Vis PL Research Articles

Ag3PO4 anchored SnWO4 Z-scheme heterojunction for reactive blue 21 degradation: Performance analysis and mechanism insights

The Ag3PO4–SnWO4 heterostructured nanocomposites have been prepared by the chemical precipitation process. The prepared nanocomposites were examined through XRD, TEM, UV–visible NIR, PL, BET, Mott Schottky, EIS, and ESR measurements. The diffraction peaks of Ag3PO4–SnWO4 nanocomposite showed the peaks of SnWO4 nanoparticles that are orthorhombic in the Ag3PO4 tetragonal structure, which suggested that they are present in the mixed phase of the composite. Photoluminescence spectra displayed efficiency in charge separation of e−-h+ pairs in Ag3PO4–SnWO4-1 nanocomposite. The Ag3PO4–SnWO4 nanocomposites have been examined for degrading the aqueous solution of reactive blue (RB 21) under natural sunlight irradiation. The superior photoactivity of Ag3PO4–SnWO4-1 could be ascribed to the existence of a heterostructure between Ag3PO4 and SnWO4 nanoparticles that improved the light absorption ability of the heterostructure. Also, a low rate of recombination of electron and hole pairs between Ag3PO4 and SnWO4 nanoparticles was observed. The Mott–Schottky plot revealed both Ag3PO4 and SnWO4 as n type semiconductor with flat-band potential values as 0.34 and −0.54 eV respectively. The photocatalytic rate reached the fastest on the incorporation of 100 mg SnWO4 compared to pristine Ag3PO4 and SnWO4 particles with 91.4% degradation efficiency and a rate constant of 0.257 min−1. The photogenerated O2∙−, h+ and ∙OH radicals indicated by the radical trapping experiment were mainly liable for the RB 21 degradation.

Magnetic and dielectric characteristics of rGO modified BFO nanoparticles produced using sol-gel via auto-combustion method

The study examined the structural, optical, dielectric, and magnetic characteristics of Bismuth Ferrite nanoparticles modified by rGO prepared by using the solgel via auto-combustion process. Each sample has a non-uniform surface morphology and a rhombohedral structure with space group R3c. With increasing rGO doping concentrations, the bandgap energy drops, and visible area PL emissions were detected. A frequency dependent dielectric experiment conducted at room temperature (0–1 MHz) reveals that as applied frequencies increase, the dielectric constant and loss factor both drop. The presence of grain and grain boundaries within the particles crystalline structure is shown via impedance analysis. It was discovered that magnetization rise as rGO concentration rise. The BFO and rGO-doped BFO nanoparticles demonstrated strong magnetoelectric coupling.

Impact of Cu2+ precursor on physical and photoelectrochemical properties of electrodeposited nanostructured CuS thin films for biosensor applications

Nanostructured CuS films were synthesized on FTO substrates employing low-cost electro deposition technique. XRD, Raman, SEM, UV–visible spectroscopy, photocurrent, PL, Mott-Schottky, and electrochemical impedance spectroscopy (EIS) measurements were used to examine physical and photoelectrochemical properties of samples. XRD results indicated that CuS films have hexagonal crystal structure where the crystallite size raises from 32 to 53 nm with increasing the Cu2+ molarity. Raman results displayed two peaks at 270 and 450 cm−1 that related to A1g transverse optical mode (TO) and A1g longitudinal optical (LO) mode for the vibrations of the S–S stretching and Cu–S bonds, respectively. SEM images displayed that fabricated CuS cover the substrate surface entirely, where grains are distributed uniformly with increasing the Cu+2 molarity. UV–visible measurements exhibited an absorption band edge between 450 and 550 nm as a characteristic of CuS films direct band gap. PL results presented strong blue-green emission at about 500 nm for CuS thin films. The photocurrent studies demonstrated that the CuS films are p-type semiconductors where the current density increases from 0.8 mA/cm2 to 1.1 mA/cm2 with the Cu2+ molarity increasing. The EIS analysis confirmed that charge transfer resistance reduces with increasing molarity. Mott- Schottky measurements established that carrier concentrations and the flat band varied from 5 × 1019 to 6.7 × 1019 cm−3 and from 1.1 to 0.75V, respectively. The fabricated CuS film was tested as glucose biosensor where a fast response and higher stability were noticed. Our results indicated that nanostructured CuS films are gifted candidates for optoelectronics applications especially biosensors.

