Surface Of Foam Research Articles

Devisable three-dimensional Cu2Se nanoarrays boosts high rate Na-Ion storage

Because of its low cost and abundant sodium resource, sodium ion batteries (SIBs) are regarded as an excellent substitute for lithium-ion batteries (LIBs). However, due to the slow sodium kinetics and serious volume expansion of the anode material, the high power density and stability of the anode material are unsatisfactory. Here we demonstrate Cu2Se nanoarrays with three-dimensional (3D) skeleton structure that grow on the surface of copper foam (pretreated at different pressures) by in situ selenization, used as high-performance binder-free anodes for sodium ion batteries. The results show that Cu2Se-1 nanoarrays can deliver a reversible capacity of 679 mAh/g and remarkable rate capability: 85 % capacity retention when the current density increases from 0.1 to 2 A/g. Specifically, after 600 cycles at a high current of 5 A/g, the capacity remains as high as 368 mAh/g. Finally, the assembled Cu2Se-1//Na3V2(PO4)3 full battery shows a stable storage capacity of 270 mAh/g at 0.1 A/g. The design of 3D nanoarrays in Cu2Se-1 greatly increases electrochemical active sites, accelerates the diffusion and insertion of sodium ions, increases the contribution of pseudocapacitance, enhances the storage kinetics of sodium ions.

Promoted oxygen evolution reaction efficiency by Ni3S2/WO3 nanocomposite anchored over rGO

To develop a high-efficient catalyst for oxygen evolution reaction (OER), creating high current densities at low overpotentials is highly desirable. Herein, an effective and low cost catalyst based on anchoring Ni3S2/WO3 nanocomposite over the reduced graphene oxide (rGO) was hydrothermaly synthesized and characterized using spectroscopic and microscopic techniques, and its electrochemical parameters as a suitable OER electrocatalyst in alkaine media at surface of nickel foam (NF) was studied. Electrochemical measurements showed that, anchored Ni3S2/WO3 on rGO increased ionic conductivity, surface area, active sites of electrocatalyst, decreased the charge transfer resistance and exhibit the overpotential of 280 mV to reach 50 mA cm−2, with a Tafel slope of ∼48 mV/dec and good stability for the OER in comparison to other tested composites. As a result, this catalyst can work at high and low current densities for a long time.

3D emerging nanosheets comprising hierarchical CoMoO4/MnO2 composites for flexible all-solid-state asymmetric supercapacitors

Flexible and portable energy storage gadgets have aroused mounting interest because of the remarkable achievement in the field of intelligent and wearable devices. In this paper, perpendicularly organized CoMoO4/MnO2 (CMO/MO) heterostructures are produced in situ on the surface of Ni foam, and the porous 3D architectures and rough nanoplates outside could offer substantial active sites and decrease the ion diffusion distances. Such splendid architecture with massive electrochemically active sites exhibits greater areal capacity in contrast to CoMoO4. Subsequently, an all-solid-state asymmetric supercapacitor (ASSC) based on the CMO/MO and PVA/KOH gel electrolyte is prepared. The ASSC could work under high voltages ranging from 0 to 1.4 V and deliver a maximum areal capacitance of 0.467 Fcm−2 (1 mAcm−2). It also exhibits a great energy density of 35.81 Wh kg−1 at a watt density of 198.22 W kg−1, and the capacity retention could keep 75% even after 8000 cycles. Collectively, this research offers enlightenment regarding the synthesis of electrode materials.

CuO nanomesh hierarchical structure for directional water droplet transport and efficient fog collection

Collecting water from fog is a promising approach to solve the shortage of water resources by micro-nano scale hierarchical structure material surface. Inspired by the structures of cactus and pine needles, CuO micro-nano scale structures attached to the surface of Cu foam are designed to increase the efficiency of fog collection and droplet transport. The structural evolution from CuO nanowires to CuO nanomesh and CuO nanosheets is achieved by regulating the synthesis conditions. The results show that the synthesized CuO nanomesh hierarchical structure is more favorable for fog collection, and the collection efficiency can achieve a rate of up to 34.6 mg/cm2 s. The tip structure can rapidly capture and coalesce small droplets in a foggy environment, which significantly improves the fog collection efficiency. In addition, the synthesized mesh structure and inter-neighborhood gaps have a strong ability to confine air, making the surface has small adhesion and enabling water droplets to fall quickly, which realizes the transport of the collected water efficiently and sustainably. The research work opens a new path for constructing surface structures to improve fog collection performance and has reference value and promotion for the design and development of fog collectors.

