Scanning Force Microscopy Research Articles

Fascinating study of elastic, FTIR, and antimicrobial properties of silver nanochromite at different annealing temperatures

AbstractIn this work, Ag0.5Cr2.5O4 nanochromite is fabricated utilizing a simple process (flash technique) at various annealing temperatures (room and 900 °C). The particle sizes of the materials under study were shown to be in the nanoscale range by atomic force microscopy (AFM) and field emission scanning electron microscopy (FESEM). Fourier transform infrared (FTIR) analysis was performed to verify the fabrication of the examined nanosamples and evaluate the bands behavior. The tetrahedral A-site (622.9 cm−1 for room temperature, 630.6 cm−1 for 900 °C) and the octahedral B-site (557.3 cm−1 for room temperature, 563.1 cm−1 for 900 °C) were the two prominent bands measured by FTIR analysis. The elastic characteristics of Ag0.5Cr2.5O4 nanoparticles were examined using FTIR measurements, revealing that the interatomic bonding of the atoms at 900 °C is higher than at room temperature. In addition, the elastic characteristics may be understood by analyzing the transverse and longitudinal velocities. Both Gram-positive and Gram-negative bacteria were effectively inhibited by the samples evaluated for antibacterial properties; however, neither sample showed any antifungal activity. Therefore, it is highly suggested that the investigated samples could be used in different applications, particularly biological ones.

Moiré fringes in conductive atomic force microscopy

Moiré physics plays an important role in characterization of functional materials and engineering of physical properties in general, ranging from strain-driven transport phenomena to superconductivity. Here, we report on the observation of moiré fringes in conductive atomic force microscopy (cAFM) scans gained on the model ferroelectric Er(Mn,Ti)O3. By performing a systematic study of the impact of key experimental parameters on the emergent moiré fringes, such as scan angle and pixel density, we demonstrate that the observed fringes arise due to a superposition of the applied raster scanning and sample-intrinsic properties, classifying the measured modulation in conductance as a scanning moiré effect. Our findings are important for the investigation of local transport phenomena in moiré engineered materials by cAFM, providing a general guideline for distinguishing extrinsic from intrinsic moiré effects. Furthermore, the experiments provide a possible pathway for enhancing the sensitivity, pushing the resolution limit of local transport measurements by probing conductance variations at the spatial resolution limit via more long-ranged moiré patterns.

Effect of thermal annealing on structure and magnetic properties in a Ni–Cr multilayer

Abstract Evolution of structural and magnetic properties in a nickel/chromium (Ni/Cr) multilayer, as a function of different annealing temperatures was investigated. The Ni/Cr multilayer of nominal structure [Cr (50 Å)/Ni (50 Å)]×10/Cr (30 Å) was grown on a Si substrate by radio frequency ion beam sputtering at room temperature. X-ray diffraction, X-ray reflectometry, atomic force microscopy and crossectional scanning electron microscopy were employed for the complete structural characterization of the multilayer whereas superconducting quantum interference device vibration sample magnetometer was used for the bulk magnetisation study. The effect of in-situ and ex-situ annealing on overall structural property of the multilayer also reported in present work. From in-situ X-ray reflectometry (50–400 °C), 300 °C was detected as the optimum temperature for improved structural properties of the Ni/Cr multilayer. Initiation of alloying in the multilayer sample was noticed at 350 °C. The multilayer found to exhibit polycrystalline nature observed by X-ray diffraction. Total thickness of the multilayer system was confirmed by crossectional scanning electron microscopy and in well agreement with X-ray reflectivity results. The Ni/Cr sample found to exhibit soft ferromagnetic behaviour after annealing at 300 °C and 400 °C. However the net magnetic moment reduced upon annealing at higher temperature (400 °C).

