Two Coordination Polymers and Their Silver(I)-Doped Species: Synthesis, Characterization, and High Catalytic Activity for the Photodegradation of Various Organic Pollutants in Water.

Solvothermal reactions of M(NO3)2 (M = Cd, Co) with isophthalic acid (1,3-H2bdc) and N-(pyridin-2-yl)- N-{4-[2-(pyridin-4-yl)vinyl]phenyl}pyridin-2-amine (ppvppa) at 150 °C afforded two two-dimensional (2D) coordination polymers (CPs) [M(ppvppa)2(1,3-bdc)] · xH2O [M = Cd, x = 2 ( 1·2H2O); M = Co, x = 1.5 ( 2·1.5H2O)]. In 1 and 2, the uncoordinated di(pyridin-2-yl)amine of ppvppa can further bind additional metal ions. Their AgI-doped polymers, [Cd(ppvppa)2(1,3-bdc)] ·AgNO3 ( 1a) and [Co(ppvppa)2(1,3-bdc)] ·0.75AgNO3 ( 2a), were obtained by immersing 1 and 2, respectively, into an aqueous solution of AgNO3. Compared with 1 and 2, 1a and 2a exhibited greatly enhanced catalytic activity towards the photodegradation of RhB, Acid Red 27, and theophylline in water due to their narrower band gaps. For 2a, the apparent rate constants for the photodecomposition of the three pollutants are around 4.4, 2.3, or 1.76 times larger than those of 2, respectively. The results provide an insight into a metal-ion doping strategy that can narrow the band gaps of the CPs and thus greatly improve their photocatalytic performance in degrading organic pollutants in water. [ABSTRACT FROM AUTHOR]