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In the present study, Mo-BiVO4-loaded and metal oxide (MO: Ag2Ox, CoOx, and CuOx)-loaded Mo-BiVO4 photocatalysts were synthesized using a wet impregnation method and applied for microbial inactivation (Escherichia coli and Staphylococcus aureus) and orange II dye degradation under visible-light (VL) conditions (λ ≥ 420 nm). The amount of MO cocatalysts loaded onto the surface of the Mo-BiVO4 photocatalysts was effectively controlled by varying their weight percentages (i.e., 1-3 wt %). Among the pure Mo-BiVO4, Ag2Ox-, CoOx-, and CuOx-loaded Mo-BiVO4 photocatalysts used in bacterial E. coli and S. aureus inactivation under VL irradiation, the 2 wt % CuOx-loaded Mo-BiVO4 photocatalyst showed the highest degradation efficiency of E. coli (97%) and S. aureus (99%). Additionally, the maximum orange II dye degradation efficiency (80.2%) was achieved over the CuOx (2 wt %)-loaded Mo-BiVO4 photocatalysts after 5 h of radiation. The bacterial inactivation results also suggested that the CuO x -loaded Mo-BiVO4 nanostructure has significantly improved antimicrobial ability as compared to CuOx/BiVO4. The enhancement of the inactivation performance of CuOx-loaded Mo-BiVO4 can be attributed to the synergistic effect of Mo doping and Cu2+ ions in CuOx, which further acted as an electron trap on the surface of Mo-BiVO4 and promoted fast transfer and separation of the photoelectron (e-)/hole (h+) pairs for growth of reactive oxygen species (ROS). Furthermore, during the bacterial inactivation process, the ROS can disrupt the plasma membrane and destroy metabolic pathways, leading to bacterial cell death. Therefore, we provide a novel idea for visible-light-activated photocatalytic antibacterial approach for future disinfection applications.

Green synthesis of high-quality reduced graphene oxide (rGO) from agro-industrial waste resources remains attractive owing to its outstanding environmental benefits. The remarkable properties of rGO include excellent morphology, uniform particle size, good optical properties, high conductivity, nontoxicity, and extraordinary chemical stability. Traditional methods for the synthesis of rGO nanomaterials involve several chemical reactions including oxidation, carbonization, toxic solvent, and pyrolysis which produce harmful byproducts. Green preparation of rGO is an emerging area of research in graphene technology which is cost-effective and sustainable in the procedure. Owing to the uniform particle rGO particle size, these smart nanomaterials have wide applicability, including in metal ions and pollutant sensing and adsorption, photocatalysis, optoelectrical devices, medical diagnosis, and drug delivery. Here we review the physicochemical properties of rGO, the biowaste sources and green methods of rGO synthesis, and the diverse applications of rGO, including in water purification and the biomedical fields. With this review, covering more than 200 research articles published on rGO in the last eight years ending in 2022, we aim to provide a quick guide for researchers seeking up-to-date information on the properties, production, and applicability of rGO, with special attention to rGO applications in water purification and the biomedical fields.

In recent days, natural fibers are extremely influential in numerous applications such as automobile body building, boat construction, civil structure, and packing goods. Intensification of the properties of natural fibers is achieved by blending different natural fibers with resin in a proper mixing ratio. This investigation aims to synthesize a hybrid polymer matrix composite with the use of natural fibers of flax and loops of hemp in the epoxy matrix. The synthesized composites were characterized in terms of tribological and mechanical properties. The Taguchi L16 orthogonal array is employed in the preparation of composite samples as well as analysis and optimization of the synthesis parameters. The optimization of compression molding process parameters has enhanced the results of this investigation. The parameters chosen are percentage of reinforcement (20%, 30%, 40%, and 50%), molding temperature (150 °C, 160 °C, 170 °C, and 180 °C), molding pressure (1 MPa, 2 MPa, 3 MPa, and 4 MPa), and curing time (20 min, 25 min, 30 min, and 35 min). From the analysis, it was observed that the percentage of reinforcement is contributing more to altering the fatigue strength, and the curing time is influenced in the impact and wear analysis.

This Paper describes the synthesis of nickel doped ZnO is planned by chemical co-precipitation techniques. The prepared nanostructured nickel doped zinc oxide samples were analyzed by thermogravimetric differential thermal analysis (TG/DTA), X-ray diffraction (XRD), Fourier transform infra red (FTIR), field emission scanning electron microscopy (FESEM), high resolution transmission electron microscopy (HRTEM), electron paramagnetic resonance (EPR), and cyclic voltametry (CV). Nanostructure nickel doped ZnO materials have developed as promising for the basis of its broad range of employing in diverse areas. The attractive properties of nickel doped ZnO materials are highly demanded in high-energy potential applications. The nickel doped zinc oxide materials are hexagonal wurtzite arrangement is confirmed by XRD. The morphological -features of FE-SEM show nickel doped zinc oxide NPs are the structure of spherical type with agglomeration. The calculated particle size 11 nm is confirmed by HR-TEM. EPR spectra of nickel doped zinc oxide nanoparticles are ferromagnetic nature. Further, CV studies of Ni doped ZnO materials of the specific capacitance value is 133 Fg

