Two novel porous MOFs with square-shaped cavities for the removal of toxic dyes: adsorption or degradation?

In this article, two new networks, namely, {[Co(L)]center dot 0.5(CH3CN)center dot 5(H2O)}(n) (HPU-5) and {[Mn-2(L)(2)(H2O)(2)]center dot 2(CH3OH)center dot(3)(H2O)center dot 2(DMA)} (HPU-6) (H2L = (5-(3,5-di-pyridin-4-yl-[1,2,4] triazol-1-ylmethyl)-isophthalic acid)) with different-sized pores were constructed. The photogradation and adsorption of dyes by the two MOFs were studied in detail. The results showed that the dye removal efficiency of degradation was much higher than that of adsorption. Additionally, when the pores of MOFs were enlarged, the contribution of dye removal through adsorption was still relatively low. Our findings suggest that MOFs with high photocatalytic activities should be synthesized to enhance dye removal efficiency to the maximum.