Regulating the valence and size of the active center of Co/Al2O3 catalyst improved the performance and selectivity of NH3-SCO.

To improve the activity of Co/Al2O3 catalysts in selective catalytic oxidation of ammonia (NH3-SCO), valence state and size of active centers of Al2O3-supported Co catalysts were adjusted by conducting H2 reduction pretreatment. The NH3-SCO activity of the adjusted 2Co/Al2O3 catalyst was substantially improved, outperforming other catalysts with higher Co-loading. Fresh Co/Al2O3 catalysts exhibited multitemperature reduction processes, enabling the control of the valence state of the Co-active centers by adjusting the reduction temperature. Changes in the state of the Co-active centers also led to differences in redox capacity of the catalysts, resulting in different reaction mechanisms for NH3-SCO. However, in situ diffuse reflectance infrared Fourier transform spectra revealed that an excessive O2 activation capacity caused overoxidation of NH3 to NO and NO2. The NH3-SCO activity of the 2Co/Al2O3 catalyst with low redox capacity was successfully increased while controlling and optimizing the N2 selectivity by modulating the active centers via H2 pretreatment, which is a universal method used for enhancing the redox properties of catalysts. Thus, this method has great potential for application in the design of inexpensive and highly active catalysts.

Bamboo-like MnO2⋠Co3O4: High-performance catalysts for the oxidative removal of toluene.

The manganese-cobalt mixed oxide nanorods were fabricated using a hydrothermal method with different metal precursors (KMnO4 and MnSO4·H2O for MnOx and Co(NO3)2⋅6H2O and CoCl2⋅6H2O for Co3O4). Bamboo-like MnO2⋅Co3O4 (B-MnO2⋅Co3O4 (S)) was derived from repeated hydrothermal treatments with Co3O4@MnO2 and MnSO4⋅H2O, whereas Co3O4@MnO2 nanorods were derived from hydrothermal treatment with Co3O4 nanorods and KMnO4. The study shows that manganese oxide was tetragonal, while the cobalt oxide was found to be cubic in the crystalline arrangement. Mn surface ions were present in multiple oxidation states (e.g., Mn4+ and Mn3+) and surface oxygen deficiencies. The content of adsorbed oxygen species and reducibility at low temperature declined in the sequence of B-MnO2⋅Co3O4 (S) > Co3O4@MnO2 > MnO2 > Co3O4, matching the changing trend in activity. Among all the samples, B-MnO2⋅Co3O4 (S) showed the preeminent catalytic performance for the oxidation of toluene (T10% = 187°C, T50% = 276°C, and T90% = 339°C). In addition, the B-MnO2⋅Co3O4 (S) sample also exhibited good H2O-, CO2-, and SO2-resistant performance. The good catalytic performance of B-MnO2⋅Co3O4 (S) is due to the high concentration of adsorbed oxygen species and good reducibility at low temperature. Toluene oxidation over B-MnO2⋅Co3O4 (S) proceeds through the adsorption of O2 and toluene to form O*, OH*, and H2C(C6H5)* species, which then react to produce benzyl alcohol, benzoic acid, and benzaldehyde, ultimately converting to CO2 and H2O. The findings suggest that B-MnO2⋅Co3O4 (S) has promising potential for use as an effective catalyst in practical applications.

Sensitive visual detection of norfloxacin in water by smartphone assisted colorimetric method based on peroxidase-like active cobalt-doped Fe3O4 nanozyme.

