Mechanism and kinetic of piezo-catalytic desulfurization of model and actual fuel samples over CexOy/SrO nanocomposite at room temperature.

SOx emissions are primarily caused by compounds containing sulfur in petroleum and fuels, which lead to severe air pollution. For this reason, it is necessary to develop a fast and simple desulfurization method in order to comply with ever-increasing environmental regulations. The newly discovered piezo-catalyst nanocomposite CexOy/SrO can convert mechanical energy directly into chemical energy, thereby enabling mechanically oxidative sulfur desulfurization. 320 W of bath sonication were used to polarize and activate the prepared piezo-catalyst nanocomposite CexOy/SrO for sulfur removal from thiophene and dibenzothiophene as model fuels and kerosene as a real fuel. Using uniform and spherical CeO2/SrO nanocomposites resulted in the highest desulfurization rates of 95.4 %, 97.3 %, and 59.7 %, respectively, for thiophene and dibenzothiophene. This study examined the effect of several parameters, such as sulfur concentration, pH of fuel, dosage of CexOy/SrO nanocomposite, power and time of ultrasonic, and shaking time, on the piezo-desulfurization of thiophene (TP) and dibenzothiophene (DBTP). To identify the major active species in piezo desulfurization, radical trapping experiments were conducted. This study investigated the possibility of reusing the catalyst, and the piezo-desulfurization activity that was demonstrated in the removal of TP and DBTP after 11 cycles as well as the ability of the catalyst to remove real fuel even after 14 cycles was promising. As the kinetic results show, the reaction follows the second order with K = 0.0050. Also, thermodynamic results showed the oxidation of sulfide to sulfoxide and sulfoxide is endothermic. Activation energy for second order rate constant is (3.824 Kj/mole). 0.0236 mol-1. Sec-1 was calculated for Arrhenius Constant.

Retraction: Synthesis and characterization of AFe2O4 (A: Ni, Co, Mg)-silica nanocomposites and their application for the removal of dibenzothiophene (DBT) by an adsorption process: kinetics, isotherms and experimental design.

[This retracts the article DOI: 10.1039/D1RA02780H.].

Studying the mechanism and kinetics of fuel desulfurization using CexOy/NiOx piezo-catalysts as a new low-temperature method.

In order to advance desulfurization technology, a new method for excellent oxidative desulfurization of fuel at room temperature will be of paramount importance. As a novel desulfurization method, we developed piezo-catalysts that do not require adding any oxidants and can be performed at room temperature. A microwave method was used to prepare CeO2/Ce2O3/NiOx nanocomposites. Model and real fuel desulfurization rates were examined as a function of synthesis parameters, such as microwave power and time, and operation conditions, such as pH and ultrasonic power. The results showed that CeO2/Ce2O3/NiOx nanocomposites demonstrated outstanding piezo-desulfurization at room temperature for both model and real fuels. Furthermore, CeO2/Ce2O3/NiOx nanocomposites exhibited remarkable reusability, maintaining 79% of their piezo-catalytic activity even after 17 repetitions for desulfurization of real fuel. An investigation of the mechanism of sulfur oxidation revealed that superoxide radicals and holes played a major role. Additionally, the kinetic study revealed that sulfur removal by piezo-catalyst follows a second-order reaction kinetic model.

Boost piezocatalytic activity of BaSO4 by coupling it with BaTiO3, Cu:BaTiO3, Fe:BaTiO3, S:BaTiO3 and modify them by sucrose for water purification.

The purpose of this study is to improve the efficiency of decontamination using BaSO4 as a piezocatalyst. Three techniques are employed in this study to enhance the piezocatalytic activity of BaSO4. The first method involves coupling BaSO4 with BaTiO3. The acid red 151 and acid blue 113 decontamination rates improved from 56.7% and 60.9% to 61.3% and 64.4%, respectively, as a result of this strategy. Additionally, the composite of BaSO4 and BaTiO3 was doped with copper, iron, sulfur, and nitrogen. By doping BaTiO3, acid red 151 and acid blue 113 achieved 86.7% and 89.2% efficiency, respectively. Finally, the nanostructures were modified with sucrose. These strategies improved degradation efficiency for acid red 151 and acid blue 113 to 92.9% and 93.3%, respectively. The reusability results showed that the piezo-catalytic activity of the m-S-BaSO4-BaTiO3 catalyst did not show a significant loss after five recycles for the degradation of AB113.

