Design of nanoscaled heterojunctions in precursor-derived t-ZrO/SiOC(N) nanocomposites: Transgressing the boundaries of catalytic activity from UV to visible light.

In this work, nanocomposites made of nanosized zirconia crystallized in situ in an amorphous silicon oxycarbo(nitride) (SiOC(N)) matrix have been designed through a precursor route for visible light photocatalytic applications. The relative volume fraction of the starting precursors and the pyrolysis temperatures not only influences the phase fraction of zirconia crystallites but also stabilizes the tetragonal crystal structure of zirconia (t-ZrO) at room temperature. The presence of carbon in interstitial sites of zirconia and oxygen vacancy defects led to drastic reduction in the band gap (2.