Norfloxacin is widely used owing to its strong bactericidal effect on Gram-negative bacteria. However, the residual norfloxacin in the environment can be biomagnified via food chain and may damage the human liver and delay the bone development of minors. Present work described a reliable and sensitive smartphone colorimetric sensing system based on cobalt-doped Fe3O4 magnetic nanoparticles (Co-Fe3O4 MNPs) for the visual detection of norfloxacin. Compared with Fe3O4, Co-Fe3O4 MNPs earned more remarkably peroxidase-like activity and TMB (colorless) was rapidly oxidized to oxTMB (blue) with the presence of H2O2. Interestingly, the addition of low concentration of norfloxacin can accelerate the color reaction process of TMB, and blue deepening of the solution can be observed with the naked eye. However, after adding high concentration of norfloxacin, the activity of nanozyme was inhibited, resulting in the gradual fading of the solution. Based on this principle, a colorimetric sensor integrated with smartphone RGB mode was established. The visual sensor exhibited good linearity for norfloxacin monitoring in the range of 0.13-2.51 µmol/L and 17.5-100 µmol/L. The limit of visual detection was 0.08 µmol/L. In the actual water sample analysis, the spiked recoveries of norfloxacin were over the range of 95.7%-104.7 %. These results demonstrated that the visual sensor was a convenient and fast method for the efficient and accurate detection of norfloxacin in water, which may have broad application prospect.

Co-doped cryptomelane-type manganese oxide in situ grown on a nickel foam substrate for high humidity ozone decomposition.

Monolithic catalysts with excellent O3 catalytic decomposition performance were prepared by in situ loading of Co-doped KMn8O16 on the surface of nickel foam. The triple-layer structure with Co-doped KMn8O16/Ni6MnO8/Ni foam was grown spontaneously on the surface of nickel foam by tuning the molar ratio of KMnO4 to Co(NO3)2·6H2O precursors. Importantly, the formed Ni6MnO8 structure between KMn8O16 and nickel foam during in situ synthesis process effectively protected nickel foam from further etching, which significantly enhanced the reaction stability of catalyst. The optimum amount of Co doping in KMn8O16 was available when the molar ratio of Mn to Co species in the precursor solution was 2:1. And the Mn2Co1 catalyst had abundant oxygen vacancies and excellent hydrophobicity, thus creating outstanding O3 decomposition activity. The O3 conversion under dry conditions and relative humidity of 65%, 90% over a period of 5 hr was 100%, 94% and 80% with the space velocity of 28,000 hr-1, respectively. The in situ constructed Co-doped KMn8O16/Ni foam catalyst showed the advantages of low price and gradual applicability of the preparation process, which provided an opportunity for the design of monolithic catalyst for O3 catalytic decomposition.

Ti3+/Ti4+ and Co2+/Co3+ redox couples in Ce-doped Co-Ce/TiO2 for enhancing photothermocatalytic toluene oxidation.

Cerium and cobalt loaded Co-Ce/TiO2 catalyst prepared by impregnation method was investigated for photothermal catalytic toluene oxidation. Based on catalyst characterizations (XPS, EPR and H2-TPR), redox cycle between Co and TiO2 (Co2+ + Ti4+ ↔ Co3+ + Ti3+) results in the formation of Co3+, Ti3+ and oxygen vacancies, which play important roles in toluene catalytic oxidation reaction. The introduction of Ce brings in the dual redox cycles (Co2+ + Ti4+ ↔ Co3+ + Ti3+, Co2+ + Ce4+ ↔ Co3+ + Ce3+), further promoting the elevation of reaction sites amount. Under full spectrum irradiation with light intensity of 580 mW/cm2, Co-Ce/TiO2 catalyst achieved 96% of toluene conversion and 73% of CO2 yield, obviously higher than Co/P25 and Co/TiO2. Co-Ce/TiO2 efficiently maintains 10-hour stability test under water vapor conditions and exhibits better photothermal catalytic performance than counterparts under different wavelengths illumination. Photothermal catalytic reaction displays improved activities compared with thermal catalysis, which is attributed to the promotional effect of light including photocatalysis and light activation of reactive oxygen species.

Tailored design of novel Co0-Coδ+ dual phase nanoparticles for selective CO2 hydrogenation to ethanol.

