Co3O4 Nanoarrays Research Articles

Logical formulation and in-situ assembly of MnCo2O4@MnO2 nanoflower arrays on nickel foam as monolithic catalyst for formaldehyde degradation at indoor temperature

The development and design of efficient and cost-effective catalysts for oxidizing low concentrations of formaldehyde at low temperatures, has been a significant challenge in HCHO oxidation. In this study, MnCo2O4@MnO2-NF (Ni foam) was synthesized as a monolithic catalyst for the degradation of HCHO in indoor environments. Using carrier immobilization, morphology modulation, and doping modification. The results revealed that the Co3O4 nanoarrays could be grown in a directional and orderly manner on the surface of the substrate through morphological modulation, showing a pompom-like, flower-like shape of the nanoneedles, thus providing sufficient growth sites for MnO2. Doping the Co3O4 nanoarrays with Mn via in-situ growth resulted in MnCo2O4 nanoarrays, following which the MnO2 expanded the pore sizes of the sample and provide more surface adsorption sites upon using MnCo2O4 as the carrier. In addition, numerous oxygen vacancies formed on the catalyst surface because of the synergistic interaction between Co and Mn, which formed more Mn3+ species and Oads, resulting in superior low-temperature redox ability and catalytic cycle stability. The catalyst achieved a HCHO removal efficiency of over 85 % within 60 min for five test cycles when the KMnO4 concentration was 0.05 M and Mn/Co ratio was 1:2.

Synergistic effect between Ru cluster and Co3O4 nanowires assisted by B-O bonding for hydrogen evolution

Anchoring noble metal nanoclusters (NCs) on appropriate supports through structural engineering is an effective strategy for reducing the noble metal loading and improving catalytic activity for alkali hydrogen evolution reaction (HER). Generally, the local coordination environment of the active sites is key factor to regulate the interaction between the metal atoms and support. Here, a simple boronation method is proposed for preparing ruthenium nanoclusters anchored on B-doped Co3O4 nanowires supported on Ni foam (denoted as Ru/B-Co3O4) for alkaline HER. B embedded into Co3O4 nanoarrays through B-O bonding can change the electronic structure between Ru active sites and Co3O4. After optimizing electronic structure of Ru and Co sites, Ru/B-Co3O4 showed remarkable activity for HER, with current density of 100 and 500 mA cm−2 at overpotential of 143 and 233 mV, respectively. The experimental and theoretical studies display that the embedding of B into Co3O4 effectively induces the electron transfer from Co to Ru atoms by bridging O atom, leading to the formation of electron-deficient Co sites. The charge redistribution of Ru accelerates the cleavage of H-OH, which optimizes H* adsorption energy and finally promotes HER. This study provides further insight into the regulation of metal-support interaction for HER electrocatalysts.

Catalytic membrane electrode with Co3O4 nanoarrays for simultaneous recovery of water and generation of hydrogen from wastewater

Tremendous research efforts have been devoted to new methods of water decontamination and water splitting at low cost and less energy consumption. Herein, we developed a robust electrochemical strategy with an efficient membrane electrode to remove refractory organic pollutants and simultaneously produce pure hydrogen in wastewater. Firstly, the membrane anode was constructed with a three-dimensional (3D) nanoneedle array of Co3O4 and Ti membrane, exhibiting superior degradation of phenol and dye with Na2SO4 as the electrolyte in a conventional electrocatalytic membrane reactor (ECMR). For the phenol degradation, ≥99% removal efficiency of phenol, 99.5% chemical oxygen demand (COD) removal rate, 92.5% total organic carbon (TOC) removal rate, 88.7% current efficiency and 0.061 kW h (g COD)−1 energy consumption can be obtained. For the dye degradation, ≥99% decolor efficiency and 95.2% COD removal rate, 87.6% TOC removal rate, 82.1% current efficiency and 0.12 kW h (g COD)−1 energy consumption can be achieved. The obtained membrane electrode can provide more active CoOOH sites, dramatically increase the electric fields and overcome mass transfer limitation in a flow-through configuration, thereby significantly enhance the catalytic performance. Finally, we designed a H-type ECMR with the proton exchange membrane (PEM) as the separator for pure H2 production, i.e., PEM-ECMR, demonstrating superior degradation performance of phenol and dye, stable production of high-purity hydrogen (11–15 mL h−1), and excellent long-term stability (100 days) and low voltage input (below 3.0 V). This work demonstrates a promising pathway towards reducing cost and energy consumption for water decontamination and simultaneous hydrogen production.