Kinetic and thermodynamic study in piezo degradation of methylene blue by SbSI/Sb2S3 nanocomposites stimulated by zirconium oxide balls.

Mechanical energy harvesting by piezoelectric materials to drive catalysis reactions received extensive attention for environmental remediation. In this work, SbSI/Sb2S3 nanocomposites were synthesized as a catalyst. ZrO2 balls were used as an alternative mechanical force to ultrasonic for stimulating the piezocatalyst for the first time. The kinetics and thermodynamics of the piezo degradation of methylene blue (MB) were studied deeply. Besides the effect of the type of mechanical force, the number of ZrO2 balls, and temperature of the reaction on the degradation efficiency were studied. Here mechanical energy came from the collision of the ZrO2 balls with the catalyst particles. Using ZrO2 balls instead of ultrasonic vibration led to enhance degradation efficiency by 47% at 30 ± 5 °C. A kinetic study revealed that piezo degradation of methylene blue (MB) by SbSI/Sb2S3 catalyst followed pseudo-second-order kinetics. Based on thermodynamic results piezo degradation of MB was an exothermic reaction.

Correction: Synthesis and characterization of AFe2O4 (A: Ni, Co, Mg)-silica nanocomposites and their application for the removal of dibenzothiophene (DBT) by an adsorption process: kinetics, isotherms and experimental design.

[This corrects the article DOI: 10.1039/D1RA02780H.].

Facile sonochemical method for preparation of Cs2HgI4 nanostructures as a promising visible-light photocatalyst.

Attempts are continuing to discover novel and efficient solutions to promote water grade and industrial sewage treatment. For the first time, we present a novel Cs2HgI4 photocatalyst functional below visible radiation. Cs2HgI4 nano photocatalyst has been prepared via an accelerated sonochemical approach to examine its photocatalytic progression. Several construction circumstances, including variations of power and time of sonication and performance of different surfactant types, were conducted to produce fine particles with uniform morphology. FESEM images attested that the presence of surfactant had an adverse and destructive effect on the morphology of products. The bandgap for Cs2HgI4 nanostructures was determined to be approximately 2.3 eV, making these nanostructures desirable for photocatalytic applications. The photocatalytic data confirmed that Cs2HgI4 could destroy acidic coloring agents greater than basic ones. The highest photodegradation was observed for methyl orange with 76.8%.

La2Sn2O7/g-C3N4 nanocomposites: Rapid and green sonochemical fabrication and photo-degradation performance for removal of dye contaminations.

The deficiency of drinking water sources has become a serious crisis for the future of the world that the photocatalytic process is one of the most favorable methods for removal of artificial dyes and poisonous organic impurities. In the present study, rapid ultrasonic treatment was performed to obtain La2Sn2O7/Graphitic carbon nitrides (LSO/CN) nanocomposites with advanced photo-catalytic performance. Broccoli extract was utilized as a natural surfactant with active surface groups to control nucleation and growth of formed crystals with the creation of spatial barriers around the cations, and finally prevent nano-product agglomeration. Changing experimental parameters in synthesis reaction in turn offers a virtuous control over the nano-products size and shape. The shape and size distribution of particles was considered via diverse characterization techniques of microscopic and spectroscopic. The photocatalytic behaviors along with a kinetic study of the nanoparticles were examined by elimination and degradation of different artificial dyes under the UV waves. Effect of particle size, weight ratio of LSO:CN, type of dye, scavenger kind, dye and catalyst loading was designated on altering proficiency of nano-catalyst function. Also, the probable mechanism of removal dye by photocatalytic function was studied.

Porous hollow Ag/Ag2S/Ag3PO4 nanocomposites as highly efficient heterojunction photocatalysts for the removal of antibiotics under simulated sunlight irradiation.

