Field Emission Gun Research Articles

Low-density polyethylene films incorporated with silver nanoparticles to promote antimicrobial efficiency in food packaging.

Technological innovations in packaging are intended to prevent microbiological contaminations for ensuring food safety and preservation. In this context, researchers have investigated the antimicrobial effect of low-density polyethylene films incorporated with the following concentrations of silver nanoparticles: 1.50, 3.75, 7.50, 15.00, 30.00, 60.00, and 75.00 µg/ml. The films were characterized using field emission gun scanning electron microscopy, Fourier transform infrared spectroscopy, X-ray diffraction, thermogravimetry, and differential scanning calorimetry. From the results of these techniques, it could be concluded that the silver nanoparticles incorporated in the low-density polyethylene films did not influence their physical, chemical, and thermal properties. The direct contact assays, shake-flask assays, and bacterial images obtained using scanning electron microscopy were used to analyze the antimicrobial activity of the films. In the microbial analyses, it was verified that the nanostructured films exhibited antimicrobial properties against all the microorganisms studied, although more notably for fungi and Gram-negative bacteria than the Gram-positive bacteria. Moreover, it was discovered that the packages, in which silver nanoparticles were incorporated, inhibited the growth and reproduction of bacterial cells during the early stages. These results suggest that the extruded low-density polyethylene films incorporated with silver nanoparticles may be an essential tool for improving food quality and safety.

Pre-nucleation and particle attachment of bismuth tri-iodide onto graphene substrates

Abstract BiI3 nucleation was performed by physical vapor transport (PVT) onto graphene covered TEM grids and graphene covered SiO2 substrates. Depositions were characterized by High Resolution Transmission Electron Microscopy (HR-TEM) and by Scanning Electron Microscopy with Field Emission Gun (SEM-FEG). Amorphous entities 2–3 nm in size were observed. They continue to be present even under the TEM beam and suffer rapid transformations between ordered and disordered structures. Given their size and amorphous character, we conclude that they are pre-nucleation entities, similar to the ones observed in solution and chemical vapor deposition (CVD) systems in the reports of non-classical nucleation research. The oriented attachment and amorphous addition of entities about 2–3 nm in size, giving larger ones of about 10–20 nm was observed. Nanoparticles interact among them by these non-classical mechanisms giving stable and oriented crystalline structures, in agreement with the different pathways reported in non-classical nucleation investigations. Platelets up to about 100–200 nm in size were also obtained, similar when imaged by TEM and by SEM. They give TEM clear Moire diagrams, similar to the ones obtained for other van der Waals superstructures. Non-classical nucleation here reported is similar to the one obtained for bismuth tri-iodide onto amorphous substrates, although the post growth – dictated by the crystalline substrate – is different, and gives van der Waals heterostructures. Results may be a valuable contribution to the development of a general theory for non-classical nucleation mechanisms in all kind of systems, and, as well, of 2D van der Waals materials and their applications.

Influence of silver nanoparticle deposition on self-assembled thin films of weak polyelectrolytes/TiO2 for bezafibrate photodegradation through central composite experimental design

This study evaluated, through a central composite experimental design, the influence of silver nanoparticles (AgNPs) deposition, synthesized at different pH and silver concentration [Ag+], on the photocatalytic efficiency of self-assembled thin films (SATFs) of poly(allylamine hydrochloride) (PAH)/poly(acrylic acid) (PAA) and TiO2 over bezafibrate (BZF) drug. The SATFs were produced by dip coating on glass substrates using the layer-by-layer technique and were characterized by ultraviolet and visible absorption spectroscopy, scanning electron microscopy with a field emission gun and energy dispersive spectroscopy. The results revealed that the SATF that represents the optimum point of the central composite design (pH = 7.0 and [Ag+] =0.46 mmol L−1) reduced the initial concentration of BZF by 81.4 %. The presence of AgNPs on the polyelectrolytes/TiO2 thin film was responsible for an increase of 64 % in its photocatalytic efficiency when compared to the film containing only polyelectrolytes and TiO2. Silver is present mostly in the form of nanoparticle agglomerates with sizes under 90 nm. Moreover, the optimized SATF showed no reduction in its photocatalytic efficiency after four reuse cycles. Finally, the data set showed that the SATFs of this work possess a high potential for photo-oxidation, which makes them attractive for domestic and industrial wastewater treatment.

