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In this work, the biomass charcoal from rubber wood, coconut shell, corn cob, palm kernel shell, as a reductant in the smelting process of saprolitic nickel laterite has been observed in a laboratory submerged arc furnace. A total of 5 kg of saprolite, some reductant and limestone were smelted together in this furnace, which was adjusted to 0.8 of carbon stoichiometric and 0.8 of slag basicity. The smelting process was carried out for 1 h, and the pouring temperature was 1400 °C–1500 °C. From the result, the smelting process using corn cob charcoal and palm kernel shell charcoal showed almost similar nickel grade and recovery compared with using coke as a reductant, which is above 12% and 90%, respectively. It also has the same slag phase, that is, diopside, with a low melting point. These two types of biomass waste reductants could be replaced using coke in the future. [ABSTRACT FROM AUTHOR]

Herein, the use of economically and environmentally friendly bis(pinacolato)diboron (B2Pin2) is described as a non‐metallic reductant in mediating Ni‐catalyzed C(sp3)–C(sp2) reductive cross‐coupling of alkyl electrophiles with aryl/vinyl halides. This method exhibits excellent suitability for heteroaryl halides and alkyl halides/Katritzky salts. The present study is compatible with an in situ halogenation of alcohol method, allowing for selective mono‐functionalization of diols and bio‐relevant alcohols (e.g., carbohydrates). The use of B2Pin2 shows potential for easy scalability without introducing additional metal impurities into the products. It is observed for the first time in the realm of cross‐electrophile coupling chemistry that B2Pin2 can sever as a reductant to reduce NiII to Ni0. This mechanistic insight may inspire the development of new reductive bond‐forming methodologies that can otherwise be difficult to achieve with a metal reductant. [ABSTRACT FROM AUTHOR]

Abstract This study focuses on the effect of an emerging source of waste, lithium iron phosphate (LFP) cathode materials, on the hydrometallurgical recycling of the currently dominant industrial battery waste that is rich in transition metals (Ni, Co, Mn, and Li). The effects of the dosage of LFP, initial acidity, and timing of LFP reductant addition were investigated in sulfuric acid (H2SO4) leaching (t = 3 h, T = 60 °C, ω = 300 rpm). The results showed that addition of LFP increased both transition metal extraction and acid consumption. Further, the redox potential was lowered due to the increased presence of Fe2+. An initial acidity of 2.0 mol/L H2SO4 with acid consumption of 1.3 kg H2SO4/kg black mass provided optimal conditions for achieving a high leaching yield (Co = 100%, Ni = 87.6%, Mn = 91.1%, Li = 100%) and creating process solutions (Co 8.8 g/L, Ni 13.8 g/L, Li 6.7 g/L, Mn 7.6 g/L, P 12.1 g/L) favorable for subsequent hydrometallurgical processing. Additionally, the overall efficiency of H2O2 decreased due to its decomposition by high concentrations of Fe2+ and Mn2+ when H2O2 was added after t = 2 h, leading to only a minor increase in final battery metals extraction levels.

In the steelmaking industry, the kind of silica and carbon sources utilized in the ferrosilicon manufacturing process have a big impact on the operation's stability, energy usage, and cost. Biomass resources have gained attention due to their potential to replace existing materials to produce activated carbon as it is the best way to preserve the environment. Thus, this study focused on the synthesis of ferrosilicon from coconut char as a reductant at different reduction times (30, 60, 90 and 120 minutes). The coconut char was prepared by physical activation method via pyrolysis process at 450 °C within 2 hours under a nitrogen atmosphere. X-ray Diffraction (XRD), Xray fluorescence (XRF), and Optical Microscope (OM) were used to characterize the activated carbon from coconut shells. CHNS analysis found an increment of about 65% in carbon content after pyrolyzed, which could potentially be used as a reductant in ferrosilicon synthesis. Next, the ferrosilicon synthesis study was conducted in a muffle furnace at a reduction temperature of 1200 °C with a flow rate of 10 °C/min for 30, 60, 90, and 120 minutes of reduction times. Phase transformation of reduced samples at different reduction times was analyzed by X-ray Diffraction (XRD). XRD pattern found that at 120 minutes reduction times, the iron silicon peak is observed as the morphology analysis showed a presence of metallic grey particles which represent the existence of iron silicon. The possibility of converting the biomass into an alternate supply that was discovered in ferrosilicon synthesis also would minimize the landfill waste. [ABSTRACT FROM AUTHOR]

Open shell species are alluring significant attention owing to their unique physiochemical properties in redox chemistry for activating remarkably stable bonds. Solvated electrons are one of them that have been extensively investigated due to their high reduction potential (Ered=−2.9 V vs SHE in CH3CN), diverse substrate activation, and promising applications. If the activating species have a larger redox potential with a longer lifetime, then the broader range of substrates will be activated. Hence, the solvated electron qualifies as a super‐reductant with these qualities. However, due to safety issues, generating solvated electrons by dissolving alkali metals in an ammoniated solvent limits its use towards complicated organic transformations. Instead photochemically generated solvated electron overcome this limitation and is identified as a user‐friendly, sustainable, and much safer alternative approach for producing solvated electrons. In this minireview, we have comprehensively highlighted the recent key methods to generate the solvated electron photochemically, characterization techniques, and its application in organic transformations with selected examples. The minireview provides new opportunities for chemists to understand the conceptual, physical, and mechanistic chemistry principle of this super reductant for exploiting a new photochemical route for the transformations that are difficult to achieve by other means. [ABSTRACT FROM AUTHOR]

