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Facile template–free controllable growth of freestanding polyhedron–like CoS onto microporous Ni foam with three-dimensional architecture via a mild hydrothermal technique is reported. The as-obtained CoS catalyst phase was first tailored to N-Co9S8 (nitrogen doped Co9S8), and its inherent reaction kinetics and conductivity were then enhanced through sulfur incorporation via a hydrothermal process. The electrochemical performance of the pristine CoS and a sulfur-enriched N-Co9S8 (S, N-Co9S8) electrode in alkaline 1.0 M KOH was examined. The optimized polyhedral S, N-Co9S8 structured catalyst exhibits significantly enhanced electrocatalytic activity for both oxygen evolution reaction (OER) and hydrogen evolution reaction (HER). As a result, low overpotentials of 244 and −92 mV is required to achieve the current density of 10 mA cm−2 for the OER and HER, respectively. Furthermore, when the polyhedral S, N-Co9S8 catalyst was employed as a bifunctional catalyst in a two-electrode electrolyzer cell exhibiting a cell voltage of 1.549 V at 10 mA cm−2 and demonstrates excellent long-term (50 hrs.) chronopotentiometric electrolysis at various current rate, reveals excellent bifunctional OER and HER activities at different applied current densities. The superior OER and HER activities of the S, N-Co9S8 catalyst is result of the improved electronic conductivity and enhanced intrinsic reaction kinetics, which led to the enhanced electrocatalytically active sites after the incorporation of heteroatoms in the catalyst structure.

The oxygen evolution reaction (OER) plays a key role in determining the performance of overall water splitting, while a core technological consideration is the development of cost-effective, efficient, and durable catalysts. Here, we demonstrate a robust reduced Fe-oxide@NiCo2O4 bilayered non-precious-metal oxide composite as a highly efficient OER catalyst in an alkaline medium. A bilayered oxide composite film with an interconnected nanoflake morphology (Fe2O3@NiCo2O4) is reduced in an aqueous NaBH4 solution, which results in a mosslike Fe3O4@NiCo2O4 (reduced Fe-oxide@NiCo2O4; rFNCO) nanostructured film with an enhanced electrochemical surface area. The rFNCO film demonstrates an outstanding OER activity with an extraordinary low overpotential of 189 mV at 10 mA cm–2 (246 mV at 100 mA cm–2) and a remarkably small Tafel slope of 32 mV dec–1. The film also shows excellent durability for more than 50 h of continuous operation, even at 100 mA cm–2. Furthermore, density functional theory calculations suggest that the unintentionally in situ doped Ni during the reduction reaction possibly improves the OER performance of the rFNCO catalyst shifting d-band centers of both Fe and Ni active sites.

Commercial lithium–ion batteries (LIBs) are insufficient to bridge the energy density gap between demand and supply in advanced heavy and portable electronic devices because of graphite anodes (poor theoretical capacity: 372 mAh g−1). Ternary chalcogenide metal‐sulfides are promising as alternative anode materials in high power and energy densities but suffer from capacity fading with poor long‐term cycling stability due to the dissolution of polysulfide species created during the lithium‐ion insertion/de‐insertion process. Here, we report the hydrothermal synthesis of graphene integrated CuCo2S4 microparticles as a high‐capacity and sustainable anode material for LIBs. We solve the concentration gradient of lithium polysulfide at the interface of electrode/electrolyte via integrating graphene into the active metal sulfide anode material. The mechanically flexible and highly conductive nature of graphene helps relieve undesirable elongation and shrinkage during battery cycling, suppressing active material dissolution and enhancing electron/ion transport through the electrochemical double‐layer (EDL). Our one step approach demonstrates towards the practical application of advanced metal sulfide anodes for LIBs.

The oxygen evolution reaction (OER) plays a key role in determining the performance of overall water splitting, while a core technological consideration is the development of cost-effective, efficient, and durable catalysts. Here, we demonstrate a robust reduced Fe-oxide@NiCo

The invention of cost-effective, clean, and eco-friendly energy storage technology has been capturing a lot of worldwide interest. Herein, biogenically synthesized TiO

A copper phosphide (Cu3P) thin film is synthesized on a Ni foam using a one-step electrodeposition method at room temperature and annealed at 300 °C in Ar atmosphere. The Cu3P film is amorphous and has a flat morphology with surface voids. It works as an electrocatalyst for water oxidation in an alkaline 1 M KOH electrolyte. It exhibits excellent catalytic oxygen evolution reaction with an overpotential of 310 mV, Tafel slope of 88 mV/dec, and good stability over 20 h of operation at 10 mA/cm2. The excellent OER performance is due to its large electrochemically active surface area and low charge transfer resistance at the catalyst-electrolyte interface after the annealing.

