Dual-Functionalized Fluorescent Cationic Organic Network: Highly Efficient Detection and Removal of Dichromate from Water

Abstract

Dichromate is a widespread contaminant in wastewater, threatening the health of humans and other organisms. Therefore, effective detection and removal of dichromate from water is of great significance. Herein, a tetraphenylethylene functionalized cationic organic network (CON-LDU2) was constructed via a facile quaternization reaction. CON-LDU2 was successfully integrated with both detection and removal functionalities toward dichromate. On the one hand, benefiting from the strong fluorescence, CON-LDU2 was employed as a chemosensor, it could efficiently and selectively probe Cr2O7 2– in water with “turn-off” fluorescent response. On the other hand, the cationic skeleton and free anions inside framework make CON-LDU2 an excellent adsorbent for Cr2O7 2–, it could capture Cr2O7 2– from water with rapid kinetics and high capacity. The kinetic constant for adsorption of Cr2O7 2– can reach up to 1.784 g mg–1 min–1, while the capacity is determined as 325 mg g–1. Furthermore, CON-LDU2 displayed good recyclability and can be reused for at least 5 cycles. Therefore, CON-LDU2 can serve as an ideal candidate not only in detection but also in removal of Cr2O7 2– in water medium.

Deep-Red Luminescent Cuprous-Lead Bromide as a Dual-Responsive Sensor for Fe3+ and Cr2O72–

“…Anal. calcd (%) for C 20 H 16 Br 4 Cu 2 N 12 Pb: C,22.28;H,1.48;N,15.59. Found: C,22.32;H,1.52;N,15.47.…”

“…calcd (%) for C 20 H 16 Br 4 Cu 2 N 12 Pb: C,22.28;H,1.48;N,15.59. Found: C,22.32;H,1.52;N,15.47. IR (cm −1 ): 3105 (w), 3050 (w), 1553 (s), 1447 (s), 1350 (m), 1285 (w), 1196 (m), 1106 (w), 1050 (m), 1017 (w), 952 (m), 896 (m), 839 (vs), 758 (vs), 660 (s), 619 (vs), 554 (vs), 481 (vs).…”

Amino Acid Groups Enable Electrosynthesized Polyfluorenes to Specifically Recognize Cr2O72–

“…In the environment, Cr 2 O 7 2– can be traced in industrial waste or natural waters. − In order to effectively remove Cr 2 O 7 2– , the efficient detection and recognition of Cr 2 O 7 2– is an indispensable step. At present, fluorescent sensors for detecting Cr 2 O 7 2– based on various materials have been reported, such as metal–organic frameworks, − nanoclusters, , carbon dots, − quantum dots, , ionic liquids, small organic molecules, coordination polymers, , and CPs . Until now, there are several reports about Cr 2 O 7 2– based on CPs.…”

Development of Cationic Benzimidazole-Containing UiO-66 through Step-by-Step Linker Modification to Enhance the Initial Sorption Rate and Sorption Capacities for Heavy Metal Oxo-Anions

“…Some heavy metal oxo-anions (e.g., CrO 4 2– /Cr 2 O 7 2– and HAsO 4 2– /H 2 AsO 4 – ), as a class of priority pollutants of the U.S. Environmental Protection Agency, have become a more and more serious threat to environmental sustainability and human health because of their toxicity, long persistence, and bioaccumulation. − In particular, Cr­(VI) oxo-anions are extensively utilized in various industrial applications and can rapidly diffuse into the water environment. However, these oxo-anions cannot be degraded naturally. − Ultimately via the biological chain, they are enriched into the human body, leading to DNA damage and disruption of the protein and enzyme system of the human body. , Besides Cr­(VI) oxo-anions, the presence of some radioactive metal oxo-anion pollutants, such as pertechnetate (TcO 4 – ) ions in radioactive waste vitrification or nuclear water sources, poses serious disposal issues because of their long half-life and facile mobility. , Thus, it is significant to focus on the removal of Cr­(VI) oxo-anions and TcO 4 – (or its nonradioactive surrogate, MnO 4 – ) from the aquatic environment . To effectively remove heavy metal oxo-anions from wastewater, numerous technologies have been developed, such as adsorption, ion exchange, chemical precipitation, biological treatments, etc .…”

“…4−6 Ultimately via the biological chain, they are enriched into the human body, leading to DNA damage and disruption of the protein and enzyme system of the human body. 7,8 Besides Cr(VI) oxoanions, the presence of some radioactive metal oxo-anion pollutants, such as pertechnetate (TcO 4 − ) ions in radioactive waste vitrification or nuclear water sources, poses serious disposal issues because of their long half-life and facile mobility. 9,10 Thus, it is significant to focus on the removal of Cr(VI) oxo-anions and TcO 4 − (or its nonradioactive surrogate, MnO 4 − ) from the aquatic environment.…”