The aim of this research is to develop an efficient photocatalyst for the degradation of acrylonitrile under simulated sunlight. In this work, Zr-doped FS–TiO2/SiO2 photocatalyst was reported for the degradation of acrylonitrile. Sol–gel method were used for the preparation of Zr-doped FS–TiO2/SiO2 with the molar ratio of Ti:Zr varied from 1:0.07. The prepared photocatalyst was calcined at 450 °C for 2 h. The characteristics of Zr-doped FS–TiO2/SiO2 were examined by X-ray diffraction (XRD), ultraviolet–visible diffuse reflectance spectroscopy (UV–Vis DRS), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Brunauer–Emmett–Teller (BET) and X-ray photoelectron spectroscopy (XPS). XRD results confirmed the presence of anatase phase of TiO2, and it also reveals that the Zr doping did not change the crystal phase of TiO2. The absorbance of Zr-doped FS–TiO2/SiO2 was significantly enhanced, as confirmed by the red shift in UV–Vis DRS spectra. Zr doping inhibits the recombination of electron–hole pairs and enhanced the photocatalytic activity. The UV–Vis DRS spectra show stronger absorption in Zr-doped FS–TiO2/SiO2 photocatalysts compared to FS–TiO2/SiO2. XPS analysis illustrated the presence of Zr4+, Ti3+, Ti4+, O2− and OH groups in Zr-doped FS–TiO2/SiO2. Then, the photocatalytic activity of the prepared photocatalyst was tested for the photocatalytic degradation of acrylonitrile under simulated sunlight. Zr doping, together with F and S would enhance the surface area and charge separation, making it serve as a more effectual photocatalyst than TiO2 and FS–TiO2/SiO2. The degradation ratio of acrylonitrile reached 79.2% within 6 min of simulated sunlight due to the doping effect of Zr into FS–TiO2/SiO2 photocatalyst. Zr doping could enhance the thermal stability of anatase phase of TiO2 and improve its surface properties.

In this study, the green treated aluminium oxide nanoparticles (Al2O3 NPs) were synthesized through simple biological reduction method and studied the effect of pH disparity on particle size variation. Green synthesis of Al2O3 NPs from Prunus × yedoensis leaf extract (PYLE) used for removal of nitrate and antibacterial activities for the first time. The synthesized Al2O3 NPs were characterized by different standard analytical and microscopy techniques. The Al2O3 NPs formation occurred through reduction of metal ions followed by nucleation. The size of the pH = 7 Al2O3 NPs are spherical and hexagonal shape and the size ranges between 50–100 nm, although some nanoparticles are agglomerated. The band gap energy values of the pH = 7 Al2O3 NPs were 3.1 eV, which corresponds to the reflectance edge of 420 nm. The surface area of pH = 7 Al2O3 NPs determined from BET measurement was found to be 54.5014 m2/g. The green synthesized Al2O3 NPs were found to be highly efficient in removing nitrates upto 94% from aqueous solutions at pH = 7 under the influence of sunlight irradiation. This removal efficiency of the synthesized NPS is appreciable when compared with previously reported materials of same kind and hence proves its potential for its use in various ion removal from contaminant systems. The detailed in vitro antibacterial activities of the green treated Al2O3 NPs also investigated. The synthesized Al2O3 NPs at pH = 7 was found to have effective antibacterial activity against gram-positive Staphylococcus aureus (S. aureus) and gram-negative Escherichia coli (E. coli). The experimental results of the study reveals that on tuning the size of synthesized Al2O3 NPs and optimizing its pH exhibited higher catalytic activity and antibacterial activity. Hence, these green synthesized Al2O3 NPs is found to have promising applications in pollutant ion removal in aquatic systems.

Green synthesis of TiO2 nanoparticles (NPs) from Prunus × yedoensis leaf extract (PYLE), and their application for removal of phosphate and their antibacterial activity, were studied for the first time. NPs were obtained using a green chemistry approach from 0.1 M TiO2 and PYLE at ratio of 1:1 (v/w). Initial confirmation of production of TiO2 NPs was provided by a color change from white to light yellow, then calcination was performed at 500 °C for 1 h. The TiO2 NPs were characterized using various analytical techniques such as ultraviolet–visible (UV–Vis) spectroscopy, X-ray diffraction analysis, Fourier-transform infrared spectroscopy, Raman spectroscopy, UV–Vis diffuse reflectance spectroscopy, X-ray photoelectron spectroscopy, and high-resolution transmission electron microscopy. The results indicated that the optimal amount of TiO2 NPs for removal of phosphate was 10 mg/l (10 ppm) with duration of 25 min. Furthermore, the antibacterial activity of TiO2 NPs was also investigated using two different bacteria (Gram-positive Staphylococcus aureus and Gram-negative Escherichia coli) in aqueous medium. The results revealed highly efficient sunlight-driven photocatalytic and antibacterial activity of TiO2 NPs.