Sulfur-rich covalent triazine polymer nanospheres for environmental mercury removal and detection

Abstract

We describe a facile one-pot synthesis of porous covalent sulfide-bridged polytriazine nanospheres (NOP-28), which can be employed as highly efficient sorbents and at the same time act as selective sensitive sensors towards trace Hg²⁺. The as-made nanospheres were integrated with abundant thioether moieties, which are stable even under strong acid and base conditions, and they exhibit extremely high adsorption capacities (up to 658 mg g⁻¹) from environmental sources such as water. Over 99.9% of the mercury was removed even at an initial concentration as low as 1.0 ppm despite their moderate BET surface areas. On the other hand, the π-conjugated NOP-28 features a strong photoluminescence that is distinctly quenched after trace Hg uptake. An excellent sensing performance is achieved in terms of high sensitivity (detection limit 12.0 ppb), excellent selectivity and real-time response for Hg²⁺. This study provides a new pathway for both removing and sensing toxic metals for the remediation of contaminated spaces, and suggests the great versatility of nanoporous organic polymers targeting various environmental challenges.