title: Fe-, Co-, and Ni-Loaded Porous Activated Carbon Balls as Lightweight Microwave Absorbents.
abstract: Porous activated carbon ball (PACB) composites impregnated with iron, cobalt, nickel and/or their oxides were synthesized through a wet chemistry method involving PACBs as the carrier to load Fe(3+), Co(2+), and Ni(2+) ions and a subsequent carbothermal reduction at different annealing temperatures. The results show that the pyrolysis products of nitrates and/or the products from the carbothermal reduction are embedded in the pores of the PACBs, with different distributions, resulting in different crystalline phases. The as-prepared PACB composites possessed high specific surface areas of 791.2-901.5 m(2)  g(-1) and low densities of 1.1-1.3 g cm(-3). Minimum reflection loss (RL) values of -50.1, -20.6, and -20.4 dB were achieved for Fe-PACB (annealed at 500 °C), Co-PACB (annealed at 800 °C), and Ni-PACB (annealed at 800 °C) composites, respectively. Moreover, the influence of the amount of the magnetic components in the PACB composites on the microwave-absorbing performances was investigated, further confirming that the dielectric loss was the primary contributor to microwave absorption.
authors.affiliation: Key Laboratory of Carbon Materials, Institute of Coal Chemistry, Chinese Academy of Sciences, Taiyuan, 030001, P. R. China.|University of Chinese Academy of Sciences, Beijing, 100049, P. R. China.
authors.forename: Guomin
authors.initials: G
authors.lastname: Li
authors.affiliation: Key Laboratory of Carbon Materials, Institute of Coal Chemistry, Chinese Academy of Sciences, Taiyuan, 030001, P. R. China.
authors.forename: Liancheng
authors.initials: L
authors.lastname: Wang
authors.affiliation: Key Laboratory of Carbon Materials, Institute of Coal Chemistry, Chinese Academy of Sciences, Taiyuan, 030001, P. R. China.|University of Chinese Academy of Sciences, Beijing, 100049, P. R. China.
authors.forename: Wanxi
authors.initials: W
authors.lastname: Li
authors.affiliation: Key Laboratory of Carbon Materials, Institute of Coal Chemistry, Chinese Academy of Sciences, Taiyuan, 030001, P. R. China. xuyao@sxicc.ac.cn.
authors.forename: Yao
authors.initials: Y
authors.lastname: Xu
keywords: cobalt; iron; microwave absorption; nickel; porous activated carbon balls