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The goal of this research was to assess the efficiency of the liquid digestate treatment conducted with algal, environmental isolates illuminated entirely with sunlight. The photobioreactor was exposed to natural conditions and evaluated based on the reduction of chemical oxygen demand (COD), nitrogen compounds, and soluble phosphates. Microalgal and bacterial communities growing during the treatment process were studied. A high removal rate of soluble COD (= 91%) and nutrients (= 86%) was achieved. The average concentrations of nitrogen, phosphates, and COD in the reactor effluent were 95 mgN/L, 49 mg/L, and 735 mg O2/L, respectively. The overall algae-bacteria biomass productivity of 22 mg/L/d, calculated on the total suspended solids (TSS) basis, was recorded. The microbial analysis revealed the dominance of Tetradesmus obliquus followed by Microglena sp. in the first 14 weeks of the experiment. At the end of the experimental run, Chlorella sorokiniana cells appeared as a result of illumination intensity changes. The dominating bacteria belonged to Firmicutes (26.31%), Patescibacteria (17.38%), and Actinobacteriota (14.86%) and could have been responsible for the transformation of nitrogen and oxidation of organic contaminants. The research demonstrated that natural sunlight can successfully be used for efficient liquid digestate treatment with the algae-bacterial community. [ABSTRACT FROM AUTHOR]

The as-prepared and thermally treated Ni–P and Ni–Fe–P alloy powders obtained by chemical reduction were studied regarding the microstructure, as an important factor affecting the functional properties of the materials. Also, the influence of the microstructure and thermally induced transformations of the studied materials on the corrosion behavior in neutral, alkaline, and acidic media is presented. For a detailed study of the mentioned phenomena, different structural and electrochemical techniques were used, including XRD, TEM, DTA, potentiodynamic, and EIS measurements. The composition and microstructure of the studied alloy powders were shown to be dependent on the reactant ratio and thermal history of the material. Small amounts of crystalline phases present in the as-prepared powders, as well as crystalline phases formed during crystallization, included some or all of the following phases: Ni, Ni3P, and Ni12P5. It was shown that the addition of small amount of Fe into the Ni–P powder alloy considerably affects the microstructure and thermal stability of the material, having beneficial effect on the formation of protective oxide layers and thus on the corrosion resistance in chloride environments. [ABSTRACT FROM AUTHOR]

The present work deals with developing a method for revalorizing steel residues to create sunlight-active photocatalysts based on iron oxides. Commercial-grade steel leftovers are oxidized under different combinations of pH and temperature (50–90 °C and 3 ≥ pH ≤ 5) in a low energy-intensive setup. The material with the highest production efficiency (yield > 12%) and magnetic susceptibility (χm = 387 × 10−6 m3/kg) was further explored and modified by diffusion of M2+ (Zn and Co) ions within the structure of the oxide using a hydrothermal method to create ZnFe2O4, CoFe2O4 and combined Co–Zn ferrite. (Co–Zn)Fe2O4 displayed a bandgap of 2.02 eV and can be activated under sunlight irradiation. Electron microscopy studies show that (Co–Zn)Fe2O4 consists of particles with diameters between 400 and 700 nm, homogeneous size, even distribution, and good dispersibility. Application of the developed materials in the sunlight catalysis of black liquors from cellulose extraction resulted in a reduction of the Chemical Oxygen Demand (− 15% on average) and an enhancement in biodegradability (> 0.57 BOD/COD) after 180 min of reaction. Since the presented process employs direct solar light, it opens the possibility to large-scale water treatment and chemical upgrading applications. [ABSTRACT FROM AUTHOR]

Cu2O has been successfully synthesized in different morphologies/sizes (nanoparticles and octahedrons) via a low-temperature chemical reduction method. Trapping metal ions in an ice cube and letting them slowly melt in a reducing agent solution is the simplest way to control the nanostructure. Enhancement of charge transfer and transportation of ions by Cu2O nanoparticles was shown by cyclic voltammetry and electrochemical impedance spectroscopy measurements. In addition, nanoparticles exhibited higher current densities, the lowest onset potential, and the Tafel slope than others. The Cu2O electrocatalyst (nanoparticles) demonstrated the Faraday efficiencies (FEs) of CO, CH4, and C2H6 up to 11.90, 76.61, and 1.87%, respectively, at −0.30 V versus reference hydrogen electrode, which was relatively higher FEs than other morphologies/sizes. It is mainly attributed to nano-sized, more active sites and oxygen vacancy. In addition, it demonstrated stability over 11 h without any decay of current density. The mechanism related to morphology tuning and electrochemical CO2 reduction reaction was explained. This work provides a possible way to fabricate the different morphologies/sizes of Cu2O at low-temperature chemical reduction methods for obtaining the CO, CH4, and C2H6 products from CO2 [ABSTRACT FROM AUTHOR]

