This work aims to synthesize and characterize a material that can be used as an effective catalyst for photocatalytic application to remove both organic and inorganic compounds from wastewater. In ...this context, sillenite Bi12ZnO20 (BZO) in a pure phase was synthesized using the sol–gel method. Before calcination, differential scanning calorimetry (DSC) analysis was done to determine the temperature of the formation of the sillenite phase, which was found to be 800 °C. After calcination, the phase was identified by X-ray diffraction (XRD) and then refined using the Rietveld refinement technique. The results prove that BZO crystals have a cubic symmetry with the space group I23 (N°197); the lattice parameters of the structure were also determined. From the crystalline size, the surface area was estimated using the Brunauer-Emmett-Teller (BET) method, which was found to be 11.22 m2/g. The formation of sillenite was also checked using the Raman technique. The morphology of the crystals was visualized using electron scanning microscope (SEM) analysis. After that, the optical properties of BZO were investigated by diffuse reflectance spectroscopy (DRS) and photoluminescence (PL); an optical gap of 2.9 eV was found. In the final step, the photocatalytic activity of the BZO crystals was evaluated for the removal of inorganic and organic pollutants, namely hexavalent chromium Cr(VI) and Cefixime (CFX). An efficient removal rate was achieved for both contaminants within only 3 h, with a 94.34% degradation rate for CFX and a 77.19% reduction rate for Cr(VI). Additionally, a kinetic study was carried out using a first-order model, and the results showed that the kinetic properties are compatible with this model. According to these findings, we can conclude that the sillenite BZO can be used as an efficient photocatalyst for wastewater treatment by eliminating both organic and inorganic compounds.
This research aims to treat wastewater that has been contaminated with one of the most prevalent toxic heavy metals, Cu
2+
. The thermal pyrolysis process was used to manufacture MgO nanoparticles. ...Spectroscopy, X-ray diffraction (XRD). The production of MgO nanoparticles was validated using X-ray photoelectron spectroscopy (XPS) and energy-dispersive X-ray spectroscopy (EDX). Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) tests revealed spherical particles at the nanoscale (50 nm), with a BET surface area of 67 m
2
. g
−1
. The Cu
2+
adsorption process was fast and well represented by the pseudo-second-order kinetic and Langmuir models. With a regression coefficient of 0.9960, the Langmuir pattern achieved the highest adsorption capability of Cu
2+
: 546.45 mg/g. The MgO nanoparticles generated for Cu
2+
uptake are promising and could be used to eradicate other poisonous heavy metals in the aquatic media.
This research aims to investigate the effect of copper doping on the photocatalysis performance of TiO
2
nanoparticles for disposal wastewater from organic pollutants. X-ray diffraction analysis ...manifests the crystallization of a rutile phase for pure and copper-doped TiO
2
except for 2% resulting in a rutile-to-anatase phase transformation. The crystallite size is found less affected by Cu doping, i.e., ~30 nm. BET analysis indicates a decrease in the specific surface area as the doping loading increases. Scanning electron microscopy observations reveal spherical particles at the nanometer range for pure TiO
2
and then larger agglomerates of ultrafine particles with Cu doping. FTIR analysis notifies the existence of hydroxyl groups, which will promote the photocatalysis process. The photodegradation of azucryl red (AR) has been investigated under different conditions; i.e., Cu-loading, initial concentration of AR, and pH. The kinetics of the photodegradation process is further found to comply with the Lagergren kinetic law, regardless the experimental conditions. Nevertheless, the photodegradation process is not only controlled by the intra-particle diffusion mechanism, but also by mass transfer through a liquid film boundary. The maximum degradation of AR, i.e., 86%, has been achieved at pH = 5.0 during 60 min of contact time for the 2% Cu doping, with effective regeneration. The Freundlich model exhibits a better fitting for AR dye photodegradation equilibrium data, compared to Langmuir, Temkin, and Dubinin-Radushkevich.
