Conversion of Amorphous MOF Microspheres into a Nickel Phosphate Battery-Type Electrode Using the “Anticollapse” Two-Step Strategy

Abstract

Metal–organic frameworks (MOFs) have attracted great attention as templates for preparation of functional porous materials owing to their adjustable structures, rich porosity, and controllable components. However, collapsed templates during the conversion process hinder their application and synthesis of derivatives. In this study, we demonstrate a novel two-step etching strategy during which amorphous MOF microspheres are initially transformed into nickel hydroxide and then subsequently transformed into microspherical nickel phosphates. Through this strategy, the prepared nickel phosphates maintain the microspherical morphology of MOFs but with no MOF residuals, exhibiting ultrahigh specific surface area, uniform pore size, and good structural robustness. Examined as a supercapacitor electrode, they show an outstanding specific capacity of 820 C g–1 at 0.5 A g–1 and remarkable cycling stability of 88% capacity retention after 10 000 cycles. Moreover, an asymmetric supercapacitor constructed utilizing reduced graphene cross-linked with p-phenylenediamine oxide (PPD-rGO) as the cathode displays a preeminent energy density of 64.56 Wh kg–1 at a power density of 507 W kg–1. This strategy has important significance in guiding the preparation of high-performance MOF-derived electrodes.

Fabrication of Nanometer-Sized Nickel-Based Metal Organic Frameworks on Carbon Nanotubes for Electro-Catalytic Oxidation of Urea and Arsenic Removal

“…The XRD pattern of nickelocene-derived NiO@CNT (Figure a) shows the broad carbon peak centered at 24.1° corresponding to (1 1 0) oxidized carbon peaks in addition to the nickel moiety-related (1 1 1) peak at 43.45°, (2 0 0) peak at 47.67°, and (2 2 0) peak at 69.8°, whereas in Ni-MOF@CNT, the XRD plot is dominated by the intense peak at 23.44° corresponding to either (1 0 0) oxidized carbon peak or (1 0 4) peak of nickel-based MOFs . Besides this two sharp peaks at 44.07 and 51.45° corresponding to (2 0 0) and (2 2 0) and minor peaks at 30.55, 58.89, and 64.45° corresponding to (2 2 1), (1 1 1), and (0 0 4), respectively, can also be observed. , The calculated crystallite size is found to be 39.22 nm, which is consistent with a crystallite size reported in other TPA-based nickel MOFs …”

“…67 Besides this two sharp peaks at 44.07 and 51.45°corresponding to (2 0 0) and (2 2 0) and minor peaks at 30.55, 58.89, and 64.45°corresponding to (2 2 1), (1 1 1), and (0 0 4), respectively, can also be observed. 56,57 The calculated crystallite size is found to be 39.22 nm, which is consistent with a crystallite size reported in other TPA-based nickel MOFs. 58 Further variation in structural properties of NiO@CNT and NiMOF@CNT was studied by Raman spectroscopy.…”

Tungsten-doped cobalt sulfide/selendie as high-efficient electrocatalyst for outstanding overall water splitting

“…The Fig. 4a con rms the existence of numerous mesopores in W-CoS 1.097 /CoSe 2 [50,51] . Particularly, W-CoS 1.097 /CoSe 2 acquires the high speci c surface area of 27.00 m 2 /g.…”

A Multifunctional Coordination Polymer Constructed by Viologen Derivatives: Photochromism, Chemochromism, and MnO4– Sensing

“…Coordination polymers (CPs), constructed by metal ions and organic ligands, are considered to be a promising class of hybrid materials because they integrate the merits of inorganic and organic materials. − In the past two decades, CPs feature determined crystal structures, tailorable compositions, and designable properties, thus providing wide application prospects in gas adsorption and separation, − catalysis, − energy conversion, , luminescence and sensing, − CO 2 capture and catalysis, − photochromism, , magnets − and so on. − Therefore, it is expected to obtain CPs with targeted structures and properties through the judicious choices and modifications of synthesis conditions, metal nodes, and organic linkers. However, multifunctional CPs combining a set of well-defined properties for specific applications are still rarely reported. − It remains quite challenging to fuse a variety of necessary properties into the backbone of a CP.…”