Hybrid Nanobelts Research Articles

Structuring MoO3-polyoxometalate hybrid superstructures to boost electrocatalytic hydrogen evolution reaction

Improving the surface atoms utilization efficiency of catalysts is extremely important for large-scale H2 production by electrochemical water splitting, but it remains a great challenge. Herein, we reported two kinds of MoO3-polyoxometalate hybrid nanobelt superstructures (MoO3-POM HNSs, POM = PW12O40 and SiW12O40) using a simple hydrothermal method. Such superstructure with highly uniform nanoparticles as building blocks can expose more surface atoms and emanate increased specific surface area. The incorporated POMs generated abundant oxygen vacancies, improved the electronic mobility, and modulated the surface electronic structure of MoO3, allowing to optimize the H* adsorption/desorption and dehydrogenation kinetics of catalyst. Notably, the as-prepared MoO3-PW12O40 HNSs electrodes not only displayed the low overpotentials of 108 mV at 10 mA/cm2 current density in 0.5 mol/L H2SO4 electrolyte but also displayed excellent long-term stability. The hydrogen evolution reaction (HER) performance of MoO3-POM superstructures is significantly better than that of corresponding bulk materials MoO3@PW12O40 and MoO3@SiW12O40, and the overpotentials are about 8.3 and 4.9 times lower than that of single MoO3. This work opens an avenue for designing highly surface-exposed catalysts for electrocatalytic H2 production and other electrochemical applications.

Conjugate electrospinning-constructed special-shaped Janus nanobelt with improved upconversion luminescence and regulable magnetism Bi-functionality

Developing multifunctional nanomaterials through the design and construction of advanced nanostructures that are highly compatible with various substances is a crucial approach. In this work, special-shaped Janus nanobelt with both up-conversion luminescence (UCL) and magnetism is firstly designed and fabricated via a conjugate electrospinning coupled with a di-crucible fluorination. [YF3: Yb3+, Ho3+@SiO2] belt-in-belt nanobelt//CoFe2O4 nanobelt conjugate electrospinning-constructed special-shaped Janus nanobelt (shorted as C-SJNB) was designed and successfully prepared for a case study. C-SJNB is composed of two mutually independent micro-zones, which are YF3: Yb3+, Ho3+@SiO2 belt-in-belt nanobelt (BNB) called as luminescent micro-zone, and CoFe2O4 magnetic nanobelt acted as magnetic micro-zone. In the C-SJNB structure, the design ensures that the luminescent substance does not directly contact with the magnetic substance, thereby reducing the adverse effects of the dark-brown magnetic CoFe2O4 on the luminescent performance. C-SJNBs with structural advantages exhibit 7 times the UCL intensity compared to counterpart luminescent-magnetic YF3: Yb3+, Ho3+/SiO2/CoFe2O4 hybrid nanobelts (HNBs) prepared by uniaxial electrospinning. Further, compared with [YF3: Yb3+, Ho3+@SiO2]//CoFe2O4 parallel electrospinning-constructed special-shaped Janus nanobelt (shorted as P-SJNB), C-SJNB possesses a higher quality of micro-morphology, and avoids the degradation of luminescence performance caused by the mixing of magnetic and luminescent substances at the interface. The UCL intensity and magnetism of C-SJNBs can be adjusted by changing the content of CoFe2O4. When the CoFe2O4 content increases from 0.5 mmol to 4 mmol, the saturation magnetization of C-SJNBs increases from 4.42 to 13.94 emu·g−1. The newly established technology eliminates the needs for complex electrospinning and post-processing procedures. The formation mechanism of C-SJNBs has been established, providing technical support for synthesizing other Janus nanobelts with a belt-in-belt structure on one side. These advanced Janus nanobelts are ideal for developing poly-functional nanomaterials and have important applications in dual-mode imaging, display devices, batteries, drug loading and delivery.