Electrocatalytic oxidation of gaseous toluene in an all-solid cell using a foam Ti/Sb-SnO2/β-PbO2 anode

Mineralization of benzene, toluene, and xylene (BTX) with high efficiency at room temperature is still a challenge for the purification of indoor air. In this work, a foam Ti/Sb-SnO2/β-PbO2 anode catalyst was prepared for electrocatalytically oxidizing gaseous toluene in an all-solid cell at ambient temperature. The complex Ti/Sb-SnO2/β-PbO2 anode, which was prepared by sequentially deposing Sb-SnO2 and β-PbO2 on a foam Ti substrate, shows high electrocatalytic oxidation efficiency of toluene (80%) at 7 hr of reaction and high CO2 selectivity (94.9%) under an optimized condition, i.e., a cell voltage of 2.0 V, relative humidity of 60% and a flow rate of 100 mL/min. The better catalytic performance can be ascribed to the high production rate of ⋅OH radicals from discharging adsorbed water and the inhibition of oxygen evolution on the surface of foam Ti/Sb-SnO2/β-PbO2 anode when compared with the foam Ti/Sb-SnO2 anode. Our results demonstrate that prepared complex electrodes can be potentially used for electrocatalytic removal of gaseous toluene at room temperature with a good performance.

Facile and Rapid Electrochemical Conversion of Ni into Ni(OH)2 Thin Film as the Catalyst for Direct Growth of Carbon Nanotubes on Ni Foam for Supercapacitors

In this paper, a facile and rapid aqueous-based electrochemical technique was used for the phase conversion of Ni into Ni(OH)2 thin film. The Ni(OH)2 thin film was directly converted and coated onto the network surface of Ni foam (NF) via the self-hydroxylation process under alkaline conditions using a simple cyclic voltammetry (CV) strategy. The as-formed and coated Ni(OH)2 thin film on the NF was used as the catalyst layer for the direct growth of carbon nanotubes (CNTs). The self-converted Ni(OH)2 thin film is a good catalytic layer for the growth of CNTs due to the fact that the OH- of the Ni(OH)2 can be reduced to H2O to promote the growth of CNTs during the CVD process, and therefore enabling the dense and uniform CNTs growth on the NF substrate. This binder-free CNTs/NF electrode displayed outstanding behavior as an electric double-layer capacitor (EDLC) due to the large surface area of the CNTs, showing excellent specific capacitance values of 737.4 mF cm-2 in the three-electrode configuration and 319.1 mF cm-2 in the two-electrode configuration, at the current density of 1 mA cm-2 in a 6 M KOH electrolyte. The CNTs/NF electrode also displayed good cycling stability, with a capacitance retention of 96.41% after 10,000 cycles, and this the excellent cycling performance can be attributed to the stable structure of the direct growth of CNTs with a strong attachment to the NF current collector, ensuring a good mechanical and electrical connection between the NF collector and the CNTs.

Solution combustion synthesis of high-entropy metal spinel oxide as oxygen evolution reaction catalyst

High-entropy metal spinel oxide (HEO) is proved to be a promising oxygen evolution reaction (OER) catalyst with high catalytic performance and stability. A short routine synthesis process based on solution combustion synthesis was proposed to prepare (Co0.25Ni0.25Mn0.25Zn0.25)Fe2O4 spinel HEO in this work. During the process, the products were rapidly synthesized and melted due to the high-temperature reaction, and then quickly crystallized on the surface of nickel foam to form a nano-structure coating. With the aid of nano-scale spinel structure, the overpotential of non-activation HEO electrode reaches 276 mV at the current density of 10 mA·cm−2, and after 100 h i-t test, it can be further reduced to 230 mV, which proves the high activity of OER catalysis. The promotion of OER catalytic performance can be attributed to the surface reconstruction caused by the selective element leaching and the boost of oxygen vacancy, leading to the formation of nano-scale flocculation around spinel core after the long-term OER process. This work indicates a special casting process for functional materials and explores the application of rapid crystallization.