Catalytic hydrogenation of CO2 to ethanol is a promising solution to address the greenhouse gas (GHG) emissions, but many current catalysts face efficiency and cost challenges. Cobalt based catalysts are frequently examined due to their abundance, cost-efficiency, and effectiveness in the reaction, where managing the Co0 to Coδ+ ratio is essential. In this study, we adjusted support nature (Al2O3, MgO-MgAl2O4, and MgO) and reduction conditions to optimize this balance of Co0 to Coδ+ sites on the catalyst surface, enhancing ethanol production. The selectivity of ethanol reached 17.9% in a continuous flow fixed bed micro-reactor over 20 mol% Co@MgO-MgAl2O4 (CoMgAl) catalyst at 270 °C and 3.0 MPa, when reduced at 400 °C for 8 h. Characterisation results coupled with activity analysis confirmed that mild reduction condition (400 °C, 10% H2 balance N2, 8 h) with intermediate metal support interaction favoured the generation of partially reduced Co sites (Coδ+ and Co0 sites in single atom) over MgO-MgAl2O4 surface, which promoted ethanol synthesis by coupling of dissociative (CHx*)/non-dissociative (CHxO*) intermediates, as confirmed by density functional theory analysis. Additionally, the CoMgAl, affordably prepared through the coprecipitation method, offers a potential alternative for CO2 hydrogenation to yield valuable chemicals.

Bimetallic Fe/Co-MOF dispersed in a PVA/chitosan multi-matrix hydrogel as a flexible sensor for the detection of lactic acid in sweat samples.

A novel bimetallic Fe/Co-metal-organic framework (MOF) hydrogel-based wearable sweat sensor was developed. Morphological and structural analysis of the hydrogel shows uniformly sized spines and spindle-shaped particles of the Fe/Co-MOF, and it has a high surface area (132.306 m2 g-1) and porosity (0.059 cm3 g-1) as confirmed by Brunauer-Emmett-Teller (BET) studies. The integration of the bimetallic MOF into a polyvinyl alcohol/chitosan (PVA/CS)-mixed matrix resulted in a multiple network hydrogel. The optimisation study investigated  the effects of different pH of the PBS electrolyte, scan rates, and accumulation time in voltammetry. The electrochemical methods such as cyclic voltammetry (CV), square wave voltammetry (SWV), and electrochemical impedance spectroscopy (EIS) provided information on the redox behaviour, electrochemical stability, and catalytic activity of the hydrogel. The sensor demonstrates a wide linear detection range from 0.05 µM to 100 mM, a superior sensitivity of 0.02 mA mM-1 cm-2, and a lower limit of detection of 0.01 µM . Active sites distributed over the hydrogel surface, specifically Fe2+ and Co2+ within the MOF structure, catalyse the oxidation of L-lactic acid, resulting in electron transfer and the formation of pyruvic acid. Notably, the fabricated sensor exhibits high selectivity, effectively discriminating against interfering species such as uric acid, ascorbic acid, glucose, urea, dopamine, NaCl, and CaCl2. Real-time analysis conducted in a simulated sweat sample via the standard addition method resulted in good recovery percentages of a minimum of 98%. The work presented here is a versatile and simple platform for point-of-care testing, especially for athletes and military personnel.

High Efficiency Removal Performance of Tetracycline by Magnetic CoFe2O4/NaBiO3 Photocatalytic Synergistic Persulfate Technology.

The widespread environmental contamination resulting from the misuse of tetracycline antibiotics (TCs) has garnered significant attention and study by scholars. Photocatalytic technology is one of the environmentally friendly advanced oxidation processes (AOPs) that can effectively solve the problem of residue of TCs in the water environment. This study involved the synthesis of the heterogeneous magnetic photocatalytic material of CoFe2O4/NaBiO3 via the solvothermal method, and it was characterized using different characterization techniques. Then, the photocatalytic system under visible light (Vis) was coupled with peroxymonosulfate (PMS) to explore the performance and mechanism of degradation of tetracycline hydrochloride (TCH) in the wastewater. The characterization results revealed that CoFe2O4/NaBiO3 effectively alleviated the agglomeration phenomenon of CoFe2O4 particles, increased the specific surface area, effectively narrowed the band gap, expanded the visible light absorption spectrum, and inhibited recombination of photogenerated electron-hole pairs. In the Vis+CoFe2O4/NaBiO3+PMS system, CoFe2O4/NaBiO3 effectively activated PMS to produce hydroxyl radicals (·OH) and sulfate radicals (SO4-). Under the conditions of a TCH concentration of 10 mg/L-1, a catalyst concentration of 1 g/L-1 and a PMS concentration of 100 mg/L-1, the degradation efficiency of TCH reached 94% after 100 min illumination. The degradation of TCH was enhanced with the increase in the CoFe2O4/NaBiO3 and PMS dosage. The solution pH and organic matter had a significant impact on TCH degradation. Notably, the TCH degradation efficiency decreased inversely with increasing values of these parameters. The quenching experiments indicated that the free radicals contributing to the Vis+CoFe2O4/NaBiO3+PMS system were ·OH followed by SO4-, hole (h+), and the superoxide radical (O2-). The main mechanism of PMS was based on the cycle of Co3+ and Co2+, as well as Fe3+ and Fe2+. The cyclic tests and characterization by XRD and FT-IR revealed that CoFe2O4/NaBiO3 had good degradation stability. The experimental findings can serve as a reference for the complete removal of antibiotics from wastewater.