High Adhesion and Increased Cell Death Contribute to Strong Biofilm Formation in Klebsiella pneumoniae.

Klebsiella pneumoniae (Kp), is a frequent cause of hospital and community-acquired infections and WHO had declared it as a “priority pathogen”. Biofilm is a major virulence factor of Kp and yet the mechanism of strong biofilm formation in Kp is unclear. A key objective of the present study is to investigate the differences between strong and weak biofilms formed by clinical isolates of Kp on various catheters and in different media conditions and to identify constituents contributing to strong biofilm formation. Quantification of matrix components (extracellular DNA (eDNA), protein, exopolysaccharides (EPS), and bacterial cells), confocal laser scanning microscopy (CLSM), field emission gun scanning electron microscopy (FEG-SEM) and flow-cytometry analysis were performed to compare strong and weak biofilm matrix. Our results suggest increased biofilm formation on latex catheters compared to silicone and silicone-coated latex catheters. Higher amounts of eDNA, protein, EPS, and dead cells were observed in the strong biofilm of Kp. High adhesion capacity and cell death seem to play a major role in formation of strong Kp biofilms. The enhanced eDNA, EPS, and protein in the biofilm matrix appear as a consequence of increased cell death.

Bipolar Analog Memristive Switching of In2O3 Using Al Nanoparticles

Aluminum nanoparticles (AlNPs) were embedded into a sol-gel synthesized In₂O₃ thin film by using a combination of thermal evaporation and glancing Angle Deposition technique. Presence of different sizes of aluminum nanoparticles was confirmed from field emission gun scanning electron microscopy. The high-resolution X-ray diffraction confirms the formation of Al₂O₃ NPs by surface oxidation of aluminum nanoparticles. Embedded Metal-Oxide-Semiconductor like device Al/In₂O₃/AlNPs/In₂O₃/p-Si was fabricated, and its memristor behavior was analyzed. The Al/In₂O₃/AlNPs/In₂O₃/p-Si device possessed high current conduction and analog resistive switching as compared to Al/In₂O₃/p-Si device. Significant and consistent memory window up to 150 current (I)-voltage (V) loop was obtained for Al/In₂O₃/AlNPs/In₂O₃/p-Si device between ±6 V applied bias. The Al/In₂O₃/AlNPs/In₂O₃/p-Si device measured high free carrier concentration, i.e., (Nd)~1.93 × 1020 cm-3 calculated from capacitance (C)-Voltage (V) measurement. The memory was retained in accumulation and depletion regions as obtained from the C-V looping curves.

A high current focused electron ring-beam column design

There are many applications in electron microscopy, electron spectroscopy, as well as accelerator physics that require the combination of minimizing a focused electron beam’s probe size while maximizing its beam current. This paper describes how this can be done through the use of annular focused electron beam column designs, where an electron beam is propagated and focused in the form of a ring beam. For probe semi-angles of [Formula: see text] radians, a column consisting of two identical electric sectors and two identical focusing lenses functioning with odd symmetry will be presented, together with a wide-angle cold field emission gun design. The column is designed to cancel energy dispersion while limiting geometric aberrations to the third order at the point of final focus. This design is predicted to have over two orders of magnitude higher beam current than the corresponding conventional on-axis focused electron beam columns for the same final probe size. For a 1.2 keV annular electron beam, simulation results predict a spot radius of 4.8 nm at a working distance of 3.4 mm, final beam angle of [Formula: see text] mrad, and energy spread of [Formula: see text] eV.

Development of analytical ultrafast transmission electron microscopy based on laser-driven Schottky field emission

A new design scheme for ultrafast transmission electron microscopy (UTEM) has been developed based on a Schottky-type field emission gun (FEG) at the Institute of Physics, Chinese Academy of Sciences (IOP CAS). In this UTEM setup, electron pulse emission is achieved by integrating a laser port between the electron gun and the column and the resulting microscope can operate in either continuous or pulsed mode. In pulsed mode, the optimized electron beam properties are an energy width of ~0.65 eV, micrometer-scale coherence lengths and sub-picosecond pulse durations. The potential applications of this UTEM, which include electron diffraction, high-resolution imaging, electron energy loss spectroscopy, and photon-induced near-field electron microscopy, are demonstrated using ultrafast electron pulses. Furthermore, we use a nanosecond laser (~10 ns) to show that the laser-driven FEG can support high-quality TEM imaging and electron holography when using a stroboscopic configuration. Our results also indicate that FEG-based ultrafast electron sources may enable high-performance analytical UTEM.

