Co3O4 Nanorods Research Articles

Magnetic field-augmented photoelectrochemical water splitting in Co3O4 and NiO nanorod arrays

Effective charge separation is crucial for improving the sensitivity of photoelectrochemical studies. Here, we provide an immense magnetic field-based electron spin polarization approach for an efficient charge carrier separation. We have fabricated NiO and Co3O4 thin film and nanorod arrays by electron beam evaporation glancing angle method followed by annealing in a two-zone furnace. The photoelectrochemical performance was investigated for NiO and Co3O4 samples in the presence and absence of a magnetic field. The NiO and Co3O4 nanorods array samples exhibit better absorption compared with the thin film samples. The Co3O4 and NiO nanorod arrays showed the highest photocurrent density of 0.12 and 0.55 mA/cm2 in a magnetic field. The superior photoelectrochemical response of NiO and Co3O4 nanorods in a magnetic field could be ascribed to the limitation of non-radiative recombination of carriers manipulated by Lorentz force and spin polarization. Furthermore, the electrochemical impedance spectra of NiO and Co3O4 nanorod arrays in a magnetic field show the least charge transfer resistance. This study sheds light on the interaction process between external fields and radiative/non-radiative recombination of manipulating carriers. Thus, the application of a magnetic field presents an efficient and versatile approach to enhance the performance of photoelectrodes in solar water splitting.

Low Zn-doped Co3O4 nanorods for enhanced hydrogen evolution reaction

Transition metal oxides have been identified as the best potential candidates to replace Pt-based HER catalysts. But they are still limited by the high HER overpotential, due to the undesirable adsorption/desorption of surface hydrogen. In this work, Zn with low concentrations were incorporated into the tetrahedral Co2+ sites of Co3O4 by hydrothermal and subsequent annealing treatment. They exhibit excellent HER performance. Particularly, when the Zn content in Co3O4 is 6.3 at%, an overpotential of 79.2 mV at the current density of 10 mA cm−2 was obtained in alkaline medium, which significantly better than pure Co3O4 catalyst (196.3 mV). Moreover, the current density of the Zn-doped Co3O4 catalyst can maintained 93 % after 10 h and 80 % after 20 h. DFT calculations reveal that the ΔGH* of Zn-doped Co3O4 (0.827 eV) is smaller and closer to zero than pure Co3O4 (1.023 eV). This work provides a deep insight into the rational design of low-level metal-doped cobalt oxide-based electrocatalysts.

Enhanced oxygen evolution reaction by controlled assembly of Co3O4 nanorods on TiB2 nanosheets

Cobalt oxide (CO) and Titanium boride hybrid composites are synthesized via hydrothermal reaction conditions followed by attentive calcination. Exfoliated Titanium boride (ETB) nanosheet templates are used for the first time to skillfully decorate CO nanorods on it. As-synthesized diverse hybrid composites ETB@CO (1, 3, and 5) are optimized for the electrochemical properties and weight ratios of CO and ETB nanosheets altered accordingly. Various spectroscopic techniques are used to characterize the as-synthesized hybrid composite materials. Standard electrochemical techniques such as cyclic voltammetry (CV), linear sweep voltammetry (LSV), electrochemical impedance spectroscopy (EIS), and Chronopotentiometry (CP) are used to discover the electro-catalytic behavior of hybrid composites. The composite ETB@CO-3 recorded outstanding performance by exhibiting a lower overpotential of 271 mV, with a cramped Tafel slope of 42.4 mV dec−1 for electrochemical oxygen evolution reaction (OER). The composite ETB@CO-3 clamour a lower overpotential of 271 mV to attain the current density of 10 mA/cm2 than the other composite ratio. Furthermore, the composite ETB@CO-3 displayed remarkable stability over 24 h with continuous OER reaction by maintaining stable voltage at 10 mA/cm2 current density and exhibited no noticeable increase in overpotential, suggesting its feasibility in practical applications.

