Anion-Directed Self-Assembly of Calix[4]arene-Based Silver(I) Coordination Polymers and Photocatalytic Degradation of Organic Pollutants

Abstract

Coordination polymers (CPs) have recently emerged as promising candidates for heterogeneous photocatalysis due to their structural designability and tunable properties. Herein, we developed two novel Ag­(I)-calix[4]­arene coordination polymers with the formula {[Ag2(μ-NO3)L1 ]} n (CP 1) and {[AgL1 ]·PF6} n (CP 2) (L1 = 2-mercapto-5-methyl-1,3,4-thiadiazole resorcinol calix[4]­arene). Crystallography revealed that anion coordination and self-inclusion behavior induced the cavitand and silver ions to self-assemble into well-defined CPs 1 and 2 with different topological coordination frameworks, respectively. Furthermore, CPs 1 and 2 display high photocatalytic activity for the photodegradation of rhodamine B (RhB) and methyl orange (MO) in an aqueous solution under mild conditions (WLED and UV irradiation). The comparison results demonstrate that CP 1 exhibited better photocatalytic performance than CP 2, which correlated well with the differences in their molecular structure and HOMO–LUMO energy gaps. The photocatalysis products and possible intermediates were successfully monitored and determined using mass spectrum, gas chromatography, and electron paramagnetic resonance measurements. The rational photocatalysis mechanism was further investigated and proposed.

Synergistic Multisystem Photocatalytic Degradation of Anionic and Cationic Dyes Using Graphitic Phase Carbon Nitride

“…Under the synergistic systems, Rhb was completely degraded within 90 min, while MO was completely degraded within 150 min and 210 min, respectively. After reviewing the literature summaries for comparison, it was found that the photocatalyst in this study is comparatively simple to prepare and can be mass produced [ 54 , 55 , 56 , 57 , 58 , 59 ]. With synergistic photocatalysis, 100% of the dye can be degraded in a relatively short time, as shown in Table 3 .…”