This study focuses on the effect of an emerging source of waste, lithium iron phosphate (LFP) cathode materials, on the hydrometallurgical recycling of the currently dominant industrial battery waste that is rich in transition metals (Ni, Co, Mn, and Li). The effects of the dosage of LFP, initial acidity, and timing of LFP reductant addition were investigated in sulfuric acid (H2SO4) leaching (t = 3 h, T = 60 °C, ω = 300 rpm). The results showed that addition of LFP increased both transition metal extraction and acid consumption. Further, the redox potential was lowered due to the increased presence of Fe2+. An initial acidity of 2.0 mol/L H2SO4 with acid consumption of 1.3 kg H2SO4/kg black mass provided optimal conditions for achieving a high leaching yield (Co = 100%, Ni = 87.6%, Mn = 91.1%, Li = 100%) and creating process solutions (Co 8.8 g/L, Ni 13.8 g/L, Li 6.7 g/L, Mn 7.6 g/L, P 12.1 g/L) favorable for subsequent hydrometallurgical processing. Additionally, the overall efficiency of H2O2 decreased due to its decomposition by high concentrations of Fe2+ and Mn2+ when H2O2 was added after t = 2 h, leading to only a minor increase in final battery metals extraction levels. [ABSTRACT FROM AUTHOR]

In the recent research we compared the solar energy performance of photogalvanic cell (PG cell) for two food dyes that act as photosensitizer tatrazine and sunset yellow in the DSS-EDTA (Dioctyl sodium sulphosuccinate-Ethylenediamine tetraacetic acid) system for power generation and its storage. Both are azo food dyes and act as photosensitizer, DSS acts as an anionic Surfactant and EDTA act as a reductant. The electrical parameters of both dye systems were studied and compared. The observed conversion efficiencies and fill factor for both systems in the DSS-EDTA system were 0.6163%, 0.2800, and 1.2186%, 0.2900, respectively. The stable photopotential (Voc) was 879 mV and 864.0 mV whereas the stable photocurrent (isc) was 220 µA and 390 µA, respectively. In addition to having built-in storage capacity, the photogalvanic cell can operate in dark conditions. The amount of time required for the cell to reach half the value of power at power point, which was measure its performance called t1/2 of the cell. Cell performance of both PG cell was determined and for the Tartrazine-EDTA-DSS system it has been obtained 100 min while for the sunset yellow-EDTA-DSS system it was observed at 140 minutes. The current-voltage (i-v) characteristics of both the systems have been studied. [ABSTRACT FROM AUTHOR]

The complete electrolyte of photogalvanic cells consists of the sensitizer, reductant, surfactant, alkali, and water solvent. In the present research, the electrochemical properties of the individual chemicals of electrolyte and complete electrolyte (including surfactant) have been studied both in the dark and illuminated conditions. Individual chemical components or combination of any two or three chemical components at low pH show very low potential (≤ 401 mV) and current (≤ 13 µA) under both pre-illuminated (dark) and illuminated conditions. For complete electrolyte (including surfactant) at high pH, the observed dark potential, photo potential, current (in dark), and current (in sunlight) is 495 mV, 720 mV, 522 µA, and 2460 µA, respectively. It has been observed that, in the case of high pH conditions of the complete electrolyte, the abrupt jump in the potential coupled with high photo-current is observed during illumination of the cell. Therefore, it is concluded that high potential and current can be obtained by combining all chemical components of the electrolyte at a time under necessary conditions including the high pH. The photogalvanics is achievable only from complete electrolyte at very high pH. The complete electrolyte (excluding surfactant) at high pH also shows photogalvanics. But, a bit low electrical output for complete electrolyte (excluding surfactant) vis-à-vis that of complete electrolyte (including surfactant) is observed and that may be attributed to the lack of role of surfactant in the dye solubility and stability. It is a reported fact that the surfactant enhances the electrical output of the photogalvanic cells. So by taking all these facts, it may be concluded that the requirement of a surfactant is not a necessary condition for photogalvanics, but its presence in the electrolyte enhances it (photogalvanics). Further, the potential and current of the cell at its initial stage and post-sensitizer degradation stage may be attributed to the polar and ionic nature of the individual chemical components of the electrolyte. [ABSTRACT FROM AUTHOR]

Photogalvanic cells (PG) are capable of generating solar power with storage, which predominantly dependent on the sensitizer/electrolyte/electrode nature. Therefore, the exploitation of suitable combination of photo-sensitizer/electrode/electrolyte is the key for enhancing the electrical output of these cells. Titan Yellow (a novel dye) has good absorbance in the visible region and good water solubility. These characteristics of this dye have prompted authors to exploit it for further enhancing electrical output of PG cells. Therefore, in present study, the Titan yellow dye photo sensitizer-Ethylenediaminetetraacetate (EDTA) reductant-NaOH alkali medium-Pt/Graphite electrodes photogalvanic system has been exploited. The observed power, current, potential, and efficiency is of the order of 126.4 µW, 2200 µA, 770 mV and 4.34%, respectively. PG performance is observed better in the high pH range (for example, ∼22% enhancement in the power with 0.87% rise in the pH; 37.6 µW power at pH 13.65; 46 µW power at pH 13.77). Spectroscopic study shows that the Titan Yellow is the actual light absorbing material in the electrolyte as other chemical components (reductant EDTA, NaOH, water) of the electrolyte do not show any absorbance in the visible spectral range. A comparison of present results with published results shows both sides, i.e., present results are higher than some reported data, and lower than some other reported data. The use of graphite counter electrode in the present study is the reason behind the present results being higher than some reported data. The heat induced precipitation of dye from the electrolyte in the present study is the reason behind the present results being lower than some reported data. Therefore, controlling the Titan Yellow precipitation at elevated temperature is the challenge for future research. In totality, the present research shows that the Titan yellow dye is not a good sensitizer in the photogalvanics.