The environmental contaminant 1,3-Dinitrobenzene (1,3-DNB), which contains two nitro groups (-NO2), has a +III nitrogen atom oxidation state, and is susceptible to electron acceptance, and subsequent reductive degradation. In this study, carpet grass was investigated as a potential source of polyphenols for the reductive degradation of 1,3-DNB. A characterization of carpet grass revealed a rapid release of polyphenols from the grass in aqueous solution, and an increase in reduction capacity. The effects of the amount of grass in solution, and effects of the pH of the aqueous phase were examined. It was found that higher grass doses (e.g., 50 g L-1) in solution resulted in complete removal of 1,3-DNB in the aqueous phase after 7 d reaction, regardless of the pH level. Kinetic analysis of 1,3-DNB degradation and its reaction intermediates, 3-nitroaniline (3-NA) and 1,3-phenylenediamine, indicated that the overall observed degradation rates (2.51-3.17 × 10-2 h-1) were similar across different doses of carpet grass, but found that the dose did impact the formation and degradation of 3-NA. Based on the results, a potential soil mixing treatment for 1,3-DNB contaminated soils, consisting of the blending of carpet grasses with soils was proposed. Soil slurry experiments simulating field remediation application suggested that enhanced degradation of 1,3-DNB contaminated soils can be achieved under reaction conditions with an appropriate solution volume and sufficiently high grass doses. This research offers valuable insights into the utilization of carpet grass for potential soil remediation through its incorporation into soils contaminated with 1,3-DNB. [ABSTRACT FROM AUTHOR]

In this study, PtNi@SWCNT (Platinum Nickel @ Single Walled Carbon Nanotube) and PtNi@MWCNT (Platinum Nickel @ Multi Walled Carbon Nanotube) catalysts were obtained using carbon nanotubes (CNTs) produced by arc discharge method and used for ascorbic acid (AA) detection. SWCNT and MWCNT were used as support structures in PtNi nanostructures and synthesis was carried out by chemical reduction method. The nanostructure was analyzed by transmission electron microscopy (TEM), and X-ray diffraction (XRD). Electrochemical analyses were carried out on catalysts of appropriate size. According to the differential pulse voltammetry (DPV) results obtained; The calculated Limit of Detection (LOD) and Limit of Quantification (LOQ) values for PtNi@SWCNT and PtNi@MWCNT catalysts were 6.94 mM/ 21.05 mM and 5.03 mM /15.26 mM, respectively. With these results, it was seen that sensitive and selective sensor was created for AA detection. The results showed that both CNTs based materials are highly effective in AA detection. In addition, this study is important for the industrial scale production of SWCNT and MWCNT by arc discharge method and performance evaluation in different applications. [ABSTRACT FROM AUTHOR]

Co-B catalyst, W-modified Co-B (Co-W-B) catalyst, and Mo-modified Co-W-B (Co-W-Mo-B) catalyst powders were synthesized via chemical reduction of metal salt solutions at room temperature. The optimal hydrogen production rate was obtained when the ratio of the reducing agent (NaBH4) to the metal solution was 4:1. Among the ternary catalysts, the Co0.1-W0.9-B catalyst showed the optimal hydrogen production rate when the content of W doping was 0.9. Furthermore, the hydrogen production rate of the quaternary catalyst was enhanced when the content of Mo doping was 0.075, denoted as Co0.1-W0.9-Mo0.075-B. The catalyst powders were characterized by SEM, XRD, XPS, and BET. The hydrogen production rates of the Co-B catalyst, Co0.1-W0.9-B catalyst, and Co0.1-W0.9-Mo0.075-B catalyst were investigated for the decomposition of alkaline sodium borohydride (NaBH4) in a water–ethanol mixture solution. The Co0.1-W0.9-Mo0.075-B catalyst exhibited the highest hydrogen production rate compared to Co-B and Co0.1-W0.9-B catalyst powders. The optimal hydrogen production rate of the Co0.1-W0.9-Mo0.075-B catalyst is 4600 ml·min−1·g−1, which is nearly 1.9 times higher than that of the Co-B catalyst. Moreover, the Co0.1-W0.9-Mo0.075-B catalyst exhibited good stability, retaining 73% of its catalytic activity after five cycles, and had a low apparent activation energy of 41.51 kJ·mol−1. [ABSTRACT FROM AUTHOR]