Spherical mesoporous activated carbon (SM-AC) nanoparticles were synthesized from green tea wastes via KOH activation combined with the hydrochloric acid treatment, and were established as an anode material for lithium-ion batteries (LIBs). The SM-AC sample showed an aggregated nanoparticle structure with a high surface area (1241 m2/g) and high porosity. The SM-AC anode exhibited an initial discharge capacity of 781 mAh/g and a reversible capacity of 498 mAh/g after 100 cycles with an excellent rate capability. It may be an encouraging candidate as an anode material for high performance LIBs.

High-density CuCo2O4 nanosheets are grown on Ni foam using electrodeposition followed by air annealing for a Li-ion battery anode. The anode exhibits a high discharge capacity of 1244 mAh/g at 0.1 A/g (82% coulombic efficiency) and excellent high-rate performance with 95% capacity retention (1100 mAh/g after 200 cycles at 1 A/g). The outstanding battery performance of the CuCo2O4 anode is attributed to its binder-free direct contact to the current collector and high-density nanosheet morphology. The present experimental findings demonstrate that the electrodeposited binder-free CuCo2O4 material may serve as a safe, low-cost, long-cycle life anode for Li-ion batteries.

The high-activity of metallic nanofilament array (NFA) embedded tungsten oxide (WO3) bifunctional electrodes for electrochromism and electrochemical energy storage is presented. The NFA reduces charge transfer resistance and increases the electrochemically active surface area at the electrode–electrolyte interface. The NFA-embedded WO3 electrode exhibits a specific capacity of 214 F g−1 (pristine WO3: 133 F g−1) at 0.25 mA cm−2, excellent cycling stability with ∼92% capacitance retention after 2000 cycles (pristine WO3: ∼75% capacitance retention) and a coloration efficiency of 128 cm2 C−1 (pristine WO3: 91 cm2 C−1) with superb optical modulation. These properties are significantly more advanced compared to the pristine WO3 electrode and superior to previously reported WO3-based composites and nanostructured materials.

A supercapacitor is well recognized as one of emerging energy sources for powering electronic devices in our daily life. Although various kind of supercapacitors have been designed and demonstrated, their market aspect could become advanced if the utilisation of other physicochemical properties (e.g. optical) is incorporated in the electrode. Herein, we present an electrochromic supercapacitor (smart supercapacitor) based on a nanoflake NiMoO4 thin film which is fabricated using a facile and well-controlled successive ionic layer adsorption and reaction (SILAR) technique. The polycrystalline nanoflake NiMoO4 electrode exhibits a large electrochemically active surface area of ~ 96.3 cm2. Its nanoporous architecture provides an easy pathway for the intercalation and de-intercalation of ions. The nanoflake NiMoO4 electrode is dark-brown in the charged state and becomes transparent in the discharged state with a high optical modulation of 57%. The electrode shows a high specific capacity of 1853 Fg–1 at a current rate of 1 Ag–1 with a good coloration efficiency of 31.44 cm2/C. Dynamic visual information is obtained when the electrode is charged at different potentials, reflecting the level of energy storage in the device. The device retains 65% capacity after 2500 charge-discharge cycles compared with its initial capacity. The excellent performance of the nanoflake NiMoO4 based smart supercapacitor is associated with the synergetic effect of nanoporous morphology with a large electrochemically active surface area and desired chemical composition for redox reaction.

The temperature-dependent performance of a Li 2 ZnTi 3 O 8 (LZTO) anode and the ultrafast-charging activity of a Li-ion battery were investigated. The LZTO anode operates at different temperatures between − 5 and 55 °C and in this work its sustainability is discussed in terms of storage performance. It delivered a discharge capacity of 181.3 mA h g −1 at 25 °C, which increased to 227.3 mA h g −1 at 40 °C and 131.2 mA h g −1 at − 5 °C. The variation in the discharge capacity with temperature is associated with the reaction kinetics and the change in internal resistance. It showed a capacity retention of 64% and a coulombic efficiency of 98% over 500 cycles. Exhibiting a discharge capacity of 107 mA h g −1 , the LZTO anode was sustainable over 100 charge-discharge cycles at an ultra-high charging rate of 10 Ag −1 . The reaction kinetics estimated from a cyclic voltammetry analysis at high scan rates revealed a capacitive-type storage mechanism.

