Green and Facile Mechano-chemical Synthesis of MIL-100(Cr) and its Adsorption Studies on Methyl Orange (MO) and Methyl Violet (MV) as Anionic and Cationic Dyes Dean Hidayat1, Dendy1, Witri Wahyu Lestari*1, Fitri Khoerunnisa2, Murni Handayani3, Eli Hendrik Sanjaya4, and Triyanda Gunawan5
1Department of Chemistry, Faculty of Mathematics and Natural Sciences, Universitas Sebelas Maret, Jl. Ir. Sutami No. 36 A Kentingan, Jebres, Surakarta, 57126, Indonesia
2 Department of Chemistry, Indonesia University of Education, Setiabudhi 229, Bandung 40154, Indonesia
3. Research Center for Advanced Materials - National Research and Innovation Agency (BRIN), Puspiptek Area, Tangerang Selatan, Banten, 15314, Indonesia
4. Department of Chemistry, Universitas Negeri Malang, Jl. Semarang No. 5 Malang 65145, Indoensia
5. Department of Chemistry, Faculty of Science and Data Analytics, Institut Teknologi Sepuluh Nopember, Surabaya 60111, East Java, Indonesia
Materials of Institute Lavoisier based on chromium(III) and benzene,1,3,5-tricarbxylate, {Cr_3X(H_2O)_2O[C_6H_3(CO_2)_3]2nH_2O} (X = OH or F), or well known as (MIL-100(Cr), is a kind of chemically and physically stable MOF with high surface area and pore volume. However, in some cases, MIL-100(Cr) was obtained under hydrothermal or solvothermal conditions in the presence of an acidic modulator which is not environmentally friendly. In this research, a facile and green synthetic approach method via mechano-chemical assisted heated synthesis was applied in the synthesis of MIL-100(Cr). The material was then employed as an efficient adsorbent for methyl orange (MO) and methyl violet (MV) as anionic and cationic dyes. X-ray diffraction and FTIR analysis confirmed the formation of MIL-100(Cr). SEM analysis revealed the synthesized MIL-100(Cr) has irregular polyhedron morphology, and it is thermally stable up to 275 (degree) C, according to TGA measurement. Nitrogen sorption measurement showed the material has a high surface area and pore volume up to 1557 m^2/g and 0.76 cm^3/g, respectively. A few parameters affecting adsorption capacity were studied: including optimum pH, contact time, and initial dye concentration. The results showed MIL-100(Cr) has the maximum adsorption capacity to MO and MV up to 430.21 mg/g (at pH 4 for 60 minutes) and 120.48 mg/g (at pH 9 for 150 minutes), respectively. The MO and MV adsorption mechanism was dominated by physisorption via electrostatic interactions due to the porosity characteristics of the material. It might also be followed by phi-phi stacking interactions, Lewis acid-base interactions, and hydrogen bonds. The adsorption kinetics of MO and MV followed pseudo-second-order, and the intraparticle diffusion plot graphs nonlinearity confirmed a contribution from the pore and surface of MIL-100(Cr). The MO and MV adsorption isotherm models matched with the Langmuir isotherm model.
