Engineering a Heterophase Interface by Tailoring the Pt Coverage Density on an Amorphous Ru Surface for Ultrasensitive H₂S Detection

Amorphous/crystallineheterophase engineering is emerging as anattractive strategy to adjust the properties and functions of nanomaterials.Here, we reveal a heterophase interface role by precisely tailoringthe crystalline Pt coverage density on an amorphous Ru surface (cPt/aRu)for ultrasensitive H2S detection. We found that when theatomic ratio of Pt/Ru increased from 10 to 50%, the loading modesof Pt changed from island coverage (1cPt/aRu) to cross-linkable coverage(3cPt/aRu) and further to dense coverage (5cPt/aRu). The differencesin coverage models further regulate the chemical adsorption of H2S on Pt and the electronic transformation process on Ru, whichcan be proved by ex situ X-ray photoelectron spectroscopy experiments.Notably, a special cross-linkable coverage 3cPt/aRu on ZnO shows thebest gas-sensitive performance, in which the operating temperaturereduces from 240 to 160 degrees C compared with pristine ZnO and theselectivity coefficient for H2S gas improves from similar to 1.2to similar to 4.6. This is mainly benefit from the maximized exposureof the amorphous/crystalline heterophase interface. Our work thusprovides a new platform for future applications of amorphous/crystallineheterogeneous nanostructures in gas sensors and catalysis.