M-008: A stable and reusable metalorganic framework with high crystallinity applied in the photocatalytic hydrogen evolution and the degradation of methyl orange

In this work we studied the photocatalytic hydrogen evolution from water splitting and MO degradation over a novel metalorganic framework, M-008, studying the effect of the synthesis method on the crystallinity of the material and the catalytic performance. The Metal Organic Framework (M-008) with the general formula ([Zn (4,4'-bipy) (OAc)(2)]}(n)2 was obtained by two approaches, mechanochemistry and slow evaporation. The sample obtained by slow evaporation showed high crystallinity and lower recombination of charges, which conduced to a higher photocatalytic hydrogen evolution rate under UV light (103 mu mol g(-1) h(-1)); while the sample prepared by mechanochemistry exhibited production of 53 mu mol g(-1) h(-1). The samples also exhibited considerable activity under solar light irradiation. This activity was further improved with the use of diethanolamine as sacrificial agent, showing an increase of more than 2 times. M008 was tested additionally in the degradation of MO, reaching efficiencies of degradation of 95 and 81 %. The best photocatalytic activity of the material synthesized by slow evaporation is attributed to its high crystallinity observed by XRD and the best charge transport properties exhibited in the electrochemical tests. Based on these results, it is demonstrated that M-008 exhibits and excellent performance for energy and environmental applications.