Carbon Cloth Substrate Research Articles

Needle-like Co3O4 nanoarrays as a dual-responsive amperometric sensor for enzyme-free detection of glucose and phosphate anion

The high cost and easy denaturation of natural enzymes under environmental conditions largely hinder their practical usefulness in sensing devices. Currently, great efforts have been focused on exploring of novel functional nanomaterials to replace natural enzymatic systems. In this study, we developed a hydrothermal growth of free-standing cobalt oxide (Co3O4) nanoneedle arrays on a flexible carbon cloth (CC) substrate and used them as electrode materials with a high catalytic activity for nonenzymatic glucose sensing. Benefiting from the densely arrayed and free-standing Co3O4 nanoneedles with a large surface area, the resulting Co3O4/CC electrode exhibits an excellent sensing performance for glucose with a broad linear range and low detection limit (0.23 μM). More importantly, the Co3O4/CC electrode also exhibited a good performance for determining phosphate ions in a glucose containing alkaline solution. Under optimal condition, the resulted electrode exhibits a linear range of 0.1–1.0 mM and 1.0–30.0 mM with a detection limit of 10 μM for phosphate anion. The as-proposed electrode was further used for the determination of glucose and phosphate ions in human blood serum and urine samples with satisfactory recoveries, verifying the feasibility and great potential as a sensitive, selective, potable, and low-cost electrochemical electrode in sensing application.

Evolution of intrinsic 1-3D WO3 nanostructures: Tailoring their phase structure and morphology for robust hydrogen evolution reaction

The use of non-noble electrocatalyst to harness molecular hydrogen by splitting water is highly appreciated. WO3 is one such high-caliber electrocatalyst for Hydrogen evolution reaction (HER) which can be tuned to attain various crystallographic phases and morphologies by altering the surfactants and synthesis parameters of hydrothermal synthesis. Seven different morphologies of WO3 ranging from 1 to 3D nanostructures were synthesized and subjected to HER under extreme pH conditions. The kinetic performance of 1D – nanorods of WO3 outperformed all its counterpart electrocatalysts with an exceptional Tafel slope of 96 and 105 mV dec−1 at pH = 0 and 14 respectively. The very high aspect ratio of WO3 nanorods in conjunction with an excellent specific surface area by precision tailoring of the crystallographic facets along the (0 0 1) direction enabled better adsorption energies necessary for HER. The nanorod structures of WO3 were further screened by Stainless steel (SS) and Carbon cloth (CC) substrates to determine their efficacy as a real-time electrode for hydrogen production. The nanorods deposited on CC in acidic media displayed an outstanding endurance of 12 h under a static overpotential of −0.5 V vs. RHE and a striking Tafel slope of 76 mV dec−1 comparable with standard Pt/C. The intrinsic interface of CC compared to SS along with the inherent complexity of WO3 nanorods has enriched the overall kinetic performance required for hydrogen evolution. This research has a promising scope for engineering the morphology and phase structure of WO3 metal oxide at the molecular level for boosting the interfacial active sites required for large scale production of hydrogen.

In-situ growth of bimetallic sulfide NiCo2S4 nanowire on carbon cloth for asymmetric flexible supercapacitors

Fully flexible, lightweight, and high-performance supercapacitor was designed, with in-situ grown NiCo2S4 nanowire on activated carbon cloth (CC) by a simple two-step hydrothermal method. Needle-like NiCo2S4 nanowire uniformly arranged on CC substrate, not only increases the sufficient contact area between the electrode and the electrolyte, but also favor rapid electron transfer. Benefitting from these advantages, this designed NiCo2S4@CC electrode expresses high area capacitance of 1568.8 mF cm−2 at 1 mA cm−2 and good capacitance retention with 9.9% capacitance lost after 10000 cycles. Moreover, a flexible asymmetric supercapacitor using NiCo2S4@CC as the anode and Fe2O3@CC as the cathode is assembled, which displays high specific capacitance (343.2 mF cm−2) at 1 mA cm−2, energy density (93.43 µWh cm−2), and power density (700.7 µW cm−2) with the capacitance retention of 81.8% at 20 mA cm−2 after 5000 cycles, proving the feasibility for flexible wearable energy storage device.