Sensing properties and mechanisms of LaF3–Co3O4 nanorods for low-concentration methanol detection

Sensing properties and mechanisms of LaF3–Co3O4 nanorods for low-concentration methanol detection

Mesoporous Co3O4@CdS nanorods as anode for high-performance lithium ion batteries with improved lithium storage capacity and cycle life.

Transition metal oxides based anodes are facing crucial problems of capacity fading at long cycles and high rates due to electrode degradations. In this prospective, an effective strategy is employed to develop advanced electrode materials for lithium-ion batteries (LIBs). In the present work, a mesoporous Co3O4@CdS hybrid sructure is developed and investigated as anode for LiBs. The hybrid structure owning porous nature and large specific surface area, provides an opportunity to boost the lithium storage capabilities of Co3O4 nanorods. The Co3O4@CdS electrode delivers an initial discharge capacity of 1292 mA h g-1 at 0.1C and a very stable reversible capacity of 760 mA h g-1 over 200 cycles with a capacity retention rate of 92.7%. In addition, the electrode exhibits excellent cyclic stability even after 800 cycles and good rate performance as compared to previously reported electrodes. Moreover, density functional theory (DFT) and electrochemical impedance spectroscopy (EIS) confirm the enhanced kinetics of the Co3O4@CdS electrode. The efficient performance of the electrode may be due to the increased surface reactivity, abundant active sites/interfaces for rapid Li+ ion diffusion and the synergy between Co3O4 and CdS NPs. This work demonstrates that Co3O4@CdS hybrid structures have great potential for high performance batteries.

Insights into Co3O4 nano-rod/peroxymonosulfate catalytic oxidation system for chemical cleaning ultrafiltration membrane: Performance, mechanisms, and effects on the membrane stability

In this study, Co3O4 nano-rod (Co3O4-NR) with (110) crystal plane predominant exposure is prepared by a hydrothermal method, and peroxymonosulfate (PMS) was activated via them for ultrafiltration membrane (PVDF and PES membrane) cleaning. Co3O4-NR with (110) planes exposed obtained abundant oxygen vacancies (OV) and low oxidation state Co (Co2+) and therefore showed excellent ability for PMS activation. The Co3O4-NR/PMS system did not require long-term immersion in a high-concentration chemical reagent solution compared with conventional ultrafiltration membrane chemical cleaning. The cleaning process, which was conducted for only 15 min in Co3O4-NR (1.6 g/L)/PMS (2 mM) solution, was sufficient to restore almost all the permeate flux and could remove essentially all the irreversible foulants. The excellent membrane cleaning performance of the Co3O4-NR/PMS system was attributed to the generation of 1O2 and O2•−, which degraded the large-molecule, hydrophobic natural organic matter (NOM) into small-molecule, hydrophilic organic matter. Cyclic experiments showed that Co3O4-NR had excellent reusability, which offered significant cost savings. The consecutive chemical cleaning experiments indicated that the Co3O4-NR/PMS maintained the membrane stability better than the traditional chlorine cleaning method. The system effectively averts membrane damage and polymer structure changes caused by long-term exposure to oxidants. In conclusion, the Co3O4-NR/PMS system has significant advantages in membrane cleaning and broad application prospects.

Fe and Cu Double-Doped Co3O4 Nanorod with Abundant Oxygen Vacancies: A High-Rate Electrocatalyst for Tandem Electroreduction of Nitrate to Ammonia.