Antibiotic pollutants are a serious and growing threat to human health and the environment that efficient measures must be taken to eliminate them. Here, we report the facile fabrication of porous hollow Ag/Ag2S/Ag3PO4 heterostrucutres for efficient photocatalytic degradation of tetracycline under simulated sunlight irradiation. The morphology manipulation and hetero-nanocomposites construction through a coprecipitation-refluxing approach were applied to enhance the photocatalytic performance of the Ag/Ag2S/Ag3PO4 products. The photodegradation outcomes indicated that the heterojunction Ag/Ag2S/Ag3PO4 photocatalyst with a suitable band gap energy of 2.17 eV, has better degradation performance (∼95%) than individual Ag2S and Ag3PO4 structures after 120 min of simulated sunlight irradiation, even after five recycles. The good photocatalytic activity of Ag/Ag2S/Ag3PO4 nanocomposites could be mainly attributed to the unique hierarchical architectures, promoted visible-light harvesting, reduced a recombination and boosted separation of electron-hole pairs originated from the as-formed heterojunctions. Moreover, we proposed a photocatalytic degradation mechanism based on the radical scavenging results, which disclosed that the •O2- and •OH species perform essential tasks for the photodegradation of antibiotics by Ag/Ag2S/Ag3PO4 nanocomposites.

Efficient purification of wastewater by applying mechanical force and BaCO3/TiO2 and BaTiO3/TiO2 piezocatalysts.

In typical advanced oxidation catalysis, a semiconductor should have a robust capacity to generate separated electron-hole pairs on a material's surface under irradiation of photons with energy more than the material's bandgap. However, rapid charge carrier recombination and low photon to current yield of semiconductor photocatalysts and low percentages of UV light in sunlight leads to a low level of photocatalytic efficiency for practical application. Mechanical energy is a natural energy that can be considered as a form of rich, clean and renewable energy which can be harvested by using piezoelectric materials. Here, we developed BaCO3/TiO2 and BaTiO3/TiO2 composites as mechanical harvesting materials to decontaminate pollutants. Results showed that BaCO3 has a great effect on the piezocatalytic activity of products. The control sample (sample without Ba) only degraded 11.2% of Acid Red 151 (AR151) , while the sample containing Ba degraded 96.7% of AR151. Besides, the effects of several parameters, including the natural surfactant, reaction time and temperature, calcination, and ultrasonic power and pulse on the catalytic activity of the as-prepared piezocatalysts were studied. Results showed that it is possible to degrade 99.1% of AR151 by controlling ultrasonic parameters during 2 h of mechanical energy force.

Facile preparation and characterization of a novel visible-light-responsive Rb2HgI4 nanostructure photocatalyst.

Visible photocatalytic procedures exhibit encouraging potential in water purification by increasing the photocatalytic performance. Therefore, the improvement of low-cost and efficient photocatalysts for environmental remediation is an increasing demand, and photocatalysts based on semiconductors have gained considerable attention due to their superior stability and activity. In the current study, novel Rb2HgI4 nanostructures were prepared via a simple, low-cost, and low-temperature solid-state method. The effects of different parameters such as type of surfactants, reaction temperature, and reaction time were studied on the structure, crystallinity, particle size, and shape of nanostructures. This new compound has a suitable band gap (2.6 eV) in the visible region. The photocatalytic performance of Rb2HgI4 was examined for the removal of coloring agents under visible light irradiation and it was found that this compound could degrade and eliminate acid black 1 by about 72.1%.

Synthesis and characterization of cotton-silver-graphene quantum dots (cotton/Ag/GQDs) nanocomposite as a new antibacterial nanopad.

