Effect of p-n type nano-heterojunction formed between two narrow bandgap semiconductors in Cu~+ doped GeSe_2-Sb_2Se_3 glass ceramics on photocatalytic activities

摘要

Cu+ doped GeSe2-Sb2Se3 glass ceramics were prepared using the melt-quenching method. The effect of the p-n type nano-heterojunction formed between two narrow bandgap semiconductors in the prepared glass ceramics on the photocatalytic activity was studied by x-ray diffraction, ultraviolet-visible spectrophotometer and high resolution transmission electron microscopy. Cu+ induced the formation of granular Cu2GeSe3 crystals, which was distributed in the parallel rod-like Sb2Se3 clusters, forming the heterojunction in nano-scale. The prepared glass ceramics powder decomposed 94% methyl orange under visible light irradiation. The excellent photocatalytic activity was ascribed to the nano-heterojunction structure and the effective separation of electrons from holes caused by inter-semiconductor transfer mechanism.