Facile design and synthesis of a nickel disulfide/zeolitic imidazolate framework-67 composite material with a robust cladding structure for high-efficiency supercapacitors

A core–shell structured ZIF-67 composite electrode material has been synthesized by a two-step method. The sample shows superior specific capacitance and the assembled HSC exhibits prominent power/energy density and durability.

Fabrication of selective and sensitive chemical sensor probe based on ternary nano-formulated CuO/MnO2/Gd2O3 spikes by hydrothermal approach

In this approach, thin spikes (NSs) of ternary nano-formulated mixed CuO/MnO₂/Gd₂O₃ were synthesized by the hydrothermal approach for efficient detection of 3-methoxyphenyl hydrazine (3-MPHyd) chemical from various environmental samples. The NSs were systematically characterized by using XPS, EDS, TEM, FTIR, UV/vis, and XRD. The fabricated NSs onto the glassy carbon electrode (GCE) was successfully applied for the selective and sensitive detection of 3-MPHyd in the phosphate buffer system (PBS), which displayed the highest sensitivity, good selectivity with ultra-trace detection limit, high stability, good reproducibility, and quick response time. The real environmental samples were tested for validation from stand point of the ternary doped nanomaterials for sensing in the practical applications using by electrochemical method.

CuO Hollow Cubic Caves Wrapped with Biogenic N-Rich Graphitic C for Simultaneous Monitoring of Uric Acid and Xanthine

Herein, we synthesized hollow cubic caves of CuO (HC) and wrapped it with N-rich graphitic C (NC), derived from a novel biogenic mixture composed of dopamine (DA) and purine. The synthesized NC wrapped HC (NC@HC) sensor shows enhanced electrocatalytic efficacy compared to unwrapped CuO with shapes including HC, sponge (SP), cabbage (CB), and solid icy cubes (SC). The shape and composition of synthesized materials were confirmed through field-emission scanning electron microscopy (FE-SEM), X-ray diffraction (XRD), Raman spectroscopy, and X-ray photoelectron spectroscopy (XPS), whereas interfacial surface energy was calculated through contact angle measurement. The designed NC@HC sensor shows a remarkable response toward the simultaneous detection of uric acid (UA) and xanthine (Xn) with detection limits of 0.017 ± 0.001 (S/N of 3) and 0.004 ± 0.001 μM (S/N of 3), respectively. In addition, this platform was successfully applied to monitor UA from the gout patient serum. To the best of our knowledge, this is the first report on using such novel NC@HC materials for the simultaneous monitoring of UA and Xn.

Chemical-resistant ammonia sensor based on polyaniline/CuO nanoparticles supported on three-dimensional nitrogen-doped graphene-based framework nanocomposites

A novel ammonia (NH₃) chemical sensor is presented with ultra-high response, good selectivity, fast response, and long-term stability using detecting layer of polyaniline/cupric oxide nanoparticles supported on three-dimensional nitrogen-doped graphene-based frameworks (PANI/CuO@3D-NGF) nanocomposite. The NH₃ gas sensing response of the PANI/CuO@3D-NGF nanocomposite was studied by resistivity method in low concentration range of 50 ppb-100 ppm at room temperature. The PANI/CuO@3D-NGF nanocomposite was prepared through in situ polymerization of PANI on the CuO@3D-NGF with a high surface area. Morphological and structural analysis revealed that the ultrathin 3D interconnected graphene substrate maximizes the surface area. It is also shown that the CuO nanoparticles offer active adsorption sites for free NH₃ molecule. The PANI/CuO@3D-NGF nanocomposite gas sensor shows the response of 930% to 100 ppm NH₃ with an outstanding low detection limit of 50 ppb and an average response time of 30 s at room temperature. The excellent sensing performance of the PANI/CuO@3D-NGF nanocomposite was attributed to 3D interconnected porous structure, remarkable enhancement of charge carriers as a result of CuO@3D-NGF, and modified π-interactions between molecules. Graphical abstract.

Fabrication of a hydrazine chemical sensor based on facile synthesis of doped NZO nanostructure materials

In this approach, nickel-doped zinc oxide (NZO) nanostructure materials were synthesized by the solution method in the basic phase.

MOFs-Derived Nano-CuO Modified Electrode as a Sensor for Determination of Hydrazine Hydrate in Aqueous Medium

It very important to be able to efficiently detect hydrazine hydrate in an aqueous medium due to its high toxicity. Here, we have proposed a new idea: to construct a sensor for the rapid determination of hydrazine hydrate based on the nano-CuO derived by controlled pyrolysis of HKUST-1 [Cu3(BTC)2(H2O)3]. The as-prepared CuO at 400 °C possesses a uniform appearance with nano-structure via SEM images, and the nano-CuO-400 has exhibited excellent electrocatalytic activity towards hydrazine oxidation. Amperometric i-t curves shows the peak current as linearly proportional to the hydrazine concentration within 1.98-169.3 μmol L-1 and 232-2096 μmol L-1 with the detection limit of 2.55 × 10-8 mol L-1 and 7.01 × 10-8 mol L-1, respectively. Moreover, the sensor constructed in the experiment shows good selectivities, and it is feasible to determining actual water samples.

Selective hydrazine sensor fabrication with facile low-dimensional Fe2O3/CeO2 nanocubes

Here, the binary-doped metal oxides of Fe₂O₃/CeO₂ nanocubes were prepared using reliable hydrothermal process, which is applied to fabricate an efficient and selective hydrazine chemical sensor shows good analytical sensing performances as well as validated the sensor prove with the environmental and extracted real samples.