Hierarchical Oα-rich Co3O4 nanoarray anchored on Ni foam with superior lithiophilicity enabling ultrastable lithium metal batteries

Lithium metal batteries (LMBs) are considered as the ultimate choice in the next-generation high performance energy-storage systems due to their outstanding theoretical energy density (≥500 Wh kg−1). However, the unavoidable dendrite issues and infinite volume change during repeated plating/stripping induce poor electrochemical performance and serious safety issues. Here, we designed and prepared an integrated Oα (O- or O22–)-rich Co3O4 nanoarrays anchored on Ni foam (Oα-Co3O4@NF) scaffold as a stable host for ultra-fast lithium metal infusion. Remarkably, the highly reactive Oα behaves low energy bonding and strong electron affinity, which are further verified by the results of density functional theory, giving rise to high lithiophilicity and inhibiting the dendrites formation effectively. Moreover, the by-product NiO formed on the NF during the calcination process combines with Oα-Co3O4 to display superior dual-wettability toward molten Li. As a result, the Oα-Co3O4@NF electrode achieves a Coulombic efficiency above 99.00% more than 450 cycles at a current density of 1 mA cm−2, and the Oα-Co3O4@NF-Li anode presents a super-long and stable lifetime of 800 h during the repeated plating/striping process. When coupled with a high-loading LiFePO4 cathode, the full cells deliver excellent rate capability and 88.96% capacity retention after 200 cycles under 0.5C.

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.

Nanostructure-Mediated Phase Evolution in Lithiation/Delithiation of Co3O4.

Nanostructured transition-metal oxides have been under intensive investigation for their tantalizing potential as anodes of next-generation lithium-ion batteries (LIBs). However, the exact mechanism for nanostructures to influence the LIB performance remains largely elusive. In this work, we discover the nanostructure-mediated lithiation mechanism in Co3O4 anodes using ex situ transmission electron microscopy (TEM) and X-ray diffractometry: while Co3O4 nanosheets exhibit a typical two-step conversion reaction (from Co3O4 to CoO and then to Co0), Co3O4 nanoarrays can go through a direct conversion from Co3O4 to Co0 at a high discharge rate. Such nanostructure-dependent lithiation can be rationalized by the slow lithiation kinetics intrinsic to Co3O4 nanoarrays, which at a high discharge rate may cause local accumulation of lithium to initiate a one-step Co3O4-to-Co0 conversion. Combined with the larger volume change observed in Co3O4 nanoarrays, the slow lithiation kinetics can lead to inhomogeneous expansion with large stress developed at the reaction front, which can eventually cause structure failure and irreversible capacity loss, as explicitly observed by in situ TEM as well as galvanostatic discharge-charge measurement. Our observation resolves the nanostructure-dependent lithiation mechanism of Co3O4 and provides important insights into the interplay among lithiation kinetics, phase evolution, and lithium-storage performance, which can be translated into electrode design strategies for next-generation LIBs.

Dual-defective Co3O4 nanoarrays enrich target intermediates and promise high-efficient overall water splitting

Exploiting high-efficient oxide-based electrocatalysts to accelerate water dissociation kinetics in hydrogen evolution reaction (HER) is crucial for alkaline water electrolysis system. Herein, we demonstrate a dual-defective Co3O4 nanoarrays (F-Co3O4-x) electrocatalyst with well-modulated electronic structure of Co-centers for greatly enhanced overall water-splitting (OWS). DFT calculations and kinetic analysis disclose that F-doping and O-vacancy can synergistically break the energy barrier limit of water dissociation step for facilitating the production of hydrogen free radical (H*) in alkaline HER. The F-Co3O4-x experimentally exhibits supersmall overpotentials of 77 and 192 mV at 10 and 100 mA cm−2, respectively, outperforming the most reported CoOx-based electrocatalysts. Furthermore, F-induced surface self-reconstruction is observed during oxygen evolution reaction (OER), in which abundant key intermediates (*OOH) generate with the F- leaching. The obtained F-Co3O4-x as a dual-functional electrocatalyst therefore gives an ultralow cell voltage of 1.56 V at 10 mA cm−2 with a long-term durability of 120 h in OWS configuration. This work exhibits a rational design of multiple-defect engineered electrocatalysts for high-performance overall water-splitting.

