Self-assembled hollow mesoporous Co3O4 hybrid architectures: a facile synthesis and application in Li-ion batteries

Abstract

We report a facile and template-free soft chemical approach that employs a low-temperature calcination treatment to synthesize a new class of materials comprising self-arranged hollow mesoporous Co 3 O 4 and Co 3 O 4 -carbon nanotube composites. Each hollow particle is formed by a double-layered nanowall with a thickness of around 50-100 nm. The inner wall consists of a uniform amorphous layer, while the outer layer consists of self-assembled aggregates of ultrafine nanoflakes and particles. Our synthesis method is scalable and produces high yield with high reproducibility. When applied as negative electrodes in Li-ion batteries, the Co 3 O 4 -carbon nanotube composite exhibited superior performance with large reversible capacity, good cycling property and rate capability benefiting from the unique hollow and mesoporous Co 3 O 4 particle structures as well as the hybridization with carbon nanotubes.

Hollow Co3O4 Mesoporous Structures with Predominantly Exposed (111) Planes for CO Oxidation

“…3c are illustrated in Fig. S1c, d. The SAED patterns agreed well with the XRD results, indicating that the polycrystalline structure displayed high intensified rings corresponding to (111) and (311) planes [17,19]. Meanwhile, the EDS results showed an elemental composition of cobalt and oxygen with the stoichiometric ratio of Co 3 O 4 .…”

“…These observations were also confirmed by the microscopic investigations, as described later. The longer annealing time using in this study resulted in a larger pore size for hm-Co 3 O 4 when compared to that previously reported with a fixed annealing time of about 2 h [19]. This variation in the pore size of hm-Co 3 O 4 is suitable for heterogeneous gas-phase catalysis [17].…”

“…Mesoporous hollow structures of Co 3 O 4 were sysnthesized using a slightly modified version of a previously reported method [19]; Li 2 O 2 (0.6 g, fine white-colored powder; Aldrich, [90 %) powder was added rapidly to 100 mL of Co(NO 3 ) 2 Á6H 2 O (0.06 M, Fluka, [99 %) dissolved in isopropanol under vigorous stirring at 55°C until a black color precipitate was formed based on the complete evaporation of the solvent from the reaction mixture. The resulting solid product was thoroughly washed with deionized water, ethanol, and acetone and dried in an oven at 100°C overnight.…”

“…Thus, a simple template-free method is needed for preparing hollow nanocatalysts with clean surfaces and crystal planes with a high surface energy. Accordingly, this study investigated the CO oxidation catalytic activity of the hollow structures of Co 3 O 4 synthesized using a previously reported simple chemical method [19].…”

Synthesis of 2D/2D Structured Mesoporous Co3O4 Nanosheet/N‐Doped Reduced Graphene Oxide Composites as a Highly Stable Negative Electrode for Lithium Battery Applications

“…Even after 200 cycles at ah igh current rate, the reversible capacity is still highert han the theoretical limitations of conventionalg raphite;t he 2D/2D nanostructures also improve the electrochemical properties like interfacial and surface Li storage, apart from the classical conversion reaction. Also, the carbon coating on the Co 3 O 4 core-shell nanoparticlesm aintainst he electrical conduction pathway,a cts as ab uffer matrix to prevent particlea gglomeration, and maintains structural stability during the discharging/ [40,[45][46][47][48][49] Furthermore, we strongly believe that the high capacity and rate capability are undoubtedly derived from their unique hierarchical mesoporous morphology.…”