Cobalt concentration effect on the Structural, Magnetic and Optical properties of Zn1-xCoxSe Nanoparticles

Cobalt doped Zinc selenide (Zn1-xCoxSe where x = 0.00,0.03, 0.05, 0.07, 0.09, 0.1, 0.15) nanoparticles are synthesized using co-precipitation method. For studying structural properties of prepared samples, nanoparticles are characterized by XRD (X-ray diffraction),SEM (Scanning Electron Microscope) with EDX (Energy Dispersive X-ray Diffractometer), HRTEM (High resolution transmission electron microscope),Elemental composition confirmed by EDX (Energy Dispersive X-ray Diffractometer), Inductively coupled plasma (ICP) spectroscopy test and XPS (X-ray photoelectron microscope). XRD study confirms that prepared samples are crystalline in nature and size is appeared in nanometer range with cubic structure. Optical investigation is done by UV–visible spectra and PL spectra at room temperature which indicates change in energy band gap as doping of cobalt increases in host material due to quantum confinement which shows the altered optical properties due to doping of transition metal in host material. FTIR (Fourier transform infra-red) spectroscopy reports presence of different functional groups in nanoparticles and thermal stability is confirmed by TG/DTA(Thermogravimetric) analysis. Magnetic analysis by using ESR (electron spin resonance) and VSM (Vibrating Sample Magnetometer) confirms presence of ferromagnetic coupling in cobalt doped zinc selenide nanoparticles which make these nanoparticles suitable for using in different devices e.g. in magnetic storage devices, magnetic imaging, magneto-optics and sensors etc. Combined semiconducting and magnetic nature of these Co doped ZnSe nanoparticles make them useful in spintronics, magnetic storage devices etc applications.

Fabrication and adsorption/photocatalytic degradation activities of (ZIF-8/Ag-AgVO3) composites

The utilization of porous materials such as metal–organic frameworks (MOFs) presents novel prospects for advancing photocatalyst research. One particularly promising avenue involves combining Zn-zeolitic imidazolate framework-8 (ZIF-8) with Ag-based semiconductors as photocatalyst heterostructures. Herein, a visible-light-sensitive heterojunction of Ag-AgVO3 nanorods with ZIF-8 have been assembled via simple hydrothermal method. Different characterization methods like XRD, FESEM, EDX, TEM, UV–visible DRS, PL, and BET-surface area were utilized to describe the phase purity, composition, morphology, elemental analysis, optical, and surface features of the assembled ZIF-8/Ag-AgVO3 hybrids. Due to unique nanoconstruction, the ZIF-8/Ag-AgVO3 presented improved photodegradation (98.2%) toward Congo red dye (CR) under visible light, which was 1.3, 3, and 9 times higher than ZIF-8/AgVO3, Ag-AgVO3 and ZIF-8, respectively. The boosted photocatalytic efficiency and stability of ZIF-8/Ag-AgVO3 is credited to its efficient carrier transfer and separation through the Z-type heterojunction and surface plasmonic resonance (SPR) action. The potential mechanism was confirmed by the reactive oxygen species (ROS) quenching experiments, demonstrating that the ·O2– and ·OH were the main active ROS. In the cyclic photodegradation tests, the ZIF-8/Ag-AgVO3 presented great stability, in which maintained 96.9 % photodegradation efficiency after 5 runs. When compared with the first photodegradation run, the degradation efficiency of ZIF-8/Ag-AgVO3 was merely decreased by 1.32%. Therefore, this study offers new perspectives on designing and constructing MOFs as efficient photocatalysts that can harness visible light to degrade organic pollutants.

