2-Nitrophenol sensor-based wet-chemically prepared binary doped Co3O4/Al2O3 nanosheets by an electrochemical approach

Herein, the wet-chemical process (co-precipitation) was used to prepare nanosheets (NSs) of Co₃O₄/Al₂O₃ in an alkaline medium (pH ∼ 10.5). The synthesized NSs were totally characterized by Fourier-transform infrared spectroscopy (FTIR), ultraviolet visible spectroscopy (UV/vis), field emission scanning electron microscopy (FESEM), energy-dispersive X-ray spectroscopy (EDS), X-ray photoelectron spectroscopy (XPS), and powder X-ray diffraction (XRD). The synthesized NSs were deposited onto a glassy carbon electrode (GCE) to prepare a very thin layer with a conducting binder for detecting 2-nitrophenol (2-NP) selectively by a reliable electrochemical method. The proposed chemical sensor exhibits good sensitivity (54.9842 μA μM⁻¹ cm⁻²), long-term stability, and enhanced chemical response by electrochemical approaches. The resultant current is found to be linear over the concentration range (LDR) from 0.01 nM to 0.01 mM. The estimated detection limit (DL) is equal to 1.73 ± 0.02 pM. This study introduces a potential route for future sensitive sensor development with Co₃O₄/Al₂O₃ NSs by an electrochemical approach for the selective detection of hazardous and carcinogenic chemicals in environmental and health care fields.

This potential research work introduces a route of future sensitive sensor development with Co₃O₄/Al₂O₃ NSs by electrochemical approach to selective detection of hazardous and carcinogenic chemicals in environmental and health care fields.     

Co3O4 composite nano-fibers doped with Mn4+ prepared by the electro-spinning method and their electrochemical properties

In this work, based on the electrospinning method, pure Co₃O₄, pure MnO₂, and Co₃O₄ composite nano-fiber materials doped with different ratios of Mn⁴⁺ were prepared. XRD, XPS, BET and SEM tests were used to characterize the composition, structure and morphology of the materials. An electrochemical workstation was used to test the electrochemical performance of the materials. The results showed that the material properties had greatly improved on doping Mn⁴⁺ in Co₃O₄ nano-fibers. The relationship between the amount of Mn⁴⁺ doped in the Co₃O₄ composite nano-fiber material and its electrochemical performance was also tested and is discussed in this report. The results show that when n_Co : n_Mn = 20 : 2, the Co₃O₄ composite nano-fiber material had a specific surface area of 68 m² g⁻¹. Under the current density of 1 A g⁻¹, the 20 : 2 sample had the maximum capacitance of 585 F g⁻¹, which was obviously larger than that of pure Co₃O₄ nano-fibers (416 F g⁻¹). After 2000 cycles of charging/discharging, the specific capacitance of the 20 : 2 sample was 85.9%, while that of the pure Co₃O₄ nano-fiber material was only 76.4%. The mechanism of performance improvement in the composite fibers was analyzed, which demonstrated concrete results.

In this work, based on the electrospinning method, pure Co₃O₄, pure MnO₂, and Co₃O₄ composite nano-fiber materials doped with different ratios of Mn⁴⁺ were prepared.     

Wet-chemically prepared low-dimensional ZnO/Al2O3/Cr2O3 nanoparticles for xanthine sensor development using an electrochemical method