Advanced oxidation/reduction processes (AO/RPs) are considered as effective water treatment technologies and thus could be used to solve the problem of water pollution. These technologies of wastewater treatment involve the production of highly reactive species such as •OH, H•, e−aq, SO4•−, and SO3•−. These radicals can attack the targeted contaminants present in aqueous media and result in their destruction. The efficiency of AO/RPs is highly affected by various operational parameters such as initial concentration of contaminant, solution pH, catalyst amount, intensity of light source, nature of oxidant and reductant used, and the presence of various ionic species in aquatic media. Among AO/RPs, the solar light-based AO/RPs are most widely used nowadays for contaminant removal from aqueous media because of their high environmental friendliness and cost effectiveness. By using these techniques, almost all types of pollutants can be easily removed from aquatic media within short intervals of time, and hence, the problem of water pollution can be solved effectively. This review focuses on various AO/RPs used for wastewater treatment. The effects of different operational parameters that affect the efficiency of these processes toward contaminant removal have been discussed. Besides, challenges and future recommendations are also briefly provided for the researchers in order to improve the efficiency of these processes. [ABSTRACT FROM AUTHOR]

Comprehensive Summary: This review provides a comprehensive summary of progress to date in the utilization of rongalite as a versatile reagent in organic synthesis, with a focus on recent researches. The contents have been organized according to the functions exhibited by rongalite. Reaction mechanisms are provided, demonstrating the multifaceted roles of this compound in various transformations, including as a sulfone, C1 or masked proton source and as a single electron donor or reducing agent. [ABSTRACT FROM AUTHOR]

Comprehensive Summary: This review provides a comprehensive summary of progress to date in the utilization of rongalite as a versatile reagent in organic synthesis, with a focus on recent researches. The contents have been organized according to the functions exhibited by rongalite. Reaction mechanisms are provided, demonstrating the multifaceted roles of this compound in various transformations, including as a sulfone, C1 or masked proton source and as a single electron donor or reducing agent. [ABSTRACT FROM AUTHOR]

Groundwater contamination by trichloroethylene (TCE) presents a pressing environmental challenge with far-reaching consequences. Traditional remediation methods have shown limitations in effectively addressing TCE contamination. This study reviews the limitations of conventional remediation techniques and investigates the application of oxidant-based controlled-release materials, including encapsulated, loaded, and gel-based potassium permanganate since the year 2000. Additionally, it examines reductant controlled-release materials and electron donor-release materials such as tetrabutyl orthosilicate (TBOS) and polyhydroxybutyrate (PHB). The findings suggest that controlled-release materials offer a promising avenue for enhancing TCE degradation and promoting groundwater restoration. This study concludes by highlighting the future research directions and the potential of controlled-release materials in addressing TCE contamination challenges. [ABSTRACT FROM AUTHOR]

Photo-galvanic cells are based on the diffusion of ions in the electrolyte (a mixture of sensitizer, reductant, alkali, surfactant, and solvent). The photogalvanics is characterized by the abrupt jump in the photo-potential during charging of the cell. Photo-galvanic cells have been widely studied using the complete electrolyte. The migration of current by ions gives impression that any of the ionic species individually (like sensitizer/reductant/etc.) may show current, potential, and photogalvanics. This aspect of photogalvanics of individual chemical components is missing in the literature. Therefore, the photogalvanics of the individual chemicals, mixtures of the chemicals, and complete electrolyte have been studied in present research to have insight into (i) the genesis of the current and potential generated from the cell in non-illuminated state (dark conditions), and (ii) the necessary chemical conditions required for the photogalvanics.The average open-circuit potential (Voc) and short-circuit current (Isc) in dark conditions for water, Lactic acid reductant, Cocamidopropyl betaine surfactant, Carmoisine-A dye, NaOH alkali, complete electrolyte (at low pH), and complete electrolyte (at very high pH) is 286 mV, 4 µA; 214 mV, 3 µA; 278 mV, 4 µA; 268 mV, 9 µA; 295 mV, 8 µA; 278 mV, 8 µA; and 463 mV, 253 µA, respectively. The average Voc and Isc from illuminated water, Lactic acid reductant, Cocamidopropyl betaine surfactant, Carmoisine-A dye, NaOH alkali, complete electrolyte (at low pH), and complete electrolyte (at very high pH) is 296 mV, 3 µA; 182 mV, 4 µA; 218 mV, 4 µA; 135 mV, 3 µA; 275 mV, 9 µA; 167 mV, 6 µA; and 731 mV, 2500 µA, respectively. Thus, no photogalvanics has been observed for individual chemical components, and mixtures of two or more chemical components of the electrolyte. The photogalvanics is observed only for complete electrolyte at high pH.

