Tunable Co₃O₄ hollow structures (from yolk–shell to multi-shell) and their Li storage properties

Abstract

In this work, we report a facile approach to synthesize uniform Co3O4 hollow spheres with tunable shell numbers via controllably annealing cobalt(ii) complex precursors at different heating rates.

A Simple and Scalable Route to Synthesize CoxCu1−xCo2O4@CoyCu1−yCo2O4 Yolk–Shell Microspheres, A High‐Performance Catalyst to Hydrolyze Ammonia Borane for Hydrogen Production

“…The possible formation processes for the yolk–shell structured Co 3 O 4 and Co x Cu 1− x Co 2 O 4 @Co y Cu 1− y Co 2 O 4 are illustrated in Figure . It should be mentioned that yolk–shell structured Co 3 O 4 @Co 3 O 4 had also been prepared by other approaches . In contrast, our synthetic process is very simple.…”

A Core‐Shell NiFe2O4@SiO2 Structure as a High‐Performance Anode Material for Lithium‐Ion Batteries

“…In the voltage range of 0.01–3.0 V, the charge and discharge curves of the 1st, 2nd, and 5th electrodes of the NiFe 2 O 4 and NiFe 2 O 4 @SiO 2 electrodes with a current density of 0.1 C are shown in Figure . It can be seen in Figure a, the pure NiFe 2 O 4 and NiFe 2 O 4 @SiO 2 electrodes exhibited a broad and stable discharge platform in the first cycle, with discharge ranging from 0.7 V (vs Li/Li + ) to 1 V (vs Li/Li + ), and then the voltage gradually decreased ,. The initial discharge/charge capacity of the bare NiFe 2 O 4 electrode was 1460.5/1040.0 mAh g −1 , and the Coulombic efficiency (CE) was 71.2 %, whereas 2022.3/1722.3 mAh g −1 with a Coulombic efficiency (CE) of 85.1 % for hybrid NiFe 2 O 4 @SiO 2 electrodes.…”

Synthesis of Single‐Component Metal Oxides with Controllable Multi‐Shelled Structure and their Morphology‐Related Applications

“…More recently, a solution‐based method under atmospheric pressure has succeeded in preparing multi‐shelled Co 3 O 4 hollow spheres . The desired products are obtained by two steps: (1) cobalt (II) nitrate hexahydrate, acetylacetone and hydrazine hydrate together react at 80 °C in solution to fabricate Co‐based precursors, (2) by decreasing the heating rate, e. g., from 10 °C/min to 5 °C/min then to 1°C/min, the hollow structures of Co 3 O 4 gradually evolve from yolk‐shell to multi‐shell.…”