In Situ Growth of Self-Supporting MOFs-Derived Ni2P on Hierarchical Doped Carbon for Efficient Overall Water Splitting

The in situ growth of metal organic framework (MOF) derivatives on the surface of nickel foam is a novel type of promising self-supporting electrode catalyst. In this paper, this work reports for the first time the strategy of in situ growth of Ni-MOF, where the metal source is purely provided by a nickel foam (NF) substrate without any external metal ions. MOF-derived Ni2P/NPC structure is achieved by the subsequent phosphidation to yield Ni2P on porous N, P-doped carbon (NPC) backbone. Such strategy provides the as-synthesized Ni2P/NPC/NF electrocatalyst an extremely low interfacial steric resistance. Moreover, a unique three-dimensional hierarchical structure is achieved in Ni2P/NPC/NF, providing massive active sites, short ion diffusion path, and high electrical conductivity. Directly applied as the electrode, Ni2P/NPC/NF demonstrates excellent electrocatalytic performance towards both the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER), with low overpotentials of only 58 mV and 208 mV to drive 10 mA cm−2, respectively, in 1 M KOH. Furthermore, Ni2P/NPC/NF acting as the overall water splitting electrodes can generate a current density of 10 mA cm−2 at an ultralow cell voltage of 1.53 V. This simple strategy paves the way for the construction of self-supporting transition metal-based electrocatalysts.

(Digital Presentation) Development of a Novel pH Sensor Based Polyaniline Supported on Nickel Modified Nickel Foam Electrode

pH is an essential parameter that has to be regularly monitored in biological and environmental applications [1]. Typically, handling fragile electrodes and a number of calibration steps make the measuring process time-consuming. Polyaniline-modified electrodes have several advantages in terms of dependability, miniaturization, and cost-effectiveness, all of which are important features for in vivo applications.In this work, a hybrid material made of polyaniline, nickel, and nickel foam (PANI/Ni/NF) was combined together to detect H+ ions. First, using cathodic electrodeposition, nickel (Ni) was electrodeposited onto the surface of nickel foam (NF) [2]. Then, the surface of Ni/NF was modified by a self-assembled polyaniline (PANI) membrane to improve the ability of Ni to transform charges. SEM, EDX, Raman spectroscopy and XPS were used to characterize the morphology of PANI/Ni/NF. Fig. 1 shows SEM image of PANI on the surface of nickel oxide modified nickel foam electrode. Cyclic voltammetry (CV) and Open circuit potential (OCP) were used to monitor the potential shift based on different pH in the buffer solutions. The pH sensor displays the sensitivity of −46.00 mV/pH (R2=0.99) with stable performance in the physiological pH range from 3–11. This prototype has been tested along with a commercial pH meter on real samples (orange, baking powder solution). The durability and repeatability tests also show promising results. This porous and tiny pH sensor opens up new horizons for monitoring H+ in biological, environmental or wet laboratory based samples.AcknowledgmentsUniversity of Grants Commission of Bangladesh (2021-22) for funding this research.References F. Song et al., ACS Appl. Energy Mater., 2018, 1, 1, 3–8.M. Jamal et al., J. Electrochem. Soc., 2022, 169, 057517M. Jamal et al., Microsys t. Technol . , 2018, 24, 4217–4223. Fig. 1. SEM image of PANI modified Ni/NF Figure 1