Comprehensive investigations into the synergy of S-scheme heterojunction between nitrogen-doped ZnO nano-rods and g-C3N4 nanosheets for improved photocatalytic degradation

In this work, N-ZnO nanorods decorated with 2D g-C3N4 prepared by hydrothermal synthesis are studied for their synergistic effect in regard to enhanced photocatalytic activity. The synthesized material is characterized with XRD, FESEM, EDX, TEM and HR-TEM to perform the structural, morphological and elemental analysis along with XPS and FTIR for tracking sample purity and to study the elemental composition on the surface of the material; UV–Visible spectroscopy and PL spectroscopy for investigating the optical properties, bandgap calculation and to inquire about the defects in the structure. N-ZnO/g-C3N4 shows remarkable photocatalytic MB degradation ability upon solar irradiation which is 2.8 and 1.2 times exceeds than pristine ZnO and g-C3N4, attributed to the s-scheme mechanism for charge migration. The construction of s-scheme heterojunction among N-ZnO and g-C3N4 generates an internal electric field that saliently promotes charge separation at the interface. Furthermore, post-stability test for 8 cycles with XRD and FTIR analysis to verify the material integrity is presented. The scavenger experiments revealed the involved active species. This research does seem to pique interest in the creation of cutting-edge photocatalysts that utilize the solar spectrum to remove harmful organic dyes from water.

Unveiling Carrier Relaxation Mechanism in Protonated/Deprotonated Carbon Dots and Their Solvent Effects via Ultrafast Spectroscopy.

The intricate nature of the surface structure of carbon dots (CDs) hinders a comprehensive understanding of their emission behavior. In this study, we employ two types of CDs created through acid-alkali treatments, one with surface protonation and the other with surface deprotonation, with the objective of investigating the impact of these surface modifications on carrier behavior using ultrafast spectroscopy techniques. TEM, XRD, FTIR and Raman spectra demonstrate the CDs' structure, featuring graphitic core and abundant surface functional groups. XPS confirms the successful surface modifications of CDs via protonation and deprotonation. Ultrafast transient absorption (TA) spectroscopy reveals that deprotonation modification may decelerate the relaxation process, thereby increasing the visible PL quantum yields (PLQY). Conversely, protonation may accelerate the relaxation process due to the induced low-energy absorption band, resulting in self-absorption and reduced PLQY. Furthermore, TA analysis of CDs in mixed solvents with different proportions of ethanol shows the beneficial effect of ethanol in decelerating the relaxation process, leading to an increased PLQY of 33.7 % for deprotonated CDs and 22.1 % for protonated CDs. This study illuminates the intricate relationship between surface deprotonation/protonation modifications and carrier behavior in CDs, offering a potential avenue for the design of high-brightness CDs for diverse applications.

Facile fabrication of Z-scheme ZnO/MoO3 heterojunction as an excellent visible-light responsive photocatalyst for the degradation of rhodamine B and alizarin yellow dyes

xZnO-(1-x) MoO3(x = 0.0,0.1,0.3,0.5,0.7) nanocomposite materials have been efficiently fabricated by the facile hydrothermal method to enhance the photocatalytic activities for the environmental applications. The fabricated samples were characterized via XRD, SEM, EDX, XPS, UV–Visible spectroscopy, PL and FTIR analysis. The 5% ZnO-M nanocomposite material exhibits reduced band gab energy and superior photocatalytic activity for rhodamine B (RhB) and alizarin yellow (AY) dyes degradation of 94% and 81% within 120 min under visible light irradiance. Our reported study reveals that the 5% ZnO-M photocatalyst is extremely stable and reusable for more than five reaction of cycles. The photocatalytic enactment of the 5% ZnO-M composite was mostly endorsed due to Z-scheme photocatalysts, higher visible light adsorption on the surface morphology, improved charge separation/transfer, and decreased recombination rate. This study may provide new ideas for developing effective, innovative Z-scheme heterojunction photocatalysts and encouraging their extensive application for the degradation of dyes from wastewater.

