Common Metal Research Articles

CdS/ZnS quantum dots based on an amphipathic polymer platform for fluorescent probe of dopamine with high sensitivity and selectivity

Due to the widespread presence of dopamine in living organisms and its physiological and pharmacological effects, developing rapid and sensitive methods for detecting dopamine has been of great significance. Fluorescent probes are a commonly used and highly sensitive detection method. In this work, based on a self-developed amphipathic polymer template, CdS/ZnS fluorescent quantum dots (QDs) with a maximum absorption wavelength of 500–550 nm were synthesized and characterized. They exhibited stable fluorescence in the pH range from weak acid to alkaline, and fluorescence quenching occurred at pH = 4.5. The QDs could be applied as fluorescent probes for detecting dopamine, with a limit of detection 0.027 mM and high selectivity, unaffected by common metal ions, amino acids, glucose, etc. Compared to the high activity of dopamine being oxidized easily, this fluorescent QDs and its template polymer PEI played a stabilizing role during the testing process. Therefore, this work provides a promising dopamine fluorescent probe with application prospects.

Preparation and properties of gel-type low-temperature phase change materials

In the context of the dual‑carbon target, there is a high emphasis on the energy efficiency of traditional mechanical cold storage systems with significant power consumption. Additionally, the implementation of time-of-use electricity pricing has played a crucial role in driving the rapid advancement of energy storage technology. The application of energy storage technology in cold storage can significantly reduce the energy consumption of the refrigeration system, save operating costs by shifting peak demand to valleys, and reduce start and stop frequencies. Therefore, studying phase-change materials with high latent heat, low cost, and good performance for cold storage is of great practical application in cold storage. The paper developed four types of gel-type phase-change cold storage materials with high latent heat, low cost, and good cycle stability. These materials mainly consist of NH4Cl, KCl, and deionized water. The phase transition temperature ranges from −18 to −21 °C, the latent heat of phase change is approximately 260 to 289 J/g, and the thermal conductivity ranges from 0.58 to 0.60 W/(m·K), which can meet the cooling demand of cold storage facilities. Furthermore, by comparing the phase transition temperature, latent heat value of phase change, and cyclic stability, a gel-type PCM with good comprehensive properties was selected for corrosion and corrosion inhibition studies with five common metal samples in welded and non-welded forms. The results showed that material B2 had slight corrosion on 1060 aluminum, 6061 aluminum, and 304 stainless steels, but no obvious corrosion phenomenon was found on 316 stainless steels. The corrosion rate of the material on red copper was the highest, and the corrosion was too strong. In addition, the corrosion of welded parts is more serious than that of non-welded parts, and the welding points are more susceptible to corrosion. Adding the corrosion inhibitor BTA to material B2 can reduce the corrosion rate of red copper by more than 94 %.

Selective electrocatalytic oxidation of ammonia to nitrogen by using titanium dioxide nanorod array decorated with ultrasmall Ir nanoparticles and non-noble metal Fe nanoparticles

Electrochemical ammonia oxidation process through active chlorine has been proposed as a potentially effective method for ammonia removal. Currently, most of the anodes require to use high-stable TiO2 loaded with large particles of noble metal Ru or Ir, which have low activity and high cost. Herein, we prepare ultrasmall and uniform metal nanoparticles of Ir on TiO2 to remove ammonia. Moreover, we use non-noble metal Fe to replace noble metals. The ammonia removal efficiency of Fe/TiO2 under 2 VVS Ag / AgCl during 2 h is 100 % and 94 % of ammonia is converted to N2. The Fe/TiO2 anodes not only have higher catalytic activity but also show excellent stability and reusability. Fe/TiO2 anodes still exhibit excellence activity and selectivity after 1 year. As a common metal, Fe will have more application space than iridium in ammonia removal for its low cost and selectively high efficiency.

