NGQD 2 (IMAGE) Rice University Caption Nitrogen-doped graphene quantum dots stand out from a substrate in a transmission electron microscope image. The dots are effective electrocatalysts that can reduce carbon dioxide, a greenhouse gas, to valuable hydrocarbons like ethylene and ethanol. Credit Ajayan Group/Rice University Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.