Time-evolution of microstructure and mechanical behaviour of double annealed medium Mn steel

Cold rolled 0.1C-4.7Mn (wt-%) steel was submitted to double annealing. The holding time of second intercritical annealing at 650°C was varied between 3 min and 30 h. Tensile behavior after each treatment was measured and analysed. Microstructure characterisation was performed using field emission gun scanning electron microscope, transmission electron microscope and saturation magnetisation method. Moreover, interrupted tensile tests were done to obtain the kinetics of austenite destabilisation during straining. An important effect of soaking time on the microstructure and associate mechanical properties was revealed and analysed. Considering thermal and mechanical stability of retained austenite, the optimum combination of phases, providing the best strength-ductility balance, was found after 2 h holding.This paper is part of a Thematic Issue on Medium Manganese Steels.

Characterization of Subsurface Microstructural Alterations Induced by Hard Turning of Inconel 718

Conventional machining especially hard turning is commonly used in aerospace industry to produce the final shape of cylindrical parts. However, the process generates damages and microstructural alterations on the surface and at the subsurface layer, in particular the cracking of hard carbides particles. The present paper focuses on investigating the probable mechanisms responsible for carbide cracking and the formation of a softened layer at a depth between 10 and 30 µm below the machined surface. Advanced techniques, such as laser confocal microscopy and field emission gun scanning electron microscope equipped with in situ picoindenter and electron backscatter diffraction, were used to characterize and analyze the evolution of the microstructure in the affected layer and propose the possible governing mechanisms for the observations.

Effect of minor rare earth cerium addition on the hot ductility of a reactor pressure vessel steel

The hot ductility of the specimens for a reactor pressure vessel steel (SA508-III), undoped and doped with minor rare earth Ce, is studied through hot tensile tests by means of a Gleeble machine in conjunction with scanning electron microscopy, optical microscopy, and field emission gun scanning transmission electron microscopy. Both the undoped and Ce-doped specimens are heated at 1300 °C and then cooled down to different test temperatures between 650 and 1050 °C, followed by tensile deformation up to fracture. As demonstrated by the results, for the undoped steel, there is a wide and deep hot ductility trough and the bottom of the trough is flat and wide (700–850 °C), being only about 60% in reduction of area (RA). However, for the Ce-doped steel, the hot ductility trough becomes considerably narrower and shallower. In addition, the flat and wide bottom of the trough disappears. Overall, the Ce-doped specimens exhibit a much higher hot ductility than the undoped ones, being over 70%RA at temperatures above 800 °C. Therefore, the minor addition of rare earth Ce can considerably enhance the hot ductility of the steel. It may be expected that this Ce-doped steel will have a high performance in hot working. As shown by microanalysis, the segregation of Ce to austenite grain boundaries occurs, which could play an important role in the enhancement of ductility in the high-temperature single austenite range (above 700 °C). Moreover, the Ce-induced grain refinement may also contribute to the hot ductility improvement.

CryoEM at 100 keV: a demonstration and prospects.

100 kV is investigated as the operating voltage for single-particle electron cryomicroscopy (cryoEM). Reducing the electron energy from the current standard of 300 or 200 keV offers both cost savings and potentially improved imaging. The latter follows from recent measurements of radiation damage to biological specimens by high-energy electrons, which show that at lower energies there is an increased amount of information available per unit damage. For frozen hydrated specimens around 300 Å in thickness, the predicted optimal electron energy for imaging is 100 keV. Currently available electron cryomicroscopes in the 100-120 keV range are not optimized for cryoEM as they lack both the spatially coherent illumination needed for the high defocus used in cryoEM and imaging detectors optimized for 100 keV electrons. To demonstrate the potential of imaging at 100 kV, the voltage of a standard, commercial 200 kV field-emission gun (FEG) microscope was reduced to 100 kV and a side-entry cryoholder was used. As high-efficiency, large-area cameras are not currently available for 100 keV electrons, a commercial hybrid pixel camera designed for X-ray detection was attached to the camera chamber and was used for low-dose data collection. Using this configuration, five single-particle specimens were imaged: hepatitis B virus capsid, bacterial 70S ribosome, catalase, DNA protection during starvation protein and haemoglobin, ranging in size from 4.5 MDa to 64 kDa with corresponding diameters from 320 to 72 Å. These five data sets were used to reconstruct 3D structures with resolutions between 8.4 and 3.4 Å. Based on this work, the practical advantages and current technological limitations to single-particle cryoEM at 100 keV are considered. These results are also discussed in the context of future microscope development towards the goal of rapid, simple and widely available structure determination of any purified biological specimen.