Flexible free-standing cathode enabled via multifunctional Mo2C for high sulfur loading lithium–sulfur batteries

A free-standing and flexible sulfur host material composed of Mo2C nanoarrays growing on the surface of carbon cloth (Mo2C/CC) is designed for the binder-free cathode of the Lithium-sulfur (Li–S) batteries. The carbon cloth substrate is flexible together with the conductive bottlebrush-like Mo2C, this host material can provide more active sites and a large inner space to accommodate the volume expansion of sulfur to Li2S2/Li2S. The electric conductive Mo2C nanoarrays can not only adsorb the polysulfides through forming Mo–S bonds to inhibit the shuttle of lithium polysulfides (LiPSs), but also can boost the electron transfer and promote the direct conversion of the LiPSs to Li2S2/Li2S on their surface. As a result, the sulfur cathodes based on the Mo2C/CC host material exhibit an impressive specific capacity of 1213 mA h g-1 at 0.1 C, maintain a long-term cyclability with a decay of 0.011% per cycle. More remarkably, excellent capacity of 8.57 mA h cm-2 can be attained with a high sulfur loading (10.8 mg cm−2) benefit from the 3D nanoarrays structure of the Mo2C/CC host material. Meanwhile, a pouch cell based on Mo2C/CC@S cathode can cycle steadily.

Hydrothermal synthesis of brush-like ZnO NWAs@CC composites with enhanced photocatalytic and field emission performance

Flexible substrates are very advantageous for optimal performance of highly ordered nanoscale semiconductor nanowire arrays, which is beneficial for flexible device fabrication. Herein, the highly vertically alignment ZnO NWAs (Zinc oxide nanowires arrays) have been successfully fabricated on the high-conductivity flexible CC (Carbon cloth) substrates spin-coated with ZnO seed layers to form a brush-like ZnO NWAs@CC heterojunction composites. XPS spectra shows the C–O–Zn interface chemical bonds between the CC and ZnO seed layers, which not only reduces the contact resistance between ZnO NWAs and CC substrates, but also conducive to the transfer of efficient electrons. The brush-like ZnO NWAs@CC-18 composites were demonstrated to possess excellent photocatalytic activity under visible light irradiation (degradation of 91.65% for 120 min for MB (Methyl blue) dyes) and field emission properties (the turn-on and threshold field of 0.32 V/μm and 1.02 V/μm, the field enhancement factor of 64438), suggesting a promising flexible cold candidate for photocatalytic decontamination and field emission (FE) devices.

Accessible active sites activated by cobalt-doping into MoS2/NiS2 nanosheet array electrocatalyst for enhanced hydrogen evolution reaction

It is of great importance to develop highly efficient electrocatalysts with low-cost, superior activity and good stability toward hydrogen production. The conductivity property and catalytic activity of transition metal electrocatalyst can be desirable optimized by metal doping for hydrogen evolution reaction (HER). Herein, a Co-doped MoS2/NiS2 nanosheet array was in-situ covered on the carbon cloth substrate (Co-MoS2/NiS2/CC) via facile successive three-step hydrothermal processes, in which Co-MoS2 nanosheets were hierarchically integrated with NiS2 nanosheets. Benefitting from the introduction of Co atom and numerous heterostructures, the as-obtained Co-MoS2/NiS2/CC allows high conductivity and plenty of accessible active sites, showing favorable synergistic effect for electrocatalytic HER properties. Specifically, the optimal Co-MoS2/NiS2/CC electrocatalyst requires low overpotentials of 92 and 122 mV to deliver current densities of 10 and 50 mA cm−2 in 0.5 M H2SO4. It presents excellent electrocatalytic activity in 0.1 M KOH simultaneously. Moreover, such a Co-MoS2/NiS2/CC electrocatalyst shows a small Tafel slope of 47 mV dec−1 and remarkable long-term stability. This work provides a novel strategy to synthesize transition metal-doped heterogeneous electrocatalysts for efficient hydrogen evolution reaction.