Large-scale synthesis of macroscopic layered inorganic-organic hybrid nanobelt aerogel monoliths with multifunctionality

Fabrication of freestanding nanostructured aerogel monoliths with multifunctionality on a large scale represents a great challenge due to the limited scalable methods for synthesis and assembly of multi-component nanostructures into one single gel body. Here, we report a scalable solvothermal-based in situ gelation method for synthesizing mechanically stable cobalt-based layered inorganic-organic hybrid nanobelt (Co-LIOHN) aerogel monoliths with a density as low as 2.8 mg/cm 3 , an ultralow thermal conductivity of 25 mW/(mK), and extraordinary adsorption capacities of 51–145 g/g for various solvents. Moreover, the aerogel exhibits reversible thermochromic behavior originating from the changing of the coordination environment of the Co 2+ caused by the loss and uptake of coordinating molecular water upon heating and cooling. The Co-LIOHN aerogels integrate unique features of the aerogel and intrinsic properties of the hybrid nanobelts, giving access to a truly multifunctional material that has great potential for applications in thermal insulation, environmental remediation, sensing, and camouflage. • A scalable in situ gelation method is developed for producing Co-LIOHN aerogels • The gelation is enabled by self-crosslinking of nanobelts via van der Waals forces • The Co-LIOHN aerogel shows excellent oil removal and thermal insulation capability • The Co-LIOHN aerogel demonstrates unprecedented thermochromic properties Li et al. report a facile and scalable in situ gelation method for the fabrication of macroscopic freestanding cobalt-based layered inorganic-organic hybrid nanobelt aerogel monoliths that exhibit outstanding oil removal, thermal insulation, and thermochromic properties.

In Situ Surface Restraint-Induced Synthesis of Transition-Metal Nitride Ultrathin Nanocrystals as Ultrasensitive SERS Substrate with Ultrahigh Durability.

It is a major challenge to synthesize crystalline transition-metal nitride (TMN) ultrathin nanocrystals due to their harsh reaction conditions. Herein, we report that highly crystalline tungsten nitride (W2N, WN, W3N4, W2N3) nanocrystals with small size and excellent dispersibility are prepared by a mild and general in situ surface restraint-induced growth method. These ultrafine tungsten nitride nanocrystals are immobilized in ultrathin carbon layers, forming an interesting hybrid nanobelt structure. The hybrid WN/C nanobelts exhibit a strong localized surface plasmon resonance (LSPR) effect and surface-enhanced Raman scattering (SERS) effect, including a lowest detection limit of 1 × 10-12 M and a Raman enhancement factor of 6.5 × 108 comparable to noble metals, which may be one of the best records for non-noble metal SERS substrates. Moreover, they even can maintain the SERS performance in a variety of harsh environments, showing outstanding corrosion resistance, radiation resistance, and oxidation resistance, which is not available on traditional noble metal and semiconductor SERS substrates. A synergistic Raman enhancement mechanism of LSPR and interface charge transfer is found in the carbon-coated tungsten nitride substrate. A microfluidic SERS channel integrating the enrichment and detection of trace substances is constructed with the WN/C nanobelt, which realizes high-throughput dynamic SERS analysis.

Reconstruction of Ultrahigh‐Aspect‐Ratio Crystalline Bismuth–Organic Hybrid Nanobelts for Selective Electrocatalytic CO2 Reduction to Formate

AbstractThe morphology and active site engineering of electrocatalysts is an efficient strategy to improve the intrinsic activity and selectivity of electrocatalytic CO2 reduction. Here the ultralong and thin Bi nanobelts (Bi‐NBs) are fabricated, which feature a high edge‐to‐facet ratio and high‐degree connectivity is inherited from the ultrahigh‐aspect‐ratio crystalline bismuth−organic hybrid nanobelts, through a cathodically in situ reconstruction process. The unique nanostructure of Bi‐NBs leads to a significantly enhanced performance for electrocatalytic CO2 reduction with a near‐unity formate selectivity and high formate partial current density, which is far superior to those of the discrete Bi counterparts with low edge‐to‐facet ratios. Notably, Bi‐NBs perform ultrahigh formate selectivity over a broad potential window with a high current density reaching 400 mA cm−2 for formate production in a flow cell. Moreover, it is ultrastable to continuous electrolysis for nearly 23 h at 200 mA cm−2 without compromising the selectivity. Based on calculations, the enhanced performance is closely related to the high edge‐to‐facet ratio of Bi‐NBs, since the rich edge sites are conducive to the stabilization of the key *OCHO intermediate for formate production. In addition, the ultralong and interconnected Bi‐NBs provide “expressways” for electron transfer during CO2 electroreduction, further contributing to the improved performance.

Bright and Near-Unity Polarized Light Emission Enabled by Highly Luminescent Cu2I2-Dimer Cluster-Based Hybrid Materials.

