Selenium-enriched hollow NiCo2O4/NiO heterostructured nanocages as an efficient electrocatalyst for oxygen evolution reaction.

Finding clean, sustainable, and environmentally friendly technologies is especially crucial in addressing both energy and environmental challenges. To accelerate the oxygen evolution reaction (OER) and to overcome the obstacle of high energy consumption, exploring high-performance electrocatalysts is imperative to maximize the practical applicability of water splitting. Developing electrocatalyst through strategic surface modifications represents a significant approach for the construction of active catalytic centers. In the present work, we successfully synthesized selenium-incorporated hollow NiCo2O4/NiO heterostructured nanocages as electrocatalysts for the OER by precisely controlling the structure and composition of the material. The findings demonstrated that the surface-reconstructed hollow 5 wt% Se-NiCo2O4/NiO heterostructured nanocages resulted in an increased number of active sites through interfacial engineering. Benefiting from the structural control, mass transport was further expedited and due to increased conductivity, accelerated the charge transfer processes within the system. The electrocatalyst exhibited remarkable activity for the OER and displayed a low overpotential (η = 288 mV) at a current density (j) of 10 mA cm-2, small Tafel slope (66.7 mV dec-1) and better stability. This work offers a viable and adaptable method for fabricating a range of functional coordinated MOF compounds that are capable of utilization across diverse energy applications, including storage, conversion and environmental purposes.

Recent Advancements in Ascribing Several Platinum Free Electrocatalysts Pertinent to Hydrogen Evolution from Water Reduction.

The advancement of a sustainable and scalable catalyst for hydrogen production is crucial for the future of the hydrogen economy. Electrochemical water splitting stands out as a promising pathway for sustainable hydrogen production. However, the development of Pt-free electrocatalysts that match the energy efficiency of Pt while remaining economical poses a significant challenge. This review addresses this challenge by highlighting latest breakthroughs in Pt-free catalysts for the hydrogen evolution reaction (HER). Specifically, we delve into the catalytic performance of various transition metal phosphides, metal carbides, metal sulphides, and metal nitrides toward HER. Our discussion emphasizes strategies for enhancing catalytic performance and explores the relationship between structural composition and the performance of different electrocatalysts. Through this comprehensive review, we aim to provide insights into the ongoing efforts to overcome barriers to scalable hydrogen production and pave the way for a sustainable hydrogen economy.

Electrocatalytic barium-oxide decorated MWCNT amperometric sensor for the quantification of anesthetic drug Procaine.

Procaine hydrochloride (P.HCl) is one of the earliest and most well-established local anesthetic drugs used in medicine. Though it is employed frequently for effective clinical nerve blocks during surgeries, its immoderate administration has often shown reports of systemic toxicity. To prevent such repercussions, developing a sensor for the drug is crucial to enable real-time monitoring of the drug and assist in quality control procedures during its industrial preparations. Thus, in this work, we have fabricated a simple yet highly selective and sensitive amperometric sensor for P.HCl detection based on a Barium-oxide multi-wall carbon nanotube-modified carbon paste electrode (BaO-MWCNT/CPE). Herein, we have adopted a novel approach devoid of sophisticated procedures and pretreatments for rapidly determining P.HCl. Furthermore, experimental conditions, including supporting electrolytes, pH, and scan rate, were optimized to achieve a well-defined P.HCl anodic peak current at 631 mV, which is lower than the previously reported peak potentials, indicating an advantage of reduced overpotential. Besides, a striking 66-fold rise in current responsiveness to P.HCl was achieved upon modification with BaO-MWCNT. Such an intense signal enhancement upon electrode modification compared to bare CPE was due to the strong electrocatalytic feature of BaO-MWCNT, which was verified using surface morphology studies with scanning electron microscopy (FESEM) and transmission electron microscopy (TEM). Additionally, the charge transfer kinetics analyzed via electrochemical impedance spectroscopy (EIS) justified the enhancement of electrocatalytic activity upon electrode modification. The developed sensor exhibited a remarkable analytical performance over a wide linear dynamic range of 2.0-100.0 µM with a detection limit of 0.14 µM. Moreover, a significant merit of this sensor is its excellent selectivity towards P.HCl even in the presence of various common interferants. Finally, the versatility of the sensor was further validated by implementing it for the trace analysis of urine and blood serum real samples.

