A sulfur-containing fluorescent hybrid porous polymer for selective detection and adsorption of Hg2+ ions

Abstract

Developing dual-function materials that can simultaneously detect and remove mercury ions (Hg²⁺) is significant because water contamination caused by Hg²⁺ has greatly threatened environmental and human health. However, it is difficult to achieve efficient dual-function. Herein, we report a highly efficient and selective dual-function material, that is, a sulfur-containing fluorescent hybrid porous polymer (HPP-SH), for the detection and adsorption of Hg²⁺. HPP-SH was simply prepared by the Heck reaction of octavinylsilsesquioxane and 4,4′-dibromobiphenyl and subsequent post-functionalization by a thiol–ene reaction of 1,2-ethanedithiol with retained vinyl groups in the framework. HPP-SH suspension in water can selectively and efficiently detect Hg²⁺ ions with a low limit of detection of 4.48 ppb by a fluorescence “turn-off” mode, and capture Hg²⁺ ions with a maximum adsorption capacity of 900.9 mg g⁻¹ and without the interference of other metal ions. The adsorption process conforms to the pseudo-second-order kinetic and Langmuir model. Moreover, the material can be easily recycled for repeated adsorption of Hg²⁺ ions. The excellent dual-function performance is better than those of most of the previous Hg²⁺ sensors or adsorbents. These results reveal that the present material can be utilized as a promising candidate for Hg²⁺ detection and removal from aqueous solutions. More efficient Hg²⁺ sensors and/or adsorbents can be conceived and prepared by this simple strategy.