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Dalton Transactions (Cambridge, England... Jun 2024This study employs plasma-liquid interaction technique to synthesize different phases of molybdenum oxide using air and argon as plasma-forming gases. plasma-generated...
This study employs plasma-liquid interaction technique to synthesize different phases of molybdenum oxide using air and argon as plasma-forming gases. plasma-generated nitrogen species primarily NO/NO and hydrogen species (H) facilitate the reduction of the molybdenum precursor anion (MoO). The reduced Mo species subsequently reacts with reactive oxygen species, forming MoO octahedra, which is the building block of a molybdenum oxide crystal. Varied concentrations of NO/NO and H species in air and argon plasma treatment significantly influence the growth process. Air plasma synthesis yields hexagonal molybdenum oxide microrods, which upon calcination changes its phase to orthorhombic 2D layered structure. Moreover, the argon plasma synthesized sample exhibits a mixed phase of hexagonal and orthorhombic molybdenum oxide due to the heavy argon ion bombardment, inducing material porosity and surface oxygen vacancies. The mixed-phase material exhibits superior adsorption and photo-degradation towards cationic dye compared to the other two phases. The higher photocatalytic performance may be responsible for the extended lifetime of the photo-generated charge carriers possessed by the mixed-phase material. Radical scavenging tests have identified holes and hydroxyl radicals as the key reactive species that take part in the photo-degradation process.
PubMed: 38885122
DOI: 10.1039/d4dt01620c -
Science and Technology of Advanced... 2024The hydrogen evolution reaction (HER) is an important phenomenon in water splitting. Consequently, the development of an active, earth-abundant, and inexpensive HER...
The hydrogen evolution reaction (HER) is an important phenomenon in water splitting. Consequently, the development of an active, earth-abundant, and inexpensive HER catalyst is highly desired. MoS has drawn considerable interest as an HER catalyst because it is composed of non-precious metal and exhibits high catalytic activity in the nanosheet form. In this study, size-controlled MoS particles were synthesized by ball milling. The as-prepared samples exhibited significantly enhanced electrochemical and catalytic properties compared to those of pristine bulk MoS. Furthermore, the HER activity improved further upon the introduction of graphene into the as-prepared ball-milled samples. In particular, the MoS sample ball-milled for 12 h mixed with graphene exhibited optimal performance, showing an overpotential (160 mV at 10 mA cm) that was ~ 335 mV lower than that of pristine bulk MoS. The superior catalytic activity was ascribed to the exposed edge sites, sulfur vacancies, and 1T phase of MoS, as well as the noteworthy fortifying effect of the electronically conductive flexible material, graphene. The results provide a promising strategy for its application as an efficient and stable HER catalyst.
PubMed: 38882258
DOI: 10.1080/14686996.2024.2359360 -
ACS Omega Jun 2024Transition-metal dichalcogenides (TMDs) and their alloys are vital for the development of sustainable and economical energy storage alternatives due to their large...
Transition-metal dichalcogenides (TMDs) and their alloys are vital for the development of sustainable and economical energy storage alternatives due to their large interlayer spacing and hosting ability for alkali-metal ions. Although the Li-ion chemically correlates with the Na-ion and K-ion, research on batteries with TMD anodes for K is still in its infancy. This research explores TMDs such as molybdenum disulfide (MoS) and tungsten disulfide (WS) and TMD alloys such as molybdenum tungsten disulfide (MoWS) for both sodium-ion batteries (NIBs) and potassium-ion batteries (KIBs). The cyclic stability test analysis indicates that in the initial cycle, the MoS NIB demonstrates exceptional performance, with a peak charge capacity of 1056 mAh g, while retaining high Coulombic efficiency. However, the WS KIB underperforms, with the least charge capacity of 130 mAh g in the first cycle and exceptionally low retention at a current density of 100 mA g. The MoWS TMD alloy exhibits a moderate charge capacity and cyclic efficiency for both NIBs and KIBs. This comparison study shows that decreasing sizes of alkali-metal ions and constituent elements in TMDs or TMD alloys leads to decreased resistance and slower degradation processes as indicated by cyclic voltammetry and electrochemical impedance spectroscopy after 10 cycles. Furthermore, the study of probable electrochemical intercalation and removal processes of Na-ions and K-ions demonstrates that large geometrically shaped TMD flakes are more responsive to intercalation for Na-ions than K-ions. These performance comparisons of different TMD materials for NIBs and KIBs may promote the future development of these batteries.
PubMed: 38882118
DOI: 10.1021/acsomega.4c01966 -
International Journal of Biological... Jun 2024Ethyl cellulose (EC)-based composite sponges were developed for oil spillage treatment. The EC sponge surface was decorated with helical carbon nanotubes (HCNTs) and...