The electrochemical nitrate reduction reaction (NO3RR) is an attractive green alternative to the conventional Haber-Bosch method for the synthesis of NH3. However, this reaction is a tandem process that involves multiple steps of electrons and protons, posing a significant challenge to the efficient synthesis of NH3. Herein, we report a high-rate NO3RR electrocatalyst of Fe and Cu double-doped Co3O4 nanorod (Fe1/Cu2-Co3O4) with abundant oxygen vacancies, where the Cu preferentially catalyzes the rapid conversion of NO3- to NO2- and the oxygen vacancy in the Co3O4 substrate can accelerate NO2- reduction to NH3. In addition, the introduction of Fe can efficiently capture atomic H* that promotes the dynamics of NO2- to NH3, improving Faradaic efficiency of the produced NH3. Controlled experimental results show that the optimal electrocatalyst of Fe1/Cu2-Co3O4 exhibits good performance with high conversion (93.39%), Faradaic efficiency (98.15%), and ammonia selectivity (98.19%), which is significantly better than other Co-based materials. This work provides guidance for the rational design of high-performance NO3RR catalysts.

A novel ternary nanocomposite based electrochemical sensor coupled with regularized neural network for nanomolar detection of sunset yellow FCF

Synthetic dyes are extensively used worldwide although they instigate adverse environmental and health issues at higher concentrations. A reliable and ultrasensitive electrochemical sensor for nanomolar determination of common food colorant sunset yellow FCF is reported in this paper. The electrochemical sensor was integrated with a regularized neural network to enable intelligent sensing of this azo dye. The sensor was fabricated using a ternary nanocomposite based on silver doped spinel Co3O4 nanorods embedded functionalized multi-walled carbon nanotubes (fCNTs). Co-precipitation method was employed for synthesis of porous Co3O4 nanorods and CNTs were functionalized using acid-treatment approach. Electrochemical investigations based on cyclic voltammetry and differential pulse voltammetry techniques revealed stupendous electrocatalytic performance towards sunset yellow detection. A nanomolar detection limit of 0.8 nM and high sensitivity of 8.79 μA μM−1 cm−2 was exhibited by the developed sensor and real sample analysis experiment was conducted in commercial beverages to validate its practical feasibility.

Hybrid nanostructure of sanwhich-like porous Co3O4 nanorods/exfoliate graphite composite for lithium-ion batteries

High rate capacity and long cycling life are the main properties that expand the application of Co3O4 as anode materials, which are largely dependent on their structure and conductivity. In this work, we provide a facial method to achieve sanwhich-like exfoliate graphite-Co3O4 porous nanorods (EG/Co3O4) by two-step method hydrothermal and carbonization using EG as the conductivity matrix. The SEM and TEM analyses showed that EG successfully embed into the inner part of the Co3O4 nanorods. The addition of EG not only enhances the conductivity of the Co-based materials but also alleviates the aggregation of nanoparticles, while providing a large contact area for the electrode-electrolyte interface. This leads to an excellent rate capacity of 508 mAh g−1 at 5 A g−1. Moreover, the Co3O4 nanorods consist of interconnected nanoparticles, which help reduce the distance that lithium ions need to diffuse and facilitate electron transport. This capability effectively addresses the severe volumetric variation and contributes to optimal cycling performance, resulting in a high charge capacity of 847 mAh g−1 over 200 cycles at 0.5 A g−1. The outstanding electrochemical performance of EG/Co3O4 makes it a highly favorable option for use in lithium-ion batteries.

Probing the crystal plane effect of Co3O4 for non-enzymatic electrochemistry sensing performance toward hydrogen peroxide

The crystalline structure of catalyst surfaces has an important effect on the catalytic activity. However, the crystal plane effects of Co3O4 catalysts towards H2O2 activation are rarely reported. In this work, Co3O4 hexagon nanosheets, nanosheets, nanorods and nanocubes with respective {111}, {112}, {110} and {001} dominant exposed facets were synthesized by hydrothermal synthesis, and the crystal plane effects of these Co3O4 nanocrystals were compared with respect to their viability as potential for non-enzymatic H2O2 sensors. Co3O4 as a hexagonal nanosheet with a {111} crystal plane exhibited the best performance for H2O2 detection, and exhibited a fast response of 3 s, a wide linear range from 0.0005 ∼ 8.5 mM with sensitivity of 1160.2 μA·mM-1cm-2, and detection limit of 0.049 μM. Overall, the H2O2 detection performance of Co3O4 with different exposed facets was ranked as {111} > {112} > {110} > {001}, which is consistent with the proportion of surface Co3+, indicating that the surface Co3+ exhibit higher activity for H2O2 oxidation. This study indicates that tuning of thecrystal plane of nanocrystals is important to enhancement of non-enzymatic H2O2 detection, and provides an important constraint when developing high efficiency catalysts for non-enzymatic electrochemical H2O2 sensors.