The aim of this work consists on the synthesis of a nanomaterial for heavy metal ion removal from aqueous solutions. Al-doped ZnO (ZnO:Al
x
%) nanopowders with 0 to 5% Al content are prepared via an ...amended sol-gel method. The morphology and microstructure of the prepared ZnO:Al
x
% are probed by means of scanning electron microscopy (SEM), X-ray particles diffraction (XRD) analysis, energy dispersive X-ray spectroscopy (EDS) and elemental mapping. The findings reveal the prevalence of the hexagonal wurtzite ZnO structure with increasing crystallite size (45 to 60 nm) as a result of Al doping. SEM images show nearly spherical nanoparticles with considerable aggregation. EDS and elemental mapping analysis confirm the incorporation of Al within ZnO host lattice. The relatively large surface area as estimated from N
2
adsorption makes the nanopowders very favorable for the uptake Cd(II), Cr (IV), Co (II) and Ni(II) from aqueous solution. The ZnO:Al
x
% with 1 wt% Al exhibits the highest uptake rate of heavy metal ions. The adsorption process has been found to be spontaneous and endothermic and obey Langmuir adsorption model. The high tendency of the prepared nanoparticles to eliminate heavy metal ions renders them suitable candidates for environmental remediation. Desorption studies with 0.1 M NaOH indicate that ZnO:Al
x
% can be regenerated effectively.
Organic dyes, especially Congo red, are utilized primarily in the textile industry and consequently discharged into water resources that pollute aquatic environments. This study aims to investigate ...the fabrication of Cr-doped ZnO nanoparticles by sol–gel method to eliminate Congo red dye from wastewater. The obtained Cr-doped ZnO was characterized by scanning electron microscopy, X-ray diffraction, thermogravimetric analysis, and Fourier transform infrared spectroscopy. The Cr-doped ZnO crystallizes within a hexagonal wurtzite structure with a BET surface area equal to 9.5 m
2
. g
−1
. It is found that the variation of dye concentration and pH influence the removal of Congo red by Cr-doped ZnO. Excellent efficiency of 155.52 mg.g
−1
is achieved under optimum operating conditions, i.e., the adsorbent dosage of Cr-doped ZnO (0.400 g/L), contact time of 110 min, and solution pH (7.00). Pseudo-second-order adsorption kinetics and Langmuir isotherm models best fitted Congo red adsorption onto Cr-doped ZnO. The Congo red adsorption mechanism is associated with the chemisorption and hydrogen bond, as indicated by the pH, isotherms, and Fourier transforms infrared spectroscopy studies. The examination of Cr-doped ZnO with other dyes (malachite green, crystal violet, basic fuchsin, methylene blue, and eriochrome black T) suggests the high adsorption capacity of Cr-doped ZnO towards malachite green, crystal violet, and basic fuchsin dyes compared with methylene blue and Eriochrome black T dyes. The findings demonstrate that Cr-doped ZnO nanostructures manifest excellent adsorption capability to remove organic dyes from aqueous solutions.
Graphical abstract
In this study, a V@TiO
nanocomposite is examined for its ability to eliminate carcinogenic Rhodamine (Rh-B) dye from an aqueous medium. A simple ultrasonic method was used to produce the nanosorbent. ...In addition, V@TiO
was characterized using various techniques, including XRD, HRTEM, XPS, and FTIR. Batch mode studies were used to study the removal of Rh-B dye. In the presence of pH 9, the V@TiO
nanocomposite was able to remove Rh-B dye to its maximum extent. A correlation regression of 0.95 indicated that the Langmuir model was a better fit for dye adsorption. Moreover, the maximum adsorption capacity of the V@TiO
nanocomposite was determined to be 158.8 mg/g. According to the thermodynamic parameters, dye adsorption followed a pseudo-first-order model. Based on the results of the study, a V@TiO
nanocomposite can be reused for dye removal using ethanol.