Polymer nanocomposites have been employed for various applications, including biocompatible biomedical devices, electronic devices, UV shielding, and thermal management. There is a pressing need to develop comprehensive characterization approaches that can assess the overall performance of these materials under irradiation conditions, encompassing a broader range of mechanical properties beyond those traditionally studied. In this context a hybrid polymer nanocomposite was developed using Polyvinyl Alcohol, glutaraldehyde, Silver, and Graphene Oxide nanoparticles through a straightforward in situ chemical reduction process. These prepared samples were subjected to varying doses of gamma radiation, ranging from 0 to 10 kGy, to investigate alterations in their structural and mechanical properties. To validate the elemental composition and functional groups present in both unirradiated and irradiated nanocomposites, EDX and FTIR spectra were employed. The investigation to the mechanical characteristics of these samples. In unirradiated samples, elongation at break (ϵf) was determined to be 134.67 ± 1.45%, while radiation exposure resulted in an increase in the ϵf to 175.33 ± 8.01%. Tensile strength (σult) initially declined for the 2 kGy exposure but increased at 5 kGy, only to decrease again with further dose increments. Remarkably, the material exhibited increased toughness as the dose reached 5 kGy, with a measured value of modulus of toughness (MT) at 55.30 ± 6.09 J/m3. These findings shed light on the impact of gamma radiation on the structural and mechanical properties of the polymer nanocomposite material. [ABSTRACT FROM AUTHOR]

In order to the yield maintenance along with environmental protection, the replacement or combination of chemical fertilizers with organic ones has received increasing attention recently. However, the yield and quality of production in aromatic plants differ from other plants. The present experiment was conducted for 2 years with the aim of evaluating the potential of vermicompost instead of nitrogen fertilizer for the production of geraniums without reducing its perfume quality. Regarded to the macronutrients, essential oil, and shoot yield, geranium treated with 20 ton ha−1 vermicompost and 16 ton ha−1 vermicompost + 40 kg ha−1 nitrogen had the best condition compared to other fertilizer regimes. Geranium is a perennial plant; hence the traits related to plant growth and yield were higher in the second harvest. Besides that, compared to treatments with a high amount of chemical nitrogen, the effects of vermicompost on the quality and quantity of geranium in the second yield were more effective and sustainable. Moreover, these findings suggested that an appropriate proportion of organic substitution not only provides uptake nutrients but also improves the essential oil yield and chemical composition. In fact, increasing the level of vermicompost resulted in improved oxygenated monoterpene content in geranium essential oil. According to the results of this study, cow manure-derived vermicompost could be a suited and sustained replacement for nitrogen inorganic fertilizer without any significant reduction in the quality and quantity of geranium products. Thus, it can be a practical step to reduce production costs, and environmental issues own to chemical fertilizers, particularly in aromatic plant cultivation. [ABSTRACT FROM AUTHOR]

In recent years, metal nanoparticles (MNPs) have gained significant research interest owing to their versatile characteristics in diversified applications ranging from catalysis to biomedical sciences. Due to their notable and improved properties such as higher flexibility, facile processability, thermal stability, mechanical strength, and exceptional optoelectrical and magnetic behavior as compared to pristine metal nanoparticles, the polymer mediated nanoparticles have recently drawn interest from both industry and academia. In this novel investigation, we report a sustainable synthesis of Ag, Fe, Cu, and Zn metal nanoparticles using a chemical reduction method using polyamide (PA) and polyhydrazide (PH) matrices. This work is innovative in that it makes use of these polymer matrices for improved MNP synthesis, offering a unique combination of thermal and structural features. The polymers-supported metal nanoparticles were characterized for structural, thermal, optical, chemical, and morphological characteristics using XRD, TGA, UV-Vis, IR spectroscopy, and SEM analysis, respectively. XRD measurements demonstrated a significant rise in the crystallinity index for the produced metal nanoparticles, indicating a significant increase in crystallinity quantitatively. The effective synthesis of nanoparticles with precise attributes was confirmed by UV-Vis spectroscopy, which showed a significant absorption peak in the UV region. The thermogravimetric study suggested an improvement in thermal stability of around 25%. This work offers a flexible and eco-friendly method for synthesizing metal nanoparticles, demonstrating the usefulness of polyamide and polyhydrazide matrices as platforms for the synthesis of nanomaterials for numerous applications including catalysis, electronics, sensors, and biomedical applications. Highlights: A facile synthesis of metal nanoparticles (Ag, Fe, Cu, and Zn) via chemical reduction approach. The nanoparticles of Ag, Fe, Cu, and Zn are formed utilizing polyamide (PA) and polyhydrazide (PH) matrices. The synthesized metal nanoparticles exhibited higher crystallinity, better thermal stability, high absorption in UV range. This work offers a potential for numerous applications including catalysis, electronics, sensors, and biomedical applications. [ABSTRACT FROM AUTHOR]