Appearance of antibiotic resistance in bacteria is a convoluted topic, particularly in treating pestiferous immunodeficiency correlated diseases. The main objective of the current research is to fabricate antibacterial pads by utilizing of graphene quantum dots (GQDs) as a linker, stabilizing, and reduction agent of in situ synthesized Ag nanoparticles (Ag NPs) on cotton pad. Five different antibacterial pads including cotton/Ag pad, cotton/GQDs/Ag pad, cotton/Ag/GQDs pad, cotton/GQDs/Ag/GQDs pad, and cotton/Ag/GQDs/Ag were fabricated and their antibacterial activities were compared to those of as-synthesized Ag/GQDs nanocomposites. The results indicate that cotton/GQDs/Ag pad shows a very promising minimum inhibitory concentration(MIC) of 0.09 and 0.01 against S. aureus and E. coli, respectively. Using GQDs as a linker (cotton/GQDs/Ag) and as a stabilizing agent (cotton/Ag/GQDs) significantly improves the antibacterial activity of Ag NPs.

Sol-gel auto combustion synthesis, characterization, and application of Tb2FeMnO6 nanostructures as an effective photocatalyst for the discoloration of organic dye contaminants in wastewater.

In this study, the auto-combustion sol-gel method was used to prepare novel Tb2FeMnO6 (TFMO) double perovskite nanoparticles. Chemical and natural fuels were used to achieve these particles with appropriate size. The resulting particles were examined via X-ray powder diffraction (XRD) and scanning electron microscopy (SEM) techniques. Rietveld analysis was also performed to confirm the crystallinity and lattice parameters of the formed particles. The particles obtained in the presence of maleic acid were selected as the optimal sample (S4), and the particles obtained in the presence of pomegranate paste were chosen as the non-optimal sample (S8) in terms of size and morphology. Both particles were used to investigate the photocatalytic activity. Fourier transform infrared spectroscopy (FTIR), UV-Vis diffuse reflectance spectroscopy (DRS), and vibrating sample magnetometer (VSM) analyses and N2 adsorption/desorption isotherms were performed for both samples and the results were compared. Erythrosine and malachite green dyes in aqueous solutions were used as contaminants in the photocatalysis process. The results showed 22% and 20% discoloration for S4 and 41% and 30% discoloration for S8 in the presence of erythrosine and malachite green under visible light irradiation. The photocatalytic activity was investigated under UV light for S4, which showed 80% and 50% discoloration for erythrosine and malachite green, respectively. Investigating the photocatalytic activity of TFMO double perovskite nanoparticles showed that these nanoparticles could be a desirable option for mitigating water pollution.

Synthesis and characterization of AFe2O4 (A: Ni, Co, Mg)-silica nanocomposites and their application for the removal of dibenzothiophene (DBT) by an adsorption process: kinetics, isotherms and experimental design.

The kinetics, equilibrium, and statistical aspects of the sulfur removal process from hydrocarbon fuels by AFe2O4-silica nanocomposites (A: Ni, Mg, and Co) have been investigated in the present study. Nanocomposites were prepared via the auto-combustion sol-gel method and then employed in the adsorptive desulfurization (ADS) process. Next, the prepared samples were characterized by different analytical methods including XRD, SEM, TEM, FT-IR, TGA, and BET. The contributions of conventional parameters including adsorbent dosage and contact time were then studied by central composite design (CCD) under response surface methodology (RSM). Based on the statistical investigations, optimum conditions for ADS were an adsorbent dosage of 7.82 g per 50 ml of the model fuel and a contact time of 32 min. The adsorption amounts reached 38.6 mg g-1 for DBT. The quadratic model was applied for the analysis of variance. Based on the experimental data, the pseudo-first-order (PFO) model could explain the adsorption kinetics of the compounds. Furthermore, the Langmuir isotherm demonstrated considerable agreement with the experimental equilibrium data. According to the results, the NiFe2O4-SiO2 nanocomposite showed the best performance compared to other compounds. The sulfur removal efficiency increased from 63 to 94% upon increasing the NiFe2O4-SiO2 dosage from 3 to 9 g per 50 ml of the model fuel.

Green sonochemistry assisted synthesis of hollow magnetic and photoluminescent MgFe2O4-carbon dot nanocomposite as a sensor for toxic Ni(ii), Cd(ii) and Hg(ii) ions and bacteria.