Cobalt stress enhanced dendrobine-type total alkaloids biosynthesis of Trichoderma longibrachiatum UN32 through reactive oxygen species formation.

Trichoderma longibrachiatum UN32 is a well-documented mutant strain known to produce dendrobine-type total alkaloids (DTTAs). It was serendipitously observed that the addition of Co2+ to the medium resulted in a notable enhancement in DTTAs production in the T. longibrachiatum UN32 strain, accompanied by an upregulating effect on the expression of antioxidase-related genes. Hence, the objective of the present work was to ascertain whether ROS (intracellular levels of hydrogen peroxide) induced by Co2+ treatment has a beneficial or detrimental impact on DTTAs biosynthesis. A comparison of the intracellular levels of hydrogen peroxide (H2O2) and DTTAs treated with CoCl2 and CH3COOH revealed that CoCl2 was the optimal inducer for investigating the relationship between ROS formation and DTTAs production. This was due to the observation that ROS formation was reduced by approximately 4% and DTTAs production was increased by 12.55% in comparison to the CH3COOH treatment. The physiological results revealed that the introduction of Co2+ resulted in the oxidative damage and activation of the expression of intracellular superoxide dismutase (SOD), catalase (CAT), and peroxidase (POD). Furthermore, it was confirmed that ROS induced by Co2+ was beneficial to DTTAs production by adding exogenous ROS scavengers. The inclusion of all ROS scavengers, including vitamin C, tocopherol, melatonin, mannitol, and sesamol, resulted in a reduction in ROS accumulation and a concomitant decrease in DTTAs production. Specifically, the addition of melatonin at a concentration of 0.4 mg/L demonstrated significant effects, resulting in a 32.53% (P < 0.01) decrease in ROS accumulation and a 45.22% (P < 0.01) reduction in DTTAs production. Subsequently, the timelines of accumulation of intracellular H2O2 and DTTAs content indicated that ROS are also crucial for normal fermentation without CoCl2 addition. Specifically, the proper H2O2 dose for DTTAs accumulation is between 8.82 and 18.86 µmol/g. The present study offers the initial experimental evidence indicating that CoCl2 enhance DTTAs production during the culture of T. longibrachiatum UN32 via leading an increase in intracellular ROS, which is conductive to DTTAs production and can be inhibited by the ROS scavengers. Our results provide insights into the mechanistic study of DTTAs biosynthesis.

Metal ion levels after metal-on-metal hip resurfacing: A single-center longitudinal study of Chinese patients.

