Synthesis Of Metal Organic Framework Nanostructures And Their Derived Materials As Well As Applications

The new crystalline porous materials called MOFs are made of metals as node and organic ligands as spacer by robust bonding.These metallic nods could be in the form ion or multi nuclear metal clusters.These materi als have grown in numbers very rapidly in the previous decade because of wide range available ligands.Another reason for this is the predesign synthesis and shapes from 3-1D morphology.It is of prime importance to understand variety of metals and linkers in order to prepare MOFs of choice behaviors and properties.Different organic linkers or ligands used in MOFs synthesis are mostly aromatic rings with functionalities like carboxylic,phosphate,cyano group etc.But the widely used linkers in the MOFs pr eparation are carboxylates.Carboxylate metal-organic frameworks(CMOFs)have received considerable attentions because of structural firmness,catalytic activity,and porosity.However,synthesis of CMOFs requires high temperature,pressure,and long reaction time.Here,we show the ability of 2-methylimidazole(2-MIM)as a homogenous catalyst for the synthesis of CMOF nanostructures(CMOFNs),at room temperature in aqueous medium in 10 min.Ten CMOFNs M IL-53-AL,MIL-53-Fe,MIL-53-Cr,Cu-BDC,UIO-66,MIL-53-In,Cd-BDC,ZMOF-177,DUT-4,and HKUST-1 have been successfully synthesized(BDC: 1,4-bezene dicarboxylic acid,BTB: 1,3,4-tris(4-carboxyphenyl)benzene,NDC: 2,6-nephtalindicarboxylic acid,and BTC: 1,3,5-benzenetricarboxylic acid).The obtained CMOFNs have crystal sizes of ca.200-700 nm and pore size of 2-40 nm.The 2-MIM shows excellent and universal platform to fabricate CMOFNs in aqueous medium at room temperature.MOFNs especially 2D MOFs nanosheets have attracted scientist's attention because of their more exposed active sites and easily accessible pores compared to 3D bulk MOFs.Effect of temperature and solvent upon the shape,size,and structure of MOFNs have been clearly shown in several studies but still careful investigation is needed to explore their role in shaping the morphology of resultant MOFNs.Therefore we choose MIL-53-Al being stable and widely studied MOF,to control morphology based on solvent and temperature.We successfully synthesized MIL-53-Al 2D nanosheets by controlling temperature and use of right solvent in its preparation.Moreover,we also prepared tetra metallic(Al,Fe,Ni,Co)doped porous carbon(Al Fe Ni Co-C)using the as synthesized MIL-53-Al nanosheets as template.Further the derived Al Fe Ni Co-C was used in hydrogen evolution reaction and found that this material shows excellent electro-catalytic behavior.Due to depletion of fossil fuel and pollution renewable energy sources are of great demand in today society.Therefore storage of energy is one of the ongoing field,different charging mechanisms in the super-capacitors is advantageous over batteries because of the associated higher power density,long term stability and the shorter charge discharge time.The pure MOFs display poor absorption properties because of mismatch and low permittivity.However,recently,organic-inorganic nanocomposites,and their derived metal phosphides which are considered as promising materials for super-capacitors.Motivated by these finding we prepared novel MOF(Fe)/phytic acid composite ranges from 400-800 nm.Then this MIL-88B/Iron-phytic acid nanostructures(M8/IPNs)was annealed to get calcined M8/IPNs(cal-M8/IPNs),and used it for super-capacitor performance showing an excellent capacitance with significant cyclic stability.