Synthesis of MgO nanocrystals with abundant surface defects via a carbonization method employing CO2 gas as starting material

Abstract

Taking its unique property into consideration, uniformly dispersed MgO nanoparticles with abundant surface oxygen defects was primarily synthesized via a facile carbnization method employing CO2 gas as carburizer in this study. After reaction at 60°C for 2h, Mg2+ ions were totally carbonized to caterpillar-like Mg5(CO3)4(OH)2(H2O)4 precursor. And through decarbonization and dehydration processes during calcination, as-prepared Mg5(CO3)4(OH)2 (H2O)4 precursor with micro-nano structure was thouroughly converted to well-crystallized MgO nanospheres. As-evidenced by the UV–VIS-NIR diffuse reflectance spectroscopy, due to the largely intensified low-coordinated oxide ions at the corner and kink sites with decreasing the average size, the forbidden band gap of as-prepared MgO nanocrystals is 5.3eV, which thus endows it intriguing applications in different fields.