This study aimed to investigate the long-term serum metal ion levels of patients who received metal-on-metal hip resurfacing arthroplasty (MoM HRA). We conducted a retrospective study of 99 patients (110 hips) from March 2006 to May 2017 who underwent MoM HRA. The Harris Hip Score (HHS) and the University of California at Los Angeles (UCLA) activity score were measured, and the patients underwent clinical and radiological management. Serum levels of cobalt (Co), chromium (Cr), and molybdenum (Mo) were measured using inductively coupled plasma mass spectrometry (ICPMS) at 1, 6, and 12 months, and each year follow-up after prosthesis implantation. Patients were followed up from 1 to 156 months, with a mean of 98 months. No complications occurred. Metal ion analysis revealed significantly elevated levels compared to preoperative levels. The metal ions levels increased and reached a peak after surgery, and then the levels began to decline gradually. Approximately 84-108 months after surgery, the metal ion levels increased again to approximately peak levels. Then, up to 156 months after surgery, the metal ions levels will drop approximately to preoperative levels. The serum levels of Cr in women were higher than those in men, with the difference being statistically significant. Patients with a body mass index (BMI) of ≥24.9 kg/m2 Co levels were significantly higher than those of normal-weight patients. The serum levels of metal ions showed no significant differences between the prostheses. The use of the MoM HRA was clinically effective, and the Co, Cr, and Mo levels increased significantly after HRA; however, upon long-term follow-up, serum metal ion levels tended to decrease to preoperative levels. Longer follow-up periods and larger study samples are needed to establish the long-term outcome of patients undergoing HRA with MoM bearings. Level IV, Therapeutic Study.

Ultrasensitive Imaging Assay of Multiple Mycotoxins Using Cobalt DNA-Inorganic Hybrid Superstructure with High Chemiluminescence Catalytic Property.

A multiplex assay of mycotoxins in food and medicine is urgently needed and challenging due to synergistic hazards of trace mycotoxins and a lack of sensitive and user-friendly detection approaches. Herein, a cobalt DNA-inorganic hybrid superstructure (Co@DS) was developed through isothermal rolling circle amplification (RCA) for an ultrasensitive chemiluminescence (CL) imaging assay of multiple mycotoxins. Cobalt ions were enriched in the RCA product, endowing the Co@DS with a high CL catalytic property. Experimental studies elucidated the formation and CL catalytic mechanism of Co@DS. Co@DS was facilely integrated with biotinylated DNA to function as a universal platform and combined with a disposable immunosensor array chip. After a competitive immunoassay and biotin-avidin recognition, the CL signals of luminol and hydrogen peroxide, catalyzed by Co@DS captured on each testing zone of the array chip, were imaged simultaneously. Target mycotoxins can be quantitated by CL intensities. To validate the concept, the CL imaging approach was employed for joint determination of aflatoxin B1, ochratoxins A, and zearalenone. Under optimal conditions, it showed advantages including simple sample pretreatment, acceptable throughput, high accuracy, minimal sample consumption, broad linear ranges, and detection limits as low as 0.75, 0.62, and 0.61 pg mL-1, respectively. Furthermore, the approach was applied in analyzing real coix seed samples, showcasing excellent performance in effectively distinguishing qualified and contaminated medicine, revealing the great potential in managing the complex issue of mycotoxins cocontamination in food and medicine.

Singlet oxygen dominant-activation by hollow structural cobalt-based MOF/peroxymonosulfate system for micropollutant removal.

Despite the keen interest in potentially using the metal-organic framework (MOF) in advanced oxidation processes (AOPs), their application for environmental abatement and the corresponding degradation mechanisms have remained largely elusive. This study explores the use of cobalt-based MOF (CoMOF) for peroxymonosulfate (PMS) activation to remove tetracycline (TC) from water resources. Under optimal conditions, the given catalytic system could achieve a TC removal of 83.3%. Radical quenching tests and EPR analysis revealed that SO4•-, HO•, •O2-, and 1O2 could participate in the catalytic degradation, but the discernible removal mechanism was mainly ascribed to the nonradical pathway induced by 1O2. At only 5 mg/L of CoMOF, the performance of the catalytic system was superior to that of PMS alone for different types of micropollutants. The CoMOF/PMS system could also reliably deal with typical anions in water, such as Cl-, SO42-, HCO3-, and PO43-. The MOF catalyst could last for four cycles with a minor decrease in reactivity of ∼30%. However, the removal performance decreased markedly when aromatic natural organic matter (NOM) were present in the water bodies, and the effectiveness was lower in alkaline or acidic environments. Our work offers insights into the catalytic degradation of CoMOF/PMS applied in contaminated water remediation and serves as a baseline for fabricating an efficient MOF with enhanced catalytic performance and stability.