A reliable xanthine (XNT) chemical sensor was fabricated using a facile wet-chemical method (by co-precipitation) to prepare ZnO/Al₂O₃/Cr₂O₃ nanoparticles (NPs) in an alkaline medium at low temperature. Powder X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), field emission scanning electron microscopy (FESEM), energy-dispersive X-ray spectroscopy (EDS), Fourier transform infrared spectroscopy (FTIR) and ultraviolet-visible spectroscopy (UV-vis) were implemented for detailed characterization of the NPs. To fabricate the working electrode as a XNT chemical sensor probe, a glassy carbon electrode (GCE) with a 0.0316 cm² surface area was coated with an ethanolic slurry of the prepared ZnO/Al₂O₃/Cr₂O₃ NPs to make a thin layer and used to analyse XNT in a phosphate buffer system. To evaluate the analytical performances of the XNT chemical sensor, the calibration curve of XNT was plotted as the relationship of current versus the concentration of XNT. The plotted calibration curve was found to be linear over the LDR (linear dynamic range) of 0.05 nM to 5.0 μM. The assembled XNT electrochemical sensor exhibited the highest sensitivity (70.8861 μA μM⁻¹ cm⁻²), the lowest detection limit (1.34 ± 0.07 pM), good reproducibility performance with high accuracy and long-term stability with standard results under ambient conditions. This is a simple route to selectively detect XNT with wet-chemically prepared co-doped ZnO/Al₂O₃/Cr₂O₃ nanomaterials using a reliable electrochemical method at a large scale for safety within healthcare fields.

This is a simple route to detect the selective xanthine with wet-chemically prepared co-doped ZnO/Al₂O₃/Cr₂O₃ nanomaterials by reliable electrochemical method at large scales for the safety of healthcare fields.     

Detection of toxic choline based on Mn2O3/NiO nanomaterials by an electrochemical method

In this study, a novel in situ choline sensor was assembled by attaching the binary Mn₂O₃/NiO nanoparticles (NPs) onto a glassy carbon electrode (GCE). Initially, Mn₂O₃/NiO NPs were synthesized via a wet-chemical process and fully characterized via XRD, XPS, FESEM, EDS, FTIR and UV-Vis methods. The analytical performances of the choline sensor were evaluated by an electrochemical method in the phosphate buffer phase. The estimated linear dynamic range (LDR) was found to be 0.1 nM to 0.1 mM. The other analytical performances of the choline sensor, such as sensitivity (16.4557 μA μM⁻¹ cm⁻²) and detection limit (5.77 ± 0.29 pM), were also calculated very carefully from the calibration plot. Overall, the choline sensor exhibited a reliable reproducibility, in situ validity, selectivity, interference effect, stability, and intra-day and inter-day performances with high accuracy in a short response time. Moreover, the probe was successfully applied to detect choline in real human, mouse and rabbit serum. This fabrication route would be a novel approach for the detection of selective biochemical sensor in the healthcare and biomedical fields.

In this study, a novel in situ choline sensor was assembled by attached the binary Mn₂O₃/NiO nanoparticles onto glassy carbon electrode, which might be a reliable way to develop of future sensor in the field of biomedical and healthcare fields.     

Structural and thermal properties of Na2Mn(SO4)2·4H2O and Na2Ni(SO4)2·10H2O

The title compounds were prepared via a wet chemistry route and their crystal structures were determined from single crystal X-ray diffraction data. Na₂Mn(SO₄)₂·4H₂O crystallizes with a monoclinic symmetry, space group P2₁/c, with a = 5.5415(2), b = 8.3447(3), c = 11.2281(3) Å, β = 100.172(1)°, V = 511.05(3) ų and Z = 2. Na₂Ni(SO₄)₂·10H₂O also crystallizes with a monoclinic symmetry, space group P2₁/c, with a = 12.5050(8), b = 6.4812(4), c = 10.0210(6) Å, β = 106.138(2)°, V = 780.17(8) ų and Z = 2. Na₂Mn(SO₄)₂·4H₂O is a new member of the blödite family of compounds, whereas Na₂Ni(SO₄)₂·10H₂O is isostructural with Na₂Mg(SO₄)₂·10H₂O. The structure of Na₂Mn(SO₄)₂·4H₂O is built up of [Mn(SO₄)₂(H₂O)₄]²⁻ building blocks connected through moderate O–H⋯O hydrogen bonds with the sodium atoms occupying the large tunnels along the a axis and the manganese atom lying on an inversion center, whereas the structure of Na₂Ni(SO₄)₂·10H₂O is built up of [Ni(H₂O)₆]²⁺ and [Na₂(SO₄)₂(H₂O)₄]²⁻ layers. These layers which are parallel to the (100) plane are interconnected through moderate O–H⋯O hydrogen bonds. The thermal gravimetric- and the powder X-ray diffraction-analyzes showed that only the nickel phase was almost pure. At a temperature above 300 °C, all the water molecules evaporated and a structural phase transition from P2₁/c-Na₂Ni(SO₄)₂·10H₂O to C2/c-Na₂Ni(SO₄)₂ was observed. C2/c-Na₂Ni(SO₄)₂ is thermally more stable than Na₂Fe(SO₄)₂ and therefore it would be suitable as the positive electrode for sodium ion batteries if a stable electrolyte at high voltage is developed.