Ethyl cellulose (EC)-based composite sponges were developed for oil spillage treatment. The EC sponge surface was decorated with helical carbon nanotubes (HCNTs) and molybdenum disulfide (MoS) (1 phr) using the inside-out sugar templating method. The inside surface of a sugar cube was coated with HCNTs and MoS. After filling the sugar cube pores with EC and the subsequent sugar leaching, the decorating materials presented on the sponge surface. The EC/HCNT/MoS sponge had a high level of oil removal based on its adsorption capacity (41.68 g/g), cycled adsorption (∼75-79 %), separation flux efficiency (∼85-95 %), and efficiency in oil/water emulsion separation (92-94 %). The sponge maintained adsorption capacity in acidic, basic, and salty conditions, adsorbed oil under water, and functioned as an oil/water separator in a continuous pump-assisted system. The compressive stress and Young's modulus of the EC sponge increased following its decoration using HCNTs and MoS. The composite sponge was robust based on cycled compression and was thermally stable up to ∼120 C. Based on the eco-friendliness of EC, the low loading of HCNTs and MoS, and sponge versatility, the developed EC/HCNT/MoS sponge should be good candidate for use in sustainable oil adsorption and separation applications.
PubMed: 38880452
DOI: 10.1016/j.ijbiomac.2024.133119 -
Talanta Jun 2024In this work, a novel molecularly imprinted electrochemical aptasensor (MIEAS) was developed for highly selective detection of dexamethasone (Dex) in natural water...
In this work, a novel molecularly imprinted electrochemical aptasensor (MIEAS) was developed for highly selective detection of dexamethasone (Dex) in natural water environment. Gold nanoparticles (AuNPs) modified by nitrogen doped molybdenum carbide-graphene (N-MoC-Gr) were employed as the supports, where N-MoC-Gr improved the conductivity of the electrode and provided a larger specific surface area to polymerize more active substances. Using Dex as template molecule, o-phenylenediamine (o-PD) as the chemical functional monomer and aptamer as the biofunctional monomer, a molecularly imprinted polymer (MIP) membrane with Dex specific recognition sites was formed by electropolymerization. Due to the synergistic effect of MIP and aptamers, the as-prepared MIEAS exhibited a decent linear relationship to Dex detection within a relatively wide range of 10 - 10 M, and the detection limit was 1.79 × 10 M. The recovery in actual water and tablet samples is satisfactory, which confirms the potential application prospects of this sensor in the determination of Dex.
PubMed: 38879945
DOI: 10.1016/j.talanta.2024.126404 -
The Science of the Total Environment Sep 2024The characteristics of radon exhalation in the hygroscopic properties of powder solid wastes are immensely significant for environmental safety and their transportation,...
The characteristics of radon exhalation in the hygroscopic properties of powder solid wastes are immensely significant for environmental safety and their transportation, storage, and landfill. This study detected the radon concentration of superfine cement and five kinds of powder solid waste: fly ash, silica fume, coal gangue, S95 mineral powder, and molybdenum tailing powder, at different hygroscopic times for 1-5 d under 95 % relative humidity. Additionally, the influence of particle size and porosity of solid waste on radon exhalation characteristics was analyzed using a laser particle size analyzer and nitrogen adsorption technology. The results show that the radon exhalation rate of the solid waste was at a low level in dry conditions. Although the presence of water due to the increased moisture absorption rate inhibited the radon exhalation to a certain extent, it was higher than that in dry conditions. The reciprocal of the moisture absorption rate had a strong linear relationship with the ratio between the radon exhalation rate after hygroscopy and radon exhalation rate from dry materials. The pore structure has a significant effect on the exhalation rate of radon, and the macropores inhibits the exhalation rate of radon. The results of this study have guiding significance for the reuse of solid waste and the prevention of radiation risk of radon exhalation during transportation.
PubMed: 38879029
DOI: 10.1016/j.scitotenv.2024.173956 -
ACS Applied Materials & Interfaces Jun 2024Metal-semiconductor junctions play an important role in the development of electronic and optoelectronic devices. A Schottky junction photodetector based on...
Metal-semiconductor junctions play an important role in the development of electronic and optoelectronic devices. A Schottky junction photodetector based on two-dimensional (2D) materials is promising for self-powered photodetection with fast response speed and large signal-to-noise ratio. However, it usually suffers from an uncontrolled Schottky barrier due to the Fermi level pinning effect arising from the interface states. In this work, all-2D Schottky junctions with near-ideal Fermi level depinning are realized, attributed to the high-quality interface between 2D semimetals and semiconductors. We further demonstrate asymmetric diodes based on multilayer graphene/MoS/PtSe with a current rectification ratio exceeding 10 and an ideality factor of 1.2. Scanning photocurrent mapping shows that the photocurrent generation mechanism in the heterostructure switches from photovoltaic effect to photogating effect at varying drain biases, indicating both energy conversion and optical sensing are realized in a single device. In the photovoltaic mode, the photodetector is self-powered with a response time smaller than 100 μs under the illumination of a 405 nm laser. In the photogating mode, the photodetector exhibits a high responsivity up to 460 A/W originating from a high photogain. Finally, the photodetector is employed for single-pixel imaging, demonstrating its high-contrast photodetection ability. This work provides insight into the development of high-performance self-powered photodetectors based on 2D Schottky junctions.