The distinctive chemical, physical, thermal and mechanical properties of graphene made it widely recognized material in wide-ranging field of science and technology. Generally, the synthesis of graphene or reduced graphene oxide (rGO) requires two main steps. The first step involves the oxidation of graphite to graphene oxide (GO) and in the second step, reducing agents or reductants contribute to the reduction of GO to form rGO. A large number of reducing agents have been applied to synthesize rGO such as hydrazine, hydroxyl amine, sodium borohydride, etc. However, the hazardous nature of such reducers created a space for the research on green reducing agents for rGO synthesis. This study introduces the low-cost green synthesis of rGO via green reducing agents such as eucalyptus hybrid extract, thiourea, lemon extract and starch. Among all the green reductants, eucalyptus hybrid extract exhibited the remarkable reduction of GO, as confirmed by VUvisible spectroscopy, Fourier transform infrared spectroscopy, and X-ray diffraction results. The absorption peak of rGO-eucalyptus is appeared at 272 nm, whereas the d-spacing between layers is determined to be 0.364 nm. The obtained band gap of rGO-eucalyptus (2 eV) is found less as compared with other reducing agents such as thiourea, lemon extract and starch. The stretching vibration of oxygen functionalities appeared in FTIR of GO, is disappeared after reduction with eucalyptus extract. The flavonoid components of eucalyptus extracts are antioxidant in nature and hence, work as reducing agents. [ABSTRACT FROM AUTHOR]

Photogalvanic cells are solar power and storage devices. Extensive study on the photo-stability and durability aspect of these cells has not attracted the attention of the researchers. With this aim, the present work reports the electrical output and stability study of the Titan Yellow sensitized photo-galvanic cells. The observed electrical output is 823 mV potential, 2800 μA current, and 511.10 μW power. The observed potential decay rate over 52.18 h is very low (i.e., 1.59 mV/h only) during illumination. This observation shows quite good photo-stability of the cell with respect to the open-circuit potential. The observed current decay rate over 52.18 h is very high (i.e., 15.67 μA/h) during illumination. This observation shows less photo-stability of the cell with respect to the short-circuit current. From initial charging to 1st re-charging to 2nd re-charging of the same cell, the power output decreases under experimental conditions. Overall, the power decay is observed with time in both dark and illuminated conditions. The trend of fall of power is suggestive of the inverse relation between half change time and initial power, and the power decay is of non-zero and non-first order decay. The dye decay and temperature rise in the electrolyte is observed. The power decay may be attributed to the photo-induced degradation of the dye electro-active species and high temperature induced aggregation (precipitation) of the Titan Yellow dye molecules. Despite this power decay, the Titan Yellow dye based photogalvanic cells are capable of producing solar power for sufficiently long hours.

• Study the reduction performance of low metamorphic degree YJL bituminous coal with abundant reserves in reducing high-phosphorus oolitic hematite. • The iron particles in the roasted product obtained from YJL bituminous coal as reductant were smaller and more dispersed, but the DRI indexes were similar to that of the DRI obtained from JS anthracite. • YJL Bituminous coal with high volatile content and H element content produced abundant reducing gas in the reduction process to reduce high-phosphorus oolitic hematite. • Reduced iron products with TFe grade, TFe recovery and phosphorus content of 94.51 %, 87.47 %, 0.062 %, respectively can be obtained by using 30 % limestone and 35 % YJL bituminous coal. Coal-based direct reduction of high-phosphorus oolitic hematite is an effective method to realize the utilization of this kind of refractory iron ore resources with huge reserves. The performance of YJL bituminous coal with low metamorphic degree was compared with JS anthracite as reductants in the process of iron extraction and phosphorus removal of high-phosphorus oolitic hematite using the technique of direct reduction-magnetic separation. The mechanisms of reduction roasting and beneficiation of high-phosphorus oolitic hematite were studied employing X-ray diffraction (XRD) and scanning electron microscope-energy dispersive spectroscopy (SEM-EDS) and thermogrvimetric-differential scanning calorimetry analysis (TG-DSC). Results showed that the reduction results using these two reductants were comparable. For treating the raw ore with total iron (TFe) grade of 50.49 % and phosphorus content of 1.35 %, the direct reduced iron (DRI) with TFe grade of 93.97 %, TFe recovery of 86.14 % and phosphorus content of 1.20 % were obtained using 30 % YJL bituminous coal. The corresponding indexes using 30 % JS anthracite were 94.58 %, 86.15 % and 1.25 %, respectively. When 30 % limestone and 30 % YJL bituminous coal were added, the DRI with phosphorus content of 0.062 %, TFe grade of 94.51 % and TFe recovery of 87.47 % were obtained. The iron minerals were proved to be reduced following the sequence of Fe 2 O 3 → Fe 3 O 4 → FeO (Fe 2 SiO 4 , FeAl 2 O 4) → Fe. The iron particles generated using YJL bituminous coal as reductant were smaller and more dispersed, they can still be recovered by grinding and magnetic separation. From TG-DSC, the total weight loss of YJL bituminous coal and JS anthracite were 33.97 % and 12.63 %, respectively. YJL bituminous coal and JS anthracite occurred depolymerization and decomposition reactions at 350 °C and 400 °C, respectively, producing and releasing a large amount of volatiles substances. YJL bituminous coal releases more reducing gases, mainly including H 2 , gaseous hydrocarbons and CO. And below 820 °C, the mixture of YJL bituminous coal and high-phosphorus oolitic hematite has a higher weight loss at 16.9 % than that of JS anthracite (7.86 %), indicating that YJL bituminous coal was more reactive to high-phosphorus oolitic hematite than JS anthracite at this stage. This work provided an effective utilization method for low metamorphic degree bituminous coal. [ABSTRACT FROM AUTHOR]

PT Timah Tbk has a vision to become a leading environmentally friendly mining company. To achieve this, efforts are being made to use biomass, specifically palm kernel shells, as a reductant in the smelting process, aiming to reduce carbon emissions associated with smelting. Palm kernel shells are selected due to their abundant availability in the Bangka Belitung Islands Province, the operational area of PT Timah Tbk. Before being utilized in the smelting process, palm kernel shells undergo carbonization at a temperature of 400°C for 15 minutes to increase the content of fixed carbon, which plays a crucial role in tin reduction. Carbonized palm kernel shells consist of 51.4% fixed carbon, 27% volatile matter, 14.54% ash, and 7.06% inherent moisture. The smelting process using carbonized palm kernel shells takes place in a Reverberatory Furnace and serves as the initial stage of the tin smelting process. In this stage, tin concentrate is smelted to produce crude tin and slag 1, with a slag 1 assay typically ranging from 15% to 20%. After three cycles of smelting, the average formation of crude tin is 83.31%, the Sn slag assay is 18.70%, and the smelting capacity reaches 50 tons per day. These results align with the standards set for stage 1 of tin smelting at PT Timah Tbk, which traditionally uses coal as a reductant. Therefore, smelting tin with carbonized palm kernel shell as a reductant is a viable and feasible option.