Ion modification of transition cobalt oxide by soaking strategy for enhanced water splitting

Heterostructure engineering carries prime importance to enhance the catalytic activity of electrocatalysts for water splitting. However, developing nonprecious metal oxides as splendid bifunctional electrocatalysts in alkaline conditions remains a great challenge. Herein, we developed a smart soaking strategy of sulfur/iron ion modification, by which we could activate Co3O4 to spontaneously form heterogeneous structure with excellent hydrogen/oxygen evolution reaction (HER/OER) performance. The nickel foam supported Co3O4 nanoarrays embellished with NiCoSx (NiCoSx@Co3O4 NAs/NF) was easily obtained via sulfur ion modification, which has rich oxygen vacancies and active sites, leading to an outstanding HER performance (η10 = 59 mV, η400 = 264.0 mV). Furthermore, Fe(Ⅱ) ion modified NiCoSx@Co3O4 NAs/NF (FeNiCoS@Co3O4 NAs/NF) achieved superior OER performance (η10 = 226 mV, η400 = 302 mV) than other recently reported cobalt-based catalysts due to the synergistic activity of Ni-Fe-S-Co. More importantly, this work offered a facile and energy-free strategy for developing transition metal oxides as splendid bifunctional catalysts and contributed to the cost and energy savings and mass production for industrial applications as well as the design of advanced functional materials for energy chemistry.

Electrochemiluminescence resonance energy transfer system fabricated by quantum state complexes for cardiac troponin I detection

Electrochemiluminescence resonance energy transfer (ECL-RET) as an energy transfer model is used to explain signal quenching or enhancement phenomena. Establishing this model requires specific conditions including efficient electrochemiluminescence (ECL) emitters and energy donors with highly overlapping spectra and sufficient distance to complete the energy transfer. In this work, a novel ECL-based biosensor was proposed by utilizing graphene quantum dots (GQDs)-coupled gold nanoclusters (Au NCs) nanocomposites supported on a well-ordered Co3O4 nanoarrays (NAs) sensing substrate as signal labels. The as-synthesized Au NCs with controllable size by using glutathione as ligand showed stable ECL signal in triethylamine (TEA) aqueous solution. After coupling with GQDs, the obtained quantum state complexes (Au NCs-GQDs) are compact in space relation, and benefiting from resonance energy transfer and synergetic effect, thus producing higher ECL response. The prepared Co3O4 NAs exhibit consistent density orientation, which can not only work as an ideal substrate for capturing more immune molecules, but also act as a conductor to accelerate electron transport. This rational designed biosensor has been constructed for detecting cardiac troponin I (cTnI), a pivotal biomarker of acute myocardial infarction (AMI). Under optimal conditions, the biosensor showed a good ECL response of cTnI with a satisfactory linear range from 500 fg/mL to 20 ng/mL and an ultralow limit of detection of 354.2 fg/mL. With the excellent repeatability and stability, this method provides a clue for the expansion of the enhance-type ECL-RET model.

Carbon-coated oxygen vacancies-rich Co3O4 nanoarrays grow on nickel foam as efficient bifunctional electrocatalysts for rechargeable zinc-air batteries