In-Doped ZnO Hexagonal Stepped Nanorods and Nanodisks as Potential Scaffold for Highly-Sensitive Phenyl Hydrazine Chemical Sensors

Herein, we report the growth of In-doped ZnO (IZO) nanomaterials, i.e., stepped hexagonal nanorods and nanodisks by the thermal evaporation process using metallic zinc and indium powders in the presence of oxygen. The as-grown IZO nanomaterials were investigated by several techniques in order to examine their morphological, structural, compositional and optical properties. The detailed investigations confirmed that the grown nanomaterials, i.e., nanorods and nanodisks possess well-crystallinity with wurtzite hexagonal phase and grown in high density. The room-temperature PL spectra exhibited a suppressed UV emissions with strong green emissions for both In-doped ZnO nanomaterials, i.e., nanorods and nanodisks. From an application point of view, the grown IZO nanomaterials were used as a potential scaffold to fabricate sensitive phenyl hydrazine chemical sensors based on the I-V technique. The observed sensitivities of the fabricated sensors based on IZO nanorods and nanodisks were 70.43 μA·mM^-1 cm^-2 and 130.18 μA·mM^-1 cm^-2, respectively. For both the fabricated sensors, the experimental detection limit was 0.5 μM, while the linear range was 0.5 μM-5.0 mM. The observed results revealed that the simply grown IZO nanomaterials could efficiently be used to fabricate highly sensitive chemical sensors.

Utilization of ultrasonic irradiation as a green and effective strategy to prepare poly(N-vinyl-2-pyrrolidone)/modified nano-copper (II) oxide nanocomposites

The present paper describes the result of investigations into preparation of novel nanocomposites (NCs) based on poly(N-vinyl-2-pyrrolidone) (PVP) as a biocompatible polymer and modified copper (II) oxide nanoparticles (NPs) as a nano-filler. To achieve optimum NCs properties, different ratios of modified copper (II) oxide NPs (3, 5, and 7wt%) were used to fabricate PVP NCs and also the ultrasonic irradiation was utilized to perform these processes as a fast and effective method. Subsequently, the structure of the obtained nanohybrids was characterized by various techniques. The suitable incorporation between PVP matrix and modified CuO NPs can be seen from the FT-IR spectra. The obtained NCs indicated an efficient thermal improvement in comparison to the pristine polymer. Also, the uniform dispersion of modified CuO NPs in the PVP matrix was detected by FE-SEM and EDX. According to UV absorption spectra, it is clear that these NCs can be used in UV protecting applications.

Fabrication and characterization of Cu(OH)2/CuO nanowires as a novel sensitivity enhancer of the luminol–H2O2chemiluminescence system: determination of cysteine in human plasma

Cu(OH)₂/CuO nanowires as a sensitivity enhancer in luminol–H₂O₂chemiluminescence system and its application for the determination of cysteine.

Interaction between copper and carbon nanotubes triggers their mutual role in the enhanced photodegradation of p-chloroaniline

Copper (Cu, 1–5 wt%) was loaded onto carbon nanotubes (CNTs) by a simple electrochemical method.

Copper nanoparticles decorated polyaniline–zeolite nanocomposite for the nanomolar simultaneous detection of hydrazine and phenylhydrazine

The high electrocatalytic activity of the CuNPs–PANI–Nano-ZSM-5 nanocomposite can be attributed to the synergistic contribution provided by the highly dispersed copper nanoparticles and conductive PANI film on high surface area Nano-ZSM-5.

Effect of Ce doping into ZnO nanostructures to enhance the phenolic sensor performance

Various Ce-doped ZnO nanostructures (Ce/ZnO NSs) were prepared by a facile wet chemical method using reducing agents in alkaline medium.

Facile Synthesis of Hierarchical CuO Microspheres and their Gas Sensing Properties for NOx at Room Temperature

In this research, hierarchical CuO microspheres have been successfully synthesised by a facile reflux method. Scanning electron microscopy results clearly revealed that the hierarchical CuO microspheres were composed of two-dimensional nanosheets. The morphology of the prepared products could be tailored by changing the precursor concentration. The CuO-2 sample shows a higher NOx gas sensing performance with a low detection limit of 0.97 ppm, high gas response of 64.93 %, and short response time of 5.33 s to 97.0 ppm NOx at room temperature. The CuO-2 sensor also presents good selectivity and stability. The significantly improved gas response was concluded to be related to the well aligned microstructures and the improved conductivity of the CuO-2 sample. The unique hierarchical structure allows effective and rapid gas diffusion towards the sensing surfaces. In addition, the sensing mechanism based on the hierarchical CuO microspheres is discussed.

Nanorod-constructed porous Co3O4 nanowires: highly sensitive sensors for the detection of hydrazine

Porous Co₃O₄ nanowires (NWs) constructed from interconnected nanorod units were synthesized, and exhibited a highly sensitive, reliable, and reproducible sensing performance for hydrazine detection.

Green material: ecological importance of imperative and sensitive chemi-sensor based on Ag/Ag2O3/ZnO composite nanorods

In this report, we illustrate a simple, easy, and low-temperature growth of Ag/Ag2O3/ZnO composite nanorods with high purity and crystallinity. The composite nanorods were structurally characterized by field emission scanning electron microscopy, X-ray powder diffraction, Fourier transform infrared spectroscopy, and X-ray photoelectron spectroscopy which confirmed that synthesized product have rod-like morphology having an average cross section of approximately 300 nm. Nanorods are made of silver, silver oxide, and zinc oxide and are optically active having absorption band at 375 nm. The composite nanorods exhibited high sensitivity (1.5823 μA.cm-2.mM-1) and lower limit of detection (0.5 μM) when applied for the recognition of phenyl hydrazine utilizing I-V technique. Thus, Ag/Ag2O3/ZnO composite nanorods can be utilized as a redox mediator for the development of highly proficient phenyl hydrazine sensor.