A simple UV-ozone surface treatment to enhance photocatalytic performance of TiO2 loaded polymer nanofiber membranes

Homogeneously dispersed titanium dioxide loaded polyacrylonitrile nanofiber membranes with increased active mass loading, Ti3+ surface defects and hydrophilicity were fabricated by combining electrospinning and UV-ozone surface treatment. The photocatalytic activity improved by a factor of ∼2 and the kinetics of photodegradation switched from pseudo-first order to pseudo-second order with increasing TiO2 content with a maximum rate constant of 20.7 h-1

Towards efficient and cost-effective inverted hybrid organic solar cells using inorganic semiconductor in the active layer

The article investigates the effects of NiO (p-type) and TiO2 (n-type) nanoparticles (NPs) on the performance of poly(3-hexylthiophene) (P3HT) and (phenyl-C61-butyric acid methylester) (PCBM) based devices with an inverse geometry. Various weight ratios of these nanoparticles were mixed in the polymer solution using 1,2-dichlorobenzene as solvent. An optimal amount of NPs-doped active layer exhibited higher power conversion efficiency (PCE) of 3.85% as compared to the reference cell, which exhibited an efficiency of 3.40% under white light illumination intensity of 100 mW/cm(2). Enhanced PCE originates from increased film roughness and light harvesting due to increased absorption range upon mixing an optimal amount of NPs in the organic-based active layer. Further addition of NiO and TiO2 concentration relative to PCBM resulted in significant agglomeration of nanoparticles leading to degraded device parameters.</p

High-performance solution-based CdS-conjugated hybrid polymer solar cells

In this study, hybrid BHJ - bulk heterojunction polymer solar cells were fabricated by incorporating CdS quantum dots (QDs) in a blend of P3HT (donor) and PCBM (acceptor) using dichlorobenzene and chlorobenzene as solvents. CdS QDs at various ratios were mixed in a fixed amount of the P3HT and PCBM blend. The prepared samples have been characterized by a variety of techniques such as I-V and EQE measurements, atomic force microscopy (AFM), scanning electron microscopy (SEM) and ultraviolet-visible (UV-vis) spectroscopy. The mixing of QDs in the polymer blends improved the PCE - power conversion efficiency of the solar cells under standard light conditions. The improved PCE from 2.95 to 4.41% is mostly due to the increase in the fill factor (FF) and short-circuit current (J(sc)) of the devices with an optimum amount of CdS in the P3HT:PCBM blend. The increase in J(sc) possibly originated from the formation of a percolation network of CdS. The conjugation of QDs has increased the absorption of the active layers in the visible region. These results well matched as reported, conjugation of CdS in the perovskite active layer increased the absorption and PCE of the devices relative to those of the perovskite films. This increment in parameters is attributed to the decrease in charge recombinations that improved the performance of the doped device

Cu-loaded C3N4-MgO nanorods for promising antibacterial and dye degradation

Photocatalytic and magnetic stability of two-dimensional nanomaterials is enhanced by metal doping, which is an environmentally friendly technique used in various industries. There is an urgent need to discover new antimicrobial compounds or extracts to address the crucial problem of increasing microbial resistance against current antibiotics. Similarliy, the whole world is facing water crisis and a possible cost-effective solution is photocatalysis. In this study, an economical and convenient co-precipitation method was adopted to synthesize copper (Cu) loaded graphitic carbon nitride (g-C3N4) and magnesium oxide (MgO) composites. Various concentrations (2.5, 5, 7.5, and 10%) of Cu were doped into a fixed amount of g-C3N4/MgO nanostructures for efficient photocatalytic and antimicrobial activities. Results showed that 2.5% Cu loaded samples exhibited best possible results for the photocatalytic activity and 10% loaded Cu nanocomposites displayed enhanced antimicrobial performance. Improved crystallinity and increase in crystal size upon doping were confirmed with X-ray differaction (XRD) analysis, which was corroborated with Selected Area Electron Diffraction (SAED) results. Fourier-transform infrared spectroscopy (FTIR) revealed that MgO spectra consisted of stretching vibrations of Mg-O bond and other functional groups with minor changes in the vibrational modes upon doping. An high resolution transmission electron microscope (HRTEM) fitted with Gatan (R) digital software indicated hexagonal phase formation in as-prepared samples and nanorods upon doping, with confirmed d-spacing values. The UV-visible spectroscopy (UV-Vis) analysis exhibited a slight redshift in absorption intensity leading to decreased bandgap (Eg) for Cu-loaded g-C3N4/MgO. Photoluminescence (PL) spectra were acquired to investigate the recombination of electron-hole pairs. X-ray photoelectron spectroscopy (XPS) was employed to evaluate the elemental and surface composition with binding energy alterations of Cu-loaded g-C3N4/MgO nanorods. The thermal stability and behavior of synthesized samples were investigated by differential scanning calorimetry thermoanalytical (DSC) analysis. Photocatalytic activity (PCA) of as-prepared samples were evaluated against methylene blue and ciprofloxacin (MB&CF) dye in acidic, neutral and basic medium. Furthermore, the efficient antimicrobial potential was evaluated against Escherichia Coli (E. coli) and Staphylococcus aureus (S. aureus) bacteria