PubMed: 38877995
DOI: 10.1021/acsami.4c04023 -
Environmental Geochemistry and Health Jun 2024High cadmium (Cd) concentrations widely occured in selenium (Se)-rich soils, which has been an important obstacle in the usage of Se-rich soils. There is still no...
High cadmium (Cd) concentrations widely occured in selenium (Se)-rich soils, which has been an important obstacle in the usage of Se-rich soils. There is still no special information detailing the enrichment process and mechanism of Cd in Se-rich soils. 4474 soils and 21 rocks in Lanshan District were sampled to detect its enrichment process. The surface soils have Cd concentrations of 0.01-9.41 mg·kg (an average of 0.16 mg·kg). The soil Cd concentrations were significantly correlated with soil Se concentrations. The relatively higher-Cd surface soils are distributed in Lower-middle Ordovician carbonate areas with Se-rich soils and Quaternary areas with typical anthropic activities. Surface soils in Ordovician carbonate area have the highest Cd concentrations. Soil Cd concentrations are significantly correlated with sulfophil elements (Zinc (Zn), Copper (Cu), Molybdenum (Mo), Lead (Pb) and Arsenic (As) etc.), Ca (Calcium) concentrations and soil organic carbon (SOC). The soil and rock samples from different geological units also confirmed soil Cd concentrations developing from Ordovician carbonates were higher than those from other rocks. The results indicate the soil Cd concentrations were the complex consequences of bedrock, soil-forming processes and anthropogenic activities. Higher Ca concentrations and more reduction environments result in high-Cd bedrock. CaCO leaching and alkaline pH, which are the special soil-forming process of carbonates, enrich Cd in soils. Agricultural and industrial activities also affect soil Cd concentrations. An enrichment model of Cd in Se-rich soils is forwarded.
Topics: China; Soil Pollutants; Cadmium; Soil; Selenium; Environmental Monitoring
PubMed: 38877343
DOI: 10.1007/s10653-024-02022-2 -
Environmental Pollution (Barking, Essex... Jun 2024Breast milk is a vital source of nutrition for breastfed infants, providing essential nutrients and elements but, in some cases, toxic ones. This is the first...
Breast milk is a vital source of nutrition for breastfed infants, providing essential nutrients and elements but, in some cases, toxic ones. This is the first case-control study that investigated the elemental profile of breast milk samples collected from mothers residing in Matiari (Sindh), a region with insufficient industrial waste management, and its potential impact on infants' anthropometrics. Precisely, 62 milk samples, including 42 cases and 20 controls, were analyzed using the ICP-MS technique. Overall, six elements showed significance between the two groups, arsenic (As) was present at 0.68 μg/L in cases and absent in controls, while lead (Pb) exhibited elevated concentrations in the case group at 4.56 μg/L compared to 0.25 μg/L in controls, well-known for their toxicity. Barium (Ba) and manganese (Mn) levels were also higher in cases, associated with reported health effects on child well-being. Essential elements molybdenum (Mo) and selenium (Se) were higher in the controls. Furthermore, the association of these metals with the child growth standards as per WHO guidelines was calculated. Linear regression analysis revealed As negatively associated with WAZ and WHZ scores, while Mo was positively associated with WAZ, WHZ, and HAZ scores. These findings highlight serious health concerns in the region, where toxic elements pervade drinking water and food sources. Immediate actions are imperative to maintain the wellness of future generations.
PubMed: 38876378
DOI: 10.1016/j.envpol.2024.124368 -
Environmental Science & Technology Jun 2024Polyamide (PA)-based nanofiltration (NF) membranes have demonstrated extensive applications for a sustainable water-energy-environment nexus. A rational control of...
Polyamide (PA)-based nanofiltration (NF) membranes have demonstrated extensive applications for a sustainable water-energy-environment nexus. A rational control of interfacial polymerization (IP) is highly efficacious to enhance NF separation performance yet remains a technical challenge. Herein, we proposed a regulation strategy of constructing amphiphilic molybdenum disulfide/cetyltrimethylammonium bromide interlayer atop the Kevlar hydrogel substrate. The amphiphilic nanosheet interlayered NF membrane exhibited a crumpled PA surface with an elevated cross-linking degree of 76.9%, leading to an excellent water permeance (16.8 L m h bar) and an impressive NaSO rejection (99.1%). Meanwhile, the selectivity coefficient of NaSO/NaCl of the optimized TFC membrane reached 91, surpassing those of the recently reported NF membranes. Moreover, the optimized membrane exhibited a desirable rejection of over 90% against Mn and Cu in actual textile wastewater. Importantly, the underlying NF membrane formation mechanism was elucidated via both experiments and molecular simulations. The synchronous control of mass and heat transfer of IP process offers a new methodology for the state-of-the-art membrane fabrication, which opens more avenues in softening of brackish water and purification of industrial wastewater containing heavy metal ions.
PubMed: 38875312
DOI: 10.1021/acs.est.4c04063