Effect of Heat Treatment on Zirconium Oxide High‐k Gate Dielectric in Silicon‐Based Metal Oxide Semiconductor Capacitors

Herein, zirconia thin films are successfully prepared on silicon substrates using the sol–gel method, and the microstructure, optical, and electrical properties of zirconia high‐k gate dielectric films are analyzed at different annealing temperatures. X‐ray diffraction results show that ZrO2 films crystallize above 500 °C and the grain size increases with the increase of annealing temperature; X‐ray photoelectron spectroscopy analysis confirms that metal–oxygen bonds can be effectively formed and defects in the films are eliminated by annealing treatment, with significant changes in the valence band shift (ΔEv) and conduction band shift (ΔEc) with increasing annealing temperature. Analysis of the optical properties of the films by UV‐Vis confirms that all zirconia films have high transmittance, with the bandgap increasing from 5.54 to 5.74 eV with increasing annealing temperature. Atomic force microscope and field emission scanning electron microscope show that the film quality is better and the root mean square roughness of the zirconia films increases from 0.551 to 1.190 nm and the film thickness decreases from 176.19 to 58.73 nm with increasing annealing temperature. Electrical performance tests show that proper annealing is effective in improving electrical properties, such as obtaining a larger dielectric constant (k) and a lower leakage current density.

The Antibacterial Activity of the Biosynthesized Copper Oxide Nanoparticles by Lantana camara Flowers Extract Against Some Bacterial Isolated from Burns

The study included 70 Surface swabs collected from patients in different ages of both genders suffering from burns infections. All the specimens were diagnosed by subculturing in differential and selective media, microscopically and by following the biochemical tests to confirm identifications. Antibiotic susceptibility test was done to all the bacterial isolates.The identification of the clinical isolates showed that the 16(22.9%) were belonged to Staphylococcus aureus and 6(8.6%) of Staphylococcus epidermidis , whereas 23(32.8%),20(28.6%) isolates were for Pseudomonas aeruginosa ,Acinetobacter baumannii respectively. Copper oxide nanoparticles were biosynthesized by Lantana camara flower extracts which acted as a reducing agent for copper nitrate salts, characterization of the metal oxide was done by using Ultra violate visible light Spectroscopy, Fourier transforms Infrared spectroscopy, X-ray Diffraction, Atomic Force Microscopy and Field Emission Scanning Electron Microscopy. The biological activity of Copper Oxide Nanoparticles was screened toward three clinical isolates that showed multiple drug resistance isolated from burns by following agar wells diffusion method which proved the ability of copper oxide nanoparticles to inhibit growth of the clinical bacterial isolates. The minimum inhibitory concentrations were determined toward the tested bacteria by using the microdilution method.

Anticancer Activity of Synthesized ZnO and ZnO/AgCl Nanocomposites against Five Human Cancer Cells

In this work, a refluxing method is used to prepare nanoparticles of zinc oxide (ZnO NPS) and zinc oxide /silver chloride nanocomposites (ZnO/AgCl NCS). The structural properties of nanocrystals are studied by Atomic Force Microscope (AFM), X-Ray Diffraction (XRD), and Field Emission Scanning Electron Microscopy (FE-SEM) to determine the average crystal size, morphology, particle size and average grain size of nanocrystals. The results of anticancer efficiency of ZnO NPs and ZnO/AgCl NCs show cytotoxic activity against five human cancer cells, namely hepatocellular carcinoma, rhabdomyosarcoma (RD), colorectal carcinoma (HCT116), mammary gland (MCF-7), and epidermoid carcinoma (Hep2) compared against doxorubicin. The anticancer mechanism of pure and nanocomposites ZnO are suggested according to the release of Zn+2 and the production of reactive oxidation species (ROS) and the effect of these species on cancer inhibition.

Role of oxygen vacancies in the structural phase transformations of granular TiO2 thin films

Tailoring the structural phases of titanium dioxide (TiO2) is nowadays highly attracting for diverse applications, ranging from optical coatings, where rutile outperforms anatase, to photocatalysis, where a mix of the two is preferred. In this framework, the very high temperature transformation of anatase to rutile constitutes a big drawback. Here, we investigate the structural transformations of granular TiO2 thin films subjected to thermal treatments in different gaseous environments, such as air, oxygen, and vacuum, with the latter expected to enhance the formation of oxygen vacancies. To this aim, we used a combined approach of X-ray diffraction (XRD), Raman Spectroscopy (RS), Atomic Force Microscopy (AFM) and Field Emission Scanning Electron Microscopy (FESEM), and we demonstrate that the achievement of a crystallization temperature as low as 150 °C for the anatase and 250 °C for the rutile is possible. By using a Gibbs free energy minimization approach, the combination of granular morphology and oxygen vacancies is proposed to tune both the amorphous to anatase transition and the anatase to rutile transformation. Finally, we explore the possibility of a low-dimensional growth of anatase-TiO2 by studying phonon confinement-like effect and crystallization kinetics thanks to time-dependent RS experiments.