Reduced graphene oxide supported tin oxide-boron oxide flexible paper anodesfor Li-ion batteries

Freestanding tin oxide-boron oxide/reduced graphene oxide (SnO$_{2}$-B$_{2}$O$_{3}$/rGO) nanocomposite anode was produced for Li-ion cells. This binder-free flexible paper anode structure was fabricated by combining SnO$_{2}$-B$_{2}$O$_{3}$ composite and graphene oxide which were synthesized through the sol-gel method and Hummers' method, respectively. Field emission gun scanning electron microscopy, high-resolution transmission electron microscopy, energy dispersive X-ray spectrometer, Fourier transform infrared spectroscopy, Raman spectroscopy, and X-ray diffraction were utilized to characterize anode materials. The Williamson-Hall (W-H) analysis was applied using XRD data to determine crystal size and strain of the lattice. Electrochemical tests, cyclic voltammetry, and electrochemical impedance spectroscopy measurements were performed to determine electrochemical properties of the anodes. The results indicated that the anode formed with SnO$_{2}$-B$_{2}$O$_{3\, }$particles anchored on the rGO layers provided higher discharge capacity (838 mAh g$^{-1})$ than that of SnO$_{2}$/rGO (395 mAh g$^{-1})$ after 100 cycles. The electron-deficient nature of boron supplied an effective increase in electrochemical energy storage performance.

Different 2D materials based polyetherimide mixed matrix membranes for CO2/N2 separation

Keeping the global warming and climate change issues in mind, various efforts are being taking place worldwide to separate/capture CO2 from flue gas mixture in order to reduce its emission in the atmosphere. Therefore, in this work, we improve the gas transport properties of polyetherimide (PEI) membrane for CO2/N2 separation by embedding three different fillers of two-dimensional materials such as graphene oxide (GO), molybdenum disulfide (MoS2), and hexagonal boron nitride (h-BN) in its matrix. Additionally, the effect of different weight fraction (0.5, 1.5, and 2.5 wt.%) of these fillers on the CO2/N2 gas separation performance have been investigated. Membrane morphology, variation in the chemical bonds and membrane surface roughness were observed by employing Field Emission Gun Scanning Electron Microscopy (FEG-SEM), Fourier Transform Infrared Spectroscopy (FTIR), and Atomic Force Microscopy (AFM) analysis. Results obtained from the gas permeation showed that PEI embodied with GO exhibited higher gas permeation compared to when embodied with h-BN and MoS2. However, the maximum separation was achieved with MoS2 particles.

Physicochemical characterization of South African coals upon short-term flue gas exposure using conventional and advanced techniques

In the view of the current environmental problems, especially in the light of mitigating the effect of global warming due to anthropogenic carbon dioxide (CO2) emissions to the atmosphere, numerous technologies have been proposed like CO2 sequestration in deep and unmineable coal seams. This paper presents advanced characterization of two South African coals upon short-term flue gas exposure. A synthetic industrial flue gas containing 12% CO2, 5.5% O2, 82% N2, 0.38% SO2, and 0.12% NO2 was used in the study. The two coals were exposed to the flue gas at a temperature of 60 °C and pressure of 9.0 MPa for up to 120 h. Subsequently, the coals were analysed using conventional characterization techniques (density Stereopycnometer, proximate and ultimate, textural, and petrographic) and advanced characterization techniques (carbon 13 nuclear magnetic resonance (13C NMR), attenuated total reflectance-Fourier transform infrared (ATR-FTIR), wide-angle X-ray diffraction (WXRD), and field emission gun scanning electron microscopy (FEG-SEM)) to check the physical and chemical structural changes during the CO2/flue gas sorption to simulate sequestration.The conventional analytical techniques have revealed significant observable changes of the physical and chemical structure of the coal upon flue gas exposure. However, clear changes in chemical structure were observed through ATR-FTIR analysis. The observable change in surface chemistry of the coals suggests that there is most certainly a chemical interaction between the coals and the flue gas components at high pressure. Slight structural changes were observed from FEG-SEM and WXRD characterization. Lastly, there were no obvious structural changes from the results obtained from 13C NMR, except for slight changes in the aliphatic carbons bonded to oxygen of 37% for Coal EML and 27% for Coal SML. These changes could be due to the presence of oxygen in the flue gas; thus, substituting to form stronger intensities of the C-O and COO bonds as observed in the ATR-FTIR spectra.

