Sheets of flexible graphene oxide (GO) can be contracted to yield wrinkled hierarchical morphologies with high surface area. Such structures with ultrathin walls are not easily obtained in inorganic materials that are not flexible enough to sustain the mechanical deformation upon contraction.

Robert Hurt, Brown University, Providence, USA and his team have produced a large variety of ultrathin inorganic material architectures by using GO as the template. The team intercalated hydrated metal ions in different wrinkled textures of GO by immersion in solutions of the respective metal salts. After drying and dehydration at low temperature, the samples were calcined under air to remove the GO template. As a result, accurate ZnO, Al₂O₃, and Mn₂O₃ replicas of the wrinkled GO morphologies were obtained.

The researchers demonstrated the high catalytic activity of these materials, associated with the high specific surface area, in photocatalytic and electrochemical experiments.

• Hierarchical Metal Oxide Topographies Replicated from Highly Textured Graphene Oxide by Intercalation Templating,
  Po-Yen Chen, Muchun Liu, Thomas M. Valentin, Zhongying Wang, Ruben Spitz Steinberg, Jaskiranjeet Sodhi, Ian Y. Wong, Robert H. Hurt,
  ACS Nano 2016.
  DOI: 10.1021/acsnano.6b05179