Two compounds were prepared via a supersaturation method. Their crystal structures were solved and compared to Na₂M(SO₄)₂·nH₂O (M = Mn, Ni and n = 0, 1, 2, 3, 4, 5, 6, 10, 16). Furthermore, phase transitions as a function of temperature were observed.     

Effect of Pr/Zn on the anti-humidity and acetone-sensing properties of Co3O4 prepared by electrospray

Co₃O₄ is a P-type metal-oxide semiconductor which can realize acetone detection at a lower temperature, but the lower working temperature brings the enhanced humidity effect. In order to solve the problem of a Co₃O₄ gas sensor being easily affected by humidity, an acetone-sensing material of Co₃O₄ mixed with Pr/Zn was prepared by electrospray in this work. The optimal working temperature of Pr/Zn–Co₃O₄ is 160 °C, and the detection limit can reach 1 ppm. The fluctuation of the acetone response is about 7.7% in the relative humidity range of 30–90%. Compared with pure Co₃O₄, the anti-humidity property of this material is obviously enhanced, but the gas-sensing response deteriorates. Compared with Pr–Co₃O₄, the anti-humidity and acetone sensing properties of Pr/Zn–Co₃O₄ were both improved. The morphology, composition, crystal state and energy state of the material were analyzed by SEM, EDS, XRD and XPS. The material of Pr/Zn–Co₃O₄ is a multi-component mixed material composed of PrCoO₃, ZnO, Pr₆O₁₁ and Co₃O₄. The improved anti-humidity and acetone sensing properties exhibited by this material are the result of the synergistic effect of ZnO and Pr³⁺.

With the synergistic effect of Pr and Zn, the material of Co₃O₄ mixed with Pr/Zn exhibits improved properties of anti-humidity and acetone sensitivity.     

Determination of heavy metals in water using an FTO electrode modified with CeO2/rGO nanoribbons prepared by an electrochemical method

The rGO/CeO₂/FTO nanocomposite modified electrode was prepared by an electrochemical method. A simple and highly sensitive electrochemical sensing platform for electrochemical rGO and modified CeO₂ nanoribbons directly on FTO electrodes was developed. Simultaneous determination of Pb²⁺ and Cd²⁺ used the differential pulse anodic stripping voltammetry (DPASV) method. The method was simple to operate, and CeO₂ nanobelts could be obtained simultaneously by electrodeposition and reduction of GO without further processing. This is an environmentally friendly electrochemical method to obtain modified electrodes under mild conditions. The experimental results showed that the linear calibration curves of Pb²⁺ and Cd²⁺ are 1–300 and 0.2–500 μg L⁻¹, respectively. At the same time, no interference from other coexisting metal ions was found during the detection process, which proved that the modified electrode had good stability and repeatability.

The rGO/CeO₂/FTO nanocomposite modified electrode was prepared by an electrochemical method.     

