Covalent organic polymers in heterogeneous catalysis and sensors

Abstract

Synthesis and characterization of covalent organic polymers (COPs) have gained great attention due to their structural periodicity and high tunable porosity. COPs show versatile applications in various fields such as storage of greenhouse gases like carbon dioxide, efficient heterogeneous catalysts, sensors and energy storage devices. In the past few years, various monomeric units with different functionalities are used to synthesize COPs. The ordered structures in COPs with organized electron systems and presence of heteroatoms in the COPs (especially N and O center) serve various purposes including electronic properties, heterogeneous catalysis and detection of metal ions in solution or solid state. The development of efficient heterogeneous catalyst for diverse organic reactions is a successful application of COPs that has gained momentum in recent past. Presently, the focus is on the development of different metal integrated COPs to increase the efficiency in various applications. COPs provide large surface areas, defined pore size, low framework density and high thermal stability which help to increase their applicability. With the choice of binding block units in the polymeric backbone, COPs can be functionalized differently with several functional groups. Functionalized COPs act as efficient heterogeneous catalyst, for various chemical, electrochemical and photoelectrochemical reactions. COPs are considered as one of the most promising materials for the detection and removal of toxic metals. COPs/COFs with various functionalities on their surface facilitates in gas sensing and adsorption properties. A two dimensional covalent organic polymer based chemiresistive gas sensor was also developed for the selective gas sensing. The overall aim of the work described in the thesis is to understand the fundamental mechanistic aspects towards synthesis, characterization and several applications of COPs. The specific objectives are as follows: To design and synthesize several functionalized COPs. To check the catalytic activity of COPs on various organic transformation reactions. To investigate the catalytic activity on the electrochemical reactions. To explore the ability of COPs in metal ions removal efficiency. To fabricate chemiresistive device with COP and to investigate the efficiency and selectivity of COPs towards toxic gas sensing.