Vanadium Doped Nickel Sulfide@ Nickel Foam Electrode for Hybrid Supercapacitors

With the depletion of energy sources, people are gradually deepening the development of new energy sources. However, energy storage devices are limiting the pace of the development of new energy sources.[1] Considering the potential of supercapacitors as a supplement or alternative to rechargeable batteries for fast energy harvesting and high power transfer has become a research focus recently. Hybrid supercapacitors (HSCs) can bridge the gap between supercapacitors and batteries. It is well known that the main components of HSC devices are anode and cathode. The anode mainly provides high electrochemical performance, while the cathode can supply a wide potential window and good stability.[2] The energy density calculation equation (E = 0.5 CV2 ) is known and deduced that can control the energy density of HSC by the operating voltage window (V) and specific capacitance (C). Obviously, constructing anode materials with high capacitance is one of the effective ways to achieve the high energy density of HSC. In addition, previous experimental results show that reasonable ion doping is beneficial to change the electronic structure of electrode materials and improving the energy storage performance of electrode materials.[3-5] One of the elements with more than one oxidation state can form two (or more) ions of different valence states under the action of a reducing agent, which will be called mixed-valence ions. Boosting the specific capacitance of the electrode, ions with mixed-valence states have higher charge storage capacity and more abundant redox reactions than most other transition metal ions. In this regard, vanadium has various stable oxidation states (+ 2, + 3, + 4, and + 5). In particular, its high oxidation states (+ 4 and + 5) can store charge in the positive potential range, thus providing a favorable pseudo-capacitance.Here, we chose Ni3S2 with high theoretical capacitance and prepared vanadium-doped nickel sulfide (V-Ni3S2, denoted as VNS) anode electrodes using vanadium ions as dopant ions (Figure 1). Using nickel foam as the nickel source, prepared the VNS electrode by a one-step hydrothermal method. Since the electrode is grown in situ on the surface of nickel foam, the electrode material can be employed as an electrode sheet directly after preparation without further fabrication. Figure 1. Schematic diagram of synthesis process of VNS electrode, and Electrochemical storage performance: (a) CV curves of the VNS and NS electrodes at 2 mV s-1 scan rate, (b) GCD curves of the VNS and NS electrodes at 1 A g-1, (c) GCD curves of VNS with different V doping amounts at 1 A g-1, (d) The Ragone plots, (e) Self-discharge of NS//AC device and VNS//AC device for five hours, and (f) Cycle performance of the VNS//AC hybrid supercapacitor with a voltage of 1.6 V at a current density of 2 A g-1. [6]The most direct effect of avoiding the use of binder and thus increasing the conductivity is that the specific capacitance of the prepared VNS electrodes is further enhanced (2072 F g− 1 at 1 A g− 1). In addition, the structure of the surface of the prepared VNS electrode material is nanoflower morphology. Integrating two-dimensional nanosheets into three-dimensional nanoflower morphologies increases the number of active sites while improving the structural stability (capacitance retention of 86.4% after 10,000 cycles, Figure 1a-f). Finally, using the VNS and activated carbon electrodes as anode and cathode to assemble the VNS//AC hybrid supercapacitors delivers an excellent energy density of 81.33 Wh kg− 1 at a power density of 160 W kg− 1. This simple preparation method and significantly enhanced performance of the electrode materials have far-reaching potential for application in HSC devices.

Gas-Liquid Interfacial Plasma engineering under dilute nitric acid to improve hydrophilicity and OER performance of nickel foam

The world has been moving rapidly to find new eco-friendly energy sources. Water electrolysis consists of two reactions of Oxygen Evolution Reaction (OER) and Hydrogen Evolution Reaction (HER), whereas the OER is considered the rate-limiting step. The most commercialized electrode for OER in the alkaline electrolyte is Ni foam, but its original surface is hydrophobic. It is possible to accelerate the adsorption and desorption process of reactants and products during OER by adding hydrophilic functional groups such as –OH on the surface of Ni foam. In this study, a novel Gas-Liquid Interfacial Plasma (GLIP) engineering at room temperature was successfully applied to modify the Ni foam surface dilute (1 ​M) HNO3 solution. At a current density of 400 ​mA ​cm−2, GLIP-treated Ni foam electrodes at 1 ​M HNO3 concentrations showed OER overpotentials of 458 ​mV. Among all, GLIP with 1 ​M HNO3 treatment of 30 ​min showed 129 ​mV less overpotential than the nickel foam before treatment. In summary, GLIP can be justified as an environmentally friendly and efficient surface treatment to improve the wettability and OER performance of Ni-based electrodes in water electrolysis.