The ATPase cycle of the AAA-ATPase protein transporter Bcs1 is highly concerted.

Bcs1, a homo-heptameric transmembrane AAA-ATPase that belongs to the superfamily of AAA proteins, acts as translocation machinery for the folded Rieske iron-sulfur protein (ISP, a key subunit of the mitochondrial complex-III) across the inner mitochondrial membrane. Cryo-EM structures depicted a ring-shaped transporter with two cavities, a cylindrical one formed by the ATPase domains on the matrix surface and a conical one formed by the transmembrane helices. Structures in different nucleotide states (ATPγS, ADP, APO) provided intuitive snapshots of the functional cycle, but the kinetics and structural transitions of the ATPase cycle remain entirely unknown. Here, using high-speed atomic force microscopy (HS-AFM) and HS-AFM line scanning (HS-AFM-LS), we characterized the ATPase cycle of Bcs1 at the single molecule level with sub-millisecond temporal resolution. We determined, in conditions where the molecules are in a continuous ATPase cycle turnover, that the ATP-bound conformational has a lifetime of ∼3700 ms while the lifetime of ADP/APO conformation is much shorter, ∼400 ms. By monitoring the conformational state of the two Bcs1 protomers on the two opposite sides of the ring at microsecond temporal resolution, we found that ATP-binding and -hydrolysis coupled conformational changes are highly concerted. We propose that the opening of the cone cavity to the intermembrane surface through the straightening of the transmembrane helices in the membrane is energetically costly and membrane elasticity drives the resealing of the gate. Overall, our results establish a working mechanism for the ATPase cycle of Bcs1 at the single molecule level and propose a mechanism for how Bcs1 can translocate a folded protein.

High content cellulomics by correlative microscopy

The exponential increase in anthropogenic chemicals in our environment necessitates methods to assess impact prior to their release to predict potential environmental and health impacts. Atomic force microscopy (AFM) and laser scanning confocal microscopy (LSCM) each provide abundant information on cell behaviour. In addition to determining cell morphology and surface ultrastructure, AFM in quantitative imaging (QI) mode probes cellular mechanics and surface biochemistry with minimal applied force, and LSCM offers a window into the cell for imaging fluorescently tagged macromolecules. Data from correlative AFM-LSCM is thus complimentary, providing a comprehensive picture of cellular physiology. I will present a correlative AFM-QI-LSCM assay for the simultaneous real-time imaging of living cells in situ that generates real-time multiplexed data, including cell morphology and mechanics, surface adhesion and ultrastructure, along with the localization of intracellular macromolecules. The broad applicability of the assay is demonstrated using disparate cell types, showing altered surface properties, internal molecular arrangement and oxidative stress in model bacterial, fungal and human cells exposed to 2,4-dichlorophenoxyacetic acid. This correlative microscopy assay is broadly applicable to a variety of cell types and can be used to assess the impact of any multitude of contaminants, alone or in combination.

Microscopic studies of binder blending on laboratory recycled asphalt mix

ABSTRACT During blending between the binders in hot mix recycling, two physical processes occur, namely blending due to diffusion and blending due to mechanical agitation. In the present study, an experimental approach is developed to observe these processes directly on the laboratory recycled asphalt mix samples. Atomic Force Microscopy (AFM) and Confocal Laser Scanning Microscopy (CLSM) are used as the probing tools. The binder concentration profile is estimated at different locations around the reclaimed asphalt pavement material (RAPM) aggregate. Diffusion is observed to be predominant in some of these locations, while, in some other locations, mechanical mixing is observed to be predominant. Assuming that pure Fickian diffusion is happening at those diffusion-spots, the coefficient of diffusion is estimated from the concentration profile at those locations. It is envisaged that the proposed approach would provide a microscopic perspective of the extent of blending during the recycling process.

