Molten Salt Method Research Articles

Preparation and Growth Mechanism of Pyramid‐Shaped Cu2ZnSnS4 Monocrystal and the Simulation of Its Monograin Layer Solar Cells

AbstractThe Cu2ZnSnS4(CZTS) monocrystal as an important component of the optical absorption layer in monograin layer solar cells, has excellent crystallization characteristics and adjustable photogenerated carrier concentration. The shape of the CZTS monocrystal directly affects the utilization of incident light and the contact area during the preparation of the back electrode when they are densely packed to form a single‐layer absorption layer. Herein, a kesterite‐phase pyramid‐shaped CZTS monocrystal prepared by the molten salt method is reported, which can improve the efficiency of incident light utilization and increase the contact area during back electrode preparation. The X‐Ray diffraction, Raman spectroscopy, transmission electron microscopy, and scanning electron microscopy are used to characterize the crystallinity and crystal shape of pyramid‐shaped CZTS monocrystal. Besides, Finite‐Difference simulation calculation is employed to reveal the optical response and corresponding monograin layer solar cells performance of densely packed CZTS. The results show that the pyramid‐shaped structure exhibited excellent incident light trapping ability, and the simulated device achieves a cell efficiency with above 13.6% after parameter optimization. The work provides a method for preparing pyramid‐shaped CZTS monocrystal, and a new strategy to further improve the efficiency of CZTS‐based monograin layer solar cells.

Variation of magnetic properties by heat treatment of dispersed oriented sheets using plate-shaped strontium ferrite particles

Abstract Plate-shaped hexagonal SrFe12O19 particles synthesized using the molten salt method were dispersed in a resin, and oriented sheets were prepared by coating the dispersion onto quartz substrates. The oriented sheets on quartz substrates were heat treated at 300–900 ℃. The variations in the coercive force and squareness of the oriented sheets before and after heat treatment were examined. The coercive force remarkably increased with increasing heat treatment temperature, exhibiting a maximum increase rate of approximately 16 % in the heat treatment at 800 ℃. The increase in coercive force suggests a reduced effect of shape anisotropy due to the stacking of the plate surfaces, caused by the removal of resin between the particles; this highlights the influence of crystalline anisotropy.

Sustainable synthesis of pyrochlore gadolinium zirconate through the molten salt method: A green approach

Gadolinium zirconate (GZO) with pyrochlore phase exhibits exceptional promise for thermal barrier coatings due to its notable low thermal conductivity. Current synthesis methods for GZO, however, are frequently complex, energy-intensive, and environmentally hazardous. A more sustainable and eco-friendly synthesis route for GZO is thus imperative. This research introduces a green synthesis process for pyrochlore GZO utilizing the molten salt method.Experimental synthesis at varying temperatures revealed changes in the phase composition of GZO via the molten salt method. Fluorite GZO formed at 1200 °C, while pyrochlore GZO appeared at 1400 °C. XRD refinement, TEM, and Raman spectroscopy confirmed these results. Density Functional Theory (DFT) calculations established the minimum theoretical synthesis temperature for pyrochlore GZO at 1370 °C. Limiting factors for reactions at different temperatures during the molten salt synthesis process were identified. DFT calculations and experiments verified that the fluorite structure GZO transitions to pyrochlore GZO at temperatures exceeding 1370 °C. Property tests on pyrochlore GZO samples synthesized through two pathways showed minimal differences. This study thus lays a theoretical foundation for the eco-friendly synthesis of pyrochlore GZO material using the molten salt method and offers insights for future process development.

A general molten salt method to conduct doping engineering for high-performance LiMn2O4 cathode

The doping strategy is considered as an effective method to enhance the electrochemical performances of LiMn2O4 (LMO). There is little report on the simultaneous preparation and doping of LMO by molten salt method. Herein, a ternary molten salt of KCl@LiCl@MCl2 (M = Ni, Cu, and Co) is proposed to convert commercial MnO2 to M-doped LMO, the successful preparation is proved by various characterizations. More importantly, the doping engineering enhances the charge transfer and storage of LMO, and ex-situ XRD and XPS prove the improved structure stability of LMO in the cycling test. Therefore, Ni-doped LMO offers a high reversible capacity of 108.6 mA h g−1 at 0.05 A g−1 and a long cyclic life with 87.4 mA h g−1 after 800 cycles at 0.2 A g−1. This work offers a new idea for implementing doping strategy.