As one fundamental property of light, polarization has a huge impact in quantum optics and optoelectronics through light-matter interactions. However, the bright and near-unity polarized light emissions in the visible range by solid crystalline materials are scantly realized. Here, we report well-defined quasi two-dimensional (2D) hybrid crystals based on the linear alignment of Cu2I2-dimer/bidentate ligand hybrid clusters for achieving bright and near-unity linearly polarized light emissions. Using first-principle calculations, we demonstrate that the superaligned transition dipole moments are the key for the observed excellent polarized light emissions. To further enhance the photoluminescence (PL) polarization degree, we fabricate Cu2I2-dimer-based hybrid nanobelts, which display high PL quantum yield (up to 64%) and ultrahigh PL polarization degree (∼0.99). Our reported copper iodine cluster-based luminescent hybrid materials for bright and highly polarized light emissions will have great potential for future quantum optics applications.

Giant Quantum Yield Enhancement in CdS/MgF2/Ag Hybrid Nanobelt under Two-Photon Excitation

We demonstrate a giant quantum yield (QY) enhancement (230 times) in a single CdS/MgF2/Ag hybrid nanobelt under the two-photon excitation at 800 nm. The power-dependent two-photon photoluminescence...

Unconventional chemical graphitization and functionalization of graphene oxide toward nanocomposites by degradation of ZnSe[DETA]0.5 hybrid nanobelts

The high surface energy of nanomaterials endows them a metastable nature, which greatly limits their application. However, in some cases, the degradation process derived from the poor stability of nanomaterials offers an unconventional approach to design and obtain functional nanomaterials. Herein, based on the poor stability of ZnSe-[DETA]0.5 hybrid nanobelts, we developed a new strategy to chemically graphitize and functionalize graphene oxide (GO). When ZnSe[DETA]0.5 hybrid nanobelts encountered a strong acid, they were attacked by H+ cations and could release highly reactive Se2− anions into the reaction solution. Like other common reductants (such as N2H4·H2O), these Se2− anions exhibited an excellent ability to restore the structure of GO. The structural restoration of GO was greatly affected by the reaction time, the volume of HCl, and the mass ratio between GO and ZnSe[DETA]0.5 nanobelts. By carefully controlling the reaction process and the post-processing process, we finally obtained several Se-based reduced GO (RGO) nanocomposites (such as ZnSe/Se-RGO, ZnSe-RGO, and Se-RGO) and various selenide/metal-RGO nanocomposites (such as Ag2Se-RGO, Cu2Se-RGO, and Pt-RGO). Although the original structure and composition of ZnSe[DETA]0.5 nanobelts are destroyed, the procedure presents an unconventional way to chemically graphitize and functionalize GO and thus provides a new material synthesis platform for nanocomposites.

Ultrathin hybrid nanobelts of single-crystalline VO2 and Poly(3,4-ethylenedioxythiophene) as cathode materials for aqueous zinc ion batteries with large capacity and high-rate capability

Design and fabrication of cathode materials with large capacity and high-rate capability in aqueous zinc ion batteries (AZIBs) are challenging. Herein, ultrathin hybrid nanobelts comprising single-crystalline VO2 and poly(3,4-ethylenedioxythiophene) (PEDOT) (designated as VO2-PEDOT) are synthesized as cathode materials for the AZIBs. The nanobelts have a thickness below 10 nm, large amount of exposed VO2 (001) facets and discrete PEDOT conductive layers. Systematic structural and electrochemical assessment reveals that simultaneous proton and Zn2+ insertion into the VO2 host is efficient in the Zn(CF3SO3)2 electrolyte due to synergistic effects rendered by unique structure of the VO2-PEDOT nanobelts. The Zn/VO2-PEDOT battery that shows a storage mechanism involving two carriers delivers extraordinary performance including a high capacity of 540 mAhg−1 with 36.3% beyond a high operating voltage of 0.7 V at −0.05 Ag−1, high rate capability of 231.2 mAhg−1 at 10 Ag−1, excellent cycling stability up to 1000 cycles with capacity retention of 84.5%. Moreover, the 50 μm thick freestanding electrode consisting of ultrathin VO2-PEDOT nanobelts has a large areal capacity of 1.35 μAhcm−2 at 5 Ag−1. The results provide mechanistic insights into the electrochemistry of VO2-based cathodes and reveal a new strategy to improve the performance of the AZIBs especially with regard to grid-scale energy storage.

