Synthesis of metal organic frameworks based on lanthanum metal and perylene ligand as photocatalyst for hydrogen gas production

Lanthanum-Metal Organic Frameworks (La-MOFs) have been successfully synthesized based on perylene-3,4,9,10-tetracarboxylic dyes and ion lanthanum (La³⁺) as metal organic linkers using solvothermal methods. The absence of absorption at wavenumber 1700 cm^-1 as vibration stretching v(C = O) from La-MOFs, indicates that the oxygen atom from ligand can coordinate with the lanthanum metal ion. This indicates that La-MOFs has been successfully formed. Peak intensity of strong and sharp from X-ray diffraction indicates the high crystallinity of La-MOFs. La-MOFs possesses a HOMO-LUMO band gap of 2.686 eV determined by UV-Vis spectroscopy with absorbed edge at 462 nm, which present effective photocatalytic activity for hydrogen gas production in the process of water splitting under UV-Vis irradiation. The results of cyclic voltammetry from La-MOFs obtained a reduction potential value (LUMO) of - 2.0735 V vs. NHE which is more negative than the H⁺/H₂ reduction potential, it can be concluded that La-MOFs have potential thermodynamic requirements for the reduction of H⁺/H₂. The production of hydrogen gas obtained from La-MOFs reached 4112.784 μmol in 4 hours.