnO3/f-BN composite was able to determine the FLD content in human urine and wastewater samples with good recovery. Hence, the as-developed SrMnO3/f-BN modified sensor could be viable in practical applications to target the antibiotic drug FLD in both human fluids and environmental samples.

Green and renewable energy is the key to overcoming energy-related challenges such as fossil-fuel depletion and the worsening of environmental habituation. Among the different clean energy sources, hydrogen is considered the most impactful energy carrier and is touted as an alternate fuel for clean energy needs. Even though noble metal catalysts such as Pt, Pd, and Au exhibit excellent hydrogen evolution reaction (HER) activity in acid media, their earth abundance and capital costs are highly debatable. Hence, developing cost-effective, earth-abundant, and conductive electrocatalysts is crucial. In particular, various two-dimensional (2D) transition metal carbides and their compounds are gradually emerging as potential alternatives to noble metal-based catalysts. Owing to their improved hydrophilicity, good conductivity, and large surface areas, these 2D materials show superior stability and excellent catalytic performances during the HER process. This review article is a compilation of the different synthetic protocols, their impact, effects of doping on molybdenum and tungsten carbides and their derivatives, and their application in the HER process. The paper is more focused on the detailed strategies for improving the HER activity, highlights the limits of molybdenum and tungsten carbide-based electrocatalysts in electro-catalytic process, and elaborates on the future advancements expected in this field.

Hydrogen is considered to be a very efficient and clean fuel since it is a renewable and non-polluting gas with a high energy density; thus, it has drawn much attention as an alternative fuel, in order to alleviate the issue of global warming caused by the excess use of fossil fuels. In this work, a novel Cu/ZnS/COF composite photocatalyst with a core–shell structure was synthesized for photocatalytic hydrogen production via water splitting. The Cu/ZnS/COF microspheres formed by Cu/ZnS crystal aggregation were covered by a microporous thin-film COF with a porous network structure, where COF was also modified by the dual-effective redox sites of C=O and N=N. The photocatalytic hydrogen production results showed that the hydrogen production rate reached 278.4 µmol g−1 h−1, which may be attributed to its special structure, which has a large number of active sites, a more negative conduction band than the reduction of H+ to H2, and the ability to inhibit the recombination of electron–hole pairs. Finally, a possible mechanism was proposed to effectively explain the improved photocatalytic performance of the photocatalytic system. The present work provides a new concept, in order to construct a highly efficient hydrogen production catalyst and broaden the applications of ZnS-based materials.

A large volume of research on lithium–oxygen (Li–O2) batteries (LOBs) has been conducted in the recent decades, inspired by their high energy density and power density. However, these future generation energy-storage devices are still subject to technical limitations, including a squat round-trip efficiency and a deprived rate-capability, due to the slow-moving electrochemical kinetics of both the oxygen evolution reaction (OER) and oxygen reduction reaction (ORR) over the surface of the cathode catalyst. Because the electrochemistry of LOBs is rather complex, only a limited range of cathode catalysts has been employed in the past. To understand the catalytic mechanisms involved and improve overall cell performance, the development of new cathode electrocatalysts with enhanced round-trip efficiency is extremely important. In this context, transition metal carbides and nitrides (TMCs and TMNs, respectively) have been explored as potential catalysts to overcome the slow kinetics of electrochemical reactions. To provide an accessible and up-to-date summary for the research community, the present paper reviews the recent advancements of TMCs and TMNs and its applications as active electrocatalysts for LOBs. In particular, significant studies on the rational design of catalysts and the properties of TMC/TMN in LOBs are discussed, and the prospects and challenges facing the continued development of TMC/TMN electrocatalysts and strategies for attaining higher OER/ORR activity in LOBs are presented.