The purpose of this study was synthesis of photoluminescent nanoparticles for detection of toxic metal ions. Also, these controllable magnetic nanocomposites were used for detection of Pseudomonas aeruginosa bacteria. Carbon nano-templates were formed by calcination and sonication of lemon extract as a bio-compatible precursor. Then MgFe2O4 nanoparticles were incorporated on the carbon nano-templates. The composite was calcinated to decompose carbon and obtain hollow structures. Finally, photoluminescent carbon dots were deposited on the porous magnesium ferrite core. Because of the hollow structure, carbon dots can diffuse to the Mg-ferrite core so magnetic and photoluminescence properties are available simultaneously. Photoluminescence intensity decreases with increasing Ni(ii), Cd(ii), Hg(ii) metal ions and Pseudomonas aeruginosa. Results show an effective nanostructure for identification of toxic metal ions and also bacteria.

Effects of the NiFe2O4 nanoadditive on the performance and emission characteristics of diesel engines: ultrasonic green synthesis by T3 hormone.

NiFe2O4 nanosheets were successfully synthesized via combined ultrasonic and combustion methods using triiodothyronine (T3) hormone as a biotemplate. Isodiesel and heavy diesel were selected as feedstocks to evaluate the ultrasound-assisted catalytic oxidation process. In this study, we focused on high performance of diesel engine with NiFe2O4 nanosheets. Various conditions such as catalyst dosage, hydrogen peroxide dosage, frequency range and catalyst morphologies of NiFe2O4 were investigated to achieve optimized conditions. High levels of sulfur compounds (98%) were removed using NiFe2O4 catalysts under determined conditions (1.0 g L-1 catalyst, O/S mole ratio = 2, frequency = 40 kHz and morphology of the nanocatalyst = nanosheets). The nickel ferrite nano additive was mixed with isodiesel and heavy diesel using an ultrasonicator device to achieve better stability. The results indicated that under the optimum amount (1% w/v), the NiFe2O4 nanostructure is the best additive to reduce NO x , CO, HC and smoke emission in diesel engines. Moreover, a change in the flash point and viscosity of diesel fuels was observed with the addition of nanosheets. NiFe2O4 could be recycled 3 times without a significant decrease in catalyst activity.

Toxicity of Nd2WO6 nanoparticles to the microalga Dunaliella salina: synthesis of nanoparticles and investigation of their impact on microalgae.

The presence of nanoparticles in the environment and their impact on existing organisms is one of the main concerns of researchers working in this field. In this research, Nd2WO6 nanoparticles were prepared by an ultrasonic procedure for the first time. X-ray powder diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR), and energy-dispersive X-ray spectroscopy (EDS) analyses were applied to identify and prove the purity of these particles. In addition to increasing the reaction rate and efficiency with the help of a radical generation mechanism, ultrasound was able to aid the synthesis of these particles. After confirming nanoparticle formation, the optimal nanoparticles in view of scale and morphology were selected by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Optimal particles at three concentrations (25, 50, and 100 ppm) were mixed into the algae growth medium to investigate the effects of the nanoparticles on Dunaliella salina growth. Biological parameters, including the number of cells, biomass, specific growth rate, pigments, and malondialdehyde (MDA), were measured after ten days. Growth parameters showed an increasing trend in concentrations up to 50 ppm; however, at a concentration of 100 ppm, a significant decrease was observed in contrast to the nanoparticles-free treatment. The MDA content showed a linear relationship with enhanced concentration of the nanoparticles. The examination of biological parameters showed that the algae response to stress was dependent on the concentration of nanoparticles. The results showed that 50 ppm of nanoparticles are suitable for increasing algae and achieving a suitable growth rate for commercial purposes. However, in higher concentrations, algal growth inhibition occurs, which is of great importance from a biotechnological point of view.

Photocatalytic and antibacterial activities of Tl-Hg-I nanocomposites: sonochemical synthesis and characterization.

