Nickel oxide (NiO) has emerged as one of the most promising transition-metal oxides (TMOs) for electrochemical capacitors, batteries, catalysis, and electrochromic films, owing to its cost-effectiveness, abundance, and well-defined electrochemical properties. Recent studies have identified that mixing NiO with graphene or graphene derivatives results in novel composites with synergistic effects and superior electrochemical performance. This review summarizes the latest advances in composites of NiO with graphene or graphene derivatives. The synthetic strategies, morphologies, and electrochemical performance of these composites are introduced, as well as their electrochemical applications in supercapacitors, batteries, sensors, catalysis, and so forth. Finally, tentative conclusions and assessments regarding the opportunities and challenges for the future development of these composites and other TMOs/graphene or graphene-derived composites are presented. 相似文献
The modifications of electrodes using graphene and graphene composites in microbial fuel cells (MFCs) and microbial electrolysis cells (MECs) have been widely applied for enhancing the electrochemical catalytic activity and performance of MFCs and MECs. Graphene as one of advanced materials has shown outstanding features for promoting practical applications of MFCs. This review summarizes the modification methods and characterization methods of graphene and related graphene composites on electrode surfaces in MFCs and MECs. The performance improvements of MFCs and MECs by various graphene related composites have been reviewed, which will provide an efficient guide for selecting suitable graphene material to modify electrodes in MFCs and MECs for improving their performance. 相似文献
Graphene functionalization by hydroxyalkylation and grafting with polyether polyols enables polyurethane (PU) nanocomposites formation by in situ polymerization with isocyanates combined with effective covalent interfacial coupling. Functionalized graphene (FG) hydroxylation is achieved either by alkylation, transesterification, or grafting of thermally reduced graphite oxide. In the presence of K2CO3 as catalyst the reaction of FG‐OH with ethylene carbonate at 180 °C affords hydroxyethylated FG, whereas transesterification with castor oil produces riconoleiate‐modified FG polyols. In the “grafting‐from” process, FG‐alkoholate macro initiators initiate the graft polymerization of propylene oxide to produce hybrid FG polyols containing 38 and 59 wt% oligopropylene oxide. In the “grafting‐to” process 3‐ethyl‐3‐hydroxymethyl‐oxetane is cationically polymerized onto FG‐OH, producing novel hyperbranched FG‐based polyether polyols. Whereas hydroxylation and grafting of FG greatly improve FG dispersion in organic solvents, polyols and even PU, as confirmed by transmission electron microscopy, matrix reinforcement of FG/PU is impaired by increasing alkyl chain length and polyol graft copolymer content.
Injectable hydrogels have attracted a lot of attention in drug delivery, however, their capacity to deliver water-insoluble or hydrophobic anti-cancer drugs is limited. Here, we developed injectable graphene oxide/graphene composite supramolecular hydrogels to deliver anti-cancer drugs. Pluronic F-127 was used to stabilize graphene oxide (GO) and reduced graphene oxide (RGO) in solution, which was mixed with α-cyclodextrin (α-CD) solution to form hydrogels. Native hydrogel was used as control. GO or RGO slightly shortened gelation time. The storage and loss moduli of the hydrogels were tracked by dynamic force measurement. The storage modulus of GO or RGO composite hydrogels was larger than that of the native hydrogel. Hydrogels were unstable in solution and eroded gradually. GO or RGO in Pluronic F-127 solution could potentially improve the solubility of the water-insoluble anti-cancer drug camptothecin (CPT), especially with large drug-loaded CPT amount. Drug release behaviors from solutions and hydrogels were characterized. The nanocomponents (GO or RGO) were able to bind more drug molecules either for CPT or for doxorubicin hydrochloride (DXR) in solution. Therefore, GO or RGO composite hydrogel could potentially enable better controlled and gentler drug release (for both CPT and DXR) than native hydrogel. 相似文献