In this research, the generation of nanobubbles was carried out using a structure of vortex pump based on the relative blockage of flow (without the use of venturi and orifices, which consume a lot of energy to generate nanobubbles), which has made this process economical and commercial. In addition, the use of advanced synthesized nanoreactors with the Yolk@Shell structure, which forms a photoanode by coating the anode electrode and can operate in the visible light range, has highlighted this research work. An in-depth study of the synergistic effect of advanced photoelectrofenton oxidation methods in addition to the hydrodynamic reactor has shown that the intelligent selection of these three types of advanced oxidation methods together has improved the performance of each other and solved their negative aspects, including the use of hydrogen peroxide, divalent iron ion, and the removal of sludge generated by the electrofenton method. The use of hollow cylindrical electrodes allowed adequate loading of the advanced synthesized nanoreactors with Yolk@Shell structure. The investigation of the effects of micro (advanced synthesized nanoreactors with Yolk@Shell structure) and macro (vortex structure based on relative blockage of the flow) processes on the degradation of pharmaceutical pollutants, both separately and in combination, is a focus of this work. At the end, the energy consumption for each of these processes and this system in general was studied, which showed that the operating cost of this combined system according to the energy consumption requirements for the almost complete removal of the pollutant naproxen and the 90% reduction of its chemical oxygen demand is 6530 Rials/L.h (or 0.15525 USD/L.h), which presents this system as an economical method with industrialization capability. The degradability index (DI) of the introduced system under optimal operating conditions was 3.38, which shows that the development of the system based on the combination of advanced oxidation methods is a suitable method used in this research work due to its environmental friendliness, absence of side effluent production, efficiency and high degradation performance, ability to recover the nanocatalyst and consequently economic efficiency. [ABSTRACT FROM AUTHOR]

The present energy demand of the world is increasing but the fossil fuels are gradually depleting. As a result, the need for alternative fuels and energy sources is growing. Fuel cells could be one alternative to address the challenge. The fuel cell can convert CO2 to value-added chemicals. The potential of bio-fuel cells, specifically enzymatic fuel cells and microbial fuel cells, and the importance of immobilization technology in bio-fuel cells are highlighted. The review paper also includes a detailed explanation of the microbial electrosynthesis system to reduce CO2 and the value-added products during microbial electrosynthesis. Future research in bio-electrochemical synthesis for CO2 conversion is expected to prioritize enhancing biocatalyst efficiency, refining reactor design, exploring novel electrode materials, understanding microbial interactions, integrating renewable energy sources, and investigating electrochemical processes for carbon capture and selective CO2 reduction. The challenges and perspectives of bio-electrochemical systems in the application of CO2 conversion are also discussed. Overall, this review paper provides valuable insights into the latest developments and criteria for effective research and implementation in bio-fuel cells, immobilization technology, and microbial electro-synthesis systems. [ABSTRACT FROM AUTHOR]

It has long been considered that compositional homogeneity would not be altered on the macro-scale by solute segregation during friction stir processing (FSP) without additives. Yet in this study, for the first time, macro-scale compositional inhomogeneity was found to be induced by FSP in AZ91. Using micro X-ray fluorescence spectrometry, three regions that different from conventional microstructural zones were clearly divided from the processed material, i.e., R1 with obvious enrichment of Al and Zn, R2 with significant depletion of Al and Zn, R3 with a similar composition to base material. R1 was found almost identical to the stir zone, while R2 occupied only a part of thermo-mechanically affected zone where grain structure was refined, and the evolution of R2 should have a strong correlation with grain refinement in thermo-mechanically affected zone. The underlying mechanisms of this newly discovered phenomenon could be attributed to dissolution of β-Mg17(Al, Zn)12 in R2 and accelerated segregation of Al and Zn from R2 to R1 driven by the reduction in their chemical potentials in R1 caused by higher temperature in this region during FSP. The local mechanical property in regions of different composition was evaluated by micro-hardness. Local softening was observed in R2, which can be mainly attributed to significantly reduced solid solution strengthening resulting from the depletion of Al and Zn. [ABSTRACT FROM AUTHOR]