Cation-exchange strategy for a colorimetric paper sensor: Belt-like ZnSe nanoframes toward visual determination of heavy metal ions

A colorimetric paper sensor based on a cation-exchange strategy has been developed for the visual determination of heavy metal ions. Belt-like ZnSe nanoframes as colorimetric reagents were prepared from ZnSe·0.5N2H4 hybrid nanobelts as precursors via a hydrothermal method. With the decomposition and release of N2H4 ligands, the regular belt-like nanostructures of the precursors evolved into belt-like nanoframes, which consisted of numerous ZnSe nanocrystals. Inspired by the cation-exchange characteristic of chalcogenides, the as-prepared belt-like ZnSe nanoframes were employed to fabricate a colorimetric paper sensor for the detection of heavy metal ions. Owing to the color change arising from a composition change, the colorimetric paper was successfully applied to detect Ag+, Cu2+, and Hg2+ at room temperature. Depending on the color change and its intensity, heavy metal ions of Ag+, Cu2+, and Hg2+ can be individually identified and their concentrations can be determined. Particularly for Cu2+, its visually detected concentration can be down to 1 ppm. More importantly, the fabricated colorimetric paper sensor displays excellent anti-interference properties from various typical cations and anions. Considering its low cost and practicality, expectedly it can be used for practical application.

Tailored Synthesis of Coral‐Like CoTiO3/Co3O4/TiO2 Nanobelts with Superior Lithium Storage Capability

A facile yet efficient two‐step electrospinning calcination strategy is smartly developed to construct 1D hierarchical coral‐like CoTiO3/Co3O4/TiO2 hybrid nanobelts. The 1D coral‐like nanohybrid is homogeneously constructed from well‐dispersed CoTiO3 nanobelts and uniformly distributed secondary crystalline Co3O4/TiO2 nanoparticle building blocks. When evaluated as anodes for lithium‐ion batteries (LIBs), the hybrid CoTiO3/Co3O4/TiO2 nanobelt electrode exhibits a promising reversible capacity of 722.3 mAh g−1 at 100 mA g−1 after 250 cycles and has excellent cyclability with a capacity of 256.7 mAh g−1 after 1000 cycles at a current density of 2000 mA g−1. The imitating 1D coral‐like structural pattern is beneficial to alleviate the nanoparticle agglomeration and increase the contact area with the electrolyte, leading to the short diffusion path and facilitating the rapid transfer of lithium ions. The high‐level secondary nanobuilding blocks offer a large specific surface area, high surface‐to‐bulk ratio, and fast interfacial ion transport. Herein, it strongly sheds light on the elegant design concept of the hybrid for fabricating next‐generation advanced rechargeable LIBs.

Pseudocapacitive Charge Storage in Thin Nanobelts

This article reports that extremely thin nanobelts (thickness ~ 10 nm) exhibit pseudocapacitive (PC) charge storage in the asymmetric supercapacitor (ASC) configuration, while show battery-type charge storage in their single electrodes. Two types of nanobelts, viz. NiO–Co3O4 hybrid and spinal-type NiCo2O4, developed by electrospinning technique are used in this work. The charge storage behaviour of the nanobelts is benchmarked against their binary metal oxide nanowires, i.e., NiO and Co3O4, as well as a hybrid of similar chemistry, CuO–Co3O4. The nanobelts have thickness of ~ 10 nm and width ~ 200 nm, whereas the nanowires have diameter of ~ 100 nm. Clear differences in charge storage behaviours are observed in NiO–Co3O4 hybrid nanobelts based ASCs compared to those fabricated using the other materials—the former showed capacitive behaviour whereas the others revealed battery-type discharge behaviour. Origin of pseudocapacitance in nanobelts based ASCs is shown to arise from their nanobelts morphology with thickness less than typical electron diffusion lengths (~ 20 nm). Among all the five type of devices fabricated, the NiO–Co3O4 hybrid ASCs exhibited the highest specific energy, specific power and cycling stability.

A novel porous Mo3N2/MoO3 hybrid nanobelts as supercapacitor electrode material

Abstract This article is withdrawn as it is a duplicate of https://doi.org/10.1088/2399-1984/aad9b8.