Structural and optical properties of Zn2.95Ga2−xSnO8:xCr3+: An excellent X-ray charging-based persistent phosphor

This study investigates structural and luminescence properties of Cr3+ doped Zn2.95Ga2SnO8 phosphor. XRD analysis determines the phase purity and lattice parameters, while SEM and TEM analysis were utilized to study the particle size and surface morphology of the sample. UV–visible absorption and PL excitation spectra provided information on the excitation bands and the band-gap of both the undoped and Cr3+ doped Zn2.95Ga2SnO8. The optical band-gap of the material decreases upon doping with Cr3+ ions. Analysis of the Racah parameter and Tanabe Sugano diagram highlights a robust crystal field within Cr3+: Zn2.95Ga2SnO8, causing 2Eg level to become the lowest excited state with sharp emission at 699 nm. Concentration quenching at higher Cr3+ concentrations (> 0.6 mol%) is primarily attributed to the quadrupole-quadrupole interactions. Two distinct traps with trap depths at 0.51 eV and 0.73 eV were identified by using thermoluminescence measurement. The material gives persistent luminescence with a decay time of more than 30 min when charged with blue light (420 nm) and an excellent decay time of more than 16 h when charged with X-rays. Notably, this is the first report on X-ray charging-based persistent luminescence in Zn2.95Ga2SnO8. The outstanding persistent luminescence makes this material highly promising for various applications.

Co-doped polyaniline composites for biological application: Morphological, functional, optical and antibacterial activities

In the present work, we have successfully synthesized co-doped polyaniline (PANI) composites with various organic acids DBSA, phthalic acid, oxalic acid and Calotropis proceralatex using a simple chemical oxidative polymerization method. The structural, optical, surface morphology and antibacterial analyses were carried out for the synthesized PANI (DBSA-Phthalic acid), PANI (DBSA-Oxalic acid) and PANI (DBSA-C.Procera latex) composites. The structural characterization using XRD and FT-IR measurements confirmed the formation of emeraldine salt form of PANI from the observed characteristic peaks of PANI in all the composites. The observed UV–visible absorption and PL emission peaks also assured the synthesis of PANI in emeraldine form. SEM micrographs of PANI (DBSA-phthalic acid) composites exhibited continuous rock-like agglomerated structure. The antibacterial activity tested against medically important bacteria Bacillus subtilisrevealed a maximum inhibition zone for the DBSA-phthalic acid doped PANI composites when compared with other composites. The average value of zone of inhibition for the PANI composites is found to be 21–24 nm. The minimum inhibitory concentration (MIC) is found to be 1 mg/L for all the PANI composites whereas the minimum bactericidal concentration (MBC) is found to be 60 mg/L for PANI (DBSA-Phthalic acid) and 80 mg/L for PANI (DBSA-Oxalic acid), PANI (DBSA-C.Procera latex) composites. A larger and clear zone of inhibition exhibited by the synthesized co-doped PANI composites confirms their potential as an effective antibacterial agent.

Tunable efficient visible and near-infrared multi-emission in Ho3+ doped Cs2NaBiCl6 double perovskite via Ag+ alloying

Herein, we successfully obtained Ho3+ and Ag+ -codoped Cs2NaBiCl6 halide double perovskites (DPs) via a hydrothermal method, which exhibit orange-red broadband self-trapped excitons (STE) emission and visible (Vis) and near-infrared (NIR) narrow band emission attributed to Ho3+f-f transition, under 360 nm excitation. Compared to the single Ho3+-doped sample, the Vis PL intensity of the codoped sample was increased by nearly 13.8 times, and an enhanced photoluminescence quantum yield (PLQY) of 87.45 % was achieved. The PL enhancement is attributed to the partial substituting of Na+ with Ag+, leading to an efficient STE emission, and the more energy transition from STE to Ho3+. Moreover, the synthesized phosphor exhibits good stability in thermal and atmospheric environments. White light-emitting diode (WLED) is fabricated by employing Cs2Na0·997Ag0·003Bi0.935Ho0.065Cl6 on near-ultraviolet (n-UV) LED chips, achieving a color rendering index (CRI) of 95.0 and correlated color temperature (CCT) of 3814 K. Anti-counterfeit patterns and the application for night vision monitoring were also discussed. This study inspires the designing of high-quality phosphors of rare earth-doped DPs and expands the multi-domain luminescence applications of halide DPs.