Nanogranular tungsten oxide (WO3) with excess oxygen is synthesized and its battery performance is evaluated as an anode material for the Li-ion battery (LIB). The formation of a monoclinic WO3 phase is confirmed using X-ray diffraction (XRD) and micro (µ)-Raman spectroscopy analyses. The Rutherford back scattering results confirm the existence of excess oxygen in the film. The charge discharge processes are associated with the conversion of the WO3 from the oxide state to the metallic state, and vice versa, and it shows a maximum specific capacity of 778.8 mAh g−1 at a current density of 0.1 Ag−1 in the first discharge. Even at a very high current density of 1 Ag−1, the sample retains the capacity of 228.6 mAh g−1. It shows excellent rate capability and a long-term cycling stability over 500 charge–discharge cycles, with capacity retention of 217%. The observed high discharge capacity and superior long-term cyclability of the nanograin WO3 anode are attributable to the synergetic effect of the excess-oxygen induced increased donor density and enhanced electrical conductivity.

Multifunctional hybrid nanostructures continue to attract great attention since they offer multiple applications from specific architectures. This paper proposes a simple solid-state protocol to fabricate nitrogen doped carbon nanotubes (CNT) and cobalt oxide embedded with CNT (Co3O4-CNT) for oxygen evolution reaction and benzoin oxidation. The proximity between cobalt and CNT sites amplifies oxygen evolution reaction (OER) and conductivity. Embedded Co3O4-CNT form an integrated architecture, providing efficient and rapid electron/ion transfer rate. Fabricated Co3O4-CNT electrocatalyst exhibited OER activity of 317 mV, which was better than that of pristine Co3O4 electrocatalyst (340 mV) at 10 mA cm−2 current density. Impressively, Co3O4-CNT delivers stable response at low and high currents as well as excellent durability over 25 h. Experimental and analytical results verified that maximal electrocatalytic OER activity can be realized by combining a conductive CNT network and catalytically active sites could be further enhanced by nitrogen doping. Additionally, the Co3O4 embedded with CNT upon exploration as a milder, inexpensive, and eco-friendlier catalyst for air oxidation of 2-hydroxy-1,2-bis(3-methoxyphenyl)ethan-1-one (benzoin), produces 3,3′-dimethoxybenzil in high yield (96%). The Co3O4-CNT was further evaluated the catalytic activities after repetitive recycling processes and demonstrated the high yields without the significant loss in the catalytic activity.

Synthesizing hybrid nanostructures through green protocols continues to attract great attention since it offers atom economy, simple processing, and environmental friendliness; and avoids using harsh chemical reagents. Herein we report the assembly of cobalt oxide on nitrogen-doped multiwalled carbon nanotubes (Co3O4-NMWCNT) composite synthesized by a green protocol with mechanochemical grinding for supercapacitor applications. The structural and morphological properties of the composites were confirmed by the aid of X-ray diffraction (XRD) studies, Raman spectroscopy, and scanning electron microscope (SEM), X-ray photoelectron spectroscopy (XPS) and high-resolution transmission electron microscopy (HR-TEM). The synthesized composite material exhibited tube-like morphology with the distribution of Co3O4 nanoparticles. Fabricated Co3O4-NMWCNT symmetric supercapacitor device was further investigated for its electrochemical properties, thereby leading a high specific capacitance 202 F/g at 1 A/g of current density, with 25 Wh/kg of energy density at 0.9 kW/kg of power density. Therefore, Co3O4-NMWCNT composite electrodes offer excellent capacitive performance for the energy storage system.