The bifunctional electrocatalyst has an important influence on the power output and cycle life of rechargeable zinc-air batteries. Cobalt oxides, especially Co3O4, have attracted much attention due to their high catalytic activity for oxygen evolution reaction (OER). It is difficult to improve the catalytic activity of oxygen reduction reaction (ORR) for rechargeable zinc-air batteries. In this paper, Co3O4 containing rich oxygen vacancies is prepared by in-situ growth on the nickel foam, and the carbon coating treatment on the surface increases the conductivity and stability of Co3O4, which prolongs its cycle life. The results show that moderate oxygen vacancies can achieve the best catalytic performance. The peak power density of zinc-air battery assembled by this air electrode can reach 54.5 mW cm−2, which is 51.4% higher than that of the untreated Co3O4 catalyst. The cycle life of the battery can reach 716 cycles (358 h), prolonging about 250 h compared with Co3O4 without carbon coating treatment. It is proved that the improved Co3O4 can increase the power output and cycle life of the rechargeable zinc-air battery, which helps to expand the application range of cheap Co3O4 catalyst, and provides an effective and economic solution to obtain excellent electrocatalysts for metal-air batteries.

Anchoring Ni-MOF nanosheet on carbon cloth by zeolite imidazole framework derived ribbonlike Co3O4 as integrated composite cathodes for advanced hybrid supercapacitors

Metal-organic frameworks (MOFs) and their derivatives as electrode materials for energy storage and conversion are intriguing. However, the in-situ uniformly and firmly growing metal-organic framework materials directly on conductive substrates is limited and still challenging. Herein, an effective strategy is presented by constructing a ribbonlike Co3O4 nanoarrays that derived from zeolite imidazole framework (ZIF) on carbon cloth as “fixed piles” for the in-situ solvothermal synthesis of Ni-MOF nanosheets. As a result, the Ni-MOF nanosheets closely distribute on the surface of the carbon cloth with fluffy structure, which favors exposure of more active sites and rapid diffusion of electrolyte ions. The as-fabricated integrated composite electrode (Co3O4@Ni-MOF) delivers a good specific capacitance of 1416 F/g at the current density of 1 A/g, superior to the individual Co3O4 (410 F/g) and Ni-MOF electrode (690 F/g). Moreover, the specific capacitance can be kept at 90% of its original value after 3000 cycles. Based on these advantages, a hybrid supercapacitor fabricated by the Co3O4@Ni-MOF electrode and activated carbon (AC) shows prominent energy density of 68.6 Wh kg−1 at the power density of 510 W kg−1, and excellent cycling stability (about 12% capacitance loss after 5000 charge-discharge cycles).

Enhancing the water splitting performance via decorating Co3O4 nanoarrays with ruthenium doping and phosphorization.

Hydrogen is the most promising renewable energy source to replace traditional fossil fuels for its ultrahigh energy density, abundance and environmental friendliness. Generating hydrogen by water splitting with highly efficient electrocatalysts is a feasible route to meet current and future energy demand. Herein, the effects of Ru doping and phosphorization treatment on Co3O4 nanoarrays for water splitting are systemically investigated. The results show that a small amount of phosphorus can accelerate hydrogen evolution reaction (HER) and the trace of Ru dopant can significantly enhance the catalytic activities for HER and oxygen evolution reaction (OER). Ru-doped cobalt phosphorous oxide/nickel foam (CoRuPO/NF) nanoarrays exhibit highly efficient catalytic performance with an overpotential of 26 mV at 10 mA cm−2 for HER and 342 mV at 50 mA cm−2 for OER in 1 M KOH solution, indicating superior water splitting performance. Furthermore, the CoRuPO/NF also exhibits eminent and durable activities for alkaline seawater electrolysis. This work significantly advances the development of seawater splitting for hydrogen generation.

Mn-doped Co3O4 nanoarrays as a promising electrocatalyst for oxygen evolution reaction

Microstructures and electrocatalytic characteristics of a series of MnxCo3−xO4 nanostructures for oxygen evolution reaction were investigated by adjusting hydrothermal reaction time, temperature and the molar ratio of Mn2+/Co2+, followed by an alkali treatment at room temperature. The results indicate that the synthesis process is optimal when hydrothermal reaction time, temperature and the molar ratio of Mn2+/Co2+ are 10 h, 100 °C and 1:3, respectively. Under this condition, MnxCo3−xO4 possesses an optimal electrocatalytic performance for OER. Moreover, after treated in the mixed alkali solution of 1 M NaBH4 and 3 M NaOH, the catalytic performance of MnxCo3−xO4 for OER has been enhanced furtherly. The unique architecture and its corresponding morphology after alkalization treatment, such as highly exposed active sites and high surface roughness, are mainly responsible for its excellent electrocatalytic performance for the OER process.

