Rational design of hybrid nanomaterials for enhanced CO₂ capture: a way towards a greener environment

Carbon dioxide (CO₂) emission remains one of the most pressing concerns for society to achieve net-zero emissions. The functionalized nanocrystals have recently exhibited their potential to capture CO₂. We synthesized ZnO and Zn_1-xAg_xO nanocrystals by chemical co-precipitation to fulfil the aim of CO₂ capture. The X-ray diffraction spectra of ZnO nanocrystals depict their hexagonal wurtzite structure; however, Ag doping shifts the (100), (002), and (101) reflection peaks toward higher 2θ values, indicating lattice distortion and reduced crystallite size. Besides, the X-ray photoelectron spectroscopy analysis shows that Zn_1-xAg_xO nanocrystals contain around 0.5 at% Ag in the ZnO lattice. Henceforth, the nanocrystals have been functionalized with N-annulated perylene tetraester (PT) to enhance their reactivity. The ability of these nanocrystals to capture CO₂ and its relevance for sustainable climate initiatives have been examined by CO₂-temperature programmed desorption (CO₂-TPD) studies. This study reveals that the CO₂ molecules are effectively adsorbed on the PT-functionalized Zn_1-xAg_xO nanocrystals and do not detach until 400 °C, which has been explained using the Polanyi-Wigner relation. This investigation demonstrates a compelling aspect of maintaining an environmentally sustainable and pollution-free ecosystem.