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In this study, we conducted the hydrothermal synthesis of cobalt (Co)–doped NiWO4, resulting in the formation of Co–NiWO4 nanoparticles (NPs), followed by calcination at 550℃ for 12 h. Comprehensive analyses were performed to characterize the composition, structure, and morphology of the synthesized material. X-ray diffraction results confirmed the successful inclusion of Co in the NiWO4 lattice, with the presence of characteristic peaks of CoWO4. The crystallite size, determined using the Scherrer equation, was measured to be 22 nm. Using UV-Vis spectroscopy and Tauc’s equation, we calculated the band gap energy (E g) to be 3.75 eV for NiWO4 and 1.75 eV for Co–NiWO4. The potential application of the synthesized material as a photocatalyst was investigated for the degradation of the diazo dye Congo red (CR). Under optimized reaction conditions, Co–NiWO4 NPs demonstrated outstanding efficiency, degrading a total of 95% of CR. The degradation kinetics were well-described by the Langmuir–Hinshelwood (L–H) kinetic model, indicating that photoabsorption played a crucial role in the rate-controlling step. These encouraging results suggest that Co–NiWO4 NPs hold promise as a viable option for addressing other pollutants in various applications.

Few researches have explored the production of pharmaceuticals from aquatic plants. Therefore, this study explored, for the first time, the phytochemical composition and bioactivities of ten aquatic plants. Aquatic plant shoots from various Nile River canals were collected, dried, and ground for aqueous extract preparation. Phytochemical composition and antioxidant capacity were assessed using DPPH assays. Extracts were tested for antiparasitic, antibacterial, anti-biofilm, and anticancer activities through standard in vitro assays, measuring IC50 values, and evaluating mechanisms of action, including cell viability and high-content screening assays. The results showed that the aquatic plants were rich in pharmaceutical compounds. The antioxidant capacity of these extracts exceeded that of vitamin C. The extracts showed promising antiparasitic activity against pathogens like Opisthorchis viverrini and Plasmodium falciparum, with IC50 values between 0.7 and 2.5 µg/mL. They also demonstrated low MICs against various pathogenic bacteria, causing DNA damage, increased plasma membrane permeability, and 90% biofilm inhibition. In terms of anticancer activity, extracts were effective against a panel of cancer cell lines, with Ludwigia stolonifera exhibiting the highest efficacy. Its IC50 ranged from 0.5 µg/mL for pancreatic, esophageal, and colon cancer cells to 1.5 µg/mL for gastric cancer cells. Overall, IC50 values for all extracts were below 6 µg/mL, showing significant apoptotic activity, increased nuclear intensity, plasma membrane permeability, mitochondrial membrane permeability, and cytochrome c release, and outperforming doxorubicin. This study highlights the potential of aquatic plants as sources for new, safe, and effective drugs with strong antiparasitic, antibacterial, and anticancer properties. [ABSTRACT FROM AUTHOR]

In this paper, we report the hydrothermal synthesis of manganese dioxide (δ-MnO2) and its composite with sulfur-doped graphitic carbon nitride (δ-MnO2/S@g-C3N4). Advanced sophisticated physicochemical characterization techniques (powder x-ray diffraction [PXRD], scanning electron microscopy [SEM], energy-dispersive x-ray spectroscopy [EDS]) were adopted to verify and confirm the formation of the δ-MnO2 and δ-MnO2/S@g-C3N4. A dopamine (DA) sensor was fabricated by modifying the surface (active area) of the screen-printed carbon electrode (SPCE) using the δ-MnO2/S@g-C3N4 composite as electrocatalyst. Good sensitivity of 1.53 µA µM−1 cm−2 was achieved using the δ-MnO2/S@g-C3N4-modified SPCE, and the device demonstrated a good limit of detection (LOD) of 1.12 µM. The δ-MnO2/S@g-C3N4-modified SPCE also exhibited good stability, selectivity, and repeatability for the determination of DA. Furthermore, the δ-MnO2/S@g-C3N4-modified SPCE exhibited good stability, repeatability, and selectivity for detecting dopamine using linear sweep voltammetry (LSV). [ABSTRACT FROM AUTHOR]

Construction of a homojunction is an effective strategy for effective charge transfer to suppress charge carrier recombination in augmented photocatalysis. The present work reveals the synthesis of homojunction formation through the reinforcement of Cd nanostructures into a solid lattice of zinc vanadate (Zn3V2O8, ZnV) using the hydrothermal method. The formation of a homojunction between cadmium vanadate (CdV, Cd3V2O8) and ZnV was confirmed by various spectroscopic and electron microscopic techniques such as Fourier-transform infrared (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM) associated with energy-dispersive X-ray (EDX) mapping, transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and ultraviolet–visible spectrophotometry (UV–Vis). The synthesized material was explored for photocatalytic hydrogen (PC H2) production using the water splitting process under visible-light illumination. The spectroscopic and experimental results revealed that the formation of a CdV/ZnV homojunction significantly improved the transport of photogenerated charge carriers (electron–hole pairs) and thus resulted in enhanced H2 production efficiency (366.34 μmol g−1 h−1) as compared to pristine ZnV (229.09 μmol g−1 h−1) and CdV (274.91 μmol g−1 h−1) using methanol as a sacrificial reagent (SR) with water under visible-light illumination. The synergistic effect of Cd on ZnV NPs resulted in band gap reduction and broadened visible light absorption which was attributed to enhanced H2 production. The current study explains how a homojunction affects various features of important factors behind photocatalytic activity, which supports significant insights into the advancement of materials in the future. [ABSTRACT FROM AUTHOR]