Macroporous Array Induced Multiscale Modulation at the Surface/Interface of Co(OH)2/NiMo Self‐Supporting Electrode for Effective Overall Water Splitting

AbstractOutstanding electrocatalysts for high‐efficiency water splitting demand not only the high intrinsic activity determined by the electronic structure but also a favorable mass transfer (electrolyte diffusion and bubble desorption) and strong structural stability. Here, a 3D core–shell electrocatalyst consisting of Co(OH)2 cavity array‐encapsulated NiMo alloy on the flexible carbon cloth substrate (Co(OH)2/NiMo CA@CC) is proposed. Density functional theory reveals that coupling NiMo with Co(OH)2 can better optimize the water adsorption/dissociation and hydrogen adsorption energies in hydrogen evolution reaction, and also accelerate the kinetics of oxygen evolution reaction. Based on this, the open porous structure of the outer Co(OH)2 cavity array further promotes the diffusion of the electrolyte into the heterogeneous interface between NiMo and Co(OH)2, significantly shortening the electron transfer pathways and exposing multiple active sites. In addition, the macroporous array structure accelerates the bubble evolution and desorption process, thus ensuring a rapid mass transfer. When served as bifunctional electrocatalysts toward alkaline overall water splitting, Co(OH)2/NiMo CA@CC delivers a current density of 10 mA cm−2 at a low cell voltage of 1.52 V. Results support the multiscale optimization of the surface/interface engineering induced by the macroporous array.

Designing FeCoP@NiCoP heterostructured nanosheets with superior electrochemical performance for hybrid supercapacitors

The precise preparation of transition metal phosphides-based battery-type electrode materials with well-defined morphology and nanostructure have shown great potential in supercapacitors, due to their high electrical conductivity and superior redox activity. Herein, a smart nanoarchitecture comprised of a FeCoP@NiCoP core-shell hybrid is designed via a two-step electrodeposition strategy together with a phosphorization treatment. The 3D FeCoP@NiCoP nanosheet arrays grown on a flexible carbon cloth substrate can provide an efficient nanoporous framework, facilitate the electron/ion transport, and generate the effective synergy of good conductivity from FeCoP and superior redox activity from NiCoP. As a result, the as-prepared FeCoP@NiCoP electrode exhibits a high specific capacity of 973.0 C g−1 at a low current density of 1 A g−1 and excellent rate capacibity with 84.3% retention at 20 A g−1, superior to those of bare FeCoP and NiCoP electrodes. Additionally, a hybrid supercapacitor is assembled with FeCoP@NiCoP as a cathode and a barley-derived hierarchical porous carbon BPC-800 as an anode, showing a high energy density of 75.9 Wh kg−1 at a power density of 827.8 W kg−1 and outstanding cycling stability of 89.7% retention of the initial capacitance after 10000 cycles.

Copper Nanoflowers on Carbon Cloth as a Flexible Electrode Toward Both Enzymeless Electrocatalytic Glucose and H2O2

AbstractHerein, a novel electrochemical sensor for glucose and hydrogen peroxide (H2O2) detection was successfully developed through the use of Cu nanoflowers (CuNFs) combined with flexible carbon cloth (CC) substrate. The 3D flower‐like CuNFs in size uniformly and firmly grow on CC substrate by a facile, scalable, one‐step hydrothermal strategy. Morphology, size and surface property of the prepared CuNFs/CC were examined by SEM, EDS and TEM, respectively. The electrochemical mechanism of CuNFs/CC for glucose and H2O2 detection was investigated by cyclic voltammetry. High electrochemical performances were displayed with amperometric i‐t curves including a wide linear range from 1.0 nM to 6.0 mM for glucose and from 1.0 μM to 36.66 mM for H2O2, respectively. Good sensitivity, repeatability, and stability, as well as anti‐interference ability, the carbon cloth‐supported CuNFs will be the promising materials for fabricating practical non‐enzymatic glucose and H2O2 sensors.