Electrical and Structural Optimization of Nickel Sulfide Nano-Flower by Mn Modulation as Robust Bifunctional Electrocatalyst for Overall Water Splitting

Designing an efficient and low-cost bifunctional electrocatalyst for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) in alkaline electrolyte is still very important and challenging. Herein, using a simple hydrothermal and sulfidation annealing method, nanoflower-like Mn-NiS with regular morphology was grown in situ on the surface of nickel foam. Through the detailed analysis of X-ray photoelectron spectroscopy results, it is found that the successful doping of Mn2+ can effectively adjust the electronic structure of NiS. As we envisioned, the prepared Mn-NiS shows only 99 mV overpotential and 64.8 mV dec−1 Tafel slope in HER at 10 mA cm−2 and has only 320 mV and 65.5 mV dec−1 in OER at 50 mA cm−2. In addition, the alkaline electrolytic cell composed of Mn-NiS double electrodes has a cell-voltage of only 1.54 V at 10 mA cm−2, and maintains good stability. More importantly, the results of density functional theory calculations show that after Mn2+ successfully changes the electronic structure on the NiS surface, it not only promotes the HER kinetics, but also greatly increases the OER activity.

Chain-like carbon nano-onions from candle flame combustion as a high-performance cathode for aluminum-air batteries

A positive air electrode capable of a high‑oxygen reduction reaction (ORR) from chain-like carbon nano-onions (CLCNOs) was synthesized directly onto the surface of nickel foam using candle flame combustion. The 50 s synthesis positive air electrode with a carbon loading of 0.49 mgcm−2 provides higher ORR catalytic capability than that of other time synthesizers in natural pH electrolytes. Increasing the cathode-to-anode ratio increases the cell voltage from 0.41 to 0.53 V, causing the specific capacity to reach 1108 mAhg−1. In addition, a positive air electrode can work continuously for 14 days, even after repeated use and replacement of new aluminum anodes several times.

Flame retardant and anti-dripping surface treatment through a co-deposition of polydopamine/polyphosphonamide for fabric and foam materials

High efficient flame retardant surface treatment through a simple and universal strategy has attracted considerable interest. In this work, polyphosphonamide (PPA) was synthesized via an eco-friendly amine ester exchange reaction, and then the polydopamine-polyphosphonamide (PDA-PPA) coating was constructed by a mussel-inspired phenol-amine co-deposition on the surface of various substrates (cotton, polyethylene terephthalate, poly (lactic acid), polyamide, polypropylene fabrics, and flexible polyurethane foam). It was demonstrated that the PDA-PPA coating significantly improved the flame retardancy of the six substrates. For example, in the case of PDA-PPA coated cotton fabric sample, the limiting oxygen index was increased to 28.3%, the peak of heat release rate and total heat release was decreased by 70.6% and 48.2%, respectively. Especially in the vertical and horizontal burning tests, all PDA-PPA coated samples were self-extinguished and free of molten droplets. It was suggested that the PDA-PPA coating released P-containing radicals to capture active small free radicals and released non-combustible gases to dilute combustible volatiles in the gas phase. In addition, the coating showed excellent intumescent charring ability and promoted the char formation of all substates except polypropylene. Surprisingly, the coating also improved the breaking strength of the PDA-PPA coated fabric and the compressive stress of the PDA-PPA coated foam samples. It was believed that this work provides a scalable and promising strategy for preparing fire safety polymeric materials with a large specific surface area.