The potential of Gd doping as a promising approach for enhancing the adsorption properties of nickel-cobalt ferrites.

The study shows that the addition of gadolinium ions has a significant impact on the structure, morphology, and adsorption properties of Ni-Co spinel ferrite that was synthesized by the sol-gel auto-combustion method. The research also indicates that the higher the Gd content, the greater the increase in the lattice parameter, which suggests that Gd3+ ions uniformly replaced the octahedral Fe3+ ions. The morphology and chemical composition of Gd-doped Ni-Co ferrites have been studied using SEM and EDS. Gd adding to the NiCoFe matrix increases the BET surface area by 50% (from 48 to 72 m2/g) and promotes the formation of mesopores with an average radius from 3.9 to 4.9 nm. The pHPZC values of Gd-doped ferrites are in the range of 7.22-7.39, which means that the ferrite surface will acquire a positive charge at natural pH, so this will promote the adsorption of Congo red anionic dye through electrostatic interaction forces. Langmuir, Freundlich, and Dubinin-Radushkevich models were used to explain the mechanism of CR adsorption on the Ni0.5Co0.5GdxFe2-xO4 adsorbent surface. The ionic-covalent parameter has been estimated to describe the surface acid-base properties. Overall, this study highlights the potential of Gd3+ doping as a promising approach for enhancing the adsorption properties of nickel-cobalt ferrites.

Unveiling the mechanism of cysteamine dioxygenase: A combined HPLC-MS assay and metal-substitution approach.

Mammalian cysteamine dioxygenase (ADO), a mononuclear non-heme Fe(II) enzyme with three histidine ligands, plays a key role in cysteamine catabolism and regulation of the N-degron signaling pathway. Despite its importance, the catalytic mechanism of ADO remains elusive. Here, we describe an HPLC-MS assay for characterizing thiol dioxygenase catalytic activities and a metal-substitution approach for mechanistic investigation using human ADO as a model. Two proposed mechanisms for ADO differ in oxygen activation: one involving a high-valent ferryl-oxo intermediate. We hypothesized that substituting iron with a metal that has a disfavored tendency to form high-valent states would discriminate between mechanisms. This chapter details the expression, purification, preparation, and characterization of cobalt-substituted ADO. The new HPLC-MS assay precisely measures enzymatic activity, revealing retained reactivity in the cobalt-substituted enzyme. The results obtained favor the concurrent dioxygen transfer mechanism in ADO. This combined approach provides a powerful tool for studying other non-heme iron thiol oxidizing enzymes.

Coordination compounds of cobalt(II) with carboxylate non-steroidal anti-inflammatory drugs: structure and biological profile.

Fourteen cobalt(II) complexes with the non-steroidal anti-inflammatory drugs sodium meclofenamate, tolfenamic acid, mefenamic acid, naproxen, sodium diclofenac, and diflunisal were prepared in the presence or absence of a series of nitrogen-donors (namely imidazole, pyridine, 3-aminopyridine, neocuproine, 2,2'-bipyridine, 1,10-phenanthroline and 2,2'-bipyridylamine) as co-ligands and were characterised by spectroscopic and physicochemical techniques. Single-crystal X-ray crystallography was employed to determine the crystal structure of eight complexes. The biological profile of the complexes was investigated regarding their interaction with serum albumins and DNA, and their antioxidant potency. The interaction of the compounds with calf-thymus DNA takes place via intercalation. The ability of the complexes to cleave pBR322 plasmid DNA at the concentration of 500 µM is rather low. The complexes demonstrated tight and reversible binding to human and bovine serum albumins and the binding site of bovine serum albumin was also examined. In order to assess the antioxidant activity of the compounds, the in vitro scavenging activity towards free radicals, namely 1,1-diphenyl-picrylhydrazyl and 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid), and their ability to reduce H2O2 were studied.