Effect of solution concentration and electrolytes on the electrochemical performance of hydrothermally synthesized reduced graphene oxide

In the present work, we have synthesized sheet-like reduced graphene oxide using different solution concentrations on the carbon cloth substrate via the hydrothermal method. The influence of different solution concentrations on the physical as well as electrochemical characteristics of the electrode material has been investigated. Moreover, the electrochemical properties of RGO prepared using 10 mg/ml solution concentration give the highest specific capacitance of 480.38F/g at 5 mV/s scan rate in 1 M H2SO4 electrolyte. RGO exhibits a good long-term cycle stability of 2000 cycles. The supercapacitive performance of the optimized RGO electrode was studied in different aqueous electrolytes. The promising physicochemical properties of RGO, makes it superior electrode material for the next generation wearable energy storage applications.

Interface Engineering of a Sandwich Flexible Electrode PAn@CoHCF Rooted in Carbon Cloth for Enhanced Sodium-Ion Storage.

With the growth of demand for flexible devices, the development of flexible electrodes used in energy storage devices has attracted much attention of researchers. In this work, a thin flexible cathode of Prussian blue analogue@polyaniline rooted in carbon cloth has been fabricated. The Prussian blue analogue (PBA) is an electrochemically active material grafted on flexible carbon cloth substrates, which had been precoated with polyaniline. Polyaniline as an intermediate layer can not only improve the overall electronic conductivity of the electrode but also enhance the adhesion and load of the PBAs. The electrochemical properties of the flexible cathode with a "sandwich" structure were determined in half-cells, with a superior capacity of 151 mA h·g-1 and a striking cyclability with 96% capacity retention over 100 cycles at 100 mA h·g-1. This work proposes a novel perspective for the structural construction and material synthesis of flexible positive electrodes and gives new options for the practical application of flexible batteries.

Cobalt-doped cerium oxide nanocrystals shelled 1D SnO2 structures for highly sensitive and selective xanthine detection in biofluids

In this study, we prepared a three-dimensional self-supported electrocatalyst based on a thin layer of cerium oxide nanocrystals doped with cobalt heteroatoms (CeO2-Co) and then uniformly shelled over one-dimensional tin oxide (SnO2) nanorods supported by carbon cloth substrate. The material was used as a binder-free sensor that could nonenzymatically detect xanthine (XA) with an excellent sensitivity of 3.56 μA μM−1, wide linear range of 25 nM to 55 µM, low detection limit of 58 nM, and good selectivity. A screen-printed electrode based on the material accurately detected XA in food samples as well. The achievements were resulted from synergistic effects coming from the unique core@shell formation and Co-doping strategy, which efficiently modified electronic structure of the material to expose more electroactive site numbers/types and fast charge transfer, thereby producing intrinsic catalytic properties for XA oxidation. These results suggested that the SnO2@CeO2-Co is potential for developing efficient sensor to detect XA with good sensitivity and accuracy in food-quality monitoring.

Novel carbon quantum dot modified g-C3N4 nanotubes on carbon cloth for efficient degradation of ciprofloxacin

The dimensionality of materials plays an important role in the photocatalytic applications. Herein, we report a novel photocatalyst by implanting zero-dimensional carbon quantum dots (CQDs) within one-dimensional porous tubular graphitic carbon nitride (g-C3N4) on carbon cloth (CC). The degradation of ciprofloxacin under visible light irradiation can be 98% obtained within 60 min by the photocatalyst (g-C3N4/CQD/CC), due to the improvement of light absorption and reduction of rapid recombination of photogenerated carriers of the g-C3N4/CQD micro-regional heterojunction. In addition, density functional theory (DFT) calculation and a set of characterisation were applied to study the influence of implanted CQDs on the band gap and charge behavior of g-C3N4/CQD/CC. Moreover, a novel multilayer photocatalytic reactor was designed to simulate the degradation capability of g-C3N4/CQD/CC by flowing wastewater, which exhibits excellent photocatalysis performance. The introduction of a CC substrate can improve the separation and cycle life of this new photocatalyst.

