N,P-codoped carbon quantum dots-decorated TiO2 nanowires as nanosized heterojunction photocatalyst with improved photocatalytic performance for methyl blue degradation.

N,P-doped carbon quantum dots (N,P-CQDs) are deemed as a promising candidate to environmentally friendly materials owing to the inexpensive, biocompatible nature. TiO2 nanowire is a prospective photocatalyst because of its efficient migration of photoexcited carriers in wastewater treatment. However, the N,P-CQDs-decorated TiO2 nanowire (N,P-CQDs/NW-TiO2) photocatalysts have been rarely reported. In this study, we build N,P-CQDs on the surface of TiO2 nanowires via a simple deposition process. Our investigations demonstrate that N,P-CQDs/NW-TiO2 has a great photocatalytic degradation for methyl blue (MB) under irradiation. The degradation rate of can reach 93.6% within 120 min under proper conditions. The excellent degradation performance of N,P-CQDs/NW-TiO2 is ascribed to the mesoporous structure and high separation rate of photoexcited carriers. In addition, the N,P-CQDs/NW-TiO2 have outstanding recycled photocatalytic capability. After being recycled four times, the N,P-CQDs/NW-TiO2 still maintain 59.9% photocatalytic activity. The fabricated nanosized photocatalyst can be widely utilized in the field of photocatalysis for wastewater treatment.