Designing the bimetallic catalysts by the adsorption strength of metal atoms for efficient oxygen reduction: A density functional theory study

In this paper, a new design principle for bimetallic catalysts is proposed by combining strongly adsorbed atoms (SAA) with weakly adsorbed atoms (WAA) where the SAA and WAA are classified by the free adsorption energy of oxygen-containing intermediates on the metal atom. And the ORR performances of the bimetallic catalysts designed by the method are compared with the common single metal atom catalysts. The method is successfully confirmed as the overpotential of the Mn-based bimetallic catalysts decreases from 0.63 V in G-MnN4 to as low as 0.33 V, and that of the Fe-based bimetallic catalysts decreases from 0.76 V in G-FeN4 to 0.23 V. In addition, the correlation between adsorption free energy and adsorption bond length is revealed for the first time, and the optimal adsorption bond length is determined. Finally, the adsorption energy of O2 is plotted versus the free adsorption energy of three oxygen-containing intermediates for the first time, and a suitable adsorption energy of O2 is found to be -1.4∼-1.0 eV. These findings provide a new perspective for the design of high-performance bimetallic catalysts.

Polydimethylsiloxane (PDMS)-assisted non-destructive transient thermoreflectance characterizations.

The conventional pump-probe thermoreflectance (pump-probe TR) techniques are routinely performed on a thin (typically <100nm) metal transducer deposited on samples, ensuring the most fundamental principle of thermoreflectance: the reflectance change (∆R/R) of the sample surface is directly and linearly related to the temperature change (∆T) within a finite temperature range. However, general metal coating methods may damage the sample by forming a mixed layer with the sample. In this article, we present a non-destructive pump-probe transient thermoreflectance (TTR) characterization using the polydimethylsiloxane (PDMS)-assisted metal transfer technique. Our method utilizes PDMS dry transfer to transfer common transducer metals (Au and Al) to the target substrate. This method effectively avoids impurities and damage to the sample. In particular, we have utilized Au as a transition layer to study the application of Al transfer in TTR measurements. The substrate thermal conductivity measurement results show that they can all be used for TTR measurement, and the thermal boundary conductance results show that the transferred metals have low bonding to the substrate. In addition, Al/Au can be transferred over a large area at room temperature compared to Au. After measurement, the samples can be restored to their original state by a simple cleaning method. This method provides a simple and reliable way to characterize samples without metal coating for TTR.

Physical and chemical properties of aluminum tailings mud modified by metal ions

Aluminum tailings mud, a type of waste generated by bauxite washing during alumina production, is harmful. Owing to the isomorphism substitution of iron-aluminum symbiotic minerals, a large number of metal ions inevitably exist in the slurry, which causes the suspension to maintain dispersion and hinders the drainage of aluminum tailings mud. This study examined the effects of the pH and commonly associated metal ions, such as K+ and Fe3+, on the sedimentation characteristics of aluminum tailings mud. Zeta potential analyzer, X-ray fluorescence spectrum analysis, and electron scanning microscopy were used to study the effects of common metal ions in the tailings slurry on the sedimentation characteristics of aluminum tailings mud. The results showed that the sedimentation effect of the tailings slurry was superior after adding Fe3+ compared with K+. The mechanism analysis shows that at a certain pH range, the addition of metal ions can compress the thickness of the electric double layer on the surface. The high-valence ions (Fe3+) will have more electric double layer compression than monovalent ions (Na+), which is more conducive to the agglomeration of aluminum tailing mud particles. This conclusion provides guidance for efficient drainage of aluminum tailings mud.

The effect of heavy metals (Cd, Cu, and Pb) on plant growth parameters and the phytoremediation capacity of corn

Heavy metal contamination is currently a major global environmental issue. Heavy metals contaminate the soils where crops and vegetables grow. Maize (Zea mays L.) is widely employed for phytoremediation because of its high biomass output and metal accumulation capacity. Depending on the plant and soil properties, some metals can be dangerous in high amounts. During our in vitro experiment, different levels of Cd, Cu, and Pb were introduced to a growth medium to allow maize plants to develop under diverse conditions. The study examined numerous growth features under certain metal stress conditions, including seed germination, plant height, biomass, and chlorophyll content, as well as the toxicity symptoms and mechanisms of the most common heavy metals. The study revealed that, while the maize plant is a good heavy metal accumulator, high heavy metal concentrations had a negative impact on several growth indicators: at 250 ppm, Cd inhibited captive seed germination by 50% and wild seed germination by 42.9%; Pb suppressed captive seed germination by 57% and wild seed germination by 42.9%; and Cu inhibited germination in both seed types by 40%. Similarly, plant height decreased in the following order: Pb (36.2%), Cd (24.8%), and Cu (9.7%) for the captive seed plant, and Pb (46.7%), Cd (28%), and Cu (13%) for the wild seed plant. Keywords: MAIZE, STRESS, TOXICITY, HEAVY METAL, POLLUTION, PHYTOREMEDIATION, BIOACCUMULATION