The role of lignin in enzymatic saccharification of cellulose involving lytic polysaccharide monooxygenase (LPMO) was investigated in experiments with the solid and liquid fractions of pretreated Norway spruce from a biorefinery demonstration plant using hydrothermal pretreatment and impregnation with sulfur dioxide. Pretreated biomass before and after enzymatic saccharification was characterized using HPAEC, HPLC, Py-GC/MS, 2D-HSQC NMR, FTIR, and SEM. Chemical characterization indicated that relatively harsh pretreatment conditions resulted in that the solid phase contained no or very little hemicellulose but considerable amounts of pseudo-lignin, and that the liquid phase contained a relatively high concentration (∼5 g/L) of lignin-derived phenolics. As judged from reactions continuously supplied with either air or nitrogen gas, lignin and lignin fragments from both the solid and the liquid phases efficiently served as reductants in LPMO-supported saccharification. When air was used to promote LPMO activity, the enzymatic conversion of cellulose after 72 h was 25% higher in reactions with pretreated solids and buffer, and 14% higher in reactions with pretreatment liquid and microcrystalline cellulose. Research in this area is useful for designing efficient saccharification steps in biochemical conversion of lignocellulosic biomass.

This study presents a fluidization roasting technology for siderite-bearing iron ore without the use of carbon additives. Samples of Jingtieshan iron ore were subjected to fluidization magnetization roasting, and the effects of roasting temperature, time, and N2 flow rate on the magnetic separation performance were explored. An iron concentrate with an iron grade of 57.40% and recovery of 91.17% was acquired at a roasting temperature of 700 °C, roasting time of 10.0 min, an N2 flow rate of 600 mL/min, grinding particle size of −125 μm, and constant magnetic intensity of 99.47 kA/m. The samples were characterized by X-ray diffraction, optical microscopy, scanning electron microscopy–energy dispersive spectroscopy, and vibrating sample magnetometry. The results revealed that hematite and goethite were reduced to magnetite by the CO generated during siderite decomposition; meanwhile, siderite was transformed into magnetite with the consumption of CO during the reduction process. The saturation magnetization of the roasted ore significantly increased owing to the formation of ferrimagnetic magnetite, which was easily recovered in the subsequent magnetic separation. [ABSTRACT FROM AUTHOR]

The high content of iron in ilmenite ore poses a great challenge, particularly in the synthesis of titanium-containing products due to high susceptibility of iron (Fe) to corrosion. Direct leaching of ilmenite ore in hydrochloric acid (HCl) encouraging Fe dissolution was investigated. The influence of variable parameters, the use of additives, and the addition of metallic iron powder were studied to establish the optimum leaching parameters. The results showed that ilmenite with the particle size distribution of +150 µm yielded better efficiencies when leaching was performed with an acid concentration of 7.5 M and a solid-to-acid ratio of 1:10 at 90 °C. An agitation speed of 450 rpm yielded a superior Fe extraction of about 92.32% and a 2.40% titanium (Ti) loss. The addition of both metallic Fe and the MgSO4 additive significantly enhanced Fe dissolution and decreased Ti recovery in a leach solution. It was found that leaching under optimum conditions produced a solid residue with 1.37% Fe impurity while 98.63% was extracted. The leached residue was comprised of 91.4% TiO2 rutile phase and contained a high content of the ilmenite FeTiO3 (4.37%) and SiO2 (2.23%) impurities, while Al2O3, MgO, MnO2, CaO, V2O5, MnO2, and Cr2O3 were below 0.13%. The high TiO2 content in the leached residue makes it suitable for use as feed in the production of synthetic rutile. The leaching kinetics of Fe dissolution was found to conform to the shrinking core model, where diffusion through the product layer is rate controlling. The calculated activation energy according to the Arrhenius equation was 19.13 kJ/mol. [ABSTRACT FROM AUTHOR]

Vanadium carbide MXene (V2C) acts as a new type of two-dimensional (2D) graphene-like transition metal material that has attracted research interest. V2C has been widely used in various fields due to its excellent physical and chemical properties. Herein, the self-assembled V2C@gold nanoparticles (V2C@AuNPs) are prepared by water bath process at 80 °C. With the addition of glutathione (GSH), the absorbance (Abs.) at 550 nm of V2C@AuNPs was decreased. Therefore, an optical sensor is developed to detect GSH based on the properties of V2C@AuNPs. Under the optimal conditions, the detection range is 1–32 µM and the detection limit is 0.099 µM. Furthermore, the proposed GSH sensor exhibits high sensitivity, high selectivity, strong stability, and excellent recovery. The work will expand the application of V2C in biosensing. [ABSTRACT FROM AUTHOR]

Essential oils contain bioactive compounds and studies indicate diverse applications in food storage as antioxidants. Due to varying quantitative composition, it is important to identify the active ingredients and assess their individual antioxidant capacities while also considering their pharmacokinetic properties. Bioinformatics play essential role in the prediction of bioactivity as well as the toxicity of novel compounds. In this study, the antioxidant activity of the phytochemicals in Monodora myristica was predicted in silico using PASS. Systemic ADMET evaluation in the categories: physiochemical property, absorption, distribution, metabolism and excretion, of the two top-scoring compounds were analyzed using the ADMETlab free web interface. These compounds were studied alongside standard synthetic and natural antioxidants to obtain pharmacokinetic data. The parameter ‘reductant’ was observed as high scoring probable activity among the standard antioxidant compounds. E-beta-ocimene and carvacrol scored the highest probable activity among the compound studies. Pharmcokinetic properties of the two compounds were mostly optimal. The outcome of this in silico study provides fore knowledge to the ADMET profile of the compounds and will be useful in planning research to study their application in oxidation-induced food spoilage during cold preservation.

