The metal-organic-framework (MOF) approach is demonstrated as an effective strategy for the morphology evolution control of MIL-53(Fe) with assistance of microwave irradiation. Owing to the homogeneous nucleation offered by microwave irradiation and confined porosity and skeleton by MOF templates, various porous FeO nanostructures including spindle, concave octahedron, solid octahedron, yolk-shell octahedron, and nanorod with porosity control are derived by simply adjusting the irradiation time. The formation mechanism for the MOF precursors and their derived iron oxides with morphology control is investigated. The main product of the mesoporous yolk-shell octahedron-in-octahedron FeO nanostructure is also found to be a promising anode material for lithium-ion batteries due to its excellent Li-storage performance. It can deliver a reversible larger-than-theoretical capacity of 1176 mAh g after 200 cycles at 100 mA g and good high-rate performance (744 mAh g after 500 cycles at 1 A g).

A unique CoS-graphene sheet-on-sheet nanocomposite has been successfully prepared by anchoring CoS nanosheets on the surface of graphene nanosheets (GNS) with the assistance of the structure-directing agent of ethylenediamine. The shape and size of the introduced CoS nanosheets can be further adjusted by varying the amount of GNS. The unprecedented sheet-like CoS structure is believed to be matched well with GNS basically due to their similar two-dimensional structure with maximum contact areas between two components. The strong interaction between CoS and the underlying highly conductive graphene can facilitate fast electron and ion transport and improve structure stability of the composite. The composite with 26.2% GNS displays excellent electrochemical performance when evaluated as an anode for rechargeable lithium-ion battery. A larger-than-theoretical reversible capacity of 898 mAh/g can be delivered after 80 cycles at 0.1 C along with excellent highrate cycling performance. The CoS-graphene sheet-on-sheet composite is also used for the first time as a photocatalyst with promising properties for the degradation of methylene blue.

This paper reports fast microwave hydrothermal synthesis of Ni-based metal−organic frameworks (Ni-MOFs) and their derived yolk−shell NiO structures by direct calcination in air. The molar ratio of the Ni ion to the benzene-1,3,5-tricarboxylic acid (H 3 BTC) ligand has important influence on the NiO morphologies and their electrochemical performances. The obtained yolk−shell NiO microsphere displays a large reversible capacity of 1060 mAh g −1 at a small current density of 0.2 A g −1 and a good high-rate capability when evaluated as an anode for rechargeable lithium-ion batteries. Moreover, the facilitated hydrogen release from ammonia borane (AB) at a lower temperature and the depressed release of undesired volatile byproducts are also observed in the Ni-MOFs supported AB.There is a increasing demand to make efficient use of energy and to find renewable and clean energy sources that can substitute for fossil fuels. 1,2 Energy storage, an important intermediate step toward versatile, clean, and efficient energy applications, has received worldwide concern both in academia and industry. 3−7 Among various candidates of energy storage systems, lithium-ion batteries (LIB) and fuel cells have received considerable attention owing to their high energy densities and environmental benignity. 8−16 LIB, one of the most important rechargeable batteries, have been widely used due to their high energy density and long cycle life. 10,17,18 Metal oxides such as NiO have long been extensively investigated as a potential electrode material for LIBs because of their 2−3 times higher theoretical capacities than commercial graphite electrodes. 19−42 However, their cycling performances and high-rate capabilities are still not satisfactory due to the large volume change associated with lithium insertion and extraction and poor electrical conductivity. 32−38,40−42 Hydrogen is one of the most promising candidates to replace nonrenewable fuel sources because it can react with oxygen to generate electricity with high energy density without byproducts. 43−45 Thus, hydrogen has been regarded as a suitable energy carrier for energy production from primary sources. Advanced materials are highly desired that can store a large amount of hydrogen at mild conditions (common temperature and relatively low pressure) along with a fast release kinetics. 46 Over the past decade, ammonia borane (NH 3 BH 3 , AB) has received much attention as a solid-state hydrogen storage medium because of its satisfactory stability, relatively low molecular mass, and remarkably high energy density. 47−50 However, its practical application is greatly limited by the poor kinetics of hydrogen generation below 85°C and the release of impurities that are detrimental to fuel cells.Metal−organic frameworks (MOFs) are porous materials synthesized by assembling metal ions with organic bridging ligands. 51,52 The metal ions in the MOFs can be thermally transformed into metal oxides, and the C and other elements are oxidized into gas molecules after calcining the MOFs in air at e...