Efforts to find new and practical solutions to improve water quality and treatment of industrial effluents are ongoing. In this study, Tl4HgI6/HgI2 nanocomposites were synthesized by a rapid ultrasonic method to investigate their photocatalytic and antibacterial activity. Various synthesis conditions such as changes in the ratio of precursors, use of surfactants, and changes in the power and time of sonication to achieve particles with optimal size and morphology were performed. X-ray diffraction (XRD) and energy dispersive spectroscopy (EDS) analysis confirmed the purity and formation of the nanocomposite. Optimal nanoparticles in terms of size and morphology were selected by examining the images obtained from scanning electron microscopy (SEM) analysis. The nanocomposites obtained in the presence of PVP (polyvinylpyrrolidone) as a surfactant (sample no. 8) were selected as the optimal sample. Transmission electron microscopy (TEM), differential reflectance spectroscopy (DRS), Raman, N2 adsorption/desorption analyzes were performed for the optimal sample to evaluate the properties of nanocomposites. The band-gap for Tl4HgI6/HgI2 nanocomposites was calculated to be about 2.3 eV for HgI2 and 3.1 eV for Tl4HgI6. The optimal sample was used to evaluate the photocatalytic activity for decolorizing an aqueous solution of six different organic dyes. Finally, for rhodamine B, the decolorization was about 80%. Also, Tl4HgI6/HgI2 nanocomposite showed a significant inhibition zone in the antibacterial test. The maximum inhibition diameter of 50 mm was obtained against Streptococcus pyogenes. The results showed that Tl4HgI6/HgI2 nanocomposites have good potential for many industrial applications.

Magnetic Lu2Cu2O5-based ceramic nanostructured materials fabricated by a simple and green approach for an effective photocatalytic degradation of organic contamination.

Designing and fabricating an efficient photocatalytic compound with an appropriate band gap to eliminate toxic contaminants is necessary to remediate the environment. This article presents the development of a new type of nanostructure, Lu2Cu2O5-Lu2O3 nanocomposites to photo-catalytically degrade different kinds of toxic pollutants under sunlight. The oxide nanocomposites were fabricated via a quick and eco-friendly approach. In order to fabricate oxide nanostructures with appropriate features in terms of morphology and particle size, the effects of the kind of green reactant and its quantity were examined. Amylum was an appropriate and green reactant for the efficient synthesis of Lu2Cu2O5-Lu2O3 nanobundles with the most organized morphology. The features of Lu2Cu2O5-based nanostructures were carefully investigated utilizing multiple characterization methods. Then, the catalytic role of the fabricated nanobundles was evaluated for the removal of various kinds of toxic contaminants. The effects of the quantity of photocatalytic nanostructure, the concentration of the contaminant compound, and the type of light source in the catalytic degradation process were screened. The findings of this research demonstrated that utilizing 0.05 g of Lu2Cu2O5-Lu2O3 nanobundles, 98.5% of the contaminant with a concentration of 10 ppm can be degraded in 2 h under ultraviolet light irradiation. The experimental results also certified that, during the photocatalytic pathway, superoxide radicals play a meaningful role in the elimination of toxic pollutants. To our knowledge, this is the first report of the fabrication of Lu2Cu2O5-Lu2O3 nanocomposite through a facile and eco-friendly approach and its photocatalytic efficiency.

Controllable synthesis and characterization of Mg2SiO4 nanostructures via a simple hydrothermal route using carboxylic acid as capping agent and their photocatalytic performance for photodegradation of azo dyes.

Magnesium silicate (forsterite) nanoparticles were synthesized by a facile hydrothermal method, and characterized using several techniques such as XRD, SEM, EDS, DRS, Raman, TEM, and FT-IR. Several carboxylic acid structures were applied to modify the morphology and surface properties of the as-prepared particles. In this manuscript, citric acid, maleic acid, and succinic acid were used as the carboxylic acid agents. The effect of changing the ratio of carboxylic acid agent to central metal on the morphology and photocatalytic behavior was evaluated. The activities of the Mg2SiO4 nanostructures as photocatalysts were assessed by the degradation of several azo dyes (Acid Blue 92, Acid Brown 14, and Acid Violet 7) under UV and Vis light irradiation. The degradation percentages of Acid Blue 92 were about 88% and 74% in the presence of Vis and UV light respectively, and the percentages for photodegradation of Acid Brown 14 were approximately 76% and 82% in the presence of Vis and UV light, respectively. Furthermore, the degradation percentages for Acid Violet 7 were 93% and 80% under UV and Vis light, respectively.