Designed Synthesis of Multiluminescent Materials Using Lanthanide Metal-Organic Frameworks and Carbon Dots as Building-Blocks

A multiluminescent composite material, CDs@EuW-MOF, is synthesized by self-assembling molecular building-blocks in the presence of carbon dots (CDs). Using water soluble CDs within the growth media of a hydrophilic metal-organic framework (MOF) enables the incorporation of the CDs within MOF pores through a one-pot synthesis. The emission spectra obtained using a broad range of excitation wavelengths (295-400 nm) show multiple emissions including the Eu3+ red emission and the dual-color (blue and green) emissions of the CDs. The red emission intensity of Eu3+ ions decreases in the presence of water molecules, leading to the ratiometric detection of water in methanol within a wide response range of 0-30 % (V/V). Due to the quenching effect on the CDs emission, this composite can also sense acetonitrile. The results demonstrate that using a molecular building-block approach is an efficient route towards the design of multiluminescent functional materials.