Herein, we disclose cyclic(alkyl)(amino)carbenes (CAACs) to be one‐electron reductants under the formation of a transient radical cation as indicated by EPR spectroscopy. The disclosed CAAC reducing reactivity was used to synthesize acyclic(amino)(aryl)carbene‐based Thiele and Chichibabin hydrocarbons, a new class of Kekulé diradicaloids. The results demonstrate CAACs to be potent organic reductants. Notably, the acyclic(amino)(aryl)carbene‐based Chichibabin's hydrocarbon shows an appreciable population of the triplet state at room temperature, as evidenced by both variable‐temperature NMR and EPR spectroscopy. [ABSTRACT FROM AUTHOR]

L-ergothioneine is a low-molecular weight natural product, the chemical structure of which comprises oxygen-, nitrogen- and sulfur-containing functional groups. This gives L-ergothioneine specific physicochemical properties and allows a better understanding of its chemical reactivity, which is primarily due to the 2-thio-imidazole group. Here, a review is provided of how different modes of chemical reactivity account for the reported molecular biological activities of L-ergothioneine. By matching the physicochemical properties to the biological properties of L-ergothioneine, a new perspective of the function and the mode of action of this enigmatic molecule emerges. [ABSTRACT FROM AUTHOR]

In the present work, NOx conversion efficiency of the hybrid catalysts at low temperatures was investigated. ANP-TVM and ANP-TVC-TVM hybrid catalysts for OHC-SCR performance were prepared by the impregnation method. The properties of catalysts were characterized by scanning electron microscopy (SEM), Brunauer–Emmett–Teller (BET) and X-ray diffraction (XRD) analyses. The NOx conversion ratios with real diesel exhaust gases were performed using oxygenated hydrocarbon reductants such as ethanol, propanol, n-butanol and n-penthanol. Performances of the hybrid catalysts at different engine loads and low temperatures were investigated. It was determined that ANP-TVC-TVM gave better results at all temperatures and loads. In general, the performance of ANP-TVC-TVM hybrid catalyst was superior with ethanol reductant except for at 1 kW engine load. The maximum NOx conversion ratio was 90.6% on the ANP-TVC-TVM hybrid catalyst with n-butanol at 1 kW engine load and 300°C. [ABSTRACT FROM AUTHOR]

As a waste resource, waste cooking oil (WCO) has not been widely used. Based on the characteristics of WCO cracking, this study proposed to replace fossil-based reductant with WCO for copper slag cleaning, to solve the problem of carbon neutralization in this process. Copper slag cleaning experiments were carried out in a lab-scale electric furnace. The matte separated behavior from slag and the distribution of matte in slag were studied. The results showed that the Fe3O4 content decreases from 12.9 to 3.5 wt.% by injecting 2.2 mL of WCO into 300 g copper slag at 1250°C. The distribution of copper content in slag is gradient along the vertical direction. In the reduction stage, the excessive Fe3O4 is reduced and the fluidity of slag is improved. When the precipitation time is above 60 minutes, the copper content in the middle and upper slag is reduced to 0.57 wt.%, which realizes the copper slag cleaning by using WCO.

To enhance the remediation efficiency of arsenic (As) and chromium (Cr)co-contaminated soil, the effect of various combinations of reducing and chelating agents on the removal of As and Cr was studied in the present work by using electrokinetic technology coupled with a permeable reactive barrier (EK-PRB). In an experiment with EK-PRB, reducing agents (ascorbic acid and citric acid) and chelating agents (EDTA-2Na) were applied together with CaAl-layered double hydroxide (CaAl-LDH) to pretreat As and Cr co-contaminated soil. The chelating agents increased the removal efficiency of As and Cr, while the reducing agent only improved As removal in co-contaminated soil. The best removal efficiencies of As and Cr were 41.2% and 46.8%, respectively. The reducing agents promoted the production of As(III) and enhanced the migration of As. However, a large amount of Cr(VI) was reduced to Cr(III), which affected the migration of Cr. Although the addition of chelating agents partly increased the migration of Cr(III), the removal of total chromium (TCr) still decreased. In this remediation system, a PRB can effectively capture and fix As and Cr. The results indicated that As was mainly adsorbed on the surface of CaAl-LDH, while the surface adsorption and intercalation of CaAl-LDH were the main mechanisms for Cr. [ABSTRACT FROM AUTHOR]

Abstract The aim of this study is to investigate the efficacy of persimmon (Diospyros kaki L.) peel extract as a reductant for indigo dyeing. Dried persimmon peel was water extracted and its sugar contents and functionalities were determined. Its reducing power was studied in terms of redox potential of the indigo bath and color strength (K/S value) of the ramie fabrics dyed in the indigo reduction bath. Total sugar content of the extract was 74.3%. Antioxidant capacity reached up to 86.0% at 3.5 μg/mL of the extract concentration. The persimmon peel extract had an effect on indigo reduction and the maximum color strength was obtained within one or two day. At 2–3% of the extract concentration, the redox potential of the indigo bath was maintained in the range of − 550 ~ − 600 mV for 10 days. With increase in the extract concentration, reduction state lasted for longer time and higher color strength was obtained. The persimmon peel extract can be used for indigo reduction dyeing as a sustainable, nontoxic, biodegradable alternative to sodium dithionite.