Ultrathin nickel-cobalt inorganic-organic hydroxide hybrid nanobelts as highly efficient electrocatalysts for oxygen evolution reaction

The electronic properties of semiconducting electrocatalysts are of fundamental research interest and of great importance for oxygen evolution reaction (OER) from water splitting. Engineering the band levels is a promising route to design and fabricate nonprecious earth-abundant semiconducting electrocatalysts for OER. Herein, p-type semiconductor electrocatalysts of ultrathin nickel-cobalt inorganic-organic hydroxide hybrid nanobelts [CoxNi1-x(OH)(BzO)·H2O, x = 0, 0.2, 0.5, 0.8, 1.0, BzO: benzoate] with favorable band structures are proposed. The CoxNi1-x(OH)(BzO)·H2O with the energetically favorable flat band level and well matched p-p junction exhibit remarkable OER performances in alkaline environment. The optimal Co0.8Ni0.2(OH)(BzO)·H2O nanobelt electrocatalyst with nearly 4 nm in thickness achieves the superior OER performance, showing earlier onset potential (Eonset: 1.50 V vs RHE), smaller overpotential (η10: 319 mV) as well as significantly enhanced stability compared with those of IrO2 reference (Eonset: 1.51 V vs RHE and η10: 343 mV) and most previously reported OER electrocatalysts. This electronic engineering strategy would provide a new insight to the fundamental understanding of underlying OER mechanism as well as open a new avenue to rational design of semiconducting electrocatalysts with high performances.

Sequential Ligand Exchange of Coordination Polymers Hybridized with In Situ Grown and Aligned Au Nanowires for Rapid and Selective Gas Sensing.

Combining polymeric materials and conductive one-dimensional metal nanostructures is able to achieve enhanced chemical and electrical properties, but the control over their morphology and spatial arrangement remains a big challenge. Herein, by replacing benzenedicarboxylate (BDC) in ZnBDC nanoplates with oleylamine (OAM) in the presence of HAuCl4, Zn-OAM nanobelts with a highly ordered laminar structure were obtained, on which ultrathin Au nanowires (Au NWs) were deposited and aligned along the long axes of the nanobelts. The resulting Zn-OAM/Au NW hybrid further underwent an OAM-to-2-methylimidazole ligand exchange, resulting in the formation of porous nanobelts composed of ZIF-8 nanocrystals interwound with aligned Au NWs. Due to the synergistic effect between the polymeric and metallic structures, the Zn-OAM/Au NW hybrid nanobelts and ZIF-8/Au NW porous nanobelts demonstrated fast and selective gas sensing at ambient conditions, in sharp contrast to the nonresponsive Au NWs or Zn-based polymers alone.

Spatially controlled synthesis of superlattice-like SnS/nitrogen-doped graphene hybrid nanobelts as high-rate and durable anode materials for sodium-ion batteries

Superlattice-like SnS/NG anode material prepared via spatially confined carbonization and phase-transformation exhibits excellent durability, high rate capability and large capacity.

A novel porous Mo3N2/MoO3 hybrid nanobelt as supercapacitor electrode material

Mo3N2/MoO3 hybrid composites with a porous nanobelt structure are prepared by a generally applicable strategy. Benefiting from the unique porous nanobelt architecture and the synergistic contributions of the components, Mo3N2/MoO3 hybrid exhibits excellent performance as a supercapacitors. Herein, Mo3N2/MoO3 hybrid is explored as a potential capacitive material for the first time. This composite shows a significantly larger specific capacitance (282 F g−1 at the current density of 1 A g−1) than a single component with outstanding cyclic stability (with 93% retention of the original specific capacitance even after 1000 CV cycles). An asymmetric supercapacitor device is also fabricated with a maximum energy density of 17.4 Wh kg−1 at 697 W kg−1.

Layered Inorganic/Organic Hybrid (CdSe) n·Monoamine Nanobelts: Controllable Solvothermal Synthesis, Multiple Stage Amine De-Intercalation Transformation, and Two-Dimensional Exciton Quantum Confinement Effect.