Insights into the photocatalytic performance of Bi2O2CO3/BiVO4 heterostructures prepared by one-step hydrothermal method

This paper describes the synthesis of Bi₂O₂CO₃/BiVO₄ heterostructures through a one-step method based on the difference in solubility between two semiconductors that possess a metal in common. The as-synthesized Bi₂O₂CO₃/BiVO₄ heterostructures were characterized by X-ray diffraction (XRD), thermogravimetric analysis (TGA), Raman spectroscopy, ultraviolet-visible diffuse reflectance spectroscopy (UV-vis DRS), scanning electron microscopy (SEM), transmission electron microscopy (TEM), N₂ physisorption, X-ray photoelectron spectroscopy (XPS) and time resolved photoluminescence spectroscopy (TRPL). The role of the heterojunction formed was evaluated by methylene blue (MB) dye and amiloride photodegradation. The formation of the heterostructure was observed indirectly by the great increase in the thermal stability of the Bi₂O₂CO₃ phase when compared to its pure phase. The amount of heterojunctions formed between the Bi₂O₂CO₃ and BiVO₄ was tuned by vanadium precursor concentration. The proposed strategy was efficient for obtaining Bi₂O₂CO₃/BiVO₄ heterostructures with enhanced photocatalytic performance when compared to their isolated phases, MB and amiloride photodegradation occurred mainly by the action of ˙OH radicals, i.e. by an indirect mechanism. Based on TRPL spectroscopy and VB-XPS results, an enhancement of photoactivity related to an increase in the spatial separation of photo-generated electron/hole pairs was observed due to the formation of a type-II heterostructure.

A novel visible-driven heterojunction of Bi₂O₂CO₃/BiVO₄ was prepared by an efficient hydrothermal self-sacrificial synthesis method based on the difference in solubility.     

Preparation and electrochemical properties of nanostructured porous spherical NiCo2O4 materials

Porous spherical NiCo₂O₄ powders with a micro–nano structure were prepared by the spray drying method using citric acid as the chelating agent and soluble salts as cobalt and nickel sources. By calcination at 300 °C, spherical and single-phase spinel-type NiCo₂O₄ powders were obtained. The powders with particle sizes of 0.5–3 μm were aggregations of nano-sized grains (about 15–30 nm). The electrical property tests demonstrated that the synthesized NiCo₂O₄ has a specific capacitance of 430.67 F g⁻¹ at a current density of 1 A g⁻¹ and a capacitance retention rate of 100% after 3000 cycles at a current density of 4 A g⁻¹, indicating excellent cycling stability. On assembly into an asymmetric supercapacitor device, a specific capacitance of 37.06 F g⁻¹ and energy density of 13.18 W h kg⁻¹ at a power density of 800 W kg⁻¹ and a current density of 1 A g⁻¹ were demonstrated. The micro–nano structured porous NiCo₂O₄ powders have a larger specific surface area, which can allow the sample to come in full contact with the electrolyte. The nanopore channels are favourable for releasing the lattice distortion stress during the charge–discharge process, maintaining the structural stability of the crystal and improving the cycle life.

Porous NiCo₂O₄ microspheres with a micro–nano structure, prepared by the spray drying method, have excellent cycle stability and 100% capacitance retention.     

Sm2O3/Co3O4 catalysts prepared by dealloying for low-temperature CO oxidation

A series of Co₃O₄ catalysts modified by Sm were prepared by a combined dealloying and calcination approach, and the catalytic activities were evaluated using CO catalytic oxidation. The Sm₂O₃/Co₃O₄ catalysts were composed of a large number of nanorods and nanosheets, and exhibited a three-dimensional supporting structure with pores. The experimental results revealed that the addition of a small amount of Sm into the precursor AlCo alloy led to a dealloyed sample with improved catalytic activity, and the dealloyed Al₉₀Co_9.5Sm_0.5 ribbons (0.5 Sm₂O₃/Co₃O₄) calcined at 300 °C showed the highest activity for CO oxidation with complete CO conversion at 135 °C, moreover, CO conversion almost no attenuation, even after 70 hours of catalytic oxidation, which is superior to that of Co₃O₄. The enhanced catalytic activity of the Sm₂O₃/Co₃O₄ catalyst can be attributed to the large specific surface area, more reactive oxygen species and Co³⁺ ion, as well as electronic interactions between Sm and Co.

A series of Co₃O₄ catalysts modified by Sm were prepared by a combined dealloying and calcination approach, and the catalytic activities were evaluated using CO catalytic oxidation.     

