Facile Fabrication of Three-Dimensional Graphene and Metal–Organic Framework Composites and Their Derivatives for Flexible All-Solid-State Supercapacitors

Abstract

A facile and general method for the large-scale preparation of various three-dimensional (3D) graphene oxide/metal−organic framework (GO/MOF) composites is developed through a simple mixing process using MOFs and graphene oxide. This preparation method is able to rapidly produce GO/MOF composite hydrogels with controllable composition in only several minutes, which is also suitable to a series of different MOFs. The obtained GO/MOF composites are severed as the precursors for the subsequent preparation of MOF-derived composite aerogels, e.g., rGO/Fe 2 O 3 and rGO/ NiO/Ni composite aerogels, through freeze-dry and calcination processes. When used as a supercapacitor electrode, the rGO/Fe 2 O 3 composite shows a good rate capability with high specific capacitances of 869.2 and 289.6 F•g −1 at the current densities of 1 and 20 A•g −1 , respectively, as well as a long cycle life without obvious decrease of capacitance after 5000 cycles. Moreover, the flexible all-solid-state supercapacitor device is also fabricated based on the obtained rGO/Fe 2 O 3 composite aerogel, which exhibits a high volumetric capacitance of 250 mF•cm −3 at 6.4 mA•cm −3 and a capacity retention of 96.3% after 5000 cycles at 50.4 mA•cm −3 , as well as an excellent mechanical flexibility.

A Highly Reversible Long‐Life Li–CO2 Battery with a RuP2‐Based Catalytic Cathode

“…These results further suggest that Li 2 CO 3 is generated as the main product over the discharge process and CO 2 is the main recharge product, confirming the outstanding reversibility of the RuP 2 ‐NPCF‐based Li–CO 2 batteries. According to recent reports, Li–CO 2 batteries are based on the following reversible reaction: 4Li + 3CO 2 ↔ 2Li 2 CO 3 + C . To illustrate whether there is the formation of carbon species during the discharge process, the carbon‐free Au/Ni electrodes were prepared through dispersing Au nanoparticles on nickel foams and the corresponding Au/Ni cathodes at different discharge/charge stages were analyzed by ex situ SEM images, XRD patterns, XPS, and Raman spectra.…”

Structural Engineering of Low‐Dimensional Metal–Organic Frameworks: Synthesis, Properties, and Applications

“…[25][26][27][28][29] Low-dimensional (LD) nanomaterials are of particular interest due to their anisotropic-tunable properties, which greatly influence their performances. [41][42][43][44][45][46][47] More recently, LD MOFs have attracted intensive interest and been investigated in various applications. [38][39][40] As another typical LD materials, 2D nanomaterials, such as 2D nanosheets of layered double hydroxides (LDHs), transition metal dichalcogenides (TMDs), hexagonal boron nitride, and MXenes, have attracted widespread attention since the discovery of graphene.…”

Rational Microstructure Design on Metal–Organic Framework Composites for Better Electrochemical Performances: Design Principle, Synthetic Strategy, and Promotion Mechanism

“…After the subsequent vigorous vibration using Q2‐1 vortex mixer to form a hydrogel and the following freeze‐drying process, the GO/MOFs aerogel composites were obtained. including GO/Ni‐MOF, GO/Zif‐8, GO/MOF‐5, GO/Sn‐MOF, GO/Co‐MOF, and GO/Fe‐MOF/Ni‐MOF …”

“…e) Schematic for the fabrication process of various CoS hollow structures, and TEM images of the f) CoS‐nanoparticle‐assembled single‐shelled nanoboxes (CoS‐NP SSNBs), g) CoS‐nanosheet‐organized single‐shelled nanoboxes, and h) hierarchical double‐shelled hollow structures consisting of CoS‐NP nanoboxes surrounded by CoS nanosheets. Reproduced with permission . Copyright 2016, Cell.…”