Влияние тяжелых металлов (Cd, Cu и Pb) на параметры роста растений и фиторемедиационную способность кукурузы

Heavy metal contamination is currently a major global environmental issue. Heavy metals contaminate the soils where crops and vegetables grow. Maize (Zea mays L.) is widely employed for phytoremediation because of its high biomass output and metal accumulation capacity. Depending on the plant and soil properties, some metals can be dangerous in high amounts. During our in vitro experiment, different levels of Cd, Cu, and Pb were introduced to a growth medium to allow maize plants to develop under diverse conditions. The study examined numerous growth features under certain metal stress conditions, including seed germination, plant height, biomass, and chlorophyll content, as well as the toxicity symptoms and mechanisms of the most common heavy metals. The study revealed that, while the maize plant is a good heavy metal accumulator, high heavy metal concentrations had a negative impact on several growth indicators: at 250 ppm, Cd inhibited captive seed germination by 50% and wild seed germination by 42.9%; Pb suppressed captive seed germination by 57% and wild seed germination by 42.9%; and Cu inhibited germination in both seed types by 40%. Similarly, plant height decreased in the following order: Pb (36.2%), Cd (24.8%), and Cu (9.7%) for the captive seed plant, and Pb (46.7%), Cd (28%), and Cu (13%) for the wild seed plant. Keywords: MAIZE, STRESS, TOXICITY, HEAVY METAL, POLLUTION, PHYTOREMEDIATION, BIOACCUMULATION

Protective effects of gallic acid against nickel-induced kidney injury: impact of antioxidants and transcription factor on the incidence of nephrotoxicity

Nickel (Ni) is a common metal with a nephrotoxic effect, damaging the kidneys. This study investigated the mechanism by which gallic acid (GA) protects mice kidneys against renal damage induced by Nickel oxide nanoparticles (NiO-NPs). Forty male Swiss albino mice were randomly assigned into four groups, each consisting of ten mice (n = 10/group): Group I the control group, received no treatment; Group II, the GA group, was administrated GA at a dosage of 110 mg/kg/day body weight; Group III, the NiO-NPs group, received injection of NiO-NPs at a concentration of 20 mg/kg body weight for 10 consecutive days; Group IV, the GA + NiO-NPs group, underwent treatment with both GA and NiO-NPs. The results showed a significant increase in serum biochemical markers and a reduction in antioxidant activities. Moreover, levels of 8-hydroxy-2’-deoxyguanosine (8-OH-dG), phosphorylated nuclear factor kappa B (p65), and protein carbonyl (PC) were significantly elevated in group III compared with group I. Furthermore, the western blot analysis revealed significant high NF-κB p65 expression, immunohistochemistry of the NF-κB and caspase-1 expression levels were significantly increased in group III compared to group I. Additionally, the histopathological inspection of the kidney in group III exhibited a substantial increase in extensive necrosis features compared with group I. In contrast, the concomitant coadministration of GA and NiO-NPs in group IV showed significant biochemical, antioxidant activities, immunohistochemical and histopathological improvements compared with group III. Gallic acid has a protective role against kidney dysfunction and renal damage in Ni-nanoparticle toxicity.

Biomass hydrothermal carbonization solution-assisted synthesis of intercalation-expanded core–shell structured molybdenum disulfide for efficient adsorption of Cr (VI) in electroplating wastewater treatment

Cr (VI) is a common heavy metal pollutant in electroplating wastewater. This study introduces the liquid-phase product from the hydrothermal reaction of coffee grounds (CGHCL) into the synthesis process of molybdenum disulfide, assisting in the fabrication of an intercalated, expanded core–shell structured molybdenum disulfide adsorbent (C-MoS2), designed for the adsorption and reduction of Cr (VI) from electroplating wastewater. The addition of CGHCL significantly enhances the adsorption performance of MoS2. Furthermore, C-MoS2 exhibits exceedingly high removal efficiency and excellent regenerative capability for Cr (VI)-containing electroplating wastewater. The core–shell structure effectively minimizes molybdenum leaching to the greatest extent, while the oleophobic interface is unaffected by oily substances in water, and the expanded interlayer structure ensures the long-term stability of C-MoS2 in air (90 days). This study provides a viable pathway for the resource utilization of biomass and the application of molybdenum disulfide-based materials in wastewater treatment.

