A nanostructured material system for efficient collection of photo-excited carriers is provided. They system comprises a plurality of plasmonic metal nitride core material elements coupled to a plurality of semiconductor material elements. The plasmonic nanostructured elements form ohmic junctions at the surface of the semiconductor material or at close proximity with the semiconductor material elements. A nanostructured material system for efficient collection of photo-excited carriers is also provided, comprising a plurality of plasmonic transparent conducting oxide core material elements coupled to a plurality of semiconductor material elements. The field enhancement, local temperature increase and energized hot carriers produced by nanostructures of these plasmonic material systems play enabling roles in various chemical processes. They induce, enhance, or mediate catalytic activities in the neighborhood when excited near the resonance frequencies.