Blue-coke is a form of granular char prepared by medium-low temperature pyrolysis of low-rank coal. As a reductant, it has been widely used in calcium carbide production, ferroalloy, copper pyro refining, and ferrosilicon production in China due to the abundant reserves of raw coal and its excellent performance. However, there is little research on the pyrolysis process of granular coal to produce blue-coke and its characteristics as a reductant. Thus, the effects of pyrolysis temperature, heating rate, particle size and holding time at the final temperature on blue-coke preparation were investigated in a rotary kiln reactor. The quality index of blue-coke as a reductant and its properties, including the element composition, surface function groups, carbon forms, reactivity and lower heating value under different pyrolysis temperatures, were analyzed in detail. It is demonstrated that the pyrolysis temperature had a more significant impact on the quality of blue-coke compared to other pyrolysis conditions. With the rise of pyrolysis temperature, the blue-coke's C/O and C/H increased. With the particle size and heating rate increased, the temperature gradients developed within the granular coal during the pyrolysis process led to the volatile release shifting to higher temperature zone and more secondary reaction occurrence. Nevertheless, the secondary reaction was restrained in the rotary kiln with good heat and mass transfer. The indexes of blue-cokes as reductants were met by the chars produced at temperatures from 550 oC to 750 oC with a holding time 60 min at this temperature and a heating rate of 10 oC/min. As the key index of blue-coke, the electrical resistivity decreased with the increase of pyrolysis temperature. It was found to be closely related to the removal of H and O heteroatom at the pyrolysis temperature below 700 °C. While at the higher temperature, the development of graphitized carbon structure took a major role on it. Nonetheless, the crystallite sizes of the blue-coke obtained under this low temperature pyrolysis were small and the carbon forms were turbostratic. These resulted in the blue-coke's high combustion reactivity, which would gradually decline with the rise of pyrolysis temperature. • Granular coal was pyrolyzed in a rotary kiln to produce blue-coke. • Preparation conditions of blue-coke as a reductant were investigated. • Relationship between electrical resistivity and blue-coke structure was unveiled. [ABSTRACT FROM AUTHOR]

Studies have been carried out to investigation the possibility of the agglomeration of thermomagnetic manganese concentrates from the Zhomart and Western Kamys fields (Kazakhstan) with obtaining from them conglomerates suitable for chemical and mechanical properties for subsequent ferroalloy processing. Their metallurgical properties are studied and the principal possibility of obtaining standard grades of manganese alloys from them in laboratory conditions is shown.

This study investigated the optimum moral ratio of CO2 and reductants H2O and H2 to obtain high CO2 reduction performance of Pd/TiO2 photocatalyst. The Pd/TiO2 film photocatalyst is prepared by sol-gel and dip-coating process to form TiO2 film and by pulse arc plasma method to dope Pd. The prepared Pd/TiO2 film was characterized by SEM, EPMA and EELS. The impact of overlapping two Pd/TiO2 films on CO2 reduction performance was also investigated to utilize the light and prepared photocatalyst more effectively. Moreover, this study investigated the characteristics of Pd/TiO2 film to reduce CO2 under the illumination condition of Xe lamp with or without ultraviolet (UV) light. It is found when the moral ratio of CO2/H2/H2O is set at 1:0.5:0.5, the best CO2 reduction performance has been obtained under the illumination conditions of Xe lamp with and without UV light. It is revealed that the moral quantity of CH4 per weight of photocatalyst for overlapped Pd/TiO2 film is 8.14 μmol/g for the moral ratio of CO2/H2/H2O of 1:0.5:0.5 under the illumination condition of Xe lamp with UV light, which is approximately 1.1 times larger than that for one Pd/TiO2 film. It can be concluded that the optimum moral ratio of CO2/H2/H2O, for the CO2 reduction reaction, is 1:0.5:0.5.

Cu-doped TiO2 (Cu/TiO2) film photocatalyst was prepared by combination of sol-gel and dip-coating process, and pulse arc plasma method. The effect of Cu/TiO2 photocatalyst on CO2 reduction performance with reductants of H2O and H2 was investigated. In addition, this study investigated overlapping two Cu/TiO2 coated on netlike glass fiber discs in order to utilize the light effectively as well as increase the amount of photocatalyst used for CO2 reduction. The characterization of prepared Cu/TiO2 film coated on netlike glass fiber was analyzed by SEM, EPMA, TEM and EELS. Furthermore, the CO2 reduction performance of Cu/TiO2 film was tested under illumination of Xe lamp with or without ultraviolet (UV) light, respectively. As a result, the best CO2 reduction performance has been achieved under the condition of CO2/H2/H2O = 1:0.5:0.5 with UV light illumination as well as without UV light illumination. Under the illumination condition with UV light, the highest concentration of CO for Cu/TiO2 overlapped is 1.4 times as large as that for single Cu/TiO2, while the highest concentration of CH4 for Cu/TiO2 overlapped is 1.7 times as that for single Cu/TiO2. Under the illumination condition without UV light, the highest molar quality of CO per weight of photocatalyst for Cu/TiO2 overlapped is 1.1 times as that for single Cu/TiO2. The theoretical molar ratio of CO2/H2O or CO2/H2 to produce CO is 1:1, while the theoretical molar ratio of CO2/H2O or CO2/H2 to produce CH4 is 1:4. Since the molar ratio of CO2/H2/H2O = 1:0.5:0.5 can be regarded as the molar ratio of CO2/total reductants = 1:1, it is believed that the results of this study follow the reaction schemes of CO2/H2O and CO2/H2.

