Spherically Structured Ce‐Metal‐Organic Frameworks with Rough Surfaces and Carbon‐Coated Cerium Oxide as Potential Electrodes for Lithium Storage and Supercapacitors

Abstract

The rough spherical-shaped cerium metal-organic framework (Ce-MOF) is synthesized by using solvothermal technique, and after being calcined at 550 °C both with and without tannic acid, CeO 2 and C@CeO 2 are produced. As synthesized Ce-MOF, CeO 2 , and C@CeO 2 are constructed as anodes for lithium-ion batteries (LIBs), also Ce-MOF and C@CeO 2 are investigated for use in supercapacitors. In the case of LIBs, as anode, C@CeO 2 exhibits a good reversible discharge capacity of 137 mAh g À 1 with 99 % coulombic efficiency over 250 cycles at 1 C rate. It demonstrates that the conductivity is greatly improved by the carbon covering than the pristine CeO 2 and Ce-MOF. After the galvanostatic charge-discharge technique at 1 C rate, the morphology size was investigated using FESEM to conform further the following alloying and dealloying mechanism of C@CeO 2 and the dissolution of terephthalic acid (TPA) in the non-aqueous electrolyte that is connected to the core structure of Ce-MOF. In terms of supercapacitors, rough surface morphology improves the electrode electrolyte conduct also the ligand TPA of free terminal acid group attracting K + and forms the COO À K + . Thus, Ce-MOF exhibits a good specific capacitance; after 5000 cycles, it produces 118 F g À 1 at 4 A g À 1 .with 65.2 % capacitance retention. The archived maximum power and energy density outcomes of 10.6 kW kg À 1 and 0.56 Wh kg À 1 at 2 A g À 1 .

Ultra-High Cycling Stability of 3D Flower-like Ce(COOH)3 for Supercapacitor Electrode via a Facile and Scalable Strategy

“…This ultra-high cycling stability and remarkable reversibility of Ce(COOH) 3 were first discovered in this work. In fact, as summarized in Table 1, the cycling stability and capacitance retention rate of Ce(COOH) 3 are the highest among the reported Ce-organic compounds to the best of our knowledge [18,21,36,[38][39][40][41][42]. Moreover, the cycling stability and capacitance retention rate of Ce(COOH) 3 also have substantial advantages among the other most reported metal-organic compounds known for their long cycle life, such as Ni 3 (HITP) 2 (90% after 10,000 cycles at 2 A g −1 ) [16], Co-MOF (96% after 10,000 cycles at 5 mA cm −2 ) [43], Ni/Co-MOF (89.8% after 12,000 cycles at 10 A g −1 ) [44], Cu 3 (HHTP) 2 (79.9% after 5000 cycles at 5 A g −1 ) [45], V-MOF (92.1% after 10,000 cycles at 1 A g −1 ) [46], Cr-MOF (85% after 10,000 cycles at 0.5 A g −1 ) [47], Mn-MOF (81.18% after 10,000 cycles at 10 A g −1 ) [48], and Fe-MOF (74.4% after 10,000 cycles at 1 A g −1 ) [49].…”

Dual-Mode Ce-MOF Nanozymes for Rapid and Selective Detection of Hydrogen Sulfide in Aquatic Products

“…High-resolution XPS spectra of Ce 3d indicated the coexistence of Ce 4+ and Ce 3+ on the surface of Ce-MOF ( Figure 2 h). Herein, 886.28 and 900.48 eV belong to the valance state of 3 + , and 881.58 and 904.48 eV denote the 4 + state for Ce [ 31 ]. Moreover, the high-resolution C 1s spectrum displayed peaks at 286.18, 284.78 and 288.58 eV, corresponding to C–O, C–C and O–C=O bonds ( Figure 2 f), and the O 1s spectrum showed peaks at 532.48 and 531.48 eV for O–C=O and Ce–OH, confirming the chemical environment of the surface ( Figure 2 g) [ 22 ].…”

Development of MOF-Pigment Hybrids to Implement a Sustainable Coloration of Poly(ε-caprolactone) Composites

“…The thermal treatment applied at 350 °C for 4 h modified the shape of ntMOF; the sample ttMOF is indeed characterized by the presence of spherical nanoparticles having a diameter of 50−100 nm, with a rasp-like spherical morphology (a similar morphological aspect was observed in the literature for cerium and aluminum metal−organic frameworks (Ce-MOF and Al-MOF)). 19,27,28 The deMOF presented a morphology similar to the ntMOF sample with agglomeration of particles that was minimally affected by the weak heating treatment at 105 °C. Figures 2d−f show the morphological properties of MOF-based pigments obtained using ntMOF, ttMOF, and deMOF, respectively, LWP1, LWP2, and LWP3.…”