High Electrochemical Performance and Enhanced Electrocatalytic Behavior of a Hydrothermally Synthesized Highly Crystalline Heterostructure CeO₂@NiO Nanocomposite

Abstract

A CeO 2 -based heterostructure nanocomposite has been attractive as an electrode material for energy storage and as an electrochemical sensor. In the present work, a CeO 2 @NiO nanocomposite was prepared by a simple hydrothermal method. The structural and morphological information on the heterostructure CeO 2 @NiO nanocomposite were obtained by using different characterization methods like X-ray diffraction, UV−visible, Fourier transform infrared, electron paramagnetic resonance, Raman, field-emission scanning electron microscopy, high-resolution transmission electron microscopy, energydispersive X-ray elemental color mapping, X-ray photoelectron spectroscopy, and thermogravimetric analysis. Compared with pristine CeO 2 , the heterostructure CeO 2 @NiO nanocomposite exhibits a higher electrochemical performance with a specific capacitance of 317 F g −1 at a current density of 1 A g −1 in a 1 M KOH electrolyte. This device demonstrates a high energy density and a power density of 11 Wh kg −1 and 750 W kg −1 , respectively. Besides, it was found that CeO 2 @NiO/ glassy carbon electrode (GCE) shows appreciable electrocatalytic activity toward NO 2 − oxidation. The CeO 2 @NiO-modified electrode displays a linear response for NO 2 − oxidation between 0.001 × 10 −6 and 4 × 10 −3 M. Apart from high sensitivity (2260 μA mM −1 cm −2 ), the CeO 2 @NiO-modified electrode also exhibits good selectivity and long-term stability for nitrite (NO 2 − ) detection in a water real sample, and the obtained results showed excellent recovery. The encouraging electrochemical performance of the CeO 2 @NiO nanocomposite provides a promising approach for the development of multifunctional electrode materials for future energy storage devices and sensors.

Pseudo‐Periodically Coupling NiO Lattice with CeO Lattice in Ultrathin Heteronanowire Arrays for Efficient Water Oxidation

“…As presented in Figure a, within applied voltages ranging from 0.726 to 1.226 V (vs RHE), NiO/CeO 2 NW@CC exhibited two distinguishable Raman peaks at 455 and 624 cm −1 , which could be referred to as the presence of NiOCe. [ 59,60 ] Remarkably, when the voltage was increased to 1.326 V, two new peaks at 487 and 565 cm −1 belonging to NiOOH species dominated in the Raman spectra, [ 61 ] which was in accordance with the aforementioned results. As the applied voltage was further increased, the peaks related to NiOOH became stronger.…”

Bifunctional Catalytic Activity of Solvothermally Synthesized CeO2 Nanosphere/NiO Nanoflake Nanocomposites

“…34-0394, which corresponds to the fluorite-type face-centred cubic (fcc) structure. The most intense peak, that is, (111), is used to calculate the crystallite size according to the Scherrer formula 40 [D = 0.9 λ/β cos θ, where D = crystallite size, λ = wavelength of the X-ray, β = full width at half-maxima (fwhm in radian) of the (111) plane, and θ = Bragg's angle]. The calculated crystallite size was 6.3 nm, revealing that CeO 2 nanospheres are made of fine crystallites.…”

“…The OER kinetics can be established by evaluating the Tafel slope value, where the lower the value of the Tafel slope indicates faster OER kinetics. 40 The Tafel slopes for all the catalysts along with commercial IrO 2 are obtained from the potential versus log of current density plots (Figures 6b and S4b) from their corresponding LSV polarization plots. For IrO 2 , the Tafel slope value is 114.7 mV dec −1 , which matches the previous report.…”

Rare Earth‐Based Nanomaterials for Supercapacitors: Preparation, Structure Engineering and Application

“…Manibalan et al. prepared heterostructure NiO/CeO 2 nanocomposites via a hydrothermal route (Figure 2A–C), which showed two distinguished morphologies, spherical CeO 2 and hexagonal NiO nanoparticles, with average size of 8–10 nm [78] . In short, the preparation method of the 0D RE‐based nanomaterials mainly involves chemical precipitation, hydro/solvothermal method, sonochemical method, SILAR, and sol‐gel method, in which the chemical precipitation is the most frequently used method.…”