Cu-loaded C3N4-MgO nanorods for promising antibacterial and dye degradation

Photocatalytic and magnetic stability of two-dimensional nanomaterials is enhanced by metal doping, which is an environmentally friendly technique used in various industries. There is an urgent need to discover new antimicrobial compounds or extracts to address the crucial problem of increasing microbial resistance against current antibiotics. Similarliy, the whole world is facing water crisis and a possible cost-effective solution is photocatalysis. In this study, an economical and convenient co-precipitation method was adopted to synthesize copper (Cu) loaded graphitic carbon nitride (g-C3N4) and magnesium oxide (MgO) composites. Various concentrations (2.5, 5, 7.5, and 10%) of Cu were doped into a fixed amount of g-C3N4/MgO nanostructures for efficient photocatalytic and antimicrobial activities. Results showed that 2.5% Cu loaded samples exhibited best possible results for the photocatalytic activity and 10% loaded Cu nanocomposites displayed enhanced antimicrobial performance. Improved crystallinity and increase in crystal size upon doping were confirmed with X-ray differaction (XRD) analysis, which was corroborated with Selected Area Electron Diffraction (SAED) results. Fourier-transform infrared spectroscopy (FTIR) revealed that MgO spectra consisted of stretching vibrations of Mg-O bond and other functional groups with minor changes in the vibrational modes upon doping. An high resolution transmission electron microscope (HRTEM) fitted with Gatan (R) digital software indicated hexagonal phase formation in as-prepared samples and nanorods upon doping, with confirmed d-spacing values. The UV-visible spectroscopy (UV-Vis) analysis exhibited a slight redshift in absorption intensity leading to decreased bandgap (Eg) for Cu-loaded g-C3N4/MgO. Photoluminescence (PL) spectra were acquired to investigate the recombination of electron-hole pairs. X-ray photoelectron spectroscopy (XPS) was employed to evaluate the elemental and surface composition with binding energy alterations of Cu-loaded g-C3N4/MgO nanorods. The thermal stability and behavior of synthesized samples were investigated by differential scanning calorimetry thermoanalytical (DSC) analysis. Photocatalytic activity (PCA) of as-prepared samples were evaluated against methylene blue and ciprofloxacin (MB&CF) dye in acidic, neutral and basic medium. Furthermore, the efficient antimicrobial potential was evaluated against Escherichia Coli (E. coli) and Staphylococcus aureus (S. aureus) bacteria

A review of photocatalytic characterization, and environmental cleaning, of metal oxide nanostructured materials

Industrial waste is the primary source of highly toxic organic pollutants and heavy metal contaminants. Treatment of such effluence is necessary to mitigate environmental pollution to provide a clean ecosystem for living species. Various approaches have been effectively utilized for the removal of industrial waste particularly, photocatalysis being an effective, economical, and time-efficient approach to remove toxic ions. Large organic molecules found in pesticides and dyes can be removed with relative ease using nano-photocatalysts with a wide energy band gap, which is one of its major merits. For this purpose, a combination of various metal oxides with relevant materials is generally employed to activate visible regions in photocatalysts. Moreover, modification in physical parameters such as surface area of the catalyst, crystallinity, particle size and morphology, band gap, and microstructure is undertaken, which serves to enhance the photocatalytic activity. Here, advanced techniques that are presently used to synthesize different types of photocatalysts and their potential use in the degradation of the organic dye have been described in detail. The focus of the current review is various metal oxide NPs such as ZnO, TiO2, WO3, SnO2, and CuO with potential applications in photocatalysis, their structural characteristics, classification, and their photocatalytic mechanism. The review covers the influence of dopants on morphological, electrical, optical, and photocatalytic activity of selected nanocomposite systems. Moreover, the current review grasps extensive literature on the role of metal oxides as a photocatalyst that will facilitate researchers by providing guidelines to design more suitable nano-photocatalytic systems