Ji Man Kim

Mesoporous molecular sieve MCM-41 with a Si/Al ratio of 39 was obtained by hydrothermal synthesis with a gel composition of 6 SiO2:0.1 Al2O3:1 hexadecyltrimethylammonium chloride:0.25 dodecyltrimethylammonium bromide:0.25 tetrapropylammonium bromide:0.15 (NH4)(2)0:1.5 Na2O:300 H2O. The MCM-41 sample incorporating aluminum (AlMCM-41) was calcined in O-2 flow at 813 K and subsequently ion exchanged with Na+, K+, Ca2+, and Y3+. Th, ion exchange levels have been increased as high as 0.41 Na/Al, 0.36

This review summarizes organic molecule-based electrode materials for rechargeable batteries.

Truncated rhombic dodecahedral crystals of the mesoporous molecular sieve MCM-48 are synthesised by a hydrothermal procedure using sodium silicate, hexadecyltrimethylammonium bromide and various kinds of alcohol.

This work reports the synthesis and application of metal-organic framework (MOF)@microporous organic network (MON) hybrid materials. Coating a MOF, UiO-66-NH2, with MONs forms hybrid microporous materials with hydrophobic surfaces. The original UiO-66-NH2 shows good wettability in water. In comparison, the MOF@MON hybrid materials float on water and show excellent performance for adsorption of a model organic compound, toluene, in water. Chemical etching of the MOF results in the formation of ho

The formation of mesoporous silica materials has been studied using blends of diblock (C n H 2 n +1 (OCH 2 CH 2 ) x OH, C n EO x, n = 12 − 18 and x = 2−100) and Pluronic triblock (EO x PO 70 EO x, x = 5−100) amphiphilic block copolymers as the structure-directing agents and sodium silicate as the silica source. The mesostructure of the silica materials thus obtained, as determined by X-ray diffraction and transmission electron microscopy, changes as the volume of the hydrophilic EO group of the

Hollow microporous organic networks (H-MONs) were prepared by a template method using silica spheres. The shell thickness was delicately controlled by changing the synthetic conditions. The H-MONs were used as a template for the synthesis of nanoparticulate Co3O4 hollows which showed excellent catalytic performance in H2O2 oxidation.

A commercially important synthetic approach to highly ordered mesoporous silica materials (SBA-family) with 2-D hexagonal (P6mm), 3-D hexagonal (P63/mmc) and cubic (Im3m and Pm3m) structures, using sodium silicate as the silica source and amphiphilic block copolymers as the structure-directing agents is demonstrated.

Highly ordered mesoporous silica can be regenerated from a mesoporous carbon CMK-3 that is a negative replica of mesoporous silica SBA-15, indicating reversible replication between carbon and inorganic materials.

Recently, we reported on the improvement of hydrothermal stability of mesoporous silica using salts solutions (Ryoo, R.; Jun, S. J. Phys. Chem. B 1997, 101, 317. Ryoo et al. J. Phys. Chem. 1996, 100, 17718). The salt effect has been reinvestigated here to solve problems of poor reproducibility. It turned out that the time-dependent effect was missing in the previous reports. The salt effect required approximately 10 days of treatment at 373 K to give its full effect. The time dependence was a cr

Mesoporous silica structures are of increasing importance as supports for enzymes and molecular organometallic catalysts. For high-surface-area, porous 3-d catalytic supports, the relationship between the exterior particle morphology and the 3-d mesopore structure is of particular significance. This paper describes the designed synthesis of selected morphologies of mesoporous SBA-15, which can be chosen from micrometer sized spheres to hundreds or tens of nanometers sized monodispersed particles

Iron oxide anode materials for rechargeable lithium-ion batteries have garnered extensive attention because of their inexpensiveness, safety, and high theoretical capacity. Nanostructured iron oxide anodes often undergo negative fading, that is, unconventional capacity increase, which results in a capacity increasing upon cycling. However, the detailed mechanism of negative fading still remains unclear, and there is no consensus on the provenance. Herein, we comprehensively investigate the negat

Developing electrode materials with high-energy densities is important for the development of lithium-ion batteries. Here, we demonstrate a mesoporous molybdenum dioxide material with abnormal lithium-storage sites, which exhibits a discharge capacity of 1,814 mAh g(-1) for the first cycle, more than twice its theoretical value, and maintains its initial capacity after 50 cycles. Contrary to previous reports, we find that a mechanism for the high and reversible lithium-storage capacity of the me

Tin oxide-based materials, operating via irreversible conversion and reversible alloying reaction, are promising lithium storage materials due to their higher capacity. Recent studies reported that nanostructured SnO 2 anode provides higher capacity beyond theoretical capacity based on the alloying reaction mechanism; however, their exact mechanism remains still unclear. Here, we report the detailed lithium storage mechanism of an ordered mesoporous SnO 2 electrode material. Synchrotron X-ray di