N-doped hierarchical porous carbon derived from corncobs by molten salt method for high-performance supercapacitors

N-doped hierarchical porous carbon derived from corncobs by molten salt method for high-performance supercapacitors

Lattice energy transfer from homo-crystalline substitution for enhanced piezo-photocatalytic CO2 conversion

The rapid recombination of carriers and large activation energy of CO2 compromise the efficiency of CO2 photoreduction. Herein, SrTiO3 (STO) with different molar ratios of La3+ and Al3+ double-site homo-crystalline substitution is prepared by a ball-milling molten salt method. The concentration of Ti3+ and excess oxygen vacancies decrease to improve the catalytic activity. Meanwhile, the double sites act as electron transfer platforms for easy electron transfer from the bulk phase to the surface to foster CO2 photoreduction. Not only that, the energy transfer due to doping-induced lattice distortion can potentially enhance the photocatalytic activity. A piezoelectrically polarized electric field is introduced to further expedite charge transport. As a result, the activity of La, Al-STO piezo-photocatalytic CO2 reduction is improved to 39.17 µmol g-1h−1, which is more than seven times better than that of the pure STO. Furthermore, CO2 adsorbs spontaneously on the catalysts because the thermodynamic energy barrier decreases due to the piezoelectric force, which is verified by density-functional theory calculation. This study reveals the great potential of double-site homo-crystalline substitution of STO pertaining to the charge transport kinetics and thermodynamics of the catalytic reaction in the piezo-photocatalytic CO2 process.

Insight into γ-Irradiation-Induced Structure Evolution of Uranium(IV) Germanates as Crystalline Nuclear Waste Forms.

New kinds of crystalline waste forms with improved structural stability are desirable for actinide immobilization. In this work, using a molten salt method, two uranium(IV) germanate compounds, namely, K2UGe3O9 (1) and K2UGe2O7 (2), were synthesized, whose compositions consisted of trimeric and dimeric units of germanate, as well as tetravalent uranium, as proved by bond valence calculation and X-ray absorption spectra. Radiation stability assessment is further performed by γ-irradiation to assess the potential of as-synthesized uranium germanate compounds as nuclear waste forms. Powder X-ray diffraction and single-crystal diffraction analyses reveal that 1 remains stable within 1 MGy dosage and undergoes a significant structural change with increasing dosage at 2 MGy, leading to a transformation of 1 to 1-ir analogous to 2 in chemical structure. The underlying mechanism was further studied through a combination of different characterization techniques, including Raman, UV-vis, and electron paramagnetic resonance spectroscopies. Density functional theory calculations of 1 and 2 were also conducted to probe the coordination interaction of germanium and uranium with oxygen atoms. This work reports new crystalline uranium germanates by flux growth and, most importantly, provides insights into the irradiation stability of these materials, which will be beneficial to developing waste forms for long-term immobilization of radionuclides.

Enhancing Corrosion Resistance and Tribomechanical Characteristics of Powder Coatings via the Integration of Functionalized HF‐Free MXene Reinforcements

AbstractMXene, a new generation of 2D materials, is gaining attention for anti‐corrosion applications due to its large surface area, electrical conductivity, and self‐healing properties. Its low shear strength and self‐lubricating properties enhance wear resistance. Herein, silane functionalized HF‐Free MXene nanosheets “MS‐f_Ti3C2 and MS‐f_Ti3C2@Zn” synthesized through the molten salt method are integrated into the environmentally sustainable powder coating. The electrochemical tests indicate that a powder coating containing a well‐dispersed 1.5 wt.% f_Ti3C2@Zn nanosheets exhibit the highest polarization resistance (1.1 × 106 Ω cm2), lowest Icorr (2.15 × 10−8 A cm−2) and superior anti‐corrosion performance after 42 days of immersion in 3.5 wt.% NaCl. The polarization resistance (Rp) and corrosion current (Icorr) of the untreated coating are measured to be 1.6 × 103 Ω cm2 and 1.6 × 10−5A cm−2, respectively. In addition, the incorporation of MXene material reduces crack development and spalling, and enhances wear resistance during the friction process. The loading of 1.5 wt.% f_Ti3C2@Zn reduces the coefficient of friction (COF) and improves wear rate by 45% and 51%, respectively Analysis of composites via nanoindentation reveals such enhanced mechanical properties. This study presents an effective and sustainable approach to improve the mechanical, tribological, and long‐term corrosion protection of organic coating, thereby exhibiting great potential for using HF‐Free MXene as a multipurpose additive.