P-doped NiSe2 nanorods grown on activated carbon cloths for high-loading lithium-sulfur batteries

Although lithium-sulfur batteries have drawn widespread attentions due to their high energy densities at low costs, the scale-up applications are still hindered by issues such as dissolution of lithium polysulfides (LiPSs) and slow oxidation/reduction kinetics. Herein, we report a novel cathode composite composed of “moss-like” P-doped NiSe2 arrays grown on activated carbon cloth substrates (P-NiSe2/ACC). Experiments and DFT calculations together suggest that P-doping enhances the electron transfers between P-NiSe2 and LiPSs, leading to improved chemical adsorptions and catalytic effects towards the redox conversions of the active sulfur species. This effectively inhibits the shuttling of LiPSs and maximizes the utilization of sulfur towards high specific capacities and stable long-term cycling at high sulfur loadings. The strong interactions and effective catalysis of P-NiSe2 on LiPSs also enables three-dimensional growth of Li2S2/Li2S on the P-NiSe2/ACC cathode, realizing effective accommodation of volume expansions and significant alleviation of cathode passivation. As a result, the P-NiSe2/ACC cathode provides a high specific capacity of 1211 mAh g−1 at 0.2 C and an outstanding high-rate performance of 679 mAh g−1 at 3 C. At the high sulfur loading of 9.9 mg cm−2, an area capacity of 8.42 mAh cm−2 is achieved with stable cycling for 100 charge/discharge cycles.

Defect-engineered three-dimensional vanadium diselenide microflowers/nanosheets on carbon cloth by chemical vapor deposition for high-performance hydrogen evolution reaction

In the past decades, defect engineering has become an effective strategy to significantly improve the hydrogen evolution reaction (HER) efficiency of electrocatalysts. In this work, a facile chemical vapor deposition (CVD) method is firstly adopted to demonstrate defect engineering in high-efficiency HER electrocatalysts of vanadium diselenide nanostructures. For practical applications, the conductive substrate of carbon cloth (CC) is selected as the growth substrate. By using a four-time CVD method, uniform three-dimensional microflowers with defect-rich small nanosheets on the surface are prepared directly on the CC substrate, displaying a stable HER performance with a low Tafel slope value of 125 mV dec−1 and low overpotential voltage of 295 mV at a current density of 10 mA cm−2 in alkaline electrolyte. Based on the results of x-ray photoelectron spectra and density functional theory calculations, the impressive HER performance originates from the Se vacancy-related active sites of small nanosheets, while the microflower/nanosheet homoepitaxy structure facilitates the carrier flow between the active sites and conductive substrate. All the results present a new route to achieve defect engineering using the facile CVD technique, and pave a novel way to prepare high-activity layered electrocatalysts directly on a conductive substrate.

Enhanced energy storage ability of UIO66 active material on acid-treated carbon cloth for flexible supercapacitors

Metal organic framework, UIO66, has been regarded as one of potential electroactive materials for supercapacitors (SC), due to high surface area and tunable pore structures. To further improve electrochemical performance of UIO66-based SC, morphology design of UIO66 is necessary. In this work, it is the first time to study the effects of pH value of precursor solution on physical and electrochemical properties of UIO66. The pH values of 1, 2, 4 and 6 of precursor solution is prepared using acetic acid which is also acts as structure-directing agent. The different sizes of UIO66 are obtained by merely changing pH value of precursor solution. The UIO66 octahedron synthesized using pH values of 1 and 6 present the smallest size and similar dimensions to carbon black with irregular spherical morphology and size of around 75 nm which is also in paste. Carbon cloth (CC) substrate is also modified using acid to understand substrate influences on SC performance. The optimized pH value of 1 and 6 is respectively obtained for synthesizing UIO66 on acid-treated CC (ACC) and CC substrates. Due to the extra energy storage from substrate, the electrode with UIO66 prepared using pH value of 6 on ACC (M6/ACC) shows the highest areal capacitance (CA) of 3.87 mF/cm2 at 2.5 A/g. Also, the symmetric SC (SSC) fabricated using M6/ACC electrodes and aqueous medium-based electrolyte shows potential window of 0.9 V, maximum energy density of 36 mWh/kg at 89.94 W/kg, and CA retention of 130% after 10000 times charging and discharging process.

