High visible light photocatalytic activities obtained by integrating g-C3N4 with ferroelectric PbTiO3

Graphitic carbon nitride (g-C3N4) with the merits of high visible light absorption, proper electronic band structure with high conduction band edge and variable modulation, is viewed as a promising photocatalyst for practical use. To alleviate its high recombination rate of photo-excited charge carriers and maximize the photocatalytic performances, it is paramount to design highly effective transfer channels for photo-excited charge carriers. Ferroelectric materials can have the charge carriers transport in opposite directions owing to the internal spontaneous polarization, which may be suitable for constructing the heterostructure with g-C3N4 for efficient charge separation. Inspired by this concept, herein ferroelectric PbTiO3, which can be the visible-light absorber, is coupled with g-C3N4 to construct PbTiO3/g-C3N4 heterostructure with close contact via Pb-N bond by the facile post thermal treatment. The optimized PbTiO3/g-C3N4 heterostructure exhibited excellