Synthesis of Mesoporous Single Crystal Co(OH)₂ Nanoplate and Its Topotactic Conversion to Dual-Pore Mesoporous Single Crystal Co₃O₄

Abstract

A new class of mesoporous single crystalline (MSC) material, Co(OH)2 nanoplates, is synthesized by a soft template method, and it is topotactically converted to dual-pore MSC Co3O4. Most mesoporous materials derived from the soft template method are reported to be amorphous or polycrystallined; however, in our synthesis, Co(OH)2 seeds grow to form single crystals, with amphiphilic block copolymer F127 colloids as the pore producer. The single-crystalline nature of material can be kept during the conversion from Co(OH)2 to Co3O4, and special dual-pore MSC Co3O4 nanoplates can be obtained. As the anode of lithium-ion batteries, such dual-pore MSC Co3O4 nanoplates possess exceedingly high capacity as well as long cyclic performance (730 mAh g(-1) at 1 A g(-1) after the 350th cycle). The superior performance is because of the unique hierarchical mesoporous structure, which could significantly improve Li(+) diffusion kinetics, and the exposed highly active (111) crystal planes are in favor of the conversion reaction in the charge/discharge cycles.

Bamboo‐Like Hollow Tubes with MoS2/N‐Doped‐C Interfaces Boost Potassium‐Ion Storage

“…Figure i presents the N 2 adsorption–desorption isotherms and the Barret–Joyner–Halenda (BJH) pore‐size distribution curves of the MoS 2 /N‐doped‐C tube. The material has a type IV isotherm with a hysteresis loop in the Brunauer, Deming, Deming, and Teller classification, which confirms the existence of mesopores in the tubes . The Brunauer–Emmett–Teller–specific surface area is 51.9 m 2 g −1 ; it is much higher than that of the pure MoS 2 (5.9 m 2 g −1 ) (Figure S11, Supporting Information).…”

Optimization of Von Mises Stress Distribution in Mesoporous α‐Fe2O3/C Hollow Bowls Synergistically Boosts Gravimetric/Volumetric Capacity and High‐Rate Stability in Alkali‐Ion Batteries

“…The lattice fringes of 3.68 Å indicated in a representative high‐resolution transmission electron microscopy (HRTEM) image correspond to the (012) planes of α‐Fe 2 O 3 (Figure i). The adsorption–desorption isotherm (Figure S7a, Supporting Information) belongs to a type‐IV curve with an H3 hysteresis loop, and the specific surface area was calculated to be 48.9 m 2 g −1 , according to the Brunauer–Emmett–Teller method. The pore size distribution mainly ranges from 10 to 40 nm (Figure S7b, Supporting Information), confirming the mesoporous structure.…”

Nano Co3O4 as Anode Material for Li–Ion and Na‐Ion Batteries: An Insight into Surface Morphology

“…In the present investigation the observed variation in ‘a’ values was due to the self‐interstitials and mechanically induced strains developed during nucleation . Co 3 O 4 formation mechanism is given as below: …”