Rational hydrothermal-assisted green synthesis of blueish emitting carbon dots as an optical sensing platform for antibiotic detection in the milk sample

Carbon dots (CDs) derived from biological entities significantly play a major part in environmental and biomedical applications, comprising electrocatalytic oxidations, antibiotics detection, biosensing, and bioimaging. In the present work, facile green synthesis of blue-emitting CDs has been done using one-step hydrothermal treatment of pulp extract of Ziziphus mauritiana, acting as a natural source of carbon for optical determination of ciprofloxacin (CIP) antibiotics. The process is easy, safe for the environment, and doesn't require any specialized equipment or chemicals. The structural and optical characteristics of the synthesized CDs are done using XRD, FTIR, UV–visible spectroscopies, SEM-EDX, PL, and TEM. CDs were found to have a quasi-spherical shape with an average size of 2.54 nm. Nitrogen (1.2 wt.%), oxygen (41.8 wt.%), and carbon (40.7 wt.%) are the main component found in CDs, as observed by EDX. These CDs showed blue emission under UV light, excitation-dependent emission, and wide excitation-emission spectra. These prepared CDs were used to selectively detect CIP and exhibit a high quantum yield of 30% at the excitation wavelength of 340 nm. After the optimal parameters, the sensor gave the linear detection range from 10 to 100 µM along with a detection limit of 0.56 µM. Moreover, the practical applicability of the developed sensor was confirmed in real milk samples to test the consistency and accuracy of the sensor. In conclusion, the proposed method is a green, rapid, highly sensitive, and selective method for the detection of CIP in real milk samples, demonstrating the potential application of CDs in food detection.

Investigation of sunlight driven SPR assisted photocatalytic activity of Ag doped SnO2 nanoparticles

Photocatalysis triggered by visible light has emerged as a viable method for addressing environmental pollution and the energy crisis in our society. Numerous metal oxide semiconductors are transformed into visible light active photocatalysts by adopting some straightforward methods. One such efficient way of creating a visible light active photocatalyst is doping a pure semiconductor with plasmonic metal nanoparticles. Our work thoroughly investigates the photocatalytic properties of pure SnO2 nanoparticles (NP) and SnO2 doped with 1%, 3%, and 5% ‘Ag’ under sunlight. These samples are prepared using a straightforward sol–gel approach, followed by a hydrothermal procedure. To examine the different properties and morphology of the synthesized samples, several analytical tools, including UV–visible spectrometer, XRD, XPS, TEM, PL spectrometer and FTIR are used. Analysis of UV-visible absorbance spectra shows a noticeable narrowing of the band gap with increased ‘Ag’ doping. XRD analysis confirms the tetragonal structure of all samples. Methyl orange (MO) dye is used as an imitation of an organic pollutant to examine the photocatalytic activity under sunlight. When compared to pure SnO2 NP, every ‘Ag’ doped SnO2 NP sample exhibits a considerable improvement in the photodegradation of methyl orange. Analysis of PL spectra of SnO2 NPs doped with ‘Ag’ suggests that the major causes of this enhancement in photocatalysis are surface defects and the surface plasmon resonance (SPR) effect caused by ‘Ag’ doping. The scavenging test claims that the holes are the primary and the superoxide radicals are the secondary reactive species which are responsible for MO degradation under sunlight.

