A selective colorimetric and efficient removal strategy for mercury (II) using mesoporous silver-melamine nanocomposites synthesized by controlled supramolecular self-assembly

Mesoporous silver-melamine (Ag-MA) nanocomposites were synthesized by controlled supramolecular self-assembly with various structural morphologies. It was discovered that the rod-like Ag-MA nanocomposites could present the larger Hg2+-enhanced catalysis by forming Ag-Hg alloys. Also, they could display large surface-to-volume area and high aqueous stability for the selective Hg2+ enrichment and absorption of Hg2+ ions by yielding the stable coordination complexes. A catalysis-based colorimetric method was thus developed using 96-wells plates to probe Hg2+ ions in blood and wastewater with the linear Hg2+ concentrations ranging from 1.0 nM to 600 nM and 0.50 nM to 700 nM, respectively. Besides, mesoporous Ag-MA absorbents could facilitate the removal of Hg2+ ions in wastewater with the removal efficiency up to 99.76 % and the absorption capacity of 598.99 mg g−1.