Preparation of 97% pure nickel-cobalt alloy from waste Ni-MH batteries by using waste glass as a fluxing agent.

With the e-waste growing rapidly all over the globe due to growing demand of electronics, smartphones, etc., coming up with an efficient and sustainable recycling process is the need of the hour. The present work reports a novel and sustainable process of manufacturing Ni alloy by bringing together three major waste streams such as waste Ni-MH batteries, e-waste plastics, and waste glass. The chosen temperature (1550 °C) favours the reduction of nickel-oxide by e-waste plastic as the reductant and sends rare earth elements present in the waste Ni-MH battery as oxide mixture to the slag phase. Waste glass powder used in this process functions as the fluxing agent, hence not requiring any additional flux. The reduction mechanism is gas-based, controlled mainly by hydrogen and carbon monoxide gases released as a result of decomposition of e-waste plastic as reaction commenced from cold zone (∼300 °C) to hot zone (1550 °C) in the horizontal tubular furnace. Formation of nickel alloy and enrichment of slag with mixture of rare earth oxides were confirmed by XRD, SEM-EDS, and Rietveld refining analysis performed on the XRD spectra of slag phase. ICP-OES (Inductively coupled plasma optical emission spectroscopy) and LIBS (laser induced breakdown spectrometer KT-100S) confirmed the high metal content in the alloy, thereby emphasizing the purity (∼98%) which is close to the composition of nickel super alloy. A maximum of 61% by weight REO enrichment was achieved in the slag phase, having La2O3:44.6%, Pr2O3:14.8%, and Nd2O3: 1.6% under optimised experimental conditions (1550 °C, 15 min, and 20% waste glass powder). This scientific investigation evinces a promising route for efficient utilisation of waste streams emanating from e-waste, thereby devising a sustainable recycling technique and protecting the environment, too.

Revisiting the Iron(II)/Cobalt(II)-Based Homogenous Fenton-like Processes from the Standpoint of Diverse Metal-Oxygen Complexes.

The aqueous FeIV-oxo complex and FeIII-peroxy complex (e.g., ligand-assisted or interfacial FeIII-hydroperoxo intermediates) have been recognized as crucial reactive intermediates for decontamination in iron-based Fenton-like processes. Intermediates with terminal oxo ligands can undergo the oxygen atom exchange process with water molecules, whereas peroxides are unable to induce such exchanges. Therefore, these distinct metal-oxygen complexes can be distinguished based on the above feature. In this study, we identified previously unknown intermediates with a peroxy moiety and cobalt center that were generated during peroxymonosulfate (PMS) activation via aqueous CoII ions under acidic conditions. Results of theoretical calculations and tip-enhanced Raman spectroscopy revealed that the CoII ion tended to coordinate with the PMS anion to form a bidentate complex with a tetrahedral structure. These reactive cobalt intermediates were collectively named the CoII-PMS* complex. Depending on the inherent characteristics of the target contaminants, the CoII-PMS* complex can directly oxidize organic compounds or trigger PMS disproportionation to release hydroxyl radicals and sulfate radicals for collaborative decontamination. This work provides a comparative study between iron- and cobalt-based Fenton-like processes and proposes novel insights from the standpoint of diverse metal-oxygen complexes.

Dynamics of growth, physiology, radiation interception, production, and quality of autumn black gram (Vigna mungo (L.) Hepper) as influenced by nutrient scheduling.

To analyse the effect of nutrient management on the growth, physiology, energy utilization, production and quality of black gram, a field trial on black gram was conducted at eastern Indian Gangetic alluvium during the autumn of 2020 and 2021. Treatments were two soil applications of cobalt (Co) and foliar spray of potassium (K) and boron (B) in five combinations. All treatments were arranged in a split-plot design and repeated three times. Two soil applications of cobalt (Co) were assigned in the main plots and foliar spray of potassium (K) and boron (B) in five combinations were assigned in sub-plots. Applications of Co in soil and foliar K+B facilitated significantly higher (p≤0.05) values for aerial dry matter (ADM), leaf area index (LAI), nodules per plant, total chlorophyll, net photosynthetic rate and nitrate reductase content in both 2020 and 2021, with a greater realization of photosynthetically active radiation interception, and use efficiency (IPAR and PARUE respectively), seed yield, seed nutrients and protein contents. Differences in LAI exhibited positive and linear correlation with IPAR explaining more than 60% variations in different growth stages. The innovative combination of soil Co (beneficial nutrient) application at 4 kg ha-1 combined with foliar 1.25% K (macronutrient) + 0.2% B (micronutrient) spray is a potential agronomic management schedule for the farmers to sustain optimum production of autumn black gram through substantial upgradation of growth, physiology, energy utilization, production and quality in Indian subtropics.