Green synthesis of CuO nanoparticles using citrus maxima peel aqueous extract

Discarded fruit peels caused pollution problem and reused of waste product reduces pollution and sustain environmental balance. In most cases, fruits peels are land filled or composted which lead to environmental problems like methane emission to the atmosphere due to anaerobic digestion and leachate formation, which percolates into the bottom of the earth during rainfall. This communication reports on the synthesis of copper oxide nanoparticles (CuO NPs) using citrus maxima peel. The prepared CuO NPs were characterized by XRD, SEM, EDS, UV–visible spectroscopy, FTIR and PL. The characterization results confirmed that the prepared CuO NPs have a monoclinic crystalline structure with a spherical shape and the average crystallite size of CuO NPs was about 20 nm. The optical band gap (Eg) of CuO NPs calculated from UV–Visible diffuse reflectance spectroscopy was 1.5eV. The photo response V-I characteristics of CuO NPs showed good photo response under illumination conditions, which might be due to the maximum number of exciting photoelectrons due to illumination.

Improved Visible Emission from ZnO Nanoparticles Synthesized via the Co-Precipitation Method.

Since ZnO nanoparticles (NPs) possess a variety of intrinsic defects, they can provide a wide spectrum of visible emission, without adding any impurity or any doping atoms. They are attracting more and more interest as a material for light sources and energy downshifting systems. However, defect emission with a high luminescence quantum efficiency (PL QY) is difficult to obtain. Here, we present the co-precipitation synthesis parameters permitting to attain ZnO NPs with highly visible PL QYs. We found that the nature of zinc precursors and alkaline hydroxide (KOH or LiOH) used in this method affects the emission spectra and the PL QY of the as-grown ZnO NPs. LiOH is found to have an advantageous effect on the visible emission efficiency when added during the synthesis of the ZnO NPs. More precisely, LiOH permits to increase the emission efficiency in the visible up to 13%. We discuss the effects of the nanoparticle size, the morphology and the surface stabilization on the enhancement of the luminescent emission efficiency. Various spectral contributions to the luminescent emission were also examined, in order to achieve a control of the defect emission to increase its efficiency.

Strong enhancement of the optical properties of SiNWs by the deposition of snowball-like V2O5 nanoparticles

In this work, the morphological and optical properties of vanadium pentoxide (V2O5) nanoparticles deposited on silicon nanowires (SiNWs) have been investigated. SiNWs are obtained by metal-assisted chemical etching (MACE) method. The deposition of vanadium pentoxide on SiNWs layer was performed by vacuum thermal evaporation system for different durations. Scanning electronic microscope (SEM) images show the formation of snowball-like V2O5 nanoparticles on the SiNWs surface. A large condensation of V2O5 elements was observed by increasing the evaporation time. The changes in bonds and chemical composition at the surface of the SiNWs-V2O5 nanocomposites were examined by Raman and Fourier transform infrared (FTIR) spectroscopies. The X-ray Diffraction (XRD) technique revealed the presence of orthorhombic structure of V2O5 layer with good crystallinity. The SiNWs-V2O5 composites show strong visible PL due to the contribution of the radiative band edge transitions of vanadium pentoxide. The emission of V2O5 layer is in the same energy range as that of SiNWs thus leading to a large increase in PL intensity. Optical band gap (Eog) was determined from UV–Vis-IR spectroscopy. The presence of vanadium pentoxide on the SiNWs surface causes an increase in the value of Eog from 1.851 to 2.075 eV. This increase was explained by Burstein-Moss effect.

Effect of Eu3+ doping on structural, optical and magnetic characteristics of doped CdS nanoparticles

Hydrothermal method has been used to synthesize Cd1-xEuxS (x = 0, 0.01, 0.02 and 0.03) nanoparticles. With Eu-doping the changes in optical, magnetic and structural properties has been confirmed by UV–visible spectroscopy, PL, VSM and XRD. The X-ray diffraction confirmed wurtzite phase and peak shifting towards higher diffraction angle with Eu-doping can be ascribed to the smaller Eu3+ ion as compared to that of Cd2+ ion. The band gap enhances varying from 2.44 eV to 2.52 eV. The magnetic study proved the presence of ferromagnetism in both the samples i.e. undoped and doped synthesized nanoparticles with increment in magnetization. This study proposes that both the optical band gap and magnetic behavior shall be improved by suitable Eu-doping.

