Enhanced charge separation of vertically aligned CdS/g-C3N4 heterojunction nanocone arrays and corresponding mechanisms

Vertical-aligned CdS/g-C3N4 heterojunction nanocone arrays have been fabricated on silicon(100) substrates by a plasma sputting reaction deposition and pulsed laser deposition, successively. The morphology and structure of the as-fabricated nanocone arrays were characterized by scanning electron microscopy, transmission electron microscopy, X-ray diffraction and Raman spectroscopy, revealing a single-crystalline hexagonal g-C3N4 structure of the g-C3N4 nanocone arrays and a poly-crystalline hexagonal wurtzite-structure of the CdS shells. The optical properties of the CdS/g-C3N4 nanocone arrays were studied by steady-state and time-resolved photoluminence and optical absorption measurements, showing that the CdS/g-C3N4 heterojunction could efficiently promote the separation of the electron-hole pairs generated in the nanocone arrays, which indicates the attractive prospects of the CdS/g-C3N4 nanocone arrays in the field of photocatalysis.