Promoting Diesel Soot Combustion Efficiency over Hierarchical Brushlike α-MnO2 and Co3O4 Nanoarrays by Improving Reaction Sites

Improving the accessible reaction sites of catalysts is vital to diesel soot elimination. Herein, hierarchical brushlike α-MnO2 and Co3O4 nanoarrays were in situ grown on AISI304 stainless steel wi...

In-situ surface-derivation of Ni-Mo bimetal sulfides nanosheets on Co3O4 nanoarrays as an advanced overall water splitting electrocatalyst in alkaline solution

Developing high-performance overall water-splitting electrocatalysts working under alkaline condition is highly desirable but many challenges remain. Herein, the in-situ surface-derivation of Ni-Mo bimetal sulfides nanosheets on Co3O4 nanoarrays, which supported on carbon fibers (Ni-Mo-S@Co3O4/CF) was designed and constructed. The as-prepared hybrid catalyst exhibits excellent electrocatalytic performance for both OER and HER under alkaline conditions, with only a small overpotential of 275 mV and 85 mV at a current density of 10 mA cm−2, respectively. Furthermore, the hybrid catalysts assembled full electrolyzer achieved a current density of 10 mA cm−2 at 1.57 V in an alkaline condition, without decay even after a durability test of 50 h. These results demonstrate that in-situ surface-derivation is a promising strategy for the design of efficient overall water splitting catalysts.

P-type Co3O4 nanoarrays decorated on the surface of n-type flower-like WO3 nanosheets for high-performance gas sensing

Metal oxide heterostructures are significant materials for developing and improving various toxic gas detection sensors. However, the gas sensing performance, such as response, selectivity, stability and response/recovery time of the sensors, still need to be optimized for practical applications. Low dimensional heterostructures will improve the gas sensing performance remarkably. In this work, hierarchical cactus-like WO3/Co3O4 nanocomposites were directly deposited on the surface of ceramic tube via a simple two-step process. The p-type Co3O4 nanorods array were grown on the surface of n-type WO3 nanosheets by using chemical bath deposition (CBD) and thus many nanoscale p-n junctions were formed which greatly improved the gas sensing performance. A response value (Ra/Rg) of 6.19 to 1 ppm triethylamine (TEA) was achieved at 240 ℃ by the WO3/Co3O4 nanocomposite with the CBD deposition time of 30 min, which is 3 times higher than that of the pure WO3 nanosheets (Sr = 2.02). And the response/recovery time was about 13 s/152 s, which shows good gas sensing performance to TEA.

Construction of NiCo2O4 nanosheet-decorated leaf-like Co3O4 nanoarrays from metal-organic framework for high-performance hybrid supercapacitors.

A rational design of heterostructures for electrode materials is highly desired for boosting the electrochemical performance, but it is still challenging, especially through a cost-effective method. Herein, novel NiCo2O4 nanosheet-decorated leaf-like Co3O4 nanoarrays have been constructed on a Ni foam using a leaf-like Co-based metal-organic framework (Co-MOF-L) template, which can be simply prepared in an aqueous solution at room temperature. Combining the merits of MOF derivatives and the free-standing core-shell heterostructure, the leaf-like Co3O4@NiCo2O4 nanoarray electrode displayed a high specific capacity of 544.2 C g-1 at 1 A g-1, which is almost 9.3 times that of Co3O4 (58.3 C g-1) and 6 times that of NiCo2O4 (92.1 C g-1). It also displayed a good rate capacity (65.5% at 10 A g-1) and superior long-term stability (93.0% capacity retention over 5000 cycles at 10 A g-1). Moreover, a hybrid supercapacitor (HSC) assembled from the battery-type Co3O4@NiCo2O4 electrode and a capacitive activated carbon (AC) electrode delivered a high energy density of 36 W h kg-1 at a high power density of 852 W kg-1 with good cycling stability, demonstrating a capacity retention of 89.5% after 10 000 cycles at 10 A g-1. Furthermore, two connected HSCs could light up a red light-emitting diode (LED). Therefore, the as-fabricated leaf-like Co3O4@NiCo2O4 nanoarrays hold great promise as binder-free electrodes in electrochemical energy storage devices.