Tremendous efforts have been made on the development of unique electrochemical capacitors or pseudocapacitors due to the overgrowing electrical energy demand. Here, the authors report a new and simple strategy for fabricating hybrid MnOx-coated ZnO nanorod arrays. First, the vertically aligned ZnO nanorods were prepared by chemical bath deposition (CBD) as a template providing a large surface area for active material deposition. The manganese oxide was subsequently coated onto the surface of the ZnO nanorods to form a hybrid MnOx-coated ZnO nanostructure by anodic deposition in a manganese acetate (MnA)-containing aqueous solution. The hybrid structure of MnOx-coated ZnO nanorod arrays exhibits a large surface area and high conductivity, essential for enhancing the faradaic processes across the interface and improving redox reactions at active MnOx sites. A certain concentration of the deposition solution was selected for the MnOx coating, which was studied as a function of deposition time. Cyclic voltammetry (CV) curves showed that the specific capacitance (SC) of the MnOx-coated ZnO nanostructure was 222 F/g for the deposition times at 10 s when the concentration of MnA solution was 0.25 M. The unique hybrid nanostructures also exhibit excellent cycling stability with >97.5% capacitance retention after 1200 CV cycles. The proposed simple and cost-effective method of fabricating hybrid nanostructures may pave the way for mass production of future intelligent and efficient electrochemical energy storage devices.

The development of productive antibacterial agents from nontoxic materials via a simple methodology has been an immense research contribution in the medicinal chemistry field. Herein, a sol−gel one-pot reaction was used to synthesize hybrid composites of hausmannite−chitosan (Mn3O4−CS) and its innovative derivative zinc manganese oxide−chitosan (ZnMn2O4−CS). Fixed amounts of CS with different metal matrix w/v ratios of 0.5%, 1.0%, 1.5%, and 2.0% for Mn and Zn precursors were used to synthesize ZnMn2O4−CS hybrid composites. X-ray diffraction analysis indicated the formation of polycrystalline tetragonal-structured ZnMn2O4 with a CS matrix in the hybrids. Fourier-transform infrared spectroscopic analysis confirmed the formation of ZnMn2O4−CS hybrids. Detailed investigations of the surface modifications were conducted using scanning electron microscopy; micrographs at different magnifications revealed that the composites’ surface changed depending on the ratio of the source materials used to synthesize the ZnMn2O4−CS hybrids. The antibacterial activity of the Mn3O4−CS and ZnMn2O4−CS composites was tested against various bacterial species, including Bacillus subtilis, Escherichia coli, Salmonella typhi, and Pseudomonas aeruginosa. The zone of inhibition and minimum inhibitory concentration values were deduced to demonstrate the efficacy of the ZnMn2O4−CS nanocomposites as antibacterial agents.

In this paper, the synthesis of porous manganese substituted hydroxyapatite (Mn-HAp) coating on zinc oxide (ZnO) coated stainless steel (316L SS) using the electrodeposition technique is reported. The structural, functional, morphological, and elemental analyses are characterized by various analytical techniques including X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS). Results of electrochemical techniques such as cyclic polarization and impedance show that the Mn-HAp coating on ZnO coated 316L SS has the highest corrosion resistance in simulated body fluid (SBF) solution. Moreover, dissolution of metal ions was extremely reduced, as evaluated by inductively coupled plasma-atomic emission spectroscopy (ICP-AES). The adhesion and hardness of Mn-HAp/ZnO bilayer coatings have superior mechanical properties over individual coatings. Further, the biocompatibility of in vitro osteoblast attachment, cell viability, and live/dead assessment also confirmed the suitability of Mn-HAp/ZnO bilayer coating on 316L SS for orthopedic applications.

Novel chitosan–zinc copper oxide (Zn1−xCuxO) composites were electrochemically synthesized through galvanostatic deposition. The prepared chitosan-based composite thin films were elaborately investigated to determine their structural, morphological, compositional, impedance, and corrosion properties. X-ray diffraction analysis was performed to reveal their structural orientation of composite thin films. Energy dispersive analysis by X-ray evidently confirmed the existence of Zn, Cu, and O in the composite thin films. Nyquist plots revealed that the chitosan-Zn1−xCuxO thin films had obvious semi-circular boundaries, and higher resistance was observed for chitosan-ZnO due to the grain boundary effect. Corrosion properties were evaluated using both an electrochemical method and the ASTM weight gain method, which revealed good corrosion rates of 34 and 35 × 10−3 mm/y, respectively, for chitosan-ZnO thin film.