Enhanced interfacial evaporation and desalination by solar heat localisation using nitrogenated graphitic carbon and Co3O4 nanorods

The problem of worldwide scarcity of clean water can be resolved efficiently by utilizing the significant heat localizing capability of the solar-driven interfacial evaporator with a nominal impact on the environment. A novel flexible, recyclable, hydrophilic photothermal composite membrane containing a blend of mesoporous Co3O4 nanorod and nanoporous nitrogen-doped graphitic carbon hollow spheres has been proposed. The composite membrane exhibits an enhanced broadband optical absorption which leads to a high interfacial evaporation rate (2.28 kg m−2 h−1) and a notable solar-to-steam generation efficiency (93%) under sunlight (900 W/m2) at 3.5 wt% NaCl salinity. The lower salt accumulation on the evaporation surface and the remarkable recyclability of the photothermal membrane under sunlight prove its practical usability in the desalination of seawater, water purification, salt production, and solar energy harvesting.

Oxygen vacancy engineered electron structure of porous CexCo3−xO4 nanorods for wide spectrum photocatalytic hydrogen evolution

Development of high-performance semiconductors for photocatalytic hydrogen evolution is a promising solution to solve the current energy crisis. In this work, a porous and oxygen vacancy-enriched CexCo3−xO4-Vo nanorods (CexCo3−xO4-Vo NRs) with adjust electron structure were fabricated by Ce-doping for wide spectrum photocatalytic hydrogen evolution. Because Ce doping regulates the Co3+/Co2+ atomic ratio of Co3O4 nanorods (Co3O4 NRs), resulting in a reduction of oxygen vacancy formation energy and confirmed by electron paramagnetic resonance (EPR) and X-ray photoelectron spectroscopy measurements (XPS) studies. The formation of oxygen vacancy leads to a modification in the positions of conduction band and valence band positions of CexCo3−xO4-Vo NRs. The ultraviolet photoelectron spectroscopy (UPS) spectra results indicate that the generation of oxygen vacancies leads to a more negative Fermi level in CexCo3−xO4-Vo NRs. This result directly results in an enhanced capacity for H+ reduction of CexCo3−xO4-Vo NRs. Density functional theory (DFT) calculations demonstrate that Ce0.15Co2.85O4-Vo NRs have faster electron transfer rates. In addition, the porous rod-like structure endows it abundant electron diffusion pathways, facilitates electrolyte infiltration, and establishes an ideal electrolyte/catalyst contact interface. Among them, Ce0.15Co2.85O4-Vo NRs have the best photocatalytic hydrogen evolution activity (3912.8 μmol g−1), which were 2.2 times more than that of Co3O4 NRs, and an excellent stability also obtained. This work provides a new idea for elements doping Co3O4 NRs to in situ-induced oxygen vacancies for enhanced photocatalytic hydrogen evolution.

Hydrothermally synthesized mesoporous Co3O4 nanorods as effective supercapacitor material

Hydrothermally synthesized mesoporous Co3O4 nanorods as effective supercapacitor material

A Carbonate-Involved Amplification Strategy for Cathodic Electrochemiluminescence of Luminol Triggered by the Catalase-like CoO Nanorods.