Modulating Near-Infrared Persistent Luminescence via Diverse Preparation Approaches.

Near-infrared (NIR) persistent luminescence (PersL) materials have attracted extensive attention due to their great promise in medical diagnostics, bio-imaging, night vision surveillance, multi-level anticounterfeiting, and information encryption. To achieve NIR PersL (micro/nano-) materials with the desired properties, a variety of synthesis methods have been employed, including solid-phase reaction and liquid-phase synthesis. Different synthesis methods have different but important effects on the micro/nano-structure, luminescence, and PersL properties of the materials. Moreover, the influence of various synthesis methods on the properties of NIR PersL materials determines the selection of preparation approaches for other new material systems. Taking the representative NIR PersL ZnGa2O4:Cr3+ material as an example, four synthesis procedures are applied, namely, high-temperature solid-state reaction (SSR), high-temperature molten salt method (MSM), hydrothermal method (HM), and microwave-assisted solid-state (MASS) method. The structural and luminescent properties of samples made by SSR, MSM, HM, and MASS are compared. Notably, it is revealed that the MASS method can create additional trapping energy levels, which is of great significance for emerging applications. This work demonstrates the different effects of synthesis methods on PersL performance and provides a good guideline for the rapid and reasonable selection of preparation methods for diverse applications.

The potassium storage performance of carbon nanosheets derived from heavy oils

As by-products of petroleum refining, heavy oils are characterized by a high carbon content, low cost and great variability, making them competitive precursors for the anodes of potassium ion batteries (PIBs). However, the relationship between heavy oil composition and potassium storage performance remains unclear. Using heavy oils containing distinct chemical groups as the carbon source, namely fluid catalytic cracking slurry (FCCS), petroleum asphalt (PA) and deoiled asphalt (DOA), three carbon nanosheets (CNS) were prepared through a molten salt method, and used as the anodes for PIBs. The composition of the heavy oil determines the lamellar thicknesses, sp3-C/sp2-C ratio and defect concentration, thereby affecting the potassium storage performance. The high content of aromatic hydrocarbons and moderate amount of heavy component moieties in FCCS produce carbon nanosheets (CNS-FCCS) that have a smaller layer thickness, larger interlayer spacing (0.372 nm), and increased number of folds than in CNS derived from the other three precursors. These features give it faster charge/ion transfer, more potassium storage sites and better reaction kinetics. CNS-FCCS has a remarkable K+ storage capacity (248.7 mAh g−1 after 100 cycles at 0.1 A g−1), long cycle lifespan (190.8 mAh g−1 after 800 cycles at 1.0 A g−1) and excellent rate capability, ranking it among the best materials for this application. This work sheds light on the influence of heavy oil composition on carbon structure and electrochemical performance, and provides guidance for the design and development of advanced heavy oil-derived carbon electrodes for PIBs.

Effect of tungsten carbide interface decoration on thermal and mechanical properties of carbon fiber reinforced copper matrix composites

The use of carbon fiber (CF)/copper (Cu) composites as thermal management materials shows significant promise. However, inadequate interface bonding hinders their thermal properties. This study introduces a novel method to create tungsten carbide–coated CFs (CF(WC)) using the molten salt method. These coated fibers are then used to develop a CF(WC)/Cu composite through vacuum hot-pressing sintering. Results reveal that the WC coating, formed at 1100 ℃ for 60min with a tungsten trioxide/CF molar ratio of 1/10, is continuous, crack-free, and has an appropriate thickness. The WC coating facilitates excellent interface bonding between Cu and CF, thus effectively improving the initial poor interface bonding. With similar 50% fiber content, the CF(WC)/Cu composite exhibits better thermal and mechanical properties than the CF/Cu composite. The in-plane direction thermal conductivity and bending strength of the CF(WC)/Cu composite are 398.7 ± 8.1Wm−1 K−1 and 195.3 ± 6.2MPa, which are 35.3% and 90.4% higher, respectively, than those of the CF/Cu composite. Additionally, the in-plane direction coefficient of thermal expansion is 6.5 ± 0.3 × 10−6 K−1, representing a notable reduction of 37.5%. These exceptional properties, coupled with the simplicity and efficacy of the preparation process, offer valuable insights for the advancement of carbon/Cu thermal management materials.