One-pot solvothermal synthesis of highly catalytic Janus transition metal phosphides (TMPs) for high performance OER

Green hydrogen is a highly efficient and affordable energy carrier for imminent energy supply. First time, this work demonstrates the crystalline TMPs synthesized by one-pot solvothermal method. M12P5 (M = Ni, Co, Ni-Co) nanoparticles deposited on conducting surface of nickel foam (M12P5@NF) serving as highly auspicious oxygen evolution reaction (OER) electrode. Our findings demonstrate that the M12P5@NF electrodes can be cast-off as capable Janus catalysts for OER. The onset potential for OER of Janus Co12P5 befalls at 1.29 VRHE and possesses a current density of 10 mAcm−2 just at overpotential of only 160 mV. Intriguingly, Co12P5 reveals the low Tafel slope value of 33 mVdec−1. The onset potential for Ni12P5, (Ni-Co)12P5 electrodes are 1.30 and 1.46 VRHE, decade current density obtained just at bias of 300 and 340 mV, respectively. These electrocatalysts unveil the worthy electro-active zone, as compared to that of other reported nickel and cobalt based materials. These electrocatalysts also sustain an amazing stability during long-term stability experiments. Ni, Co and (Ni-Co)-phosphides show high TOF value of 8.5, 11.37 and 5.1 s−1and mass activity of 119, 68 and 48 A g−1 respectively at over potential of 350 mV which is an indicative of rapid electrochemical reaction and charge transfer kinetics of electrocatalyst. The catalytic enactment of Co12P5 is several folds superior than avant-garde catalysts (RuO2 and IrO2) under the similar set of conditions. The greater OER activity of M12P5 at such low overpotential is attributed to the mutual consequence of high electroactive sites at exterior of catalytic surface and auspicious interaction generated among intrinsically dynamic 3d-transition metal i.e. Ni, Co and phosphorous.TMPs are efficient and non-precious metal centered materials, which unwraps new prospects to exploit water electrolysis for green hydrogen fuel.

Hydrothermal synthesis of vanadium doped nickel sulfide nanoflower for high-performance supercapacitor

With the tremendous demand for high energy and power operation in energy storage devices, supercapacitors (SCs) have demonstrated to be one of the most viable devices for electrical energy conversion and storage applications due to their superior capacity than conventional capacitors and higher power density than batteries. However, the insufficient capacitance of the anode materials severely impedes the development of SCs. Due to their astonishing theoretical capacitance, nickel sulfides have aroused immense attention for the next generation of supercapacitors. But its inability to satisfy the anticipated capacitance values and insufficient structural durability severely hinder the application of capacitive energy storage. Herein, doping vanadium into nickel sulfide (V-Ni3S2, denoted as VNS) was grown on the surface of nickel foam by a one-step hydrothermal method using nickel foam as a nickel source. The results showed that Ni3S2 doped uniformly with valence-rich vanadium remarkably enhanced the redox reaction. Integrating two-dimensional nanosheets into three-dimensional nanoflower morphology not only expands the number of active sites but also enhances the stability of the structure. The VNS electrode with clearly defined ion diffusion channels and affluent redox activity centers significantly enhances the reversible capacitance and the stabilized longevity (2072 F g−1 at 1 A g−1, capacitance retention of 86.4% after 10,000 cycles). Furthermore, using the VNS and activated carbon as cathode and anode electrodes, respectively, the fabricated hybrid supercapacitor delivers an excellent energy density of 81.33 Wh kg−1 at a power density of 160 W kg−1 and agelong cycling durability (capacitance retention of 82.2% after 10,000 cycles). These strategies enlighten the electrochemical properties of various metal sulfide materials employed in energy storage devices.

Anodization of a NiFe Foam: An Efficient and Stable Electrode for Oxygen-Evolution Reaction

Water splitting for hydrogen production is a promising method for storing sustainable energy sources. The oxygen-evolution reaction (OER) through water-oxidation reactions provides electrons for hydrogen production and is a limitation for water splitting. Thus, finding an efficient and stable OER catalyst is critical for water splitting. Herein, a NiFe foam, after harsh anodization at 60 V in a two-electrode system, is reported as an efficient and stable electrocatalyst. The NiFe oxide formed on the NiFe foam’s surface was characterized by some methods. These methods show the presence of different NiFe (hydr)oxides such as Ni(OH)2, NiO, and NiO(OH) on the surface of the NiFe foam. For the prepared electrode in the KOH solution (1.0 M), the overpotential for the onset of the OER is 220 mV. The overpotentials for the activities of 1, 10, and 100 mA/cm2 are observed at 290, 346, and 500 mV, respectively. A stable NiFe-oxide-based layer protects the bare foam from further oxidation, resulting in a stable electrocatalyst for the OER.