In the recent years, molybdenum disulfide (MoS2) has been widely used in various optical applications. MoS2 has decent optical band gap and can be used as photocatalyst for hydrogen production applications. In this paper, we reported the synthesis of flower-like nickel (Ni)-doped MoS2. The as-prepared Ni@MoS2 has optical band gap of 1.71 eV which was lower than that of the pristine MoS2 (1.90 eV). Thus, Ni@MoS2 was further used as photocatalyst for hydrogen evolution. The effect of different dose (5, 10, 15, 20 and 25 mg) of the photocatalyst (Ni@MoS2) was also examined. The photocatalytic investigations exhibited the generation of good hydrogen production amount (2021.5 µmol g−1) with reasonable hydrogen generation rate of 404.3 µmol g−1 h−1 using 25 mg Ni@MoS2. These findings suggested that doping may significantly improve the photocatalytic hydrogen production. The proposed Ni@MoS2 also presented good stability and reusability for hydrogen production. [ABSTRACT FROM AUTHOR]

This research aims to explore the utilization of Ocimum basilicum leaf extract as a green and sustainable method for the synthesis of Fe3O4/NiO nanocomposites (Fe3O4/NiO NC) with potential applications in photocatalytic hydrogen evolution and organic dye degradation. The synthesized Fe3O4/NiO NC exhibited a unique bandgap energy of 2 eV, making it an effective visible-light photocatalyst. X-ray diffraction and scanning electron microscopy confirmed the successful formation of the cubic crystal structure with an average crystallite size of 25.7 nm. Fourier transform infrared spectroscopy analysis revealed the presence of hydroxyl groups on the NC surface, which contributed to its photocatalytic properties. Under sunlight exposure, the Fe3O4/NiO NC demonstrated remarkable photocatalytic degradation efficiency of 99.3% for toluidine blue, 99.0% for 4-bromophenol, and 95.0% for methyl blue within 140 min. The photocatalyst also exhibited excellent reusability with only a slight decrease in efficiency after five cycles. Additionally, the Fe3O4/NiO NC displayed high photocatalytic activity in hydrogen evolution, generating 933.9 µmol/g of H2 over 8 h at a concentration of 0.7 g/L. This green synthesis approach, utilizing Ocimum basilicum extract, provides a cost-effective and eco-friendly method to produce Fe3O4/NiO NC with enhanced photocatalytic properties, holding great promise for sustainable energy and water purification applications. The study contributes to the understanding of novel nanocomposites and their potential for addressing urgent environmental challenges, underscoring their scientific value in green chemistry and renewable energy research. [ABSTRACT FROM AUTHOR]

In the present research work, we have explored amperometric sensing properties of carbon nanospheres (Cx) (5%, 8%, and 15%) decorated over Sm2O3/Co3O4 nanocomposites (NC) that are synthesized by microwave-assisted method. The synthesized electrode materials are characterized by the techniques of X-ray diffraction (XRD), scanning electron microscopy (SEM), SEM-EDAX (energy-dispersive X-ray spectroscopy), BET (Brunauer–Emmett–Teller), XPS (X-ray photoelectron spectroscopy), and UV–visible. Phase analysis revealed mixed monoclinic crystal structure and crystallite size decreases from 32 to 22 nm. Plate/flake-like morphology resulted upon the incorporation of Cx on Sm2O3/Co3O4 crystal lattice. Redshift in the optical absorption peak resulted with an increase in Cx concentration on Sm2O3/Co3O4 NC and the optical band gap (Eg) decreases from 3.26 to 2.61 eV. The sensitive and selective determination of hydrogen peroxide (H2O2) is very important because it is a product of reactions catalyzed by oxidase enzymes, a powerful effector of redox signaling, versatile biomarker, and is widely used in the food industry. H2O2 is known to cause toxicity and they form hydroxyl radicals. The accurate detection of H2O2 can indicate the presence of enzyme activity, explosives, and cell signaling pathways. Additionally, H2O2 has become a signal propagator within signal amplification methodologies used to enhance selectivity of the diagnostic assays. The developed modified sensor (C15%:Sm2O3/Co3O4) showed amperometric detection of H2O2 with 96% steady current within 3–4 s, linear range was found to be 0.2 µM to 6 µM, limit of detection (LOD) 0.04 µM, and having a sensitivity of 0.483 µA/µM (R2 = 0.996). Further, sensitivity and selectivity were detected with glucose, dopamine, ascorbic acid, and uric acid at + 0.36 V and no current response was observed. The modified electrode material possess high selectivity, less response time, high stability, reusability, and high repeatability and can find applications in the field of real-time monitoring of hazardous materials, fabrication of biosensors, H2O2 sensors, and in optoelectronics. [ABSTRACT FROM AUTHOR]