An Original “Click and Bind” Approach for Immobilizing Copper Hexacyanoferrate Nanoparticles on Mesoporous Silica

Abstract

We present an original approach for preparing silica-based nanocomposites containing Prussian blue-type nanoparticles via click chemistry. Click reaction is used to prepare a triazole-copper complex in a single step; this complex is subsequently used to anchor copper hexacyanoferrate nanoparticles within a porous silica matrix (porous glass pearls or SBA-15). This CuAAC “click reaction” was performed using a relatively large copper concentration for two reasons: First, the Cu catalyzes the triazole ring formation, then the ring acts as a chelator, immobilizing the copper inside the silica matrix. Successively adding hexacyanoferrate precursors that coordinate with the copper ions at the triazole sites led to efficient and selective nanocomposite formation; this material was developed to mitigate Cs+ ion contamination. The efficiency of these as-prepared nanocomposites and their selectivity for Cs+ from different effluents, such as pure water, seawater, and radioactive seawater (simulating the Fukushima site), were evaluated using sorption experiments. These immobilized nanocomposites present a high Cs+ selectivity while demonstrating a Kd value above that of the bulk material.