The lumiol-O2 electrochemiluminescence (ECL) system constantly emits bright light at positive potential. Notably, compared with the anodic ECL signal of the luminol-O2 system, the great virtues of cathodic ECL are that it is simple and causes minor damage to biological samples. Unfortunately, little emphasis has been paid to cathodic ECL, owing to the low reaction efficacy between luminol and reactive oxygen species. The state-of-the-art work mainly focuses on improving the catalytic activity of the oxygen reduction reaction, which remains a significant challenge. In this work, a synergistic signal amplification pathway is established for luminol cathodic ECL. The synergistic effect is based on the decomposition of H2O2 by catalase-like (CAT-like) CoO nanorods (CoO NRs) and regeneration of H2O2 by a carbonate/bicarbonate buffer. Compared with Fe2O3 nanorod (Fe2O3 NR)- and NiO microsphere-modified glassy carbon electrodes (GCEs), the ECL intensity of the luminol-O2 system is nearly 50 times stronger when the potential ranged from 0 to -0.4 V on the CoO NR-modified GCE in a carbonate buffer solution. The CAT-like CoO NRs decompose the electroreduction product H2O2 into OH· and O2·-, which further oxidize HCO3- and CO32- to HCO3· and CO3·-. These radicals very effectively interact with luminol to form the luminol radical. More importantly, H2O2 can be regenerated when HCO3· dimerizes to produce (CO2)2*, which provides a cyclic amplification of the cathodic ECL signal during the dimerization of HCO3·. This work inspires developing a new avenue to improve cathodic ECL and deeply understand the mechanism of a luminol cathodic ECL reaction.

Co3O4@Mn-Ni(OH)2 core–shell heterostructure for hybrid supercapacitor electrode with high utilization

It is of great importance to rationally design and fabricate electrode materials with high utilization and unexceptionable re-cycling performance in energy storage device including supercapacitors (SCs). Herein, Mn-doped Ni(OH)2 nanosheets with oxygen vacancies in-situ grow on the Co3O4 nanorods on carbon cloth (CC) to form a core–shell heterostructure (Co3O4@Mn-Ni(OH)2/CC). The obtained Co3O4@Mn-Ni(OH)2/CC electrode has an outstanding specific capacity of 313.4 mA h g−1 (1128.4 C g−1 or 2051.6 F g−1) at 1 A g−1, ca. 6.4 times that of the Ni(OH)2/CC electrode (48.9 mA h g−1). The hybrid supercapacitor (HSC) constructed by activated carbon (AC) and Co3O4@Mn-Ni(OH)2/CC displays a marvelous energy density of 65.5 W h kg−1 at 800 W kg−1, and 93.0% of the capacity retention over 10,000 repeated charging/discharging cycles at 5 A g−1, superior to the Co3O4@Ni(OH)2/CC//AC HSC (36.5%) and Mn-Ni(OH)2/CC//AC HSC (53.9%). The results of the characterizations and density functional theory (DFT) calculation show that the Mn-doping and subsequent induced oxygen vacancies promote the conductivity, and inhibit the irreversible phase transition of Ni(OH)2 during the charging/discharging process which contributes to the long-time cycling stability of the electrode. Moreover, the core–shell heterostructure fosters the exposure of active sites and reduces the charge transfer resistance due to the interfacial interaction. This work provides some insight into the rational design and fabrication of electrode materials with high utilization in SCs.

Revealing the influence of conversion-type Co3O4 dimensionality on cyclic and rate performance for lithium storage