Essential and toxic elements analysis of wild boar tissues from north-eastern Romania and health risk implications

IntroductionThe level of essential minerals in meat is an important factor in human nutrition and health. Meat from responsibly managed wildlife is an alternative raw material with considerable nutritional benefits. Meat from hunted animals has essential and non-essential elements for the human body. It is important to carefully monitor the levels of heavy metals accumulated in the tissues of hunted animals in polluted areas to ensure food safety and environmental contamination. High levels of heavy metals in food and the environment can pose a danger to human health.MethodsThe study aims to investigate the levels of essential mineral elements and heavy metals in the muscle tissue and organs of wild boar harvested through the herd density control plan over the last decade in north-eastern Romania.Results and discussionThe statistical analysis indicates that the age of the animals had a significant impact on Fe, Cu, and Zn levels in Longissimus lumborum. In the kidney a highly significant difference in Fe content by sex, with males showing higher values than females. The sex was shown to significantly influence the Mg levels. However, there are concerns about the accumulation of heavy metals such as Lead (Pb) and Cadmium (Cd), which may hurt the health of game meat consumers in the study area. Cd level it shows significant differences according to both age and sex, with higher concentrations in adults and males. Statistical analysis shows a negative correlation between Fe and Zn concentrations in muscle samples, while a positive correlation was found between Fe and Mn in kidney samples. There was also a positive association between Zn and Cu in muscle samples, but a negative association in kidney samples. Principal component analysis shows significant variation in essential element and heavy metals data between muscle and kidney samples. The loading plot shows a direct correlation between Pb and Cu and between Pb and Cd. However, an opposite correlation also is observed between Cu and Mg, Cd and Mg, and Pb and Mg. HQ (Hazard Quotient) for children compared to adults indicates a potentially higher risk associated with meat consumption among children because children are more vulnerable than adults. We report for the first time, to the best authors’ knowledge, various levels of essential minerals and exceeded maximum admitted level of heavy metals in the muscle tissues and kidneys of Sus scrofa ferus from Romania intended for human consumption, moreover, our findings highlight the need for strict monitoring and implementation of appropriate corrective measures, given the significant percentages of muscle and kidney samples exceeding the allowable limits for two of the most common toxic metals in the environment.

Acridinedione-based fluorescence ‘turn-off’ sensor for real-time detection of carcinogenic Cr (VI) ions

This research introduces AR-1, a newly developed chemosensor tailored for Cr (VI) ion detection in semi-aqueous solutions. AR-1 demonstrates notable alterations in coloration and reduced fluorescence output upon interaction with Cr (VI) ions, showing remarkable selectivity even amidst other interfering metal ions. Fluorescence spectral titrations were employed to ascertain the binding constant and detection thresholds of the AR-1-Cr (VI) complex, with LOD and LOQ established at 0.639 µM and 0.021 μM, respectively. Further characterization via 1H NMR titrations, DFT calculations, Job’s plot, and HRMS analysis provided insights into the detection mechanism. The probe proved dependable within a pH range of 3.0 to 11.0, displaying resilience against interference from common metal ions. Overall, AR-1 presents a direct and efficient means for Cr (VI) ion detection in environmental samples, offering a promising alternative to traditional detection methods.

Effect of the type of ion-exchange resin on Mn&lt;sup&gt;2+&lt;/sup&gt; adsorption in the presence of competing cations

