The Selective CO2 Adsorption and Photothermal Conversion Study of an Azo-Based Cobalt-MOF Material

Abstract

A new metal–organic framework (MOF), [Co2(L)2(azpy)]n (compound 1, H2L = 5-(pyridin-4-ylmethoxy)-isophthalic acid, azpy = 4,4′-azopyridine), was synthesized by a solvothermal method and further characterized by elemental analysis, IR spectra, thermogravimetric analysis, single-crystal and powder X-ray diffraction. The X-ray single-crystal diffraction analysis for compound 1 indicated that two cis L22− ligands connected to two cobalt atoms resulted in a macrocycle structure. Through a series of adsorption tests, we found that compound 1 exhibited a high capacity of CO2, and the adsorption capacity could reach 30.04 cm3/g. More interestingly, under 273 K conditions, the adsorption of CO2 was 41.33 cm3/g. In addition, when the Co-MOF was irradiated by a 730 nm laser, rapid temperature increases for compound 1 were observed (temperature variation in 169 s: 26.6 °C), showing an obvious photothermal conversion performance. The photothermal conversion efficiency reached 20.3%, which might be due to the fact that the parallel arrangement of azo units inhibited non-radiative transition and promoted photothermal conversion. The study provides an efficient strategy for designing MOFs for the adsorption of CO2 and with good photothermal conversion performance.

Iron Porphyrin as a Cytochrome P450 Model for the Degradation of Dye

“…However, due to the small active area of photocatalysts, insufficient light absorption and instantaneous electron hole separation, the photocatalytic degradation activity of this method is reduced. In addition, adsorption is the most common technology used to remove pollution from textile, printing and dyeing industrial wastewater [28,29], but the adsorption capacity of this method is generally low, and new adsorbents are still being developed. Another example is the microbial treatment of printing and dyeing wastewater, which is considered to be an economical and feasible method without secondary pollution, yet biodegradation has the disadvantages of it being unstable and time-consuming.…”