Solvent-free synthetic protocols for the formation of nanoarchitectures continues to attract a great attention amoung the wide class of synthetic chemists in order to overcome the harsh reaction conditions. In the current work we demonstrate, for the first time, solvent-free synthesis of dodecylammonium formamidinium lead iodide (DDA)2 [FAPbI3]n−1PbI4, a quasi-two-dimensional (2D) red-light-emitting perovskite nanosheet, where DDA is dodecylammonium, a long chain ammonium cation, and FA is a formamidinium cation. By varying the amount of DDA, we controlled the dual emission of quasi-2D perovskite comprising of both 2D and three-dimensional perovskite layers. The optical properties have manifested the effect of DDA on the structure of perovskite nanosheets. As a proof-of-concept demonstration the material has been explored in perovskite solar cell. The compound containing least amount of DDA exhibited open-circuit voltage (VOC) of 0.961 V, short-circuit current density (JSC) of 23.41 mA cm−2, and PCE of 15.23% under one-sun illumination conditions.

As anodic performance can control the bio-electro-catalytic activity and overall power generation ability of cheaper compost based microbial fuel cells (MFC), bio-compatible gold nanoparticles (AuNPs) laced carbon fiber electrode is used for enhancing the efficiency. Casein peptide as a reducing and capping agent is used to synthesize bio-functional cubic AuNPs with absorption wavelength of 530 nm. The results of Cyclic Voltammetry (C–V) and electrochemical impedance spectroscopy shows that AuNPs laced electrode exhibited increased current density and better bio-electro-catalytic activity than the bare electrode which shows selective response with respect to type of compost and fuel concentration in a coin cell sized MFC. Current-Voltage (I–V) measurements show that due to the increase in the bio-electro-catalytic activity, the electrical power increases from 1.6 mW per m2 to 18.34 mW per m2 at room temperature in case of carbon rich compost at an optimized fuel concentration of 0.2 g per ml. The temperature dependence bipolar C–V measurements shows the enhancement in bio-electro-catalytic activity with increase in temperature. Also, significant improvement in durability and stability of MFC was observed with the lacing of AuNPs.

Ruthenium oxide (RuO 2 ) is fabricated on graphene (Gr)-coated Copper (Cu) foil by using a cathodic electroplating technique for flexible supercapacitor electrode applications. The electrochemical properties of the RuO 2 /Gr/Cu electrode are investigated with a conventional three electrode configuration in 0.5 M H 2 SO 4 electrolyte. The graphene insertion layer plays a key role in improving the structural and electrochemical properties of the RuO 2 electrode film under the bent condition. The electrode exhibits a specific capacitance of 1561 F g −1 (0.015 F cm −1 ) at a scan rate of 5 mV s −1 and a significantly improved retention of 98% under the bent condition. The flexible RuO 2 /Gr/Cu electrode exhibits a high energy density of ∼13 Wh kg −1 at a power density of ∼21 kW kg −1 . The excellent capacitance retention and electrochemical stability of the flexible RuO 2 /Gr/Cu electrode are due to the improved mechanical adhesion between the RuO 2 and the current collector. This flexible RuO 2 /Gr/Cu film could be used as a supercapacitor electrode with a high capacity and long-cycle life for the next-generation flexible electronic applications.

The impressive electrochemical energy storage performance of Earth-abundant ternary copper cobalt sulfide (CCS) thin film electrodes that are prepared on stainless steel substrates via a simple and cost-effective hydrothermal process is demonstrated. The optimized CCS electrode shows a high specific capacitance of ∼516 F/g at a current density of 10 A/g, a good rate capability of ∼72% at a high current density of 50 A/g, and a good cycling retention of ∼66% with a coulombic efficiency of ∼99% after 10,000 charge-discharge cycles. The CCS electrode exhibits a high energy density of ∼35.2 Wh/kg at a power density of ∼6.6 kW/kg. The excellent electrochemical supercapacitor properties of the CCS electrode are a result of a synergetic effect between the uniform full coverage, robust adhesion, and desired chemical composition. A low charge transfer resistance, resulting from the large electrochemically active surface area (ECSA) and good diffusion, significantly contributes to the enhanced electrochemical supercapacitor performance. This excellent CCS electrode material has the potential to become a low-cost and long-cycle life electrode for the next-generation high-power-capacity supercapacitors.