In-situ development of metal organic frameworks assisted ZnMgAl layered triple hydroxide 2D/2D hybrid as an efficient photocatalyst for organic dye degradation.

Metal organic framework (MOF) supported layered triple hydroxide (LTH) 2D/2D hybrid material was prepared by a simple hydrothermal method. The photophysical properties of the prepared samples were investigated through a set of analytical methods such as X-ray diffraction, Fourier-transform infrared spectroscopy, field emission scanning electron microscope, high-resolution transmission electron microscopy, energy-dispersive X-ray spectroscopy and mapping. The photocatalytic degradation activity of as prepared 2D/2D MOF-5/LTH hybrid sample was investigated against methylene blue (MB) dye under the UV-visible light irradiation. The degradation efficiency of the MOF-5/LTH hybrid sample was twice a time greater than that of pristine MOF-5, particularly degradation efficiency of the MOF-5, LTH and MOF-5/LTH hybrid samples are 43.3, 57.7 and 98.1% respectively. The Pseudo first order rate and the reusing investigation was further used to study the catalytic activity and stability of the as-synthesized 2D/2D photocatalyst. The observed improvement in the photocatalytic activity of the hybrid samples were owed to enhance visible light absorption, efficient separation and transportation of photoinduced electrons and holes.

Effect of cobalt doping on the electrochemical performance of trimanganese tetraoxide.

Nanostructured transition metal oxides (TMO) are potential materials widely explored by researchers for energy storage applications. In this study, spinel trimanganese tetraoxide (Mn3O4) and cobalt doped trimanganese tetraoxide (Co-Mn3O4) was synthesized by using a simple solvent assisted hydrothermal route. Pure Mn3O4 and Co-Mn3O4 nanomaterials were characterized by an x-ray diffractometer (XRD), Fourier transform infrared spectroscopy (FTIR), UV-diffuse reflectance spectroscopy (UV-DRS), field emission scanning electron microscope (FESEM), and high resolution transmission electron microscope (HRTEM). XRD analysis revealed the body centered tetragonal spinel structure of Mn3O4 and Co-Mn3O4 with a space group as l41/amd (141) and an approximate crystallite size of 45-33 nm. The presence of an Mn-O bond vibration was confirmed using FTIR and the band gap properties were analyzed through UV-DRS. Surface morphology and average grain size were examined using FESEM and HRTEM micrographs as nanosquares and nanospheres with diameter 126 nm and 118 nm, respectively. Electrochemical properties of Mn3O4 and Co-Mn3O4 were evaluated using cyclic voltammograms, charge-discharge curves, and electrochemical impedance spectra (EIS). Pure Mn3O4 showed a specific capacitance of 971 F g-1 at 0.1 A g-1 current density while Co-Mn3O4 achieved relatively higher specific capacitance of 1852 F g-1 at the same current density. It is observed that the increased specific capacitance of Co-Mn3O4 mainly arises from the doping effect. Electrochemical analysis shows that the Co doped Mn3O4 nanomaterials can be a promising electrode material for supercapacitor.

Unique Host Matrix to Disperse Pd Nanoparticles for Electrochemical Sensing of Morin: Sustainable Engineering Approach.

Biomass-based carbon nanospheres derived from Mimosa pudica (commonly called "Touch-me-not") smeared on carbon fiber paper have been used as a host matrix for electrochemical deposition of palladium nanoparticles. The physicochemical characterization of modified electrodes was performed by field emission scanning electron microscopy, energy-dispersive X-ray spectroscopy, X-ray diffraction spectroscopy, transmission electron microscopy, and X-ray photoelectron spectroscopy techniques. Cyclic voltammetry and electrochemical impedance spectroscopy were used to study the electroanalytical properties of the electrodes. The modified electrode demostrated an excellent electrocatalytic activity for the oxidation of a flavonoid, morin, which gave a sensitive anodic peak at -0.30 V (vs SCE). An ultralow-level detection limit of 572 fM with a linear dynamic range of 37.50-130 pM was achieved. The proposed electrochemical sensor was successfully employed for the analysis of morin in mulberry and guava leaves. This is a sustainable engineering approach where a perfect unique host matrix is created using carbon nanospheres from biomass.