6:2 Chlorinated polyfluoroalkyl ether sulfonate as perfluorooctanesulfonate alternative in the electroplating industry and the receiving environment.

Electroplating industry is an important application field of per- and polyfluoroalkyl substances (PFASs) as the chromium mist suppressants. 6:2 chlorinated polyfluoroalkyl ether sulfonate (6:2 Cl-PFAES) and perfluorooctanesulfonate (PFOS) have been the two widely used mist suppressants, and after the ban of PFOS, 6:2 Cl-PFAES will become the dominant suppressant. The behavior and mechanisms of 6:2 Cl-PFAES in the electroplating industry and the receiving environment were studied and compared with PFOS. 6:2 Cl-PFAES behaved similarly with PFOS due to their similar chemical structure. However, some difference exists for the relatively stronger hydrophobicity of 6:2 Cl-PFAES. Up to 35.7mg/L of PFOS and 13.4mg/L of 6:2 Cl-PFAES were found in the industrial wastewater influents, and were effectively reduced to 0.3-0.8mg/L by the interaction with chromium hydroxide through hydrophobic interaction and ligand exchange. The stronger hydrophobicity of 6:2 Cl-PFAES than PFOS resulted in its accumulation in the surface of foams and comparable or less removal during the industrial and municipal wastewater treatment. 6:2 Cl-PFAES exhibited higher bioaccumulation potential than PFOS in the surface water. 6:2 Cl-PFAES emitted by both mists and water may pose health risks to humans. More attentions towards 6:2 Cl-PFAES are needed after the replacement of PFOS by it in the electroplating industry as a global contaminant of emerging concerns.

Electrochemical Nonenzymatic Glucose Detection Based on the Nanostructures of NiCo2O4 Nanosheets Wrapped CuO Nanowires

A kind of NiCo2O4-based hierarchically-nanostructured composites has been synthesized for electrooxidation of glucose. The Cu(OH)2 nanowires were initially growth in situ on the surface of Cu foam (CF) and wrapped with Ni-Co precursor (Ni-Co Pre) to prepare nanocomposites (Ni-Co Pre@Cu(OH)2 NWs/CF). Then, the obtained composites were annealed in air to form the NiCo2O4 nanosheets wrapped CuO nanowires nanostructures which were supported on the Cu foam (NiCo2O4@CuO NWs/CF). Because of the synergism of Ni, Co and Cu, as well as the enhanced surface area by hierarchical nanostructure, the as-prepared NiCo2O4@CuO NWs/CF sensor exhibits outstanding electrooxidation activity for glucose detection, including high sensitivity (7.98 μA/μM cm−2), wide linear range (1.0 × 10−3−2.0 mM), low detection limit (0.68 μM) and fast response/recovery times (1.3/2.0 s). Meanwhile, the as-fabricated sensor also possesses good reproducibility, flexibility, selectivity and long-term stability, which is a promising platform for glucose electrooxidation and determination in serum sample.

Fabrication of CuFe2O4@g-C3N4@GNPs nanocomposites as anode material for supercapacitor applications

The aim of this study was to synthesize CuFe2O4 together with g-C3N4 and GNPs in various combinations on the surface of Ni foam for use as anode materials in supercapacitors. The fabricated electrodes were investigated by XRD, FTIR, XPS, BET, SEM and TEM for content and by CV, GCD and EIS analysis for electrochemistry. The characterization results showed that CuFe2O4 was successfully synthesized together with g-C3N4 and GNPs in a nanosponge-like geometry. The highest value of specific capacitance was found to be 989 mF/cm2 at 2 mA measurement in the triple combination. Moreover, the stability of this electrode was measured to be 70% after 1500 cycles at 16 mA, while the energy and power densities were calculated to be 27.8 mWh/cm2 and 300 mW/cm2, respectively. The EIS results show that the carbon-based component increased the Cs value by decreasing the charge transfer and diffusion resistances of the electrodes. Compared to its counterparts in the literature, its Cs value is quite high, but its stability is low, so it can be used in low-cycle applications.