In this study, a series of cobalt-based spinel ferrites catalysts, including nickel, cobalt, zinc, and copper ferrites, were synthesized using the sol–gel auto-combustion method followed by a chemical reduction process. These catalysts were employed for accelerating hydrogen generation via the sodium borohydride hydrolysis process. A continuous stirred tank reactor was used to perform catalytic reactor tests. All samples were subjected to analysis using XRD, FESEM, EDX, FTIR, and nitrogen adsorption–desorption techniques. The results revealed that the cobalt-based copper ferrite sample, Co/Cu-Ferrite, exhibited superior particle distribution, and porosity characteristics, as it achieved a high hydrogen generation rate of 2937 mL/min.gcat. In addition, the higher electrical donating property of Cu-Ferrite which leads to the increase in the electron density of the cobalt active sites can account for its superior performance towards hydrolysis of NaBH4. Using the Arrhenius equation and the zero-order reaction calculation, activation energy for the sodium borohydride hydrolysis reaction on the Co/Cu-Ferrite catalyst was determined to be 18.12 kJ/mol. This low activation energy compared to other cobalt-based spinel ferrite catalysts confirms the catalyst's superior performance as well. Additionally, the outcomes from the recycling experiments revealed a gradual decline in the catalyst's performance after each cycle during 4 repetitive cycles. The aforementioned properties render the Co/Cu-Ferrite catalyst an efficient catalyst for hydrogen generation through NaBH4 hydrolysis. [ABSTRACT FROM AUTHOR]

Surface-enhanced Raman spectroscopy (SERS) has shown a strong Raman enhancement with bimetallic nanoparticles. The combination of the different bimetallic nanoparticles is used in the field of SERS sensors. These sensors can resonate with the organic molecules adsorbed on their surfaces for SERS enhancement. Fabricating these bimetallic, cost-effective and ultrasensitive SERS sensors is a great challenge. To overcome this challenge, a rapid fabrication method of ultrasensitive noble SERS sensors that enable sub-femtomolar detection of molecular analytes, is reported here. SERS sensor is obtained by application of the silver nanorods (AgNRs) deposited on copper nanoflowers (CuNFs) fabricated by chemical reduction and chemical etching, respectively. Purity and structural characteristics of the SERS sensor are measured qualitatively by scanning electron microscopy, transmission electron microscopy, atomic force microscopy, UV-visible spectroscopy, X-ray diffraction, Fourier transform infrared microscopy and Raman analysis. Rhodamine 6 g as an analyte analyses the sensitivity of the SERS sensor. The detection limit and enhancement factor are found to be 10−13 M and 109 respectively for AgNRs deposited CuNFs etched for 30 min. This study reveals that the AgNRs deposited CuNFs are practically found to be sensitive SERS sensors. [ABSTRACT FROM AUTHOR]

Using a seed–growth method, chemical reduction in aqueous solution was used to create gold nanoparticles (AuNPs). As seeds, AuNPs have been created and used as a nucleating agent with regard to the gold colloids' anisotropic growth. The various seed quantities were added to the gold chloride-containing growth solution, and NPs have started to grow as a result. Au seeds are typically 20 nm in spherical and size in shape, while gold is 25–30 nm in size and spherical in shape. Peak absorption from nanospheres was measured between 535 nm and 530 nm. The surface plasmon band's absorption peaks moved to the short wavelength region. AuNPs are doped with PMMA to create thin films that can be used as saturation absorbers (passive Q-switching) for Q-switching in visible region and green LEDs at various frequencies in the RhB fluorescence region. Those properties include the suitability of the resulting NPs for optoelectronic applications. [ABSTRACT FROM AUTHOR]

Group 1 elements exhibit the lowest electronegativity values in the Periodic Table. The chemical reduction of Group 1 metal cations M+ to M(0) is extremely challenging. Common tetraaryl borates demonstrate limited redox properties and are prone to decomposition upon oxidation. In this study, by employing simple yet versatile bipyridines as ligands, we synthesized a series of redox-active borate anions characterized by NMR and X-ray single-crystal diffraction. Notably, the borate anion can realize the reduction of Li+, generating elemental lithium metal and boron radical, thereby demonstrating its potent reducing ability. Furthermore, it can serve as a powerful two-electron-reducing reagent and be readily applied in various reductive homo-coupling reactions and Birch reduction of acridine. Additionally, this borate anion demonstrates its catalytic ability in the selective two-electron reduction of CO2 into CO. Chemical reduction of alkali cations to their metals is extremely challenging. Here, the authors synthesized a series of redox-active borate anions stabilized by bipyridine ligands which can reduce lithium ions generating elemental lithium metal and borate radicals. [ABSTRACT FROM AUTHOR]