Present in soils, ground and surface waters, manganese is among the most common metals in Earth crust. It is also an essential trace element to the functioning of several enzymes in the human body. However, exposure to high manganese concentrations can also be harmful to humans with psychiatric and motor effects and therefore, manganese concentrations in drinking water and also industrial effluents are regulated. In the current work, the adsorption of Ca&lt;sup&gt;2+&lt;/sup&gt;, Mg&lt;sup&gt;2+&lt;/sup&gt; and Mn&lt;sup&gt;2+&lt;/sup&gt; on three different ion-exchange resins: (i) aminophosphonic acid - chelating (Purolite S950), (ii) polyacrylic weak acid cation (Purolite C104E) and (iii) polystyrene strong acid cation (Purolite C100) was investigated. The results revealed that Purolite S950 had the highest Mn2+ uptake (37.9 mg/mL-resin or 0.69 mmol/mL-resin) as compared to Ca&lt;sup&gt;2+&lt;/sup&gt; (3.2 mg/mL-resin or 0.08 mmol/mL-resin) and Mg&lt;sup&gt;2+&lt;/sup&gt; (~0 mg/mL-resin) and was selected for further kinetics and equilibrium studies. The results indicated Purolite S950 as particularly suited to be applied in the treatment of neutral mine waters with high Mg/Mn ratios. Additionally, Purolite S950 showed a small affinity for Ca&lt;sup&gt;2+&lt;/sup&gt; and therefore an efficient Mn&lt;sup&gt;2+&lt;/sup&gt; removal will depend on the Ca/Mn ratio of the mine water under treatment. According to the kinetic analysis, manganese sorption on Purolite S950 was described by the pseudo-second order model (r&lt;sup&gt;2&lt;/sup&gt; &gt; 0.98) with an activation energy of 10.40 kJ/mol and thus pore-difussion was the rate controlling step of the process. In terms of equilibrium studies, manganese sorption on Purolite S950 followed the Langmuir model with maximum loadings of up to 41.5 mg/mL-resin. The thermodynamic modelling indicated an exothermic process (-85.0 kJ/mol, as standard enthalpy) with a standard entropy of -274 J/mol.K, which was ascribed to the release of two adsorbed H&lt;sup&gt;+&lt;/sup&gt; ions for each Mn&lt;sup&gt;2+&lt;/sup&gt; ion taken up from solution

Genome-wide identification and expression pattern analysis of the Aux/IAA (auxin/indole-3-acetic acid) gene family in alfalfa (Medicago sativa) and the potential functions under drought stress

BackgroundAuxin/induced-3-acetic acid (Aux/IAA) is an important plant hormone that affects plant growth and resistance to abiotic stresses. Drought stress is a vital factor in reducing plant biomass yield and production quality. Alfalfa (Medicago sativa L.) is the most widely planted leguminous forage and one of the most economically valuable crops in the world. Aux/IAA is one of the early responsive gene families of auxin, playing a crucial role in response to drought stress. However, the characteristics of the Aux/IAA gene family in alfalfa and its potential function in response to drought stress are still unknown.ResultA total of 41 Aux/IAA gene members were identified in alfalfa genome. The physicochemical, peptide structure, secondary and tertiary structure analysis of proteins encoded by these genes revealed functional diversity of the MsIAA gene. A phylogenetic analysis classified the MsIAA genes into I-X classes in two subgroups. And according to the gene domain structure, these genes were classified into typical MsIAA and atypical MsIAA. Gene structure analysis showed that the MsIAA genes contained 1–4 related motifs, and except for the third chromosome without MsIAAs, they were all located on 7 chromosomes. The gene duplication analysis revealed that segmental duplication and tandem duplication greatly affected the amplification of the MsIAA genes. Analysis of the Ka/Ks ratio of duplicated MsAux/IAA genes suggested purification selection pressure was high and functional differences were limited. In addition, identification and classification of promoter cis-elements elucidated that MsIAA genes contained numerous elements associated to phytohormone response and abiotic stress response. The prediction protein–protein interaction network showed that there was a complex interaction between the MsAux/IAA genes. Gene expression profiles were tissue-specific, and MsAux/IAA had a broad response to both common abiotic stress (ABA, salt, drought and cold) and heavy metal stress (Al and Pb). Furthermore, the expression patterns analysis of 41 Aux/IAA genes by the quantitative reverse transcription polymerase chain reaction (qRT-PCR) showed that Aux/IAA genes can act as positive or negative factors to regulate the drought resistance in alfalfa.ConclusionThis study provides useful information for the alfalfa auxin signaling gene families and candidate evidence for further investigation on the role of Aux/IAA under drought stress. Future studies could further elucidate the functional mechanism of the MsIAA genes response to drought stress.

Rhizobium symbiosis improves amino acid and secondary metabolite biosynthesis of tungsten-stressed soybean (Glycine max).

