Imaging reactive surface water

Surface Microscopy Recent developments in transmission electron microscopy (TEM) have enabled imaging of single atoms, but adsorbed gas molecules have proven more challenging because of a lack of sufficient image contrast. Yuan et al. adsorbed water and carbon dioxide (CO2) on a reconstructed nanocrystalline anatase titanium dioxide (TiO2) surface that has protruding TiO3 ridges every four unit cells, which provide regions of distinct contrast. Water adsorption on this surface during environmental TEM experiments led to the formation of twinned protrusions. These structures developed dynamic contrast as the water reacted with coexposed CO2 to form hydrogen and carbon monoxide. Science , this issue p. [428][1] [1]: /lookup/doi/10.1126/science.aay2474