The scientific and industrial communities have shown considerable interest in the mass production of graphene in recent years. This heightened attention is attributed to graphene's promising applications across diverse fields such as electronics, energy storage, material science, biomedicine. While the potential benefits are substantial, large-scale graphene production poses significant challenges. Nonetheless, there have been noteworthy advances and dedicated efforts towards overcoming these challenges. This paper explores synthesis methods, structural distinctions, and a range of analytical techniques employed to compare properties among graphite, graphene oxide (GO), and reduced graphene oxide (rGO) samples subjected to varying reduction durations. The focus is on highlighting the efficacy of the chemical reduction method in successfully transforming GO into rGO. By extending the chemical reduction duration, the reduced graphene oxide exhibited reduced oxygen content and underwent a restoration of SP2 bonds, accompanied by the removal of oxygen functional groups. This process led to a reduction in the interplanar space between graphene layers and an increased number of exfoliated graphene layers. Notably, the resulting material demonstrated excellent stability with no coagulation in the dispersion medium and displayed improved electrical conductivity compared to graphene oxide (GO). The findings of this study suggest that optimizing the chemical reduction process, and varying reduction durations, can fine-tune the properties of reduced graphene oxide (rGO) to cater to diverse application needs. Furthermore, this approach holds promise for the scalable production of graphene. [ABSTRACT FROM AUTHOR]

The integrated electrocoagulation-assisted adsorption (ECA) system with a solar photovoltaic power supply has gained more attention as an effective approach for reduction chemical oxygen demand (COD) from pharmaceutical wastewater (PhWW). In this research, the ECA system was used for the treatment of PhWW. Several operating parameters were investigated, including electrode number, configuration, distance, operating time, current density, adsorption time, and temperature. A current density of 6.656 mA/cm2, six electrodes, a 20-min time, a 4 cm distance, an MP-P configuration, and a 45 °C temperature produced the maximum COD reductions, where the operating cost of conventional energy was 0.273 $/m3. The EC, adsorption, and combination of EC and adsorption processes achieved efficient COD reductions of 85.4, 69.1, and 95.5%, respectively. The pseudo-second-order kinetic model and the Freundlich isotherm fit the data of the endothermic adsorption process. Therefore, it was found that the combination processes were superior to the use of these processes in isolation to remove COD. [ABSTRACT FROM AUTHOR]

A reliable, rapid, and inexpensive nano-sized chemosensor is presented for methamidophos (MET) — an insecticide. Poly(lactic acid) (PLA)-stabilized gold nanoparticles (AuNPs) were synthesized by a simple one-pot, two-phase chemical reduction method. The synthesized PLA-AuNPs were subsequently employed for selective, efficient, and quantitative detection of MET. MET is one of the highly toxic pesticides used for eradication of agricultural and urban insects. Upon the addition of MET, the wine-red color of PLA-AuNPs swiftly transformed into greyish-blue, further corroborated by a significant bathochromic and hyperchromic shift in the SPR band. The presence of other interfering insecticides, metal salts, and drugs did not have any pronounced effect on quantitative MET detection. The detection limit, the quantification limit, and linear dynamic range of MET utilizing PLA-AuNPs were 0.0027 µM, 0.005 µM, and 0.005–1000 µM, respectively. The PLA-AuNP-based assay renders an efficient, rapid, accurate, and selective quantification of MET in food, biological, and environmental samples. The proposed sensor provides an appropriate platform for fast and on-the-spot determination of MET without requiring a well-equipped lab setup. [ABSTRACT FROM AUTHOR]

Sand storms and fine dust are known as the most important atmospheric problems in many windy regions around the world, especially in arid and semi-arid areas. Besides all the obvious negative effects of fine dust on human life, this phenomenon can extremely reduce the physical and chemical quality of output water from treatment plants into the distribution systems. In order to show and evaluate the impact of fine dust on the physico-chemical quality of the water, a long-term (three years: 2017–2020) experimental investigation was done in the Sistan region (Iran) which is one of the most popular regions in the world with high amount of annual fine dust level. The final results showed that the most physical and chemical quality indices of output water from the local treatment plants became progressively worse after the fine dust process. The total dissolved solids (TDS) and turbidity of the water, which could even obviously be seen in the samples, were increased so that the TDS level was raised to more than 850 ppm. The level of some metals such as Fe, Ca, Mg, Na, and K increased significantly but stood within the standard levels. pH level was increased to up to 8.3 in some water samples. In addition, high levels of NO3, SO4, F, EC, HCO3, Cl, CO3, and PO4 were observed in all water samples after fine dust processes. Also, the t-student analysis showed that there was a high correlation between wind speeds and the reduction of physical and chemical quality indices in most of the water samples. Finally, the experimental analysis showed that most of these chemical elements originated from the vast bed (5,660 km2) of the dried-up Hamun's Lake where the winds were blown over. [ABSTRACT FROM AUTHOR]