Exploring barium-titanium-peroxo-hydroxide as an excellent single-source precursor for crystallographically diverse barium titanate ceramics – parametric study

Barium-titanium-peroxo type amorphous materials gained importance with the advent of wet-chemical methods for the production of crystalline perovskite barium titanate (BaTiO3) electroceramics. In this paper, the chemical nature of the barium-titanium-peroxo precursor was determined by means of elemental (EPMA), spectroscopic (FT-IR and FT-Raman), XRD and thermal (DSC and TGA/DTA) analyses. Several synthesis parameters such as the barium source, the peroxide treatment time, the reaction temperature and the reaction time were investigated. The precursor was also thermally treated at varying temperatures between 30 °C and 1000 °C. Relatively high reaction temperatures are detrimental to the Ba∙O∙Ti structure, resulting in plain TiO2 formation. Though relatively low temperatures (ice bath) are needed to suppress unwanted TiOCl2, ambient synthesis conditions and short reaction time (2 h) resulted in the desired single-source properties, i.e. amorphous Ba∙O∙Ti-peroxo structure with Ba/Ti ratio of unity (1.04 ± 0.04). The addition of an extra stirring step during H2O2 addition lowered the chance of carbonate incorporation in the precursor. Thermal analysis under air and nitrogen atmosphere was performed and a stoichiometric formula of Ba2,08Ti2O(O2)1,9(OH)5,3∙3,1H2O was calculated, which was in very good agreement with literature data. The barium-titanium-peroxo-hydroxide material proved to be an excellent single-source precursor. Phase-pure, highly crystalline and facetted, stoichiometric BaTiO3 particles with differently crystallographically oriented facets were obtained via the molten-salt solid-state method ({100} or {111} oriented facets) as well as the hydrothermal route ({100} oriented facets).

One-Step Molten Salt Method For Synthesis of Perovskite-Like Sr2Nb2O7 and Sr5Nb4O15 Ceramics

Abstract In this study, Sr2Nb2O7 and Sr5Nb4O15 layered perovskite-like ceramics were synthesized by a single process using a one-step molten salt method. By optimizing the key parameters, including the choice of molten salt, reaction temperature and residence time, two materials achieve synchronous production. The crystal structures of the synthesized materials were confirmed by X-ray diffraction. It is proved that it has typical perovskite-like structural characteristics. Scanning electron microscopy reveals the morphology of these materials. Sr2Nb2O7 presents a sheet-based structure, and Sr5Nb4O15 presents a rod-based structure. This study provides an efficient and direct method for the synthesis of perovskite materials. One-step molten salt method has great potential in the synthesis of multiphase materials. These findings are expected to promote the application of perovskite materials in the fields of electronics, optics and catalysis.

Efek Pendoping Nd3+ Pada Senyawa BaBi2-xNdxNb2O9 Terhadap Struktur, Sifat Dielektrik Dan Optik

The Aurivillius compound with formula BaBi2-xNdxNb2O9 (x = 0.05, 0.1, 0.2, and 0.4) has been successfully synthesized using the molten salt method, showing potential as a ferroelectric material. The impact of Nd3+ substitution on the structure, morphology, dielectric, and optical properties has been systematically analyzed. XRD data refinement confirms that BaBi2-xNdxNb2O9 (BBNN) exhibits an orthorhombic structure with an A21am space group. Anisotropic plate-like grains were observed across all samples, decreasing their size as Nd3+ content increases. The ferroelectric transition temperature (Tc) decreases due to structural distortion caused by the reduction of the lone pair 6s2 electron effect of Bi3+ when substituted with Nd3+. Moreover, this structural distortion also contributes to an increase in bandgap energy (Eg). The diffuse ferroelectric phase transition is characterized by a broadened Tc peak induced by Nd3+ substitution due to increased cationic disruption in the bismuth layers. The ferroelectric phase with a lower and broader Tc suggests that the x = 0.4 sample has the potential for electrocaloric applications.

Topologically Close-Packed Frank-Kasper C15 Phase Intermetallic Ir Alloy Electrocatalysts Enables High-Performance Proton Exchange Membrane Water Electrolyzer.

