[en] Highlights: • Facile synthesis of tri-phase direct dual S-scheme ZnO–V₂O₅-WO₃ heterostructured NC and pure ZnO, V₂O₅, and WO₃ NPs. • SEM, EDX, XRD, Raman, FTIR, and UV–vis was carried out. • The photocatalytic performance was tested against MB, CR, RhB, MO, SO, and MR dyes. • S-scheme is more efficient than other schemes for enhancing photocatalytic activity. • The antibacterial test against different bacteria strain was performed. In this work, tri-phase direct dual S-scheme ZnO–V₂O₅–WO₃ heterostructured nanocomposite and pure ZnO, V₂O₅, and WO₃ nanoparticles were synthesized by using a facile co-precipitation approach to investigate antibacterial and photocatalytic characteristics of the grown nanocomposite. The physical properties of as-synthesized products were examined by employing characterization techniques such as Scanning electron microscope (SEM), Energy-dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), Raman, Fourier transform infrared spectroscopy (FTIR), and UV–vis spectroscopy. The XRD results confirmed the formation of pristine ZnO, V₂O₅, WO₃ nanoparticles and the existence of diffraction peaks related to hexagonal phase ZnO, orthorhombic V₂O₅, and monoclinic phase of WO₃ in ZnO–V₂O₅–WO₃ nanocomposite. The variation in structural parameters was studied by SSP, Scherrer plot, and W–H models. The energy bandgap of nanocomposite (2.63 eV) was calculated from UV–vis spectroscopy, which indicated the usability as a photocatalyst under direct sunlight. FTIR and Raman's spectra also supported the formation of the ZnO–V₂O₅–WO₃ nanocomposite. Spherical and roughly hexagonal morphology were seen in SEM images. EDX analysis has confirmed the existence of Zn, V, W, and O in the nanocomposite. The antibacterial test against Klebsiella pneumonia, Staphylococcus aureus, Proteus Vulgaris, and Pseudomonas aeruginosa bacteria showed higher activity. The photocatalytic performance of the ZnO–V₂O₅–WO₃ nanocomposite (99.8%) was the highest against methylene blue (MB) as compared to pure ZnO (78.8%), V₂O₅ (85.8%), and WO₃ (80.0%) under natural sunlight. The degradation efficiency of ZnO–V₂O₅–WO₃ against cresol red (CR), rhodamine-B (RhB), methyl orange (MO), safranin-O (SO), and methyl red (MR) dyes was 67.0%, 86.6%, 98.0%, 76.8%, and 99.0%, respectively, under direct sunlight in 80 min. Different schematic models are designed to illustrate the photocatalytic reaction mechanism, whereas the separation of charge carriers and enhanced photocatalytic performance can be efficiently explained by S-scheme.

[en] In this work, the structural, electrical, and antibacterial properties of novel Mg_0.95Cr_0.05O and Mg_0.9Cr_0.05M_0.05O (M = Co, Ag, Ni) nanocrystals were studied. The simple, low-cost, and efficient co-precipitation method was used for the synthesis of required products and characterized by different analytical techniques such as XRD, FTIR, Raman, and I–V. The XRD study inveterated the substitution or incorporation of (M = Co, Ag, Ni) dopants deprived of disturbing the basic FCC structure of magnesium oxide. The average crystalline size and micro-strain were calculated from XRD data using different methods. The FTIR revealed the existence of Mg–O, Mg–O–Mg, and Mg–O-M bond, which confirmed the doping of (M = Co, Ag, Ni) in MgO host lattice. The Raman spectra also confirm the existence of optical phonon modes related to MgO. IV curve exhibits the improvement in the optical conductivity by co-doping. The antibacterial performance was tested against gram-positive Staphylococcus aureus bacteria.