The hydrogenation of a number of carbonyl compounds with the formation of the corresponding alcohols was studied. The process was carried out in a flow-type reactor in the presence of nickel catalysts supported on γ-Al2O3 obtained by the deposition-precipitation method with chemical reduction of the active phase. The effect of the catalyst preparation method on the yield of the resulting alcohols was studied. It has been shown that the increase in the nickel content in the catalyst leads to complete substrates conversion even at 20–80°C and atmospheric hydrogen pressure. [ABSTRACT FROM AUTHOR]

This experimental study's main goal is to investigate the impact of various silver concentrations on the optical characteristics of Agshell/Aucore bimetallic nanoparticles. By using the pulsed laser ablation in liquid (PLAL) technique on the gold target at the bottom of the container full of silver colloids, the silver/gold nanoparticles are ablated. Colloidal silver nanoparticles, created through a chemical reduction process, are inside the container. The second harmonic of the pulsed Nd:YAG laser is used to irradiate the colloidal mixture of mixed nanoparticles at a wavelength of 532 nm. The Agshell/Aucore bimetallic nanoparticles are created by transferring laser energy to gold nanoparticles, which have a peak absorption of around 530 nm. The experimental variables are the volumetric ratio of nanoparticle solutions. X-ray diffraction pattern (XRD), spectroscopy in the UV–Vis-NIR and IR ranges, dynamic light scattering (DLS), energy-dispersive spectroscopy (EDS), photoluminescence spectrum (PL), and Fourier transform infrared spectroscopy (FT-IR) are used to identify bimetallic nanoparticles. Additionally, FE-SEM and TEM pictures are used to look at the size and morphology of nanoparticles. In order to test the reactivity of silver nanoparticles in the bimetallic system, one goal of this research is the production of stable bimetallic systems and the examination of optical properties. Additionally, a bimetallic structure with a variable silver concentration's shell thickness and catalytic qualities is examined. All samples in the visible range have dipole absorption observable. On the other hand, the first sample with a lower silver concentration exhibits quadrupole absorption. [ABSTRACT FROM AUTHOR]

A series of mesoporous nanoparticle P-CexZr1-xOy (PCZ) catalysts with abundant oxygen vacancies and high specific surface area were successfully prepared, exhibiting 100% formaldehyde conversion at room temperature (25 °C). The PCZ catalyst was investigated in depth utilizing TEM, BET, XRD, XPS, H2-TPR, and Raman characterization, it was found that the PCZ catalyst had an average particle size of 10 nm and a specific surface area of 108 m2/g; templating caused by P123 and effective doping of Zr atoms regulated the oxygen vacancies in the catalyst, altered the reduction characteristics and chemical state of cerium to formed the redox cyclic couple of Ce3+/Ce4+, which significantly enhanced the catalytic oxidation performance of the PCZ catalyst in the indoor environment. [ABSTRACT FROM AUTHOR]

Methanol is a renewable, low-carbon chemical that can be obtained from biomass. GeO2 is the main source for producing Ge, which is an important semiconductor. The current study aimed to investigate the reduction of GeO2 and chemical vapor deposition of Ge using gaseous species generated by methanol pyrolysis. Mass measurement, X-ray diffraction and scanning electron microscopy techniques were used to determine the extent of the oxide reduction, and to characterize the products. CO and H2 were predicted as the major reducing agents derived from the methanol pyrolysis at 1000 K to 1200 K, in agreement with the experimental measurement. It was found that the mass loss in GeO2 increased to 85.5 pct as the reaction time and temperature were raised to 10 minutes and to 1200 K. The GeO2 reduction was insignificant at 900 K, in contrast to the thermodynamic prediction, essentially owing to the sluggish reaction kinetics. At 1000 K, the significant reduction of GeO2 to Ge, close to the thermodynamic equilibrium, was attained. At 1100 K to 1200 K, the experimental mass loss was more than the thermodynamics prediction. The discrepancy was explained by a mass-transport theory involving boundary layer in the gas phase over the powder bed. Ge films were deposited from the gaseous species generated upstream at 1200 K for 10 minutes on a Si (400) substrate held downstream in the reaction tube at 723 K to 923 K. Polycrystalline rough Ge thin films with pillar-like crystals were obtained when the substrate temperatures were 723 K and 823 K. At 923 K, a denser polycrystalline Ge film was grown probably owing to the enhanced Ge diffusion on the substrate surface. [ABSTRACT FROM AUTHOR]