Dinuclear complex-induced DNA melting

Dinuclear copper complexes have been designed for molecular recognition in order to selectively bind to two neighboring phosphate moieties in the backbone of double strand DNA. Associated biophysical, biochemical and cytotoxic effects on DNA were investigated in previous works, where atomic force microscopy (AFM) in ambient conditions turned out to be a particular valuable asset, since the complexes influence the macromechanical properties and configurations of the strands. To investigate and scrutinize these effects in more depth from a structural point of view, cutting-edge preparation methods and scanning force microscopy under ultra-high vacuum (UHV) conditions were employed to yield submolecular resolution images. DNA strand mechanics and interactions could be resolved on the single base pair level, including the amplified formation of melting bubbles. Even the interaction of singular complex molecules could be observed. To better assess the results, the appearance of treated DNA is also compared to the behavior of untreated DNA in UHV on different substrates. Finally, we present data from a statistical simulation reasoning about the nanomechanics of strand dissociation. This sort of quantitative experimental insights paralleled by statistical simulations impressively shade light on the rationale for strand dissociations of this novel DNA interaction process, that is an important nanomechanistic key and novel approach for the development of new chemotherapeutic agents.

2D porphyrin-based MOFs with highly dispersed Pt nanoparticles via in-situ partial reduction strategy from porphyrin embedded with single-atom Pt for enhancing photocatalytic hydrogen production

An efficient and stable 2D MOF TMF-Pt/Pt NPs photocatalyst was prepared by in-situ partial hydrogenation reduction of TMF-Pt with single-atom Pt embedded in porphyrin center to improve photocatalytic hydrogen production. It is important to note that TMF-Pt/Pt NPs has an extremely high photocatalytic hydrogen generation rate (33185.66 µmol·g−1·h−1) in comparison to the majority of previous MOFs photocatalysts, which could be due to the in-situ uniformly grown Pt NPs are very adjacent to the Ti-oxo clusters within the 2D MOFs so that the gradually accumulated electrons around the Ti-oxo clusters via LMCT pathway could instantaneously transfer to Pt NPs through the Schottky injection field effect. Through a series of experimental characterizations, especially atomic force microscopy (AFM) and transmission scanning electron microscope (TEM), confirmed the highly dispersed Pt NPs within the 2D MOFs. This work provided us with a novel idea to realize the uniform distribution of noble metals nanoparticles in the channel cavity of MOFs through an in-situ synthesis strategy, so as to facilitate the more efficient Schottky injection field effect between noble metals nanoparticles and metal clusters of the MOFs, thereby achieving more excellent charge carrier separation efficiency.

DEPOSITION OF HYDROPHOBIC FLUOROPOLYMER COATINGS ON A PLASMA-TREATED STAINLESS STEEL SURFACE

A stainless steel surface was treated with a glow discharge plasma. As a result of surface treatment, micro- and nanostructures were obtained. The surface roughness of the samples was increased. Thin fluoropolymer coatings were deposited on treated and untreated surfaces using the hot wire chemical vapor deposition (HWCVD) method. The structure of the obtained samples was studied by scanning and atomic force microscopy. Wetting properties were measured for all samples obtained. It has been shown that pretreatment of the surface before the deposition of fluoropolymer coatings makes it possible to increase the hydrophobicity of the final surfaces. Tests of coatings carried out using an ultrasonic cleaner have shown that plasma pretreatment before deposition and subsequent annealing after deposition make it possible to obtain stable coatings with stable hydrophobic properties.

Effect of Different Etching Time on Fabrication of an Optoelectronic Device Based on GaN/Psi

Gallium nitride (GaN)/porous silicon (PSi) film was prepared using a pulsed laser deposition method and 1064 nm Nd: YAG laser for optoelectronic applications and a series of Psi substrates were fabricated using a photoelectrochemical etching method assisted by laser at different etching times for 2.5–15 min at 2.5 min intervals. X-ray diffraction, room-temperature photoluminescence, atomic force microscopy and field emission scanning electron microscopy images, and electrical characteristics in the prepared GaN on the Psi film were investigated. The optimum Psi substrate was obtained under the following conditions: 10 min, 10 mA/cm2, and 24% hydrofluoric acid. The substrate exhibited two highly cubic crystalline structures at (200) and (400) orientations and yellow visible band photoluminescence, and homogeneous pores formed over the entire surface. The pores had steep oval shapes and were accompanied by small dark pores that appeared topographically and morphologically. The GaN/Psi film fabricated through PLD exhibited a high and hexagonal crystallographic texture in the (002) plane. Spectroscopic properties results revealed that the photoluminescence emission of the deposited nano-GaN films was in the ultraviolet band (374 nm) related to GaN material and in the near-infrared band (730 nm) related to the Psi substrate. The topographical and morphological results of the GaN films confirmed that the deposited film contained spherical grains with an average diameter of 51.8 nm and surface roughness of 4.8 nm. The GaN/Psi surface showed a cauliflower-like morphology, and the built-in voltage decreased from 3.4 to 2.7 eV after deposition. The fabricated GaN/Psi film exhibited good electrical characteristics.