Influence of CNT pre-dispersion into PHBV/CNT nanocomposites and evaluation of morphological, mechanical and crystallographic features

In this work, a new strategy of carbon nanotubes (CNT) pre-dispersion (PD) in acetone to produce poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV)/CNT nanocomposites was evaluated. PHBV/CNT nanocomposites were produced in the molten state with the addition of 0.5 wt% of CNT and evaluated by scanning electron microscopy with field emission gun (FEG-SEM), differential scanning calorimetry (DSC), Izod impact tests, nanohardness, and x-ray diffraction (XRD). FEG-SEM showed well-dispersed CNT for sample subjected to pre-dispersion (PHBV/CNT-PD), and DSC showed a reduction in the degree of crystallinity from 62% to neat PHBV to 55% for PHBV/CNT-PD. Impact resistance was positively affected by the pre-dispersion, and nanohardness showed more homogeneous values for PHBV/CNT-PD sample compared to PHBV/CNT (without pre-dispersion). XRD proved that hot pressing affects plans orientation, and so does the addition of CNT into PHBV. The CNT dispersion into PHBV analyzed by the ratio between planes area showed that PHBV/CNT-PD sample had homogeneously dispersed CNT.

InN Nanowires Based Near-Infrared Broadband Optical Detector

We have reported a new method of synthesis of InN nanowires (NWs) on p-Si (100) substrate by the vapour transport cum glancing angle deposition (GLAD) technique. The field emission gun transmission electron microscopy (FEG-TEM) reveals that the InN NWs are crystalline in nature. Photoluminescence (PL) analysis shows that the optical bandgap of the NW is ~1.07 eV at 300 K. Metal-Semiconductor-Metal (M-S-M) photodetecor has been fabricated using InN NWs. The device produced trivial dark current ~7.31 μA cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-2</sup> at 3 V applied voltage. The broad band near-infrared (NIR) photo-response from 900-1400 nm was recorded for the device.

Ag-Au core-partial shell bimetallic nanoparticles applied in electrochemical determination of the potential endocrine disruptor oryzalin

Silver-gold core-partial shell bimetallic nanoparticles (Ag-Au BMNPs) stabilized in chitosan (CTS) were used to prepare a chemically modified electrode (CME) for the electrochemical determination of oryzalin (ORZ). The Ag-Au BMNPs were deposited on a glassy carbon electrode (GCE) by the simple drop-coating method to build the modified electrode surface (Ag-Au BMNPs-CTS/GCE). The nanoparticles dispersions were characterized by transmission electron microscopy (TEM), UV–vis spectroscopy (UV–vis) and energy dispersive X-ray spectroscopy (EDS). The CME was characterized by scanning electron microscopy with field emission gun (FEG-SEM) and electrochemical impedance spectroscopy (EIS). The electrochemical behavior of ORZ was investigated by cyclic voltammetry (CV) using the CME. Square-wave voltammetry (SWV) carried out under optimized experimental conditions demonstrated that the cathodic peak current increased with increasing concentrations of ORZ in the range of 0.1–7.0 μmol L−1. The limit of detection obtained from the calibration curve was 30 nmol L−1. The practical application of the Ag-Au BMNPs-CTS/GCE was demonstrated by determining the concentration of ORZ in a grape juice sample. The data obtained were in agreement with those provided by LC-MS/MS as a comparative technique.