Growth mechanism of SnC2H4O2 nanowires prepared by the polyol process as SnO2 precursor nanowires

Tin oxide (SnO₂) nanowires are produced by the calcination of tin glycolate (SnC₂H₄O₂) nanowires, which are synthesized with tin oxalate (SnC₂O₄) and ethylene glycol via the so-called polyol process. In this study, the growth mechanism of SnC₂H₄O₂ nanowires was investigated by monitoring the synthesis using scanning and transmission electron microscopy. The length and diameter of the nanowires were 9.25 μm and 0.37 μm, respectively; the former increased at a rate of 1.85 μm h⁻¹ but the latter did not increase over time. Fourier-transform IR spectroscopy showed that the nanowires were composed of SnC₂H₄O₂ instead of SnC₂O₄. Changes in the components of the reaction solution were also confirmed by ¹H NMR, ¹³C NMR, and high-performance liquid chromatography. SnC₂H₄O₂ was formed by the substitution of the oxalate coordinated to tin by ethylene glycolate, which was produced by the deprotonation of ethylene glycol. In this reaction, oxalate gradually changed to formic acid and carbon dioxide, and SnC₂H₄O₂ grew as a nanowire through O–Sn–O bond formation. In addition, when ethylene glycol was mixed with 1,2-propanediol, branched SnC₂H₄O₂ nanowires were formed. The branching was due to the interference of the methyl group of 1,2-propanediol with the growth of bundle-type nanowires. The branched nanowires had a higher surface area-to-mass ratio than the bundled ones based on dispersion measurements. Knowledge of the growth mechanism and reaction conditions that affect morphology would be valuable in modifying the physical and electrical properties of metal oxide nanowires.

Tin oxide (SnO₂) nanowires are produced by the calcination of tin glycolate (SnC₂H₄O₂) nanowires, which are synthesized with tin oxalate (SnC₂O₄) and ethylene glycol via the so-called polyol process.     

A new electrochemical DNA biosensor for determination of anti-cancer drug chlorambucil based on a polypyrrole/flower-like platinum/NiCo2O4/pencil graphite electrode

In the current study, DNA immobilization was performed on pencil graphite (PG) modified with a polypyrrole (PPy) and flower-like Pt/NiCo₂O₄ (FL-Pt/NiCo₂O₄) nanocomposite, as a new sensitive electrode to detect chlorambucil (CHB). Energy dispersive X-ray (EDX) analysis, X-ray diffraction (XRD) and scanning electron microscopy (SEM) techniques were employed to characterize the synthesized FL-Pt/NiCo₂O₄ and PPy/FL-Pt/NiCo₂O₄ nanocomposites. Moreover, differential pulse voltammetry (DPV) was selected to assess the guanine and adenine electrochemical responses on the DNA sensor. The CHB determination was performed using the maximum currents towards adenine and guanine in the acetate buffer solution (ABS). According to the results, ds-DNA/PPy/FL-Pt/NiCo₂O₄/PGE was able to detect the different concentrations of CHB in the range between 0.018 and 200 μM, with a detection limit of (LOD) of 4.0 nM. The new biosensor was also exploited for CHB determination in real samples (serum, urine and drug), the results of which revealed excellent recoveries (97.5% to 103.8%). Furthermore, the interaction between ds-DNA and CHB was studied using electrochemistry, spectrophotometry and docking whose outputs confirmed their effective interaction.

In the current study, DNA immobilization was performed on pencil graphite (PG) modified with a polypyrrole (PPy) and flower-like Pt/NiCo₂O₄ (FL-Pt/NiCo₂O₄) nanocomposite, as a new sensitive electrode to detect chlorambucil (CHB).     

