New network polymer functionalized magnetic-mesoporous nanoparticle for rapid adsorption of Hg(II) and sequential efficient reutilization as a catalyst

[Display omitted] •A novel magnetic network polymer composite (MCTP) was designed.•The adsorption capacity of MCTP reached 245.49 mg/g within only 15 min.•Coexisting ions had no significant effect on selective Hg(II) ions uptake.•The adsorption performance after 5 cycles did not obviously reduce.•The waste adsorbent was utilized for catalytic reaction with 99% yield. Herein, a novel magnetic network polymer composite (MCTP) was constructed by introducing the poly(m-aminothiophenol) and chitosan onto the magnetic-mesoporous nanoparticle under tannic acid as a crosslinking agent. Adsorption study indicated the removal rate and adsorption capacity of MCTP reached 98.16% and 245.49 mg/g within 15 min, meanwhile, it showed favorable recyclability after 5 cycles and excellent selectivity. The high-efficiency adsorption of Hg(II) is mainly dominated by chemical adsorption through forming stronger coordination bonds or Hg(II)-chelate complex between sulfur or nitrogen groups and Hg(II). Furthermore, the reutilization of toxic spent adsorbent was explored by converting MCTP/Hg(II) into a catalyst for synthesis of acetophenone with 99% yield, and most of phenylacetylene derivatives were transformed to corresponding acetophenone in excellent yields (>98%). Overall, this work not only reports a promising magnetic composite for treatment of Hg(II)-containing wastewater, but establishes the value-added utilization of waste adsorbent.