Ca-doped magnesium oxide nanosorbent has been prepared by sol-gel in the presence of gum arabic extract and assessed for the removal of cobalt ions (Co (II)) from aqueous media. X-ray diffraction ...analysis indicates the formation of MgO and CaO composites with a mean crystallite size of 6 nm having a large surface area of 50 m2/g. Scanning and transmission electron microscopy observations reveal spherical-shaped particles at the nanoscale around 20 nm. Besides, X-ray photoelectron spectroscopy and Fourier transform infrared analyses manifest the existence of functional groups, which will facilitate the adsorption of metal ions. The adsorption capability of the CaO-MgO nanosorbent achieved 469.5 mg/g for Co (II) ions under optimum operating conditions. Furthermore, the experimental data elucidate that the adsorption process is primarily diffusion-based and that both intraparticle and boundary layer diffusion appear to play a key role in the rate-controlling step. The findings of this study highlight the remediation of contaminated water by cobalt ions by CaO-MgO nanostructure and can be extended to other metal ions and organic pollutants.
In this work, ZnO, CrZnO, RuZnO, and BaZnO nanomaterials were synthesized and characterized in order to study their antibacterial activity. The agar well diffusion, minimum inhibitory concentration ...(MIC), and minimum bactericidal concentration (MBC) assays were used to determine the antibacterial activity of the fabricated nanomaterials against
ATCC 29213,
ATCC35218,
ATCC 7000603, and
ATCC 278533. The well-diffusion test revealed significant antibacterial activity against all investigated bacteria when compared to vancomycin at a concentration of 1 mg/mL. The most susceptible bacteria to BaZnO, RuZnO, and CrZnO were
(15.5 ± 0.5 mm),
(19.2 ± 0.5 mm), and
(19.7 ± 0.5), respectively. The MIC values indicated that they were in the range of 0.02 to 0.2 mg/mL. The MBC values showed that the tested bacteria's growth could be inhibited at concentrations ranging from 0.2 to 2.0 mg/mL. According to the MBC/MIC ratio, BaZnO, RuZnO, and CrZnO exhibit bacteriostatic effects and may target bacterial protein synthesis based on the results of the tolerance test. This study shows the efficacy of the above-mentioned nanoparticles on bacterial growth. Further biotechnological and toxicological studies on the nanoparticles fabricated here are recommended to benefit from these findings.
This study investigated the photocatalytic degradation of RB dye by V2O5@g-C3N4 nano-catalysts. The sonication method was utilized to create V2O5@g-C3N4 nano-catalysts. V2O5@g-C3N4 nano-catalysts ...were characterized using X-ray diffraction (XRD), energy dispersive spectroscopy (EDS), high-resolution electron microscopy (TEM), BET-surface area analyzer, X-ray photoelectron spectroscopy (XPS), and ultraviolet spectroscopy. In the meantime, the photocatalytic activity, pH, and photocatalyst dosage are investigated in depth to account for RB dye decolorization. The rate constant for RB dye photodegradation was 0.0517 (min−1) and the decolorization rate was 93.4%. The degrading efficiency of RB dye by V2O5@g-C3N4 nanocatalysts is consistent with pseudo-first-order kinetics. The results of this study demonstrated that V2O5@g-C3N4 nanocatalysts are particularly effective at destroying dyes in water.
This research examined the production of a V2O5-g-C3N4 nanocomposite to remove organic dyes from wastewater. To generate the V2O5-g-C3N4 nanocomposite, the sonication method was applied. The testing ...of V2O5-g-C3N4 with various dyes (basic fuchsin (BF), malachite green (MG), crystal violet (CV), Congo red (CR), and methyl orange (MO)) revealed that the nanocomposite has a high adsorption ability towards BF, MG, CV, and CR dyes in comparison with MO dye. It was established that the modification of pH influenced the removal of CV by the V2O5-g-C3N4 nanocomposite and that under optimal operating conditions, efficiency of 664.65 mg g−1 could be attained. The best models for CV adsorption onto the V2O5-g-C3N4 nanocomposite were found to be those based on pseudo-second-order adsorption kinetics and the Langmuir isotherm. According to the FTIR analysis results, the CV adsorption mechanism was connected to π–π interactions and the hydrogen bond.
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