New metal complexes containing a methyldopa Schiff base for carbon dioxide storage

Abstract

The high concentration of carbon dioxide in the environment, including from the burning of fossil fuels to meet our energy requirements, is a pressing environmental concern that requires urgent attention. As a result, the development of novel materials for storing gases such as carbon dioxide and hydrogen has garnered greater attention in research. The current work reports the synthesis of a Schiff base derived from methyldopa and its metal complexes. In addition, their effectiveness as carbon dioxide storage materials were assessed. The reaction of methyldopa and 4-hydroxybenzaldehyde in boiling ethanol under acidic conditions for four hours gave the corresponding Schiff base in excellent yield. The reaction of metal (copper, cobalt, and nickel) chlorides and Schiff base in boiling ethanol for three hours gave the corresponding metal complexes in high yields (77–83%). The surface morphology and surface area of the synthesized metal complexes were evaluated. The mesoporous complexes have a surface area that ranges from 3.59 to 7.36 m2/g. The average pores diameter was 7.75–12.27 nm, and the pores volume was 0.0.11–0.014 cm3/g. The carbon dioxide storage capacity of the synthesized mesoporous complexes was 27.4–30.6 cm3/gm. The complex containing nickel was the most efficient towards carbon dioxide uptake (30.6 cm3/cm) possibility due to its relatively high surface area (7.36 cm2/g) and pores volume (0.014 cm3/g) compared to the copper and cobalt complexes.