Assertion: titanium dioxide | /r/HasProperty | heterogeneous photocatalyst
Facets:
value: by converting them
type: MANNER
Source sentences:
text: The main reason of using TiO2, is that titanium dioxide is a heterogeneous photocatalyst that uses sunlight to absorb and render oxides of nitrogen (NO and NO2) harmless by converting them to nitrate ions (NO3), which then can be washed away by rain or soaked into the concrete to form stable compounds.