Process (IMAGE) Penn State Caption These are molecular models representing a 2-D heterostructure made of graphene (gray background hexagonal lattice), and islands on top of hexagonal WS2 and MoS, as well as an alloy of the two. Water (H2O) molecules in red (oxygen) and gray (hydrogen) come from the bottom left hand side and get transformed catalytically after interacting with the heterostructures into H2 bubbles (top right hand side). Credit Terrones Group/Penn State Usage Restrictions Non commercial use only 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.