Recyclable Heterogeneous Fe-Mo Nanocatalyst: Application in Solvent Free Synthesis of β-enaminones

&lt;P&gt;Background: In recent years, green organic transformation has become a challenge for a chemist in areas like social sector, health, and environment. Literature survey revealed that a nano magnetite supported heterogeneous catalysis is an emergent field with huge application in chemical synthesis. &lt;/P&gt;&lt;P&gt; Objective: In the present article, the aim was to develop a simple and facile method to carry organic reaction under benign media. So, the focus was on the synthesis of nano-magnetite supported molybdenum catalyst and its application in β-enaminones synthesis. &lt;/P&gt;&lt;P&gt; Methods: Magnetically recyclable heterogeneous ferrite-molybdenum catalyst was prepared by simple impregnation method. The synthesized nanocatalyst Fe-Mo was well analysed by spectroscopic techniques like X-ray diffraction analysis, X-ray photoelectron spectroscopy, transmission electron microscopy, field-emission gun scanning electron microscopy and vibrating-sample magnetometry. The functionalized nanocatalyst Fe-Mo was employed in the synthesis of β-enaminones under solvent free condition. &lt;/P&gt;&lt;P&gt; Results: The competency of synthesized nanocatalyst-Fe-Mo was observed to be good for the synthesis of β-enaminones derivatives under microwave irradiation and gave excellent yield (86-96%) of the product. The catalyst was recycled for more than five consecutive runs without significant loss in its activity. &lt;/P&gt;&lt;P&gt; Conclusion: In the present research article, synthesis of highly active, magnetically recyclable Fe- Mo nanocatalyst was obtained from easily available precursor. The MNP was stable under investigated conditions and effective in β-enaminones synthesis. The simple eco-friendly method, low catalyst loading, short transformation time, and reusability of the catalyst thoroughly follow the sustainable protocol.&lt;/P&gt;

Surface modification of aluminum alloys with carbon nanotubes by laser surface melting

Carbon nanotubes (CNTs) could be an excellent reinforcement for metal matrix composites, specifically for composites with aluminum or aluminum alloy matrix. Surface modification to improve hardness and other material properties has been performed by laser surface melting (LSM) process, where the laser beam melts the substrate together with alloying elements or reinforcing phase additives. In this work, Multiwalled CNTs (MWCNTs) were mixed by the electrostatic adsorption process with aluminum powder and the resulting mixed powder was laser melted on the surface of a 6061-aluminum alloy substrate. As a result, a modified substrate surface has been obtained from the Al/MWCNT – substrate co-melting, dilution and re-solidification processes. This modified layer was obtained by different LSM parameters and were characterized by Optical (OM) and Scanning Electron Microscopy (SEM), Energy Dispersive X-Ray Spectroscopy (EDS), Field Emission Gun Scanning Electron Microscopy (FEG-SEM), X-Ray Diffraction (XRD) and Raman Spectroscopy (RS). The resulting mechanical behavior was evaluated by Vickers microhardness tests. The results showed that the presence of MWCNT in the aluminum powder improves the laser energy absorption, leading to the formation of a deeper modified layer, with segregation of Si particles homogeneously dispersed and improving the hardness. The formation of Al4C3 was not observed, evidencing that the MWCNTs did not react with the molten Al matrix during the LSM process.

Synthesis of carbon nanofibers/poly(para-phenylenediamine)/nickel particles nanocomposite for enhanced methanol electrooxidation

Several studies have been conducted on direct methanol fuel cells (DMFCs) to resolve major issues such as the high cost of the catalyst and the poisoning of the electrode. Herein, a low-cost catalyst based on nickel particles (NiPs), carbon nanofibers (CNF) and poly(para-phenylenediamine) (PpPD) was carried out using a simple electrochemical method. The morphology and structure of the nanocomposite electrodes are characterized by field-emission gun scanning electron microscopy coupled with an energy dispersive X-ray detector, X-ray diffraction, Fourier transform infrared spectroscopy and Raman spectroscopy. The effects of various parameters such as the PpPD film thickness and the NiPs content on the electrocatalytic performance of CPE/CNF/PpPD/NiPs are evaluated which lead to the optimized composition. The results of the methanol electrooxidation reaction at room temperature showed that the optimized CPE/CNF/PpPD/NiPs nanocomposite exhibits a high catalytic activity (Ip = 38.11 mA cm−2), good stability and durability for more than 6 h in comparison with CPE/CNF/NiPs. These findings truly highlight the synergetic effect of CNF/PpPD in enhancing the electrochemical activity and stability and the vast potential of CPE/CNF/PpPD/NiPs as low-cost catalyst and electrodes for DMFCs.