NiCo2O4 thin film prepared by electrochemical deposition as a hole-transport layer for efficient inverted perovskite solar cells

Spinel NiCo₂O₄ is a promising p-type semiconductor for optoelectronic devices; however, it is difficult to prepare uniform and large-area NiCo₂O₄ films, which hinders its application as a hole transport material for perovskite solar cells (PSCs). In this study, a novel, mild, and low-cost KCl-assisted electrochemical deposition (ECD) approach was developed to directly prepare a uniform NiCo₂O₄ film on a fluorine-doped tin oxide (FTO) substrate. A uniform NiCo₂O₄ film prepared through an ECD approach was used as a hole-transport layer (HTL) in inverted PSCs. The resulting NiCo₂O₄ HTL-based device achieved a power conversion efficiency (PCE) of 19.24% with negligible hysteresis and excellent reproducibility. Additionally, it outperformed a NiO_x-based device (PCE = 18.68%). The unsealed devices retained 90.7% of their initial efficiency when subjected to stability measurements for 360 h in an ambient atmosphere. This study shows the great potential of ECD-prepared NiCo₂O₄ HTLs for large-area PSCs in the future.

An electrochemical deposition approach was developed to prepare a NiCo₂O₄ hole transport layer for inverted perovskite solar cells.     

Hollow ZnO nanorices prepared by a simple hydrothermal method for NO2 and SO2 gas sensors

Chemoresistive gas sensors play an important role in detecting toxic gases for air pollution monitoring. However, the demand for suitable nanostructures that could process high sensing performance remains high. In this study, hollow ZnO nanorices were synthesized by a simple hydrothermal method to detect NO₂ and SO₂ toxic gases efficiently. Material characterization by some advanced techniques, such as scanning electron microscopy, transmission electron microscopy, X-ray diffraction, and Raman spectroscopy, demonstrated that the hollow ZnO nanorices had a length and diameter size of less than 500 and 160 nm, respectively. In addition, they had a thin shell thickness of less than 30 nm, formed by an assembly of tiny nanoparticles. The sensor based on the hollow ZnO nanorices could detect low concentration of NO₂ and SO₂ gasses at sub-ppm level. At an optimum operating temperature of 200 °C, the sensor had response values of approximately 15.3 and 4.8 for 1 ppm NO₂ and 1 ppm SO₂, respectively. The sensor also exhibited good stability and selectivity, suggesting that the sensor can be applied to NO₂ and SO₂ toxic gas detection in ambient air.

Hollow ZnO nanorices with an ultrathin shell show excellent response to NO₂ and SO₂ gases.     

A comparative study on the electrochemical properties of nanoporous nickel oxide nanowires and nanosheets prepared by a hydrothermal method

Metal oxide nanostructures have been extensively used in electrochemical devices due to their advantages, including high active surface area and chemical stability. However, the electrochemical properties of metal oxides are strongly dependent on their structural characteristics. We performed a comparative study on the electrochemical performance of nanoporous nickel oxide (NiO) nanosheets and nanowires. The advanced nanoporous NiO nanomaterials were synthesized by a facile hydrothermal method followed by thermal calcination. The synthesized nanomaterials, as characterized by scanning electron microscopy, transmission electron microscopy, selected area electron diffraction, X-ray diffraction, and nitrogen adsorption/desorption isotherms, demonstrated the nanoporosity and high crystallinity of the NiO nanosheets and nanowires. Cyclic voltammetry measurement was performed using a three-electrode system to evaluate the electrochemical properties of the synthesized materials. Results showed that the nanoporous NiO nanosheets possessed a higher current density than that of the nanowires by approximately ten times. Moreover, the nanoporous NiO nanosheets showed exceptionally high stability of almost 100%, after three cycles in strong alkaline environments, thereby suggesting possible application in electrochemical devices.

Nanoporous NiO nanosheets and nanowires were synthesized by a hydrothermal method and their electrochemical properties were compared. Results show that the nanoporous NiO nanosheets have a better electrochemical performance and suitable for supercapacitor application.     

