From 1D to 2D: Controllable Preparation of 2D Ni–MOFs for Supercapacitors

Abstract

Controllable modulation strategies between onedimensional (1D) and two-dimensional (2D) structures have been rarely reported for metal−organic frameworks (MOFs). Here, 1D, 1D/2D, and 2D Ni−MOFs can be facilely prepared by adjusting the ratio of Ni 2+ and the pyromellitic acid linker. A low-dimensional structure can shorten the transmission distance, while MOFs with a high Ni 2+ content can supply rich active sites for oxidation− reduction reactions. The 2D structure Ni-MOF with an optimized Ni 2+ /pyromellitic acid ratio presents a good performance of 1036 F g −1 at a current density of 1 A g −1 with a comparable rate performance of 62% at 20 A g −1 . The study may offer a facile design to control the structure of MOFs for employing in electrochemical energy storage.

Colorimetry/Smartphone Dual-Mode Sensing Platform Based on Nanorod-Shaped Ni–Fe MOFs for Ascorbic Acid Detection

“…As exhibited in Figure a, the survey spectra of Ni–Fe MOFs possessed the coexistence of Ni, Fe, C, N, and O elements. Figure b shows the high-resolution Ni 2p of Ni–Fe MOFs located at 855.73 and 873.43 eV, which is attributed to Ni 2p 3/2 and Ni 2p 1/2 of the Ni 2+ valence form, respectively. , The high-resolution XPS spectrum of Fe 2p for the as-obtained sample indicated typical peaks at 711.27 and 724.74 eV, which were assigned to Fe 2p 3/2 and Fe 2p 1/2 of the Fe 3+ valence form (Figure c), respectively. − The XPS spectrum of C 1s of Ni–Fe MOFs displayed two peaks at 284.3 and 288.13 eV, which corresponded to the O–C=O of ligands (Figure d); while the peak at 285.52 eV could be attributed to C–C. , The XPS spectrum of N 1s (Figure e) exhibited two peaks at 399.26 and 401.44 eV, which could be assigned to C–N and N–H bonds of the ligand 2-aminoterephthalic acid, respectively. The XPS spectrum of the O 1s region (Figure f) contained two diffraction peaks at 531.37 and 533.24 eV, which corresponded to C=O and C–O bonds of Ni–Fe MOFs, respectively.…”

“…The diffraction peaks could be ascribed to the topology of MIL-88B, but with distinct structural forms. 28 The characteristic diffraction peaks located at 2θ = 7.2°, 8.8°, 10.2°, 15.0°, 15.8°, and 17.8°c orrespond to the (002), ( 101 29,30 The high-resolution XPS spectrum of Fe 2p for the as-obtained sample indicated typical peaks at 711.27 and 724.74 eV, which were assigned to Fe 2p 3/2 and Fe 2p 1/2 of the Fe 3+ valence form (Figure 2c), respectively. 31−33 The XPS spectrum of C 1s of Ni−Fe MOFs displayed two peaks at 284.3 and 288.13 eV, which corresponded to the O−C=O of ligands (Figure 2d); while the peak at 285.52 eV could be attributed to C−C.…”

Enhancement of the photocatalytic activity of the NiO-porous NiO homojunction derived from the in situ templated metal–organic framework

“…2d and e). 27 The post-annealing process in the air atmosphere converted the Ni(OH) 2 @Ni-MOF into the core–shell NiO@PNiO-48 homojunction with the dense NiO embraced by the porous PNiO shell (Fig. S1†), which showed very similar morphology to that of Ni(OH) 2 @Ni-MOF-48.…”

“…With the increased reaction time and greater dissociation of Ni(OH) 2 , the peak intensity of Ni-MOF was progressively enhanced, and the major diffraction peaks of Ni-MOF were in agreement with the pattern of Ni 2 (bdc) 2 reported in the literature. 27 NiO@PNiO derived from Ni(OH) 2 @Ni-MOF, and its homojunction were characterized and are shown in Fig. 1c.…”

Rational Design of NiCo-borate/GO Heterojunction as a High-Performance Supercapacitor Electrode

“…One of the key factors affecting ED is the performance of electrode materials. , Therefore, rational design of electrode materials is an effective approach to improving the ED of supercapacitors. Due to the high theoretical capacity of nickel-based materials and their advantages such as thermal stability, chemical stability, low cost, and environmental friendliness in various electrolytes, they can serve as potential pseudocapacitive electrode materials. , However, the poor conductivity of a single nickel-based material and its volume change during cycling hinder its further development and application in supercapacitors. To solve this problem, rational design of the material’s structure and the introduction of an appropriate amount of other conductive materials may be effective strategies.…”