Novel sonochemical synthesis of Fe3O4 nanospheres decorated on highly active reduced graphene oxide nanosheets for sensitive detection of uric acid in biological samples.

In this study, a super-active Iron (II, III) oxide nanospheres (Fe3O4 NPs) decorated reduced graphene oxide (rGOS) nanocomposite was developed. Fe3O4 NPs were stabilized on rGOS through electrostatic interactions in the aqueous medium. This process involves an ultrasound assisted reduction reaction of the GOS. The as-synthesized Fe3O4 NPs@rGOS was characterized through the HRTEM, SEM, XRD, Raman, elemental mapping and EDX analysis. The Fe3O4 NPs@rGOS modified GCE was developed for the determination of biomarker. Uric acid is important biomarker based on gout and kidney stone with high adverse effect in human body. The results obtained showed that the modified electrode Fe3O4 NPs@rGOS shows good electrochemical reduction peak compared to bare electrode and control electrodes. The Fe3O4 NPs@rGOS modified sensor linear range 0.02-783.6 µM was observed with nanomolar LOD 0.12 nM. In addition, the modified Fe3O4 NPs@rGOS/GCE sensor has been applied to determination of uric acid concentration in urine and blood serum samples. Furthermore, advantages of the modified sensor are high stability, repeatability and reproducibility.

Electrochemical Energy Storage Properties of Ni-Mn-Oxide Electrodes for Advance Asymmetric Supercapacitor Application.

In this work, we report a facile one-spot synthesis process and the influence of compositional variation on the electrochemical performance of Ni-Mn-oxides (Ni:Mn = 1:1, 1:2, 1:3, and 1:4) for high-performance advanced energy storage applications. The crystalline structure and the morphology of these synthesized nanocomposites have been demonstrated using X-ray diffraction, field emission scanning electron microscopy, and transmission electron Microscopy. Among these materials, Ni-Mn-oxide with Ni:Mn = 1:3 possesses a large Brunauer?Emmett?Teller specific surface area (127 m2 g?1) with pore size 8.2 nm and exhibits the highest specific capacitance of 1215.5 F g?1 at a scan rate 2 mV s?1 with an excellent long-term cycling stability (?87.2% capacitance retention at 10 A g?1 over 5000 cycles). This work also gives a comparison and explains the influence of different compositional ratios on the electrochemical properties of Ni-Mn-oxides. To demonstrate the possibility of commercial application, an asymmetric supercapacitor device has been constructed by using Ni-Mn-oxide (Ni:Mn = 1:3) as a positive electrode and activated carbon (AC) as a negative electrode. This battery-like device achieves a maximum energy density of 132.3 W h kg?1 at a power density of 1651 W kg?1 and excellent coulombic efficiency of 97% over 3000 cycles at 10 A g?1.

A review on ZnO nanostructured materials: energy, environmental and biological applications.

Zinc oxide (ZnO) is an adaptable material that has distinctive properties, such as high-sensitivity, large specific area, non-toxicity, good compatibility and a high isoelectric point, which favours it to be considered with a few exceptions. It is the most desirable group of nanostructure as far as both structure and properties. The unique and tuneable properties of nanostructured ZnO shows excellent stability in chemically as well as thermally stable n-type semiconducting material with wide applications such as in luminescent material, supercapacitors, battery, solar cells, photocatalysis, biosensors, biomedical and biological applications in the form of bulk crystal, thin film and pellets. The nanosized materials exhibit higher dissolution rates as well as higher solubility when compared to the bulk materials. This review significantly focused on the current improvement in ZnO-based nanomaterials/composites/doped materials for the application in the field of energy storage and conversion devices and biological applications. Special deliberation has been paid on supercapacitors, Li-ion batteries, dye-sensitized solar cells, photocatalysis, biosensors, biomedical and biological applications. Finally, the benefits of ZnO-based materials for the utilizations in the field of energy and biological sciences are moreover consistently analysed.