Chemical synthesis of unconventional topologically close-packed intermetallic nanocrystals (NCs) remains a considerable challenge due to the limitation of large volume asymmetry between the components. Here, a series of unconventional intermetallic Frank-Kasper C15 phase Ir2M (M = rare earth metals La, Ce, Gd, Tb, Tm) NCs is successfully prepared via a molten-salt assisted reduction method as efficient electrocatalysts for hydrogen evolution reaction (HER). Compared to the disordered counterpart (A1-Ir2Ce), C15-Ir2Ce features higher Ir-Ce coordination number that leads to an electron-rich environment for Ir sites. The C15-Ir2Ce catalyst exhibits excellent and pH-universal HER activity and requires only 9, 16, and 27mV overpotentials to attain 10mA cm-2 in acidic, alkaline, and neutral electrolytes, respectively, representing one of the best HER electrocatalysts ever reported. In a proton exchange membrane water electrolyzer, the C15-Ir2Ce cathode achieves an industrial-scale current density of 1 A cm-2 with a remarkably low cell voltage of 1.7V at 80°C and can operate stably for 1000 h with a sluggish voltage decay rate of 50 µV h-1. Theoretical investigations reveal that the electron-rich Ir sites intensify the polarization of *H2O intermediate on C15-Ir2Ce, thus lowering the energy barrier of the water dissociation and facilitating the HER kinetics.

Cyano-determined mercury (II) ion selective fluorescence assay over polymeric carbon nitride

Selective response is the key index to evaluate the performance of polymeric carbon nitride (PCN)-based heavy metal ion fluorescence sensors. Herein, to explore the role of cyano groups on selectivity, four kinds of PCN, including PCN-Cl, PCN-Ac, PCN-B and PCN-K were prepared by the molten salt method of sodium chloride and sodium acetate, the reduction method of sodium borohydride and the etching method of potassium hydroxide, respectively. These PCNs exhibited different surface cyano characteristics, but all of them had significant blue emission under ultraviolet excitation. It is proved that the assistant of sodium chloride or potassium hydroxide is an effective method to prepare PCNs with abundant surface cyano group. A series of fluorescence quenching experiments of metal ions showed that the cyano-rich degree of PCN is closely related to its selective response to mercury (II) ions. PCN-Cl and PCN-K emerged good selective quenching of mercury (II) ions, which may be related to the soft acid-soft base strong interaction between mercury (II) ions and cyano groups. Both PCN-Cl and PCN-K fluorescent probes for mercury (II) ions had a linear range of 5 ∼ 50 μmol L−1, and PCN-Cl exhibited a lower detection limit of 0.38 μmol L−1. This work confirmed the selective fluorescence response of cyano-rich PCN to mercury (II) ions, proposed the mechanism of selective fluorescence quenching response of mercury (II) ions, and provided a new idea for the design of efficient and accurate PCN-based fluorescence probes.

Constructing ultralow-loading Cu single atoms/Fe2O3 particles on Nb2C MXenes for efficient utilization of atomic H to boost electrochemical debromination

Bromate is a commonly identified carcinogenic and genotoxic disinfection byproduct in water. Electrochemical debromination is an environmentally friendly and effective approach but it often suffers the limited reducing atomic H (H*) ability and high metal catalyst dosage. In this study, a unique composite catalyst comprised of ultra-low loading Cu single atoms (0.016 wt%) and Fe2O3 nanoparticles supported on a Nb2C MXene (denoted as Cu0.2/Fe0.1/Nb2C) was synthesized by one-step high-temperature molten salt method. The Cu0.2/Fe0.1/Nb2C significantly outperformed the Nb2C, Cu0.2/Nb2C and Fe0.1/Nb2C counterparts in the electrochemical debromination with a 94.2 % removal efficiency of bromate. It is revealed that the introducing of Cu single atoms, efficiently promotes the adsorption of H* and inhibition of competitive H2 evolution. The incorporation of Fe2O3 nanoparticles significantly increased the electronic metal-support interaction effect between the metal components and Nb2C, thereby forming a noticeable electronic cloud bridge to facilitate efficient charge transfer. Ultimately, the synergistic interplay between Cu single atoms and Fe2O3 nanoparticles plays a crucial role in achieving the remarkable removal performance of bromate. This work not only presents a significant instance of a synergistic catalyst involving metal single atoms and metal nanoparticles for effective electrochemical debromination but also advances the understanding of the electronic metal-support interaction.