Facile fabrication of hierarchical porous Co3O4 nanoarrays as a free-standing cathode for lithium–oxygen batteries

Abstract Two shapes of Co3O4 nanoarrays (i.e., nanosheets, nanowires) with different densities of exposed catalytic active sites were synthesized through a facile hydrothermal method on Ni foam substrates and tested as the binder/carbon free and free-standing cathodes for Li–O2 batteries. Particularly, the single crystalline feature of Co3O4 nanosheets with a predominant high reactivity {112} exposed crystal plane and hierarchical porous nanostructure displayed better catalytic performance for both oxygen reduction reaction (during discharge process) and oxygen evolution reaction (during charge process). Li–O2 battery with Co3O4 nanosheets cathode exhibited a higher discharge specific capacity (965 mAh g−1), lower discharge/charge over-potential and better cycling performance over 63 cycles at 100 mA g−1 with the specific capacity limited at 300 mAh g−1. The superior catalytic performance of Co3O4 nanosheets cathode is ascribed to the enlarging specific area and increasing the exposed Co3+catalytic active sites within predominant {112} crystal plane which plays the key role in determining the adsorption energy for the reactants, enabling high round-trip efficiency and cyclic life.

Macroporous Ni foam-supported Co3O4 nanobrush and nanomace hybrid arrays for high-efficiency CO oxidation

Herein, we reported the synthesis of well-defined Co3O4 nanoarrays (NAs) supported on a monolithic three-dimensional macroporous nickel (Ni) foam substrate for use in high-efficiency CO oxidation. The monolithic Co3O4 NAs catalysts were obtained through a generic hydrothermal synthesis route with subsequent calcination. By controlling the reaction time, solvent polarity and deposition agent, these Co3O4 NAs catalysts exhibited various novel morphologies (single or hybrid arrays), whose physicochemical properties were further characterized by using several analytical techniques. Based on the catalytic and characterization analyses, it was found that the Co3O4 NAs-6 catalyst with nanobrush and nanomace arrays displayed enhanced catalytic activity for CO oxidation, achieving an efficient 100% CO oxidation conversion at a gas hourly space velocity (GHSV) 10,000hr−1 and 150°C with long-term stability. Compared with the other Co3O4 NAs catalysts, it had the highest abundance of surface-adsorbed oxygen species, excellent low-temperature reducibility and was rich in surface-active sites (Co3+/Co2+=1.26).

In situ construction of Co3O4 nanoarray catalysts on (La0.8Sr0.2)0.95MnO3–δ cathode for high-efficiency intermediate-temperature solid oxide fuel cells

In order to optimize the polarization resistance of the (La0.8Sr0.2)0.95MnO3–δ (LSM) cathode, Co3O4 nanoarray catalysts were self-assembled on the surface of the LSM substrate by a hydrothermal process. The phase composition and morphology of the precursor grown on the substrate before and after the heat treatment were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM), respectively. It was found that Co3O4 nanorods with a spinel structure and a size of 100nm × 5µm (diameter × length) had grown on the surface of the LSM cathode. Symmetric cells and single cells with modified LSM cathodes (Co3O4-LSM-SDC/SDC/Co3O4-LSM-SDC and Co3O4-LSM-SDC/SDC/NiO-SDC, respectively, where SDC = Sm0.2Ce0.8O1.9) were successfully constructed and their electrochemical performances were also investigated. The polarization impedance of the symmetric cell with the LSM cathode was 0.95Ωcm2 at 700°C but decreased to 0.55Ωcm2 upon Co3O4 modification. In addition, the loading of the Co3O4 nanoarray onto the surface of the cathode improved the output of the single cell from 211.3mWcm–2 to 340.8mWcm–2. These results indicate that the modification of the cathodes by the Co3O4 nanoarrays improved their performance dramatically. This modification serves as a new means to develop high-efficiency intermediate-temperature solid oxide fuel cells.