The industrially important transition metal tungsten (W) shares certain chemical properties with the essential plant micronutrient molybdenum and inhibits the activity of molybdoenzymes such as nitrate reductase, impacting plant growth. Furthermore, tungsten appears to interfere with metabolic processes on a much wider scale and to trigger common heavy metal stress response mechanisms. We have previously found evidence that the tungsten stress response of soybeans (Glycine max) grown with symbiotically associated N2-fixing rhizobia (Bradyrhizobium japonicum) differs from that observed in nitrogen-fertilized soy plants. This study aimed to investigate how association with symbiotic rhizobia affects the primary and secondary metabolite profiles of tungsten-stressed soybean and whether changes in metabolite composition enhance the plant's resilience to tungsten. This comprehensive metabolomic and proteomic study presents further evidence that the tungsten-stress response of soybean plants is shaped by associated rhizobia. Symbiotically grown plants (N fix) were able to significantly increase the synthesis of an array of protective compounds such as phenols, polyamines, gluconic acid, and amino acids such as proline. This resulted in a higher antioxidant capacity, reduced root-to-shoot translocation of tungsten, and, potentially, also enhanced resilience of N fix plants compared to non-symbiotic counterparts (N fed). Taken together, our study revealed a symbiosis-specific metabolic readjustment in tungsten-stressed soybean plants and contributed to a deeper understanding of the mechanisms involved in the rhizobium-induced systemic resistance in response to heavy metals.

Case of lead poisoning secondary to intake of herbal medicine for diabetes mellitus in a tertiary care hospital in Kerala.

Although most published cases of lead poisoning come from occupational exposures, some traditional remedies may also contain toxic amounts of lead. Here, we report the case of a 58-year-old female who presented with abdominal pain, generalized tiredness, and decreased food intake, with anemia and elevated levels of lead. The patient was found to be taking herbal capsules for diabetes prior to the presentation. This case highlights the need for increased awareness that some herbal remedies may contain potentially harmful levels of heavy metals, and people who use them are at risk of developing associated toxicities. Individuals who support traditional medicine often incorrectly believe that herbal remedies for diabetes are free from side effects, leading them to favor these treatments over contemporary medications. Herbal medications are freely available online, even without a prescription. The accessibility of herbal medicines without prescriptions, coupled with the false belief in their lack of side effects, misleads educated individuals toward quackery treatments. Misinformation spread via social media exacerbates this issue. Heavy metals are present in toxic levels in the drugs, causing complications. Lead is the most common heavy metal found in such herbal medicines. Lead poisoning leads to anemia and other systemic complications which could have been fatal if not found in time.

Population-based study of environmental heavy metal exposure and hearing loss: A systematic review and meta-analysis.

Previous studies have shown an association between environmental exposure to heavy metals and hearing loss. However, the findings regarding the relationship between exposure to different metals and hearing loss development are inconsistent. To address this, we conducted a meta-analysis to explore the link between common heavy metal exposures and hearing loss. This study examined the effects of lead (Pb), cadmium (Cd), and mercury (Hg) pollution on hearing loss at various levels, and systematically reviewed the literature on manganese (Mn), barium (Ba), arsenic (As), and hearing loss. We conducted systematic searches in five major databases, including PubMed, Web of Science, Embase, Cochrane Library, and Scopus. In addition, we searched three Chinese digital libraries: CNKI, Wanfang Data, and Wipu. From an initial pool of 649 articles, we carefully screened and selected 15 articles for further analysis. The effect sizes from these selected studies were synthesized through a meta-analysis to calculate the overall effect size. Our findings showed that: (1) There was a significant association between Pb and Cd exposure and hearing loss; (2) There is a proportional relationship between the increase of metal index detected in blood and hearing loss; (3) In the PTA measurement of hearing loss at different frequencies, the 4 kHz high frequency range had a stronger correlation with hearing loss than the low frequency, with OR 1.44 (1.22, 1.71); and (4) There was a more significant correlation between Barium (Ba) levels in nails and hair than in urine. The study presented evidence of a significant association between human hearing loss and exposure to lead (Pb) and cadmium (Cd). It not only revealed a positive correlation between blood heavy metal concentrations and the incidence of hearing loss but also highlighted that long-term exposure indicators of heavy metals were more indicative of the correlation with hearing loss. Lastly, the study recommends utilizing high frequency 4 kHz for the effective assessment and diagnosis of hearing loss caused by exposure to heavy metals.