Zn-Zr substituted M-type Sr-hexaferrites for effective electromagnetic wave absorptions in the 26.5–40 GHz range

This study explores the electromagnetic (EM) wave absorption properties of Zn-Zr substituted M-type Sr-hexaferrites (SrFe12–2xZnxZrxO19, x = 0.3, 0.4, 0.5, 0.6) integrated into polymer composites (10 wt%, epoxy or rubber). The hexaferrite powders were synthesized using solid-state reaction processes with and without the molten-salt (M-S) method. Compared to non-M-S samples, those processed with M-S exhibited larger grain sizes and more defined grain edge shapes without clustering. High-frequency characteristics (ε', ε", μ', and μ") and EM wave absorption properties, specifically reflection loss (RL), were evaluated over the frequency range of 26.5 ≤ f ≤ 40 GHz. Regardless of the M-S method application, hexaferrite-epoxy composites (10 wt%) demonstrated excellent EM wave absorption properties with RLmin < −40 dB and a shifting absorption band corresponding to variations in x, reflecting changes in the ferromagnetic resonance frequency (fFMR). For the x = 0.4 sample, flexible rubber binder (10 wt%) sheets dispersed with hexaferrite powder were fabricated, showing superior broadband absorption characteristics compared to epoxy composites. In rubber sheet form, M-S processed samples exhibited enhanced μ', μ" spectra and improved absorption performance compared to non-M-S samples. The M-S processed hexaferrite-rubber sheet demonstrated broad EM wave performance with RL < −10 dB across the entire frequency range, achieving RLmin = −61 dB at 32 GHz. This study underscores the potential of Zn-Zr-substituted SrM-polymer composites for robust EM wave absorption performance in the Ka-band (26.5–40 GHz), crucial for applications in 5 G communication frequencies.

Topochemical transformation mechanism and piezoelectric response of B-site complex BaZr0.1Ti0.9O3 microplatelets

The B-site complex BaZr0.1Ti0.9O3 (BZT) microplatelets with perovskite-structured were synthesized, using the Bi4(Zr0.1Ti0.9)3O12 (BIZ0.1T0.9) as a precursor. The precursor had a high aspect ratio, with an average size of ∼8.0 μm. Later, B-site complex BZT microplatelets were obtained via molten salt methods. The influence of n(BIZ0.1T0.9):n(BaCO3) ratio and calcined temperature in the composition, morphology and local piezoelectric and ferroelectric behaviour for BZT microplatelets was deeply discussed. The result showed that the reactants ratio determined the supersaturation degree in the molten salt environment, while the calcined temperature determined the crystallinity of BZT microcrystals. Overall, with the n(BIZ0.1T0.9):n(BaCO3) ratio was 1:4, the BZT microcrystal calcined at 900 °C had a better plate-like morphology. Manwhile, the micropizoelectric properties of BZT microplatelet was studied, achieving a maximum d33* of ∼330 pm/V. The result indicated that the B-site complex BZT microplatelets is a potential templates for textured ceramics.

Ce-doped cobalt-based hydroxide assisted with low-temperature molten salt for industrial oxygen evolution reaction

Developing low cost and high-performance oxygen evolution electrocatalysts is significant to improve the efficiency of water electrolysis for large-scale hydrogen production. Cobalt hydroxide is a promising electrocatalyst for oxygen evolution reaction (OER), but its poor conductivity and activity seriously restrict the practical application. A simple one-step low temperature molten salt method was applied to successfully synthesize the Ce-doped cobalt hydroxide nitrate (Ce-CoNH/CF), which exhibits outstanding OER performance with a low overpotential of 448 mV at the current density of 1000 mA/cm2 in 1 mol/L KOH. The remarkable performance of Ce-CoNH/CF electrode in OER may be the comprehensive result of fast reaction kinetics, large electrochemical active specific surface area (ECSA) and small charge transfer resistance (Rct) as revealed by the Tafel, cyclic voltammetry (CV) and electrochemical impedance spectra (EIS) analysis. Under the simulated industrial test conditions (6 mol/L KOH, 70 °C), the Ce-CoNH/CF electrode still displays excellent OER performance.