Self-assembled multifunctional Fe3O4 hierarchical microspheres: high-efficiency lithium-ion battery materials and hydrogenation catalysts

Abstract

Self-assembled Fe3O4 hierarchical microspheres (HMSs) were prepared by a one-pot synchronous reduction-self-assembling (SRSA) hydrothermal method. In this simple and inexpensive synthetic process, only glycerol, water, and a single iron source (potassium ferricyanide (K3[Fe(CN)6])) were employed as reactants without additional reductants, surfactants, or additives. The iron source, K3[Fe(CN)6], and glycerol significantly affected the synthesis of Fe3O4 HMSs. Fe3O4 HMSs with a self-assembled spherical shape readily functioned as high-performance anode materials for lithiumion batteries with a specific capacity of > 1000 mA h g−1 at 0.5 A g−1 after 270 cycles. Further charging and discharging results revealed that Fe3O4 HMSs displayed good reversible performance (> 1000 mA h g−1) and cycling stability (700 cycles) at 0.5 A g−1. Furthermore, as multifunctional materials, the as obtained Fe3O4 HMSs also exhibited high saturation magnetization (99.5 emu g−1) at room temperature (25°C) and could be further employed as efficient and magnetically recyclable catalysts for the hydrogenation of nitro compounds.