Synthesis of calix [4]arene-based nanohybrids: An efficient route for the electrochemical detection of dCO2 and its sustainable transformation for the production of formic acid, a industrially valuable chemical

Abstract

CO2 exposure has damaging effects on human health and environment; therefore, its detection and sustainable capture and conversion has applications for both industrial and domestic use. Electrochemical method is a simple and reliable technique for selective quantification of dCO2 and gCO2. Herein, we have developed electrochemical method for determination of dissolved CO2 (dCO2) employing calix [4]Arene-based nanohybrids using NaHCO3 as the carbon source exhibiting limit of detection (LOD) of 0.006 μM (1.5 × 10−6 hPa CO2). The nanohybrids were produced by reducing Ag(I) on the surface of organic nanoparticles developed from calix [4]arene molecule. The calix [4]arene based dipodal receptor was synthesized using a Schiff base condensation reaction and organic nanoparticles were prepared by reprecipitation method. To reduce the carbon footprint, we have attempted to convert dCO2 into formic acid (yield >97%) electrochemically employing AgNPs nanohybrids as an efficient catalyst in slightly acidic medium and the conversion was characterized using NMR and FT-IR spectroscopy. The proposed method is highly efficient, simple and sustainable method to reduce CO2 into formic acid and the practical utility of the proposed methodology was validated on bottled beverages (carbonated drinks), aquarium water, algae containing water, distilled water and fresh river water.