Methyl 1H-1,2,3-triazole-4-carboxyl-ate.

The title compound, C(4)H(5)N(3)O(2), features an essentially planar mol-ecule (r.m.s. deviation for all non-H atoms = 0.013 Å). The crystal structure is stabilized by inter-molecular N-H⋯O hydrogen bonds and π-π stacking inter-actions (centroid-centroid distance 3.882 Å).

1-(4-Chloro-3-fluoro-phen-yl)-2-[(3-phenyl-isoquinolin-1-yl)sulfan-yl]ethanone.

In the title compound, C(23)H(15)ClFNOS, the isoquinoline system and the 4-chloro-3-fluoro-phenyl ring are aligned at 80.4 (1)°. The dihedral angle between the isoquinoline system and the pendant (unsubstituted) phenyl ring is 19.91 (1)°.

1,3-Dimethyl-2,6-diphenyl-piperidin-4-one.

In the title moleclue, C(19)H(21)NO, the 4-piperidone ring adopts a chair conformation in which the two benzene rings and the methyl group attached to C atoms all have equatorial orientations. In the crystal structure, centrosymmetric dimers are formed through weak inter-molecular C-H⋯O hydrogen bonds [the dihedral angle between the aromatic rings is 58.51 (5)°].

Methyl 2-methyl-2H-1,2,3-triazole-4-carboxyl-ate.

In the title compound, C(5)H(7)N(3)O(2), all non-H atoms lie in a common plane, with a maximum deviation of 0.061 (2)° for the ester methyl C atom. The structure is stabilized by inter-molecular C-H⋯O hydrogen bonds.

1-(3,5-Dimethyl-1H-pyrazol-1-yl)-3-phenyl-isoquinoline.

The mol-ecular conformation of the title compound, C(20)H(17)N(3), is stabilized by an intramolecular C-H⋯N inter-action. The crystal structure shows inter-molecular C-H⋯π inter-actions. The dihedral angle between the isoquinoline unit and the phenyl ring is 11.42 (1)° whereas the isoquinoline unit and the pendent dimethyl pryrazole unit form a dihedral angle of 50.1 (4)°. Furthermore, the angle between the mean plane of the phenyl ring and the dimethyl pyrazole unit is 47.3 (6)°.

3-Acetyl-6-chloro-1-ethyl-4-phenyl-quinolin-2(1H)-one.

In the title compound, C(19)H(16)ClNO(2), the dihedral angle between the plane of the phenyl substituent and 3-acetyl-quinoline unit is 75.44 (5)°. The crystal structure is stabilized by inter-molecular C-H⋯O hydrogen bonds.

3-(4-Methoxy-phen-yl)-1H-isochromen-1-one.

The asymmetric unit of the title compound, C(16)H(12)O(3), contains two crystallographically independent mol-ecules. The isochromene ring system is planar (maximum deviation 0.024 Å) and is oriented at dihedral angles of 2.63 (3) and 0.79 (3)° with respect to the methoxy-benzene rings in the two independent mol-ecules.

Electro-oxidation of methanol on TiO2 nanotube supported platinum electrodes.

TiO2 nanotubes have been synthesized using anodic alumina membrane as template. Highly dispersed platinum nanoparticles have been supported on the TiO2 nanotube. The supported system has been characterized by electron microscopy and electrochemical analysis. SEM image shows that the nanotubes are well aligned and the TEM image shows that the Pt particles are uniformly distributed over the TiO2 nanotube support. A homogeneous structure in the composite nanomaterials is indicated by XRD analysis. The electrocatalytic activity of the platinum catalyst supported on TiO2 nanotubes for methanol oxidation is found to be better than that of the standard commercial E-TEK catalyst.