NIR heterojunction based on porous silicon and CuO:Cu2O nanoparticle for photovoltaic devices

Solar cells are considered one of the most important sources of renewable energy and have high economic quality within sustainable development programs. Nanoparticles have higher photoresponsivity than microscopic counterparts due to their increased surface area per unit volume, which considerably lowers charge carrier recombination and scattering. CuO and Cu2O are common transition metal oxides with optical band gaps appropriate for near-infrared detection. They also form a type II heterojunction, which allows for efficient charge separation. In addition to constructing this photodetector, we synthesize CuO:Cu2O composite nanoparticles by laser ablation, fabricate photodetector devices and photoelectric cells and deposit them on porous silicon by drop-casting method to examine photoresponse and specific detectivity. as a solar cell.

Collaboration strategy-based fluorescence sensor for efficient detecting Al3+ and Hg2+

Developing economical sensors and methods to efficiently detect metal ions like Hg2+ and Al3+ is still significant. Hg2+ is notorious for its strong neurotoxicity, while, Al3+ is a risk factor for Alzheimer's disease (AD) in humans. To improve the selectivity and sensitivity of Hg2+ and Al3+, in this research, the collaboration effect has been successfully applied to the design of chemosensors to enhance the detecting ability of the sensor. According to this strategy, quinoline-8-yloxy acetohydrazone and hydroxy‑naphthyl groups have been rationally introduced into one sensor molecule, based on the collaboration of these functional groups, the obtained chemosensor (QN) shows efficient “off-on-off” response for Al3+ and Hg2+. QN can ultra-sensitively detect Al3+ with fluorescent “turn-on” response, the limit of detection (LOD) of QN towards Al3+ is 4.34×10-9 M. Interestingly, after coordination with Al3+, the obtained complex QN-Al can detect Hg2+ sensitively, the LOD of QN towards Hg2+ is 5.70×10-8 M. The Al3+ and Hg2+ sensing process shows nice selectivity, and the detecting procedure cannot be interfered with by other common metal cations. The possible recognition mechanism of QN for Al3+ and Hg2+ was carefully investigated via experimental and theoretical studies. According to these studies, the selective and sensitive sensing of Al3+ and Hg2+ is based on the collaborative coordination of quinoline acetohydrazone and hydroxy‑naphthyl groups. The relay sensing procedure of Al3+ and Hg2+ is attributed to the competitive coordination of these two cations. The fluorescent response of Al3+ might be attributed to excited state intra-molecular proton transfer (ESIPT) and photoinduced electron transfer (PET), meanwhile, the Hg2+ response mechanism may be ascribed to the chelation enhancement quenching effect (CHEQ). Moreover, the detection of real samples is conducted to determine the aluminum content in food to prove that chemosensor QN is suitable for the detection of Al3+ from food samples, and the QN-based test kits for convenient detection of Al3+ and Hg2+ were also successfully prepared.

Construction of spinel (Fe0.2Co0.2Ni0.2Cr0.2M0.2)3O4 (M = Mg, Mn, Zn, and Cu) high-entropy oxides with tunable valance states for oxygen evolution reaction

High-entropy oxides (HEOs) exhibit excellent structural stability, and the synergistic effects among their constituent elements contribute to performance enhancement, providing vast opportunities for designing novel and efficient electrocatalysts. Utilizing four common transition metals such as Fe, Co, Ni, and Cr as the base and introducing a fifth metal, M (M = Mg, Mn, Zn, and Cu), with different outer electron shells, relevant high-entropy oxides with varying sizes were successfully synthesized via the hydrothermal method. Among all considered samples, FCNCMg, with the smallest particle size, possessed a much larger specific surface area, leading to the exposure of more active sites and thus favoring an improvement of the OER performance. The introduction of the fifth metal induced a redistribution of charges among Fe, Co, Ni, and Cr within the catalyst, resulting in different oxidation states for these metals. Mg addition led the XPS peaks of Fe/Ni and Cr/Co elements to shift towards lower and higher binding energies, respectively. This dynamic compensation effect between metal ions synergistically promoted their OER performance. In alkaline environments, FCNCMg exhibited the best OER performance, with an overpotential of 278 mV at 10 mA cm−2 and a Tafel slope of 49.90 mV dec−1. Moreover, it demonstrated excellent stability, achieving 50 h at 10 mA cm−2 and 20 h at 50 mA cm−2. This study, by controlling the composition of HEOs, explored the impact of particle size and synergistic effects on their performance, offering new insights for design and optimization of relevant high-performance HEOs.