Effect of the ratio of phenolic compounds to saccharides in soluble polysaccharides on ethanol fermentation

In this study, soluble polysaccharides (SPs) were used to prepare the complexes with different degrees of polymerization and ratios of saccharide to phenolic acids (PAs) and their effects on yeast growth and ethanol fermentation were studied. Time-of-flight mass spectrometry showed that the lower the degree of saccharide polymerization, the higher the PA content. Oligosaccharide-PAs played an important role in ethanol fermentation. ATP/ADP and flow cytometry indicated that oligosaccharide-PAs could improve cell viability and increase the proportion of living and dead cells. Atomic force microscopy and confocal laser scanning microscopy images showed that the oligosaccharide-PAs induced the formation of extracellular matrixes, maintained the cellular biomorphology. The oligosaccharide-PAs also regulated NAD+/NADH, NAPD+/NADPH, and reduced the intracellular peroxide content. Thus, the oligosaccharide-PAs improved the cell viability by reducing the intracellular peroxide content and maintaining the cellular biomorphology.

The interaction mechanism of photogenerated carriers and piezoelectric charges of a photoactive piezoelectric nanogenerator

Despite the fact that photoactive piezoelectric nanogenerators (PENGs) have been getting more attention due to their significant potential as a self-powered photodetector and pressure sensor, investigations on the interaction mechanism between photogenerated carriers and piezoelectric charges are still insufficient. In this study, photoactive PENGs based on methylammonium lead halides-poly(vinylidene) (MAPI-PVDF) composite were fabricated, in which the presence of MAPI in the PVDF matrix plays a dual role in enhancing the nucleation of the electroactive β-phase as well as inducing photoactivity in the composite. It has an optimal open-circuit voltage of 4.7 V and short-circuit current of 0.2 μA at 10 wt. % concentration of MAPI under illumination, which is nearly halved in the dark. Furthermore, we have thoroughly explored the interaction mechanism between photogenerated carriers and piezoelectric charges by piezoresponse scanning force microscopy techniques, photoluminescence spectroscopy, and a bandgap analysis. The results demonstrate that the photogenerated carriers screen part of the piezoelectric potential induced by the piezoelectric charges, while the piezoelectric charges promote more photogenerated carriers recombination. This work opens up horizons for the piezoelectric community in designing photoactive PENGs with multiple application modes and provides an effective approach to the development of piezoelectric materials.

Measurement of Nanometric Heights by Modal Decomposition

Measuring the height of steplike features in samples has become important in many scientific and industrial applications. It is routinely done using both tactile and optical methods, the latter being preferable due to their noncontact nature and improved speed capabilities. Nevertheless, techniques less sensitive to instabilities or without calibration or reference sample requirements would be advantageous. Here, we propose a method to measure nanometric step heights based on a modal analysis of the reflected or transmitted field. Our approach requires a minimum of four single-point measurements by detectors with no spatial resolution (photodiodes) and yet can reconstruct spatial structure with nanometric resolution. It has the benefits of not requiring a reference measurement or calibration and it is completely digital, thus offering high reliability and real-time measurement. As proof of principle, we perform measurements on reflective samples, finding excellent agreement between the set and measured values, with uncertainties comparable to those of scanning-force microscopes.

Investigation of electropolishing performance on surface residual stress and morphology of electrical discharge machined maraging steel

Electrical Discharge Machining (EDM)-machined maraging steel components are promising in the application field of aerospace and production tools. However, the unavoidable adverse effects of recast/white layer formation, high tensile residual stress, and micro-crack on the machined surface necessitate post-treatment techniques. The current study proposed Electropolishing (EP) as a post-treatment process to eliminate EDM’s adverse effects. The performance of EP on surface residual stress and morphology of ED machined surface was evaluated for an optimum combination of parameters, including applied voltage, polishing time, agitation, and temperature. Residual stress has been analyzed using the “sin2 ψ method” of X-ray Diffraction (XRD). After EDM, the generated surface residual stress was 407.17 MPa which had been relaxed to 35.27 MPa after EP. The surface morphology of maraging steel surfaces after EDM and EP were compared using an Atomic Force Microscope (AFM) and Field Emission Scanning Electron Microscope (FESEM). It is observed that micro-cracks, globules, voids, and thermal pitting marks were entirely eradicated following EP. It can also be seen that the EP has successfully removed the formed recast layer during EDM after 6 mins of polishing time. An average of 7.94 µm layer has been removed from the surface, removing all the surface defects. The optical profilometer analyzed the surface roughness profiles, and a 78% improvement in surface roughness was observed after EP.