Cover Feature: Fe‐cation Doping in NiSe2 as an Effective Method of Electronic Structure Modulation towards High‐Performance Lithium‐Sulfur Batteries (7/2021)

The Cover Feature shows a Li2S6 molecule adsorbed on Fe-cation doped NiSe2 for catalyzed conversions in Li–S batteries. Fe-doping effectively modulates the electronic structure of NiSe2 to enable improved charge transfers and stronger interactions with the adsorbed active sulfur species. Fe-NiSe2 nanosheets are grown on activated carbon cloth substrates and used as cathodes for high-performance Li–S batteries. More information can be found in the Full Paper by L. Shi et al.

Amorphous-Ni(OH)2 on a Vertically Grown Lamellar Ag-Modified MoSx Thin-Film Electrode with Surface Defects for Hydrogen Production in Alkaline Solutions

A low-temperature radio-frequency-sputtered Ag-modified MoSx lamellar thin-film electrode with a home-made target was deposited on a carbon-cloth substrate and electrochemically modified with amorp...

Boosting electrocatalytic activity of Ni2P nanosheets via incorporation of Ru nanoparticles for efficient hydrogen generation in alkaline media

In order to achieve cost-effective hydrogen production, the development of efficient and stable electrocatalysts for alkaline water splitting has aroused wide attention recently. Here, Ni2P nanosheets arrays decorated with ruthenium nanoparticles are grown in situ on a carbon cloth substrate (denoted as Ru-Ni2P/CC) via surface modification engineering, exhibiting good electrical conductivity and superior hydrophilicity. The resulting Ru-Ni2P/CC-5 with Ru content of 8.98 wt% exhibits an ultra-low overpotential of only 23 mV to achieve a current density of 10 mA cm−2 for hydrogen evolution reaction (HER) and good long-term stability in alkaline solution. The corresponding X-ray photoelectron spectroscopy characterization displays the strong electron interaction between Ru and Ni2P, which facilitates the regulation of their internal electron configuration. Density functional theory calculations reveal that the Ni sites in Ni2P nanosheets are conducive to the dissociation of water molecules owing to lower energy barrier, while Ru sites act as catalytic active center for the production of molecular hydrogen. The present work offers a reasonable design route of efficient electrocatalyst for HER in alkaline solution.

Nanostructured porous polyaniline (PANI) coated carbon cloth (CC) as electrodes for flexible supercapacitor device

Nanostructured porous polyaniline (PANI) has been synthesized and coated simultaneously on a highly flexible and conductive carbon cloth (CC) substrate using a simple in-situ chemical oxidative polymerization technique. PANI coated CC (PANI−CC) based flexible electrodes were further used for the fabrication of flexible supercapacitor devices. For the comparison purpose, pure PANI has also been synthesized and tested for its electrochemical performance. The energy storage capacity of PANI and PANI–CC composite was investigated using electrochemical techniques like CV, GCD, and EIS in a potential range from 0 to 0.8 V in 1 M H2SO4 electrolyte. PANI−CC flexible electrodes exhibited the highest specific capacitance of 691 F/g; whereas, pure PANI could only achieve 575 F/g of specific capacitance at 1 A/g. Composite also exhibited outstanding cyclic stability by recollecting 94 % of its initial capacitance after 2000 GCD cycles. For actual implementation, a flexible supercapacitor device has been fabricated using stainless steel sheets and PANI−CC flexile electrodes. The energy storage performance of the PANI−CC flexible supercapacitor device was tested at several bending angles, which resulted in 72 % of capacitance retention at a maximum bending angle of 140° compared to the capacitance obtained at an angle 0° (flat state). PANI−CC exhibited improved electrochemical performance than pure PANI due to the synergistic effect between PANI and CC. Here, CC helped in enhancing the conductivity and stability; whereas, PANI boosted the capacitance owing to its excellent porosity and fast pseudocapacitive charge storage response.