Unlocking the synergistic potential of peanut shell derived activated carbon-doped TiO2 for highly efficient photocatalytic removal of organic dye under visible light irradiation

The goal of this study was to examine the photocatalytic performance of peanut shell-derived activated carbon (AC) doped TiO2 materials (AC@TiO2) for the treatment of wastewater through degradation of Rhodamine B (RhB) dye. The synthesized materials underwent thorough characterization using XRD, SEM, EDX, UV–Visible spectroscopy, PL spectroscopy, and FTIR spectroscopy to assess their crystallinity, surface morphology, bandgap energy, and functional groups. 2% AC@TiO2 exhibited exceptional photocatalytic performance with a maximum degradation efficiency of 89.9% and a high-rate constant (k) value of 0.0401 min−1, attributed to increased surface area and reduced bandgap. The reaction rate increased with temperature up to 35 °C, but then declined. 2% AC@TiO2 exhibited high degradation efficiency and reusability for six cycles. The optimal pH for maximum efficiency was 7.4. Higher initial dye concentration and the presence of scavengers (BA, OA, Cl) reduced degradation efficiency. These photocatalysts proved highly effective for dye degradation in wastewater treatment.

Visible-light boosted photocatalytic performance of sulfonated polypyrrole-coated ZIF-8 hybrids for pollutants degradation

Enhancing the charge transfer through the cooperative effect of various materials is a promising solution to overcome the limitations of low photocatalytic efficiency with single photocatalysts. Conductive polymers have gained attention as metal free photocatalysts in recent years due to their excellent electronic and optical properties. In this work, the construction and description of sulfonated polypyrrole (SPPy) coated Zn-zeolitic imidazole framework (ZIF-8) has been reported. The synthesized SPPy/ZIF-8 heterostructures have been characterized by XRD, FESEM, BET surface area, EDX, UV–visible DRS, ELS, and PL analyses. The photocatalytic performance of the synthesized composites has been tested for degradation two types of organic pollutants, Congo red (CR) dye and antibiotic Amoxicillin (AMX) under visible-light (LED) irradiation. Significantly enhanced photocatalytic efficiency of ZIF-8 for pollutants degradation was obtained after SPPy conjunction. 2 wt%SPPy/ZIF-8 heterojunction was the optimum photocatalyst, showing highest degradation efficiency (98.5% in 90 min and 92.7% in 150 min for CR and AMX, respectively). The potential photocatalytic mechanism was proposed and supported by trapping experiments. The •O2− radicals were the main reactive specie involved in the process. This study provides the basis for the application of organic/inorganic (SPPy/ZIF-8) heterostructure as photocatalysts for decomposition organic and emerging contaminants in wastewater treatment.

Green synthesis of TiO2 nanospheres from isolated Aspergillus eucalypticola SLF1 and its multifunctionality in nanobioremediation of C. I. Reactive Blue 194 with antimicrobial and antioxidant activity

For synthesis of titanium dioxide (TiO2) nanoparticles (NPs), Green methods have been proven to be more efficient than several physiochemical methods. This article presents a non-toxic, ecofriendly, cost-effective and a facile route of green synthesis of TiO2 NPs by an isolated fungus Aspergillus eucalypticola SLF1, which exhibits excellent photocatalytic, antimicrobial and antioxidant activity without structural modification done by physicochemical methods. The TiO2 NPs are characterized by UV–Visible spectroscopy, XRD, FTIR, FE-SEM, DLS, TEM, BET, Raman spectroscopy and PL. The mesoporous, anatase phase, with a band gap 3.49 eV observed by BET, XRD. UV–Visible spectral analysis displayed sunlight driven photocatalytic performance against C. I. Reactive Blue 194 by advanced oxidation process. Decolourization and 99.70% degradation within 30 min exhibited pseudo first order kinetic with reaction rate constant 0.1935 min−1 by linear method. These findings are superior physicochemical methods. Ecofriendly degradation was confirmed by UV–Vis. HPLC and LCMS etc and phytotoxic studies.