Effect of caffeic acid and cobalt sulfate on potato (Solanum tuberosum L.) plants in the presence and absence of nanoparticles-coated urea.

Potatoes (Solanum tuberosum L.) are a significant food crop cultivated around the world. Caffeic acid (CA) can enhance plant growth by promoting antioxidant activity and stimulating root development, contributing to overall plant health and vigor. Cobalt sulfate (CoSO4) boosts plant growth by promoting nitrogen (N) fixation, healthier root development, and chlorophyll synthesis, enhancing photosynthesis and overall plant health. Nanoparticle-coated urea (NPCU) improves nutrient uptake, promoting plant growth efficiency and reducing environmental impact. This study investigates the effects of combining CA, CoSO4, and NPCU as amendments on potatoes with and without NPCU. Four treatments, control, 20 µM CA, 0.15 mg/L CoSO4, and 20 µM CA + 0.15 mg/L CoSO4 with and without NPCU, were applied in four replications using a completely randomized design. Results demonstrate that the combination of CA + CoSO4 with NPCU led to an increase in potato stem length (~ 6%), shoot dry weight (~ 15%), root dry weight (~ 9%), and leaf dry weight (~ 49%) compared to the control in nutrient stress. There was a significant rise in chlorophyll a (~ 27%), chlorophyll b (~ 37%), and total chlorophyll (~ 28%) over the control under nutrient stress also showed the potential of CA + CoSO4 with NPCU. In conclusion, the findings suggest that applying CA + CoSO4 with NPCU is a strategy for alleviating potato nutrient stress.

Protein-driven interaction enhanced electrochemiluminescence biosensor of hydrogen-bonded biohybrid organic frameworks for sensitive immunoassay of disease markers.

The oriented design of reticular materials as emitters can significantly enhance the sensitivity of electrochemiluminescence (ECL) sensing analysis for disease markers. However, due to the structural fragility of hydrogen bonds, relational research on hydrogen-bonded organic frameworks (HOFs) has not been thoroughly conducted. Additionally, the modulation of luminescence behavior through HOFs has been rarely reported. In view of this, hydrogen-bonded biohybrid organic frameworks (HBOFs) were synthesized and recruited for ECL immunoassay applications. HBOFs was easily prepared using 6,6',6″,6‴-(pyrene-1,3,6,8-tetrayl)tetrakis(2-naphthoic acid) as linkers via bovine serum albumin (BSA) activated hydrogen-bonded cross-linking. The material exhibited good fluorescence emission characteristics. And the highly ordered topological structure and molecular motion limitation mediated by BSA overcome aggregation-caused quenching and generate strong aggregation induced emission, expressing hydrogen-bond interaction enhanced ECL (HIE-ECL) activity with the participation of tri-n-propylamine. Furthermore, a sandwich immunosensor was constructed employing cobalt-based metal-phenolic network (CMPN) coated ferrocene nanoparticles (FNPs) as quenchers (CMPN@FNPs). Signal closure can be achieved by annihilating the excited state through electron transfer from both CMPN and FNPs. Using a universal disease marker, carcinoembryonic antigen, as the analysis model, the signal-off sensor obtained a detection limit of 0.47 pg/mL within the detection range of 1 pg/mL - 50 ng/mL. The synthesis and application of highly stable HBOFs triggered by proteins provide a reference for the development of new reticular ECL signal labels, and electron transfer model provides flexible solutions for more sensitive sensing analysis.