CdSe nanocrystals, including quantum dots and quantum rods, are a research hotspot in nanomaterials. Recently, it has been found that two-dimensional CdSe semiconductor nanobelts show a unique quantum confinement effect owing to their homogeneous nanoscale thickness. In this study, a series of (CdSe) n·monoamine ( n = 1, 2, and 4, monoamine = butylamine, hexylamine, and octylamine) layered inorganic/organic hybrid nanobelts was synthesized by the solvothermal method. These hybrids have a lamellar structure with a few inorganic [CdSe] layers and monoamine layers alternatively stacked along the c axis of their crystallites, which exhibit the typical preferred orientation for layered crystallites and isomorphous [CdSe] layers according to their X-ray diffraction patterns. The [CdSe] layer is a contracted (110) superlattice cell of wurtzite (WZ)-type CdSe with unit cell parameter relations of a ≈ √3 aWZ and b ≈ cWZ, and a lamellar nanobelt morphology with the [010] growth direction. These ordered hybrids exhibit prominent split exciton absorption peaks and sharp band edge luminescence owing to the homogeneous thickness of the [CdSe] layers within the hybrids, all of which are comparable with reported WZ-type CdSe colloidal nanosheets and exhibit a prominent two-dimensional exciton quantum confinement effect. The solvothermal reaction was systematically investigated. The multiple stage amine de-intercalation topotactic process was revealed for the WZ-type CdSe nanobelts with the (CdSe) n·monoamine ( n = 1, 2, and 4) hybrids as the intermediate phases. The solvothermal synthesis method (70-150 °C) is facile and milder than the traditional hot injection method (>200 °C). Therefore, these hybrids can be considered to be intermediate phases or precursors of WZ-type CdSe nanosheets with a topotactic intralayer [CdSe] structure and also a type of multiple quantum well with extremely thin [CdSe] layers orderly stacked among the monoamine insulating blocking layers.

Porous Single-Crystalline CdSe Nanobelts: Cation-Exchange Synthesis and Highly Selective Photoelectric Sensing toward Cu2.

Porous single-crystalline nanostructures are of tremendous interest for their application in the catalytic, electronic and sensing fields due to their large active surfaces, favorable diffusion, and good electronic transport. Despite the recent advances of various other components, photoelectric chalcogenides remain almost undeveloped. The present study contributes a facile strategy to prepare porous single-crystalline CdSe nanobelts through a cation-exchange reaction, in which ZnSe⋅0.5 N2 H4 hybrid nanobelts are employed as precursors. The detailed characterizations indicate the preservation of the belt-like morphology of the precursors due to the spatial confinement effect, which arises from the coated surfactant layer during the cation-exchange process. Simultaneously, CdSe nanobelts with porous and single-crystalline structures are formed following a complete exchange between Zn2+ and Cd2+ , the release of N2 H4 , and the atomic arrangement. The native photoelectric properties of the as-prepared porous single-crystalline CdSe nanobelts are systematically addressed based on the nanodevices fabricated with a single nanobelt and assembled nanobelt array. The results indicate that they present a rapid, stable, and repeatable photoelectric response. Moreover, as-prepared nanobelts exhibit highly selective photoelectric sensing toward Cu2+ with a low detection limit down to 0.1 ppm. To illuminate this phenomenon, a possible sensing mechanism is also discussed.

In Situ Synthesis of MoP Nanoflakes Intercalated N-Doped Graphene Nanobelts from MoO3 -Amine Hybrid for High-Efficient Hydrogen Evolution Reaction.

Molybdenum phosphide (MoP) is a promising non-noble-metal electrocatalyst in the hydrogen evolution reaction (HER), but practical implementation is impeded by the sluggish HER kinetics and poor chemical stability. Herein, a novel high-efficiency HER electrocatalyst comprising MoP nanoflakes intercalated nitrogen-doped graphene nanobelts (MoP/NG), which are synthesized by one-step thermal phosphiding organic-inorganic hybrid dodecylamine (DDA) inserted MoO3 nanobelts, is reported. The intercalated DDA molecules are in situ carbonized into the NG layer and the sandwiched MoO3 layer is converted into MoP nanoflakes which are intercalated between the NG layers forming the alternatingly stacked MoP/NG hybrid nanobelts. The MoP nanoflakes provide abundant edge sites and the sandwiched MoP/NG hybrid enables rapid ion/electron transport thus yielding excellent electrochemical activity and stability for HER. The MoP/NG shows a low overpotential of 94 mV at 10 mA cm-2 , small Tafel slope of 50.1 mV dec-1 , and excellent electrochemical stability with 99.5% retention for over 22 h.