Silver Nanoparticles Prepared by One-Step Reaction via Reducibility of a Metal–Organic Framework to Remove the Toxic Bromine Ions

In this work, an aluminum-based metal–organic framework (MOF), CAU-1-(OH) 2, was utilized as the reduction precursor for the first time to prepare an adsorbent with well-dispersed reduced silver (Ag 0 ) nanoparticles. The synthesized Ag 0 /carbon nanoparticle (Ag 0 /C-NP) is composed of the carbon-based matrix and Ag nanoparticles with a uniform size of 5–10 nm. Thanks to the feature of the loaded Ag nanoparticles, the obtained material exhibits a high adsorption capacity of bromide (Br – ) (177.4 mg g –1 ), fast adsorption kinetics (∼1 h for reaching adsorption saturation), and good anti-interference ability, which is superior to those of the original MOF and other reported adsorbents. The adsorption isotherms and kinetics were fitted well by using the Langmuir model, the adsorption isotherm regional analysis (Arian) model, and the pseudo-second-order kinetic model. Therefore, these results demonstrate that not only Ag 0 /C-NP is a promising material for efficient removal of Br – but also provides a convenient and universal method for developing adsorbents with the help of reductive features of MOFs.