Co2+ and nitrobenzene sensing using indium-based metal-organic framework

Abstract

A highly stable indium-based metal-organic framework, namely [In(HTCA)(OH)]·2DMF·H2O (JOU-24), was solvothermally synthesized by using fluorescent ligand H3TCA (H3TCA = 4,4′,4″-tricarboxytriphenylamine). Single-crystal X-ray diffraction analyses show that JOU-24 displays two-dimensional framework based on infinite straight In-O-In chains. Further studies show that JOU-24 can keep its stability in water with pH range from 1 to 11. Thereafter, JOU-24 was developed as an excellent fluorescence sensor for selective detection of Co2+ and nitrobenzene (NB) in water due to its good fluorescence performance. For Co2+ sensing, a high quenching content is determined to be 24,500 with a low determine limit of 4.9 × 10−6 mol/L. For NB sensing, quenching content is 10230, which is also comparable to other reported MOFs. In addition, the mechanism for Co2+ and NB sensing is also proposed. This work shows a simple method to construct high-efficient fluorescence sensor for metal ions and nitroaromatics detection.