A novel water-soluble inorganic Ca(NO 3 ) 2 salt electrode is investigated for its pseudocapacitance in an aqueous KOH electrolyte. Commercially available Ca(NO 3 ) 2 salt is directly used as the key electrode material. The supercapacitor electrode contains Ca(NO 3 ) 2 salt, carbon black, and polyvinylidene fluoride (PVDF) in a ratio of 80:10:10. The Ca(NO 3 ) 2 -based electrode demonstrates an exceptionally long life cycling stability, and a reasonably sound specific capacitance of 234 F/g is obtained at a current density of 3 A/g. Via chemical and electrochemical reactions, the in-situ activation of the Ca(NO 3 ) 2 forms an intermediate CaO which contributes to the pseudocapacitance of the electrode. The electrode undergoes a reversible redox reaction between Cu 2+ ↔ Cu + during the charge-discharge process. Superior rate capability and excellent specific capacitance retention of ∼120% over 2000 cycles are achieved compared with other inorganic salt electrodes.

Graphene nanosheets are synthesized via the carbonization of brown-rice husks followed by a one-stage KOH-activation process for the design of a sustainable electrochemical energy-storage electrode. The graphene nanosheets exhibit an ultra-thin crumpled-silk-veil-wave, sheet-like structure with a high surface area of ∼1225 m2 g−1 and a high porosity. The graphene-nanosheet electrode shows a specific capacitance of 115 F g−1 at 0.5 mA cm−2 and a high energy density of 36.8 W h kg−1 at a power density of 323 W kg−1, with an excellent cyclic stability of 88% over 2000 cycles. The observed good electrochemical energy-storage performance of the biomaterial-derived graphene-nanosheet electrode is due to the synergistic effect of the intrinsically large electrochemically active surface area, an enhanced ion diffusion, and an improved electrical conductivity.

A high activity of a two-dimensional (2D) copper oxide (CuO) electrocatalyst for the oxygen evolution reaction (OER) is presented. The CuO electrode self-assembles on a stainless steel substrate via chemical bath deposition at 80 °C in a mixed solution of CuSO4 and NH4OH, followed by air annealing treatment, and shows a 2D nanosheet bundle-type morphology. The OER performance is studied in a 1 M KOH solution. The OER starts to occur at about 1.48 V versus the RHE (η = 250 mV) with a Tafel slope of 59 mV dec−1 in a 1 M KOH solution. The overpotential (η) of 350 mV at 10 mA cm−2 is among the lowest compared with other copper-based materials. The catalyst can deliver a stable current density of >10 mA cm−2 for more than 10 hours. This superior OER activity is due to its adequately exposed OER-favorable 2D morphology and the optimized electronic properties resulting from the thermal treatment.

Efficient and low‐cost multifunctional electrodes play a key role in improving the performance of energy conversion and storage devices. In this study, ultrathin nanoporous CuCo2O4 nanosheets are synthesized on a nickel foam substrate using electrodeposition followed by air annealing. The CuCo2O4 nanosheet electrode exhibits a high specific capacitance of 1473 F g─1 at 1 A g─1 with a capacity retention of ∼93% after 5000 cycles in 3 M KOH solution. It also works well as an efficient oxygen evolution reaction electrocatalyst, demonstrating an overpotential of 260 mV at 20 mA cm─2 with a Tafel slope of ∼64 mV dec─1. in 1 M KOH solution, which is the lowest reported among other copper-cobalt based transition metal oxide catalysts. The catalyst is very stable at >20 mA cm─2 for more than 25 h. The superior electrochemical performance of the CuCo2O4 nanosheet electrode is due to the synergetic effect of the direct growth of 2D nanosheet structure and a large electrochemically active surface area associated with nanopores on the CuCo2O4 nanosheet surface.

An anti-corrosive FeO@CuCo2S4 electrocatalyst, with highly-active catalytic sites, is fabricated using a mild hydrothermal and magnetron sputtering growth technique. FeO@CuCo2S4 shows excellent hydrogen evolution reaction (HER) in an alkaline KOH electrolyte with a low overpotential of 107 mV at 10 mA/cm2 and a small Tafel slope of 136 mV/dec. Moreover, long-term stability tests at various current densities, up to 100 mA/cm2, demonstrate its excellent sustainability. The excellent HER catalytic performance and stability are attributed to the synergy between FeO and CCS elucidated by density functional theory, which is aroused from electrocatalytically activated surface, anti-corrosive surface, and the improved electronic conductivity.