[en] Highlights: • Pristine CdO and Cr-Co co-doped CdO nanowires were synthesized via a facile co-precipitation method. • Different analytical techniques such as XRD, FTIR, Raman, UV–vis, IV, SEM, CV, EIS, and GCD were used. • Enhanced photocatalytic performance against various pollutants with stability upto 5th cycle was achieved. • Improved antibacterial characteristics against different human pathogenic bacterial strain was attained. • The higher specific capacitance, energy density, and power density at optimal loading of Cr and Co were obtained. -- Abstract: Pristine CdO and chromium (Cr)-cobalt (Co) co-doped CdO nanowires via a facile co-precipitation protocol were synthesized and characterized with different analytical techniques to investigate its physical, photocatalytic, antibacterial, and electrochemical properties. The co-doping of Cr-Co into CdO matrix and their structural variations were confirmed by X-ray diffraction (XRD) data. Fourier transform infrared (FTIR) and Raman spectra also confirmed the doping of Cr and Co ions. The energy bandgap was extracted by employing different methods using UV–vis results, exhibited redshift by decreasing Co contents and blue shift by increasing Cr concentration. Scanning electron microscopy (SEM) images confirmed the preparation of nanowires. The photocatalytic and antibacterial experiments results showed the higher photodegradation efficiency against methylene blue (MB) (99.5%), methyl orange (MO) (90.6%), rhodamine-B (RhB) (87.5%), safranin-O (SF) (87.5%), and methyl red (MR) dyes (99.99%), after 60 min of sunlight illumination and the higher zone of inhibition (ZOI) against Klebsiella pneumoniae and Staphylococcus aureus for optimal doped Cd_0.90Co_0.05Cr_0.05O (Cd4) sample. The recyclability tests using Cd4 catalyst were exhibited higher stability up to 5th cycles. The higher ability to decompose dyes and kill bacteria is due to the generation of reactive species, confirmed by the radical trapping experiments. The electrochemical measurements were revealed that the Cd4 sample has a higher specific capacitance of 500 F/ g^{− 1} at 10 mV/s scan rate, excellent energy density 72 Wh/Kg, and greater power density of 4800 W kg^{− 1} at a current density of 0.1 A/g. Furthermore, the properties of CdO can be tuned by co-doping for making it a useful material for photocatalyst, supercapacitors electrodes, and antibacterial applications.

[en] Binary NiO-Fe${}_2$O${}_3$, NiO-CdO nanocomposites, and ternary NiO-Fe${}_2$O${}_3$-CdO nanocomposite are synthesized using facile co-precipitation method, and their photocatalytic and antibacterial properties are studied. The as-obtained products are characterized using different analytical techniques. The microstructural parameters were calculated using X-ray diffraction data. UV–vis spectra technique was used to calculate the bandgap and listed 3.1, 2.7, and 2.5 eV for NiO-Fe${}_2$O${}_3$, NiO-CdO, and NiO-Fe${}_2$O${}_3$-CdO nanocomposite, respectively. The photocatalytic activity of as-obtained products was tested under visible light against methylene blue (MB) dye. The NiO-Fe${}_2$O${}_3$-CdO nanocomposite has shown higher degradation efficiency as compared to binary nanocomposites and revealed improve electron–hole separation efficiency. The photocatalytic performance of NiO-Fe${}_2$O${}_3$-CdO nanocomposite was also tested for other synthetic dyes such as rhodamine-B (RhB), methyl orange (MO), and cresol red (CR). The antibacterial performance of grown products was tested against E. coli bacteria. The ternary NiO-Fe${}_2$O${}_3$-CdO nanocomposite has shown higher antibacterial activity than binary NiO-Fe${}_2$O${}_3$ and NiO-CdO nanocomposites.

[en] Highlights: • Direct dual Z-scheme TiO-WO₃-CeO₂ heterostructured nanocomposite successfully synthesized by co-precipitation route. • The nanocomposite TiO-WO₃-CeO₂ showed boosted photocatalytic activity towards different pollutants. • Systematic investigations confirmed the superior charge separation by direct dual Z-scheme. • Enhanced antibacterial activity of nanocomposite against various pathogenic bacterial strain. • The higher super-capacitive behaviour of nanocomposite. -- Abstract: Direct dual Z-scheme heterostructured nanocomposite TiO₂-WO₃-CeO₂ (NC) and pristine metal oxides nanostructures (NSs) were fabricated using a facile co-precipitation route. XRD, FTIR, and Raman data have confirmed the formation of NSs and NC. FESEM images showed quasi-mesoporous morphology of as-grown nanocomposite. EDX analysis confirmed the existence of titanium (Ti), cerium (Ce), and tungsten (W) in grown NC. The energy bandgap of NC was narrow 2.45 eV as compared to NSs. The higher electrical conductivity and lower recombination rate of NC were observed in IV and PL analysis. The photodegradation efficiency of NC was recorded 99.8% after 60 min under sunlight radiation against methylene blue (MB), which was significantly higher than NSs. NC catalyst has shown excellent photodegradation against other organic pollutants and has superior recyclability up to 7th cycle toward MB dye with a ~ 6% deficit in photodegradation efficiency. The antimicrobial activity results indicated the higher inhibition ability of NC against E. coli, K. pneumoniae, S. aureus, P. Vulgaris, and P. aeruginosa with maximum inhibition zone diameter 25, 29, 26, 28, and 27 mm, respectively. The electrochemical tests including CV, EIS, and GCD exhibited the superior capacitive behaviour of NC. These results demonstrate that grown NC is an efficient material for electrochemical devices, water purification, and biomedical applications.