The reductant is a critical factor in the hydrometallurgical recycling of valuable metals from spent lithium-ion batteries (LIBs). There is limited information regarding the use of SnCl2 as a reductant with organic acid (maleic acid) for recovering valuable metals from spent Li-CoO2 material. In this study, the leaching efficiencies of Li and Co with 1 mol·L−1 of maleic acid and 0.3 mol·L−1 of SnCl2 were found to be 98.67% and 97.5%, respectively, at 60°C and a reaction time of 40 min. We investigated the kinetics and thermodynamics of the leaching process in this study to better understand the mechanism of the leaching process. Based on a comparison with H2O2 with respect to leaching efficiency, the optimal leaching parameters, and the activation energy, we determined that it is feasible to replace H2O2 with SnCl2 as a leaching reductant in the leaching process. In addition, when SnCl2 is used in the acid-leaching process, Sn residue in the leachate may have a positive effect on the re-synthesis of nickel-rich cathode materials. Therefore, the results of this study provide a potential direction for the selection of reductants in the hydrometallurgical recovery of valuable metals from spent LIBs. [ABSTRACT FROM AUTHOR]

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The paper describes pilot smelting of low-carbon ferrochrome (LCFC) with new type of reductant – multi-component aluminum-silicon-chrome alloy (FASCh). Provisional calculations confirmed by results of pilot smelting show that use of FASCh alloy helps to stabilize LCFC slag and prevent its decomposition. Due to high Al content in FASCh the phase area of slag shifts from dicalcium silicate (larnite- Са2SiO4) area into the helenite area (2 CaO ∙ Al2O3 ∙ SiO2).

The development of highly selective homogeneous electron transfer reagents is highly desirable for synthetic chemistry. An isolable spirosilole tetra-anion described in this paper has been proved to be a promising soluble electron transfer reagent. The reduction of octaphenyl-1,1′-spirobisilole (1) with lithium resulted in the formation of the isolable spirosilole tetra-anion in good yield. The tetra-anion (2) has been characterized by nuclear magnetic resonance (NMR) and cleanly underwent electron transfer reactions with dioxygen, carbonyl groups, and transition metal halides to yield reduction products with the regeneration of 1.

Oxidative folding of proinsulin in the endoplasmic reticulum (ER) is critical for the proper sorting and secretion of insulin from pancreatic β-cells. Here, by using non-cell-based insulin aggregation assays and mouse insulinoma-derived MIN6 cells, we searched for a candidate molecular chaperone for (pro)insulin when its oxidative folding is compromised. We found that interaction between insulin and calreticulin (CRT), a lectin that acts as an ER-resident chaperone, was enhanced by reductive stress in MIN6 cells. Co-incubation of insulin with recombinant CRT prevented reductant-induced aggregation of insulin. Furthermore, lysosomal degradation of proinsulin, which was facilitated by dithiothreitol-induced reductive stress, depended on CRT in MIN6 cells. Together, our results suggest that CRT may be a protective molecule against (pro)insulin aggregation when oxidative folding is defective, e.g. under reductive stress conditions, in vitro and in cultured cells. Because CRT acts as a molecular chaperone for not only glycosylated proteins but also non-glycosylated polypeptides, we also propose that (pro)insulin is a novel candidate client of the chaperone function of CRT. • CRT prevented reductant-induced insulin aggregation in vitro. • CRT binds to proinsulin under reductive stress conditions. • Cellular degradation of proinsulin under reductive stress conditions depended on CRT. [ABSTRACT FROM AUTHOR]

• Ammonia leaching from spent LIBs is investigated by four reductants and leachants. • Thermodynamic analysis of reduction-ammoniacal leaching is expounded in details. • Increasing electrode potential of reductants accelerates leaching of Li, Co and Ni. • The shell-core layer structure is agreed with a shrinking core model. • Layer products of Co 3 (PO 4) 2 and Co 3 O 4 hamper leaching of Li, Co and Ni. Some inevitable issues of the acid leaching method used to recycle spent lithium-ion batteries (LIBs), such as toxic gas emission, excessive acid-base consumption, inferior metal selectivity and equipment corrosion, have gradually emerged and restricted the promotion and development of this method. It is therefore essential to develop a sustainable closed-loop recycling technology (reduction-ammoniacal method) for spent LIBs. In this study, the effects of various species of ammonia, ammonium salts and reductants on the leaching of Li, Co, Ni, Mn and Al from spent LIBs were investigated with a hydrothermal method. An increase of the electrode potential of the reductant greatly accelerated the selective leaching of Li, Co and Ni, which agreed with the thermodynamic analysis results. The standard electrode potentials of the LiNi x Co y Mn 1− x − y O 2 (NCM) materials were also determined by using approximate calculations. When using (NH 4) 2 SO 3 as a reductant in a one-step leaching process, 100% Co, 98.3% Ni and 90.3% Li were extracted into the ammonia-ammonium chloride solutions. From the kinetics analysis, the surface chemical reaction shrinking core model was found to control the leaching behavior of Li, Co, and Ni in the reduction-ammoniacal leaching process. A shell-core structure was composed of a product layer, a diffusion layer of the solid core and an unreacted core. Species in the product layer reduced the leaching efficiencies of Li, Co, and Ni. The results obtained for this hydrothermal reduction-ammoniacal method applied to recycle spent LIBs provide insights for the design of a high-speed, exceptionally selective, closed-loop recycling technique. [ABSTRACT FROM AUTHOR]