Nanoporous membrane filter cascade for size‐selective analysis of nano‐ and microplastic particles

AbstractAnalytical routes for sampling and analysis of microplastic particles in the range of several 10 µm to 1000 µm are well established in environmental research. However, the current scientific efforts are targeting human health impact with an enhanced focus on nanoparticle analysis in drinking water, the food chain, and its disposition in the human body. A major challenge lies in the availability of cascade filter setups spanning several orders of magnitude down to 10 nm dimensions in a single filtration workflow allowing fast and reliable routines for size‐selective nano‐ and microplastic (NMP) particle analysis. In this work, we present a novel cascade filter system containing filters made of microporous Si (pore size >10 µm) and nanoporous Al2O3 (pore size 100 nm), thus realizing the corresponding NMP size selectivity. Inorganic filter materials are chosen due to their beneficial properties as substrates for NMP particle analysis, which are nonpolymer materials with high planarity for micro‐spectroscopy investigations. In our first experiments, we demonstrate the successful NMP size separation on Si and Al2O3 filter substrates. For this purpose, we implement a well‐defined NMP test material composed of a mixture of polyethylene terephthalate microplastic reference material and monodisperse nanoscale polystyrene particles. The NMP test material is applied in a laboratory filtration workflow for samples in liquid solution. Both filter stages are subsequently investigated with optical microscopy, electron microscopy (scanning electron microscopy), Raman spectroscopy, and scanning force microscopy (atomic force microscopy) to demonstrate their applicability as combined NMP particle analytic substrates. Here, we characterize the fundamental NMP properties such as particle shape, size, and spectroscopic fingerprints—optical and chemical—both qualitatively and quantitatively. Finally, requirements and limitations for a standardized NMP filtration and analytic workflow will be discussed.

Porous structure Ni/CuCo2O4 core–shell as a novel type of three-dimensional electrode with facile fabrication and binder-free toward enhanced methanol oxidation and supercapacitor performances

In this present research, three dimensional nickel/copper cobaltite (3D-Ni/ CuCo2O4) core–shell nanocomposites have been successfully synthesized on 304 stainless steel as a substrate through the combination of electrodeposition and sol–gel methods followed by annealing treatment. The crystallographic configuration, chemical structure and surface morphology as-prepared materials are characterized systematically by different spectroscopy and microscopy techniques such as X-ray diffraction (XRD), fourier transformation spectroscopy (FT-IR), energy-dispersive X-ray spectroscopy (EDX), atomic force microscopy (AFM) and field emission scanning electron microscope (FE-SEM). Bi-functional performance of samples are studied for supercapacitor and methanol fuel cell. According to achieved galvanostatic charge–discharge (GCD) results, 3D-Ni/ CuCo2O4 and CuCo2O4 electrodes maintains nearly 89.97 % and 56.55 % of the preliminary areal capacitance in high current density of 1.27 mA cm−2, indicating high rate capability of 3D-Ni/ CuCo2O4 nanocomposite. Furthermore, it illustrates remarkable cycling stability in 1 M KOH solution during charge/discharge cycles in judgment with individual CuCo2O4. Enhanced electrochemical performances of nanocomposite are mainly due to the unique porous structure of 3D-Ni core and high electronic conductivity of CuCo2O4 as shell that synergistic effects of two component can eventually decrease the charge transfer resistance to improve the ion–electron transportations ability. More importantly, 3D-Ni/ CuCo2O4 exhibits the anodic peak current density of 18.67 mA cm−2 for methanol oxidation reaction at 0.55 V potential in 1 M KOH mixed with methanol which is greater than of 7.45 mA cm−2 CuCo2O4 when applied as catalyst of fuel cell. Unlike commonly accepted techniques, we reported a spin coater route for tight and stable deposition CuCo2O4 onto 3D-Ni surface without any adhesive.