Metal-hydroxide based materials have attracted much attention as electrode materials for electrochemical energy storage and conversion owing to their unique large interlayer spacing, enhanced active surface area and robustness that can result in high electrochemical performance. Here, we report on the synthesis of a macroporous Cu(OH)2 nanorod network via single-step surface chemical oxidation and demonstrate its impressive Li ion battery (LIB) performance as a binder-free anode material. The Cu(OH)2 nanorod network anode delivers an ultrahigh reversible discharge capacity of 2145 mAhg−1 at a current density of 0.1 Ag−1 in the first cycle that then stabilizes at 1472 mAhg−1 in the subsequent cycles. The excellent rate performance at the ultrahigh current rates of 1.0 and 2.0 Ag−1 with a Coulombic efficiency of 99% was obtained. The electrode exhibits the capacity of 506 mAhg−1 even after 100 cycles which is higher than the conventional carbonaceous materials. Our experimental findings and scalable synthesis approach can be useful for developing other free-standing binder-free transition metal hydroxide materials that can be directly used as battery electrodes and catalysts.

The high performance electrocatalysts is vital for enhancing the hydrogen production efficiency for water splitting. In light of this, biomass activated carbon-decorated tungsten oxide (WO3/B-AC) nanocomposites are synthesized through a simple sonochemical method. The WO3/B-AC nanocomposites show an aggregated structure of activated carbon nanosheet-encapsulated tungsten oxide nanoflakes. The WO3/B-AC nanocomposites exhibit the overpotential of 320 mV at 10 mA/cm2 with the Tafel slope of ~48 mV/dec and good stability for the oxygen evolution reaction. For the hydrogen evolution reaction, the nanocomposites also show the overpotential of 360 mV at 10 mA/cm2 with the Tafel slope of ~14 mV/dec and excellent durability in 1 M KOH. The superior electrocatalytic activity of the WO3/B-AC nanocomposite electrode is attributed to the synergetic effect from both the high electrical conductivity of activated carbon nanosheets and the high electrochemically-active surface area of WO3 nanoflakes. These results advocate that the sonochemically synthesized WO3/B-AC nanocomposites hold promise as excellent electrocatalysts for green energy conversion and storage applications.

Supercapacitors based on nanomaterial electrodes exhibit great potential as power sources for advanced electronic devices. From a practical viewpoint, it is desirable to fabricate highly active and sustainable nanomaterial electrodes consisting of non-precious elements using a simple technique in a controllable way. In this work, we report the synthesis of a self-assembled ultra-thin porous nanoflake Ni-Mo oxide (NMO) film using the successive ionic layer adsorption and reaction (SILAR) technique. The nanoflake NMO thin film electrode with a large electrochemically active surface area of ∼108 cm−2 exhibits a high specific capacitance of 1180 Fg−1 at a current density of 1 Ag−1 and excellent rate capability, with a negligible capacity loss of 0.075% per cycle. Even at a high current rate of 10 A g−1 it retains a capacity of 600 Fg−1. The highest energy and power densities obtained are 119 Whkg−1 and 15.7 kWkg−1, respectively. Electrochemical impedance spectroscopy analyses reveal that the electrode has considerably low charge transfer resistance. The observed excellent electrochemical energy storage performance of the nanoflake NMO electrode with a nanoporous surface is due to the synergetic effects of the large electrochemically active surface area, enhanced ion diffusion, and improved electrical conductivity.

CuCo2 O4 films with different morphologies of either mesoporous nanosheets, cubic, compact-granular, or agglomerated embossing structures are fabricated via a hydrothermal growth technique using various solvents, and their bifunctional activities, electrochemical energy storage and oxygen evolution reaction (OER) for water splitting catalysis in strong alkaline KOH media, are investigated. It is observed that the solvents play an important role in setting the surface morphology and size of the crystallites by controlling nucleation and growth rate. An optimized mesoporous CuCo2 O4 nanosheet electrode shows a high specific capacitance of 1658 F g-1 at 1 A g-1 with excellent restoring capability of ≈99% at 2 A g-1 and superior energy density of 132.64 Wh kg-1 at a power density of 0.72 kW kg-1 . The CuCo2 O4 electrode also exhibits excellent endurance performance with capacity retention of 90% and coulombic efficiency of ≈99% after 5000 charge/discharge cycles. The best OER activity is obtained from the CuCo2 O4 nanosheet sample with the lowest overpotential of ≈290 mV at 20 mA cm-2 and a Tafel slope of 117 mV dec-1 . The superior bifunctional electrochemical activity of the mesoporous CuCo2 O4 nanosheet is a result of electrochemically favorable 2D morphology, which leads to the formation of a very large electrochemically active surface area.

CuCo