Photocatalytic activity of Ag/Al2O3–Gd2O3 photocatalysts prepared by the sol–gel method in the degradation of 4-chlorophenol

The photocatalytic activity in the degradation of 4-chlorophenol (4-ClPh) in aqueous medium (80 ppm) using 2.0 wt% Ag/Al₂O₃–Gd₂O₃ (Ag/Al–Gd-x; where x = 2.0, 5.0, 15.0, 25.0 and 50.0 wt% of Gd₂O₃) photocatalysts prepared by the sol–gel method was studied under UV light irradiation. The photocatalysts were characterized by N₂ physisorption, X-ray diffraction, SEM, HRTEM, UV-Vis, XPS, FTIR and fluorescence spectroscopy. About 67.0% of 4-ClPh was photoconverted after 4 h of UV light irradiation using Ag/γ-–Al₂O₃. When Ag/Al–Gd-x photocatalysts were tested, the 4-ClPh photoconversion was improved and more than 90.0% of 4-ClPh was photoconverted after 3 h of UV light irradiation in the materials containing 15.0 and 25.0 wt% of Gd₂O₃. Ag/Al–Gd-25 was the material with the highest efficacy to mineralize dissolved organic carbon, mineralizing more than 85.0% after 4 h of UV light irradiation. Silver nanoparticles and micro-particles of irregular pentagonal shape intersected by plane nanobelts of Al₂O₃–Gd₂O₃ composite oxide were detected in the Ag/Al–Gd-25 photocatalyst. This material is characterized by a lowest recombination rate of electron–hole pairs. The low recombination rate of photo-induced electron–hole pairs in the Ag/Al–Gd-x photocatalysts with high Gd₂O₃ contents (≥15.0 wt%) confirmes that the presence of silver nanoparticles and microparticles interacting with Al₂O₃–Gd₂O₃ composite oxide entities favors the separation of photo-induced charges (e⁻ and h⁺). These materials could be appropriate to be used as highly efficient photocatalysts to eliminate high concentrations of 4-ClPh in aqueous medium.

Ag/Al₂O₃–Gd₂O₃ showed high efficacy to photodegradate 4-chlorophenol, the strong interaction between silver nano-particles and micro-particles and Al₂O₃–Gd₂O₃ entities favors the decrease in the recombination rate.     

Effect of glyphosate on X-ray diffraction of copper films prepared by electrochemical deposition

In the process of electrochemical deposition of metals, the additives can directly affect the final morphology of the metal. Using glyphosate as the additive, copper thin films were prepared by the electrochemical deposition method from a CuSO₄ aqueous solution under a specific voltage. The copper thin films were grown on the surface of the indium tin oxide (ITO) film, which was used as the working electrode in a classical three-electrode cell. Glyphosate combined with the copper ion to form a complex, and hindered further reduction and crystallization of the copper ions. The results indicated that the peak intensities of the X-ray diffraction peaks decreased with the increase in the glyphosate concentrations, which can be used as a basis for quantitative detection. The method is simple and highly sensitive.

Quantitative probing of glyphosate by combining electrochemical deposition and X-ray diffraction methods.     

Mixed-solvent liquid exfoliated MoS2 NPs as peroxidase mimetics for colorimetric detection of H2O2 and glucose

Ultra-small molybdenum disulfide nanoparticles (MoS₂ NPs) were prepared by a facile liquid exfoliation method with ethanol/water as the solvent. The produced MoS₂ NPs were of high purity due to the easily removable ethanol/water solution. The prepared MoS₂ NPs exhibited an intrinsic peroxidase-like activity in analogy to that of horseradish peroxidase (HRP). A custom-made spectrometer was employed to investigate the peroxidase-like activity of MoS₂ NPs in the presence of H₂O₂ and glucose. The change in absorption detected from MoS₂ NPs is proportional to the amount of target. The calibration curve of H₂O₂ and glucose shows a good relationship between the concentration of target and the change in the absorption of MoS₂ NPs. The limit of detection of H₂O₂ and glucose achieved by this method could approach 1.25 μM and 7 μM respectively. This method has been applied for the detection of glucose in serum from humans. Therefore, these produced MoS₂ NPs offer an alternative high-efficiency and economic way to detect diabetes.

Ultra-small molybdenum disulfide nanoparticles (MoS₂ NPs) prepared by a facile liquid exfoliation method is capable of detecting the presence of H₂O₂ and glucose. This novel colorimetric method offers an alternative way to detect diabetes.