In this study, the anaerobic sludge withdrawn from thickener in a sewage treatment plant served as the precursor for sludge-based biochar fabrication, which was further modified via sulfur (S) heteroatom doping (i.e., S-BC). The S atom doping resulted in the adjustment of the physicochemical properties towards the carbon material, endowment of abundant functional groups on biochar surface, and increasing the binding sites between biochar and Cr(VI). Compared to the primary biochar (i.e., biochar without heteroatomic doping, named BC), S-BC exhibited a rough surface and possessed remarkable advantages in ash content, specific surface area, and pore volume. The existence of graphene carbon crystal structure for S-BC was confirmed through S-BC by XRD and FTIR analysis. The studies of adsorption kinetics and isotherms showed that pseudo-second-order kinetics and the Langmuir model more fitted the Cr(VI) removal behavior in the presence of S-BC. Therefore, the chemisorption and monolayer adsorption were the primary mechanisms involved in the Cr(VI) removal process. Additionally, XPS analysis results illustrated the aqueous Cr(VI) was efficiently eliminated through the synergistic effect of chemisorption and reduction to Cr(III) in the presence of S-BC. Moreover, S-BC could still achieve the Cr(VI) eliminating efficiency of 85.31% undergoing five cycles with unchanged functional group and crystal structure via FTIR and XRD analysis. Thus, the results of this study may shed light on a new approach for simultaneous economical sludge disposal and the sustainable remediation of the Cr(VI)-contaminated wastewater. [ABSTRACT FROM AUTHOR]

Conjugated polymers are promising tools to differentiate various types of semiconducting single-walled carbon nanotubes (s-SWCNTs). However, their synthesis is challenging. Insufficient control over molecular weights, and unpredictive/unrepeatable batches hinder possible applications and scale-up. Furthermore, commercial homogeneous catalysts often require inert conditions and are almost impossible to recycle. To overcome these problems, we present a nanocatalyst consisting of magnetic nickel nanowires decorated with highly active palladium nanoparticles. A two-step wet chemical reduction protocol with the assistance of sonochemistry was employed to obtain a heterogeneous catalyst capable of conducting step-growth Suzuki polycondensation of a fluorene-based monomer. Additionally, we enhanced the performance of our catalytic system via controlled microwave irradiation, which significantly shortened the reaction time from 3 d to only 1 h. We studied the influence of the main process parameters on the yield and polymer chain length to gain insight into phenomena occurring in the presence of metallic species under microwave irradiation. Finally, the produced polymers were used to extract specific s-SWCNTs by conjugated polymer extraction to validate their utility. [ABSTRACT FROM AUTHOR]

In agriculture, there is a constant search for increased productivity, which leads to increased use of fungicides, insecticides, and inoculants, among other products to perform seed treatment before planting. After treatment, the machines and equipment are sanitized, generating a liquid residue with potentially negative environmental impacts. This study aimed to characterize and evaluate the toxicity of the effluent generated from washing soybean seed treatment machines and suggest treatment methods for this residue. The applied treatment was a combined process of coagulation followed by heterogeneous photocatalysis and ozonization. The treatments caused a significant decrease in the concentration of sedimentable solids (95.22%), total solids (25.26%), and total dissolved solids (9.14%). The chemical oxygen demand and the active ingredient thiamethoxam were also reduced by 31.55% and 40.98%, respectively. Despite the reduction of the physical and chemical parameters of the effluent, it still presented acute toxicity to the bioindicators Artemia salina L. and Eisenia fetida since these showed mortality in the tests. The results confirm the risk that this effluent presents to the environment and highlights the importance of continuing the search for new treatment technologies to promote the reduction of the physicochemical parameters and the final toxicity. [ABSTRACT FROM AUTHOR]

The chemical reduction of group 1 metal cations to their zero-valent species is challenging. Now, a bipyridine-stabilized borate anion joins the ranks of suitable reducing agents and also proves active in the two-electron reduction of CO2. [ABSTRACT FROM AUTHOR]