Cobalt tetraoxide (Co3O4) is regarded as a promising anode material for Li-ion batteries owing to its high theoretical capacity (890 mAh g−1), simple preparation, and controllable morphology. Nanoengineering has been proven to be an effective method for producing high-performance electrode materials. However, systematic research on the influence of material dimensionality on battery performance is lacking. Herein, we prepared Co3O4 with various dimensionalities (one-dimensional (1D) Co3O4 nanorod (NR), two-dimensional (2D) Co3O4 nanosheet (NS), three-dimensional (3D) Co3O4 nanocluster (NC), and 3D Co3O4 nanoflower (NF)) using a simple solvothermal heat treatment method, and their morphologies were controlled by varying the precipitator type and solvent composition. The 1D Co3O4 NR and 3D samples (3D Co3O4 NC and 3D Co3O4 NF) exhibited poor cyclic and rate performances, respectively, while the 2D Co3O4 NS exhibited the best electrochemical performance. The mechanism analysis revealed that the cyclic stability and rate performance of the Co3O4 nanostructures are closely related to their intrinsic stability and interfacial contact performance, respectively, and the 2D thin-sheet structure can achieve an optimal balance between the two, resulting in the best performance. This work presents a comprehensive study on the effect of dimensionality on the electrochemical performance of Co3O4 anodes, providing a new concept for the nanostructure design of conversion-type materials.

Bamboo-like MnO2⋅Co3O4: High-performance catalysts for the oxidative removal of toluene

The manganese-cobalt mixed oxide nanorods were fabricated using a hydrothermal method with different metal precursors (KMnO4 and MnSO4·H2O for MnOx and Co(NO3)2⋅6H2O and CoCl2⋅6H2O for Co3O4). Bamboo-like MnO2⋅Co3O4 (B-MnO2⋅Co3O4 (S)) was derived from repeated hydrothermal treatments with Co3O4@MnO2 and MnSO4⋅H2O, whereas Co3O4@MnO2 nanorods were derived from hydrothermal treatment with Co3O4 nanorods and KMnO4. The study shows that manganese oxide was tetragonal, while the cobalt oxide was found to be cubic in the crystalline arrangement. Mn surface ions were present in multiple oxidation states (e.g., Mn4+ and Mn3+) and surface oxygen deficiencies. The content of adsorbed oxygen species and reducibility at low temperature declined in the sequence of B-MnO2⋅Co3O4 (S) > Co3O4@MnO2 > MnO2 > Co3O4, matching the changing trend in activity. Among all the samples, B-MnO2⋅Co3O4 (S) showed the preeminent catalytic performance for the oxidation of toluene (T10% = 187°C, T50% = 276°C, and T90% = 339°C). In addition, the B-MnO2⋅Co3O4 (S) sample also exhibited good H2O-, CO2-, and SO2-resistant performance. The good catalytic performance of B-MnO2⋅Co3O4 (S) is due to the high concentration of adsorbed oxygen species and good reducibility at low temperature. Toluene oxidation over B-MnO2⋅Co3O4 (S) proceeds through the adsorption of O2 and toluene to form O*, OH*, and H2C(C6H5)* species, which then react to produce benzyl alcohol, benzoic acid, and benzaldehyde, ultimately converting to CO2 and H2O. The findings suggest that B-MnO2⋅Co3O4 (S) has promising potential for use as an effective catalyst in practical applications.

Tuning Oxygen Vacancies in Co3O4 Nanorods through Solvent Reduction Method for Enhanced Oxygen Evolution Activity

Oxygen vacancies can act as active centers for oxygen evolution reaction (OER), thereby enhancing the electrocatalytic activity of the catalyst. Unfortunately, effective methods are rather limited to introducing a high amount of oxygen vacancies on the surface of nanocatalysts. Here, a facile solution reduction method has been demonstrated. By simply tuning the concentration of NaBH4 solution, we fabricate typical spinel Co3O4 nanorods with a reasonable density of oxygen vacancy defects and preserve the nanorod morphology and one-dimensional (1D) charge transport behavior of the starting material. As-prepared defect-rich Co3O4 nanorods show a low overpotential of 378 mV at a current density of 10 mA cm–2 and a small Tafel slope of 58.18 mV dec–1, and at the same time, its double-layer capacitance reaches 25.62 mF cm–2, which is nearly 4 times that of pristine Co3O4. The presence of oxygen vacancies makes the reduced Co3O4 possess excellent OER activity. It is worth noting that it still exhibits high stability even after 20 h of cycles of scanning under OER working conditions. This method is simpler, cheaper, and more environmentally friendly than the existing methods of preparing oxygen vacancies. This mild solution reduction method sheds light on the understanding of defect-based electrocatalysts, opening up a new route for developing highly efficient electrocatalysts for the OER.

Ti3C2Tx MXene/graphene oxide/Co3O4 nanorods aerogels with tunable and broadband electromagnetic wave absorption

The biggest challenge for electromagnetic wave absorption (EMA) devices is to simultaneously achieve high reflection loss (RL), wide absorption bandwidth, and ultrathin thickness. According to the EMA mechanism of the electromagnetic wave (EMW) absorbers, exceptional EMA properties can be achieved by a combination of three-dimensional (3D) cellular structure and synergistically electric/magnetic losses of the electromagnetic energy. In this study, an MXene/graphene oxide (GO)/Co3O4 nanorods (NRs) (MGCR) aerogel composed of two-dimensional (2D) MXene and GO nanosheets, and one-dimensional (1D) Co3O4 NRs was developed to achieve desirable EMA properties. Here, MXene and GO manipulate the dielectric loss, and the Co3O4 NRs provide magnetic loss. The MGCR aerogel shows excellent EMA performances with an impressive minimum RL (RLmin) of − 71.87 dB at a thickness of 2.07 mm and an outstanding maximum effective absorption bandwidth (EAB) of 6.88 GHz with a density of 9 mg cm−3. And the RL ≤ − 10 dB is obtained in S-band (2–4 GHz), C-band (4–8 GHz), X-band (8–12 GHz), and Ku-band (12–18 GHz) by adjusting the thickness between 2 and 6 mm. In addition, computer simulation technology (CST) was employed to verify the radar cross-section (RCS) reduction of the MGCR in the far-field. The strongest RCS reduction value of the MGCR aerogel achieves up to 33.07 dBm2 at a scattering angle of 90°. This research provides a novel strategy for designing MXene-based electromagnetic absorbers by coupling 1D anisotropically magnetic materials with dielectric materials.

Electrochemical aspects of Co3O4 nanorods supported on the cerium doped porous graphitic carbon nitride nanosheets as an efficient supercapacitor electrode and oxygen reduction reaction electrocatalyst

Herein, the electrochemical performance of Ce-PGCN,NS/Co3O4 as a metal-free ORR electrocatalyst and supercapacitor electrode was investigated. FESEM, TEM, BET, FTIR, XRD, EDX, FTIR, and Raman tests were used to characterize the synthesized electrocatalysts. For ORR measurements, voltammetry (CV, LSV, Choronoamperometry) and EIS tests were used to investigate the electrocatalytic activity of the electrocatalysts. And for supercapacitor measurements, the CV and GCD tests were conducted to examine the electrode's capacitance. The results of the voltammetry tests show that Ce-PGCN,NS/Co3O4 with an onset potential of −0.027 V, selecting four-electron pathway (n = 3.86), Tafel slope of 137 mV/dec, charge transfer of 570 Ω, and high durability in alkaline media (0.1 M KOH) show an excellent electrochemical performance as an ORR electrocatalyst and can be introduced as a promising substitution for commercial Pt/C catalysts. On the other hand, the results of CV in supercapacitor mode and GCD reveal that Ce-PGCN,NS/Co3O4 electrode with the specific capacitance of 789 F g−1 at the current density of 1 A g−1 and high stability in alkaline media (2 M KOH), have superior performance as a supercapacitor electrode than other electrode based on the g-C3N4. Also, it is observed that converting bulk g-C3N4 to PGCN,NS, doping Cerium atoms on the structure of the PGCN,NS, and adding Co3O4 nanorods impact the electrocatalytic activity of g-C3N4 positively.