Thiophene-Based Porous Triazine Polyamide (Tb-PTPa) as the Next Promising and Cost-Effective Eliminator of Hg<sup>2+</sup> in Aqueous Media
Chaoji Xiong, Xingmao Zhang, Kun Liang, Chunhua Wu, Wei Wu, Xiaoping Rao, Qian Chen
Abstract
Research suggests that wastewater is highly polluted by Hg 2+, threatening the sustainability of our environment and the health conditions of human beings. However, most of the existing adsorbents have a poor adsorption performance and require expensive raw materials. A low-cost adsorbent material with a very high adsorption performance is therefore an urgent need. In this work, we have successfully prepared thiophene-based porous triazine polyamide (Tb-PTPa) for the first time, using two inexpensive raw materials and a simple amidation reaction. Tb-PTPa was then used for the efficient adsorption of Hg 2+ in the aqueous media. The adsorption capacity of Tb-PTPa for Hg 2+ was up to 2562 mg g –1 and the adsorption rate was 12.9 mg g –1 min –1 . In addition, Tb-PTPa shows good selectivity for the adsorption of Hg 2+ . The removal rate is still higher than 91% after five adsorption cycles. The interfering substances present in water only slightly affect the capture of Hg 2+ by Tb-PTPa. The combination of our experimental results and density functional theory calculations clearly shows that the introduction of amide bonds can greatly enhance the chelating ability of the N atoms of triazine and the S atoms of thiophene for Hg 2+ . Based on our extensive investigation, we have demonstrated that Tb-PTPa is a low-cost adsorbent with excellent adsorption properties. Therefore, Tb-PTPa is expected to be a new adsorbent material for the treatment of Hg 2+ in the wastewater.