Surface defects decorated zinc doped gallium oxynitride nanowires with high photocatalytic activity

- Zinc doped gallium oxynitride nanowires enriched with surface defects were prepared via a simple electrospinning and controlled calcination process.
- We designed a way to adjust the surface defects of the nanowires via tuning the ammonification temperature carefully.
- The nanowires show high and stable photocatalytic activity, and the apparent quantum efficiency can reach up to 30%.
- The mechanism relies on the enhanced lifetime of the photogenerated electron-hole pairs due the high density of surface oxygen vacancies.

It is known that surface defect is playing an important role in the photocatalytic performance. Defect engineering has become a common approach in the development of novel photocatalytic materials nowadays. In this paper, zinc doped gallium oxynitride nanowires enriched with surface defects are fabricated via a simple electrospinning and controlled calcination process under ammonia atmosphere. The surface defects are tuned by varying the ammonification temperature carefully, resulting in controlled doping content as well as adjustable crystallinity in the nanowire. The nanowire exhibits high photocatalytic activity and very good stability for the degradation of Rhodamine B organic dye. The apparent quantum efficiency reaches up to 30% under visible light irradiation, which is about 13 and 8 times higher than the nanowires with few surface defects. Structure analysis demonstrates that the surface oxygen vacancy is found to be the key factor for enhancing the photocatalytic efficiency. Hence, the enhanced photocatalytic activity can be attributed to the efficient charge transfer on the surface oxygen vacancy. The results in this work may be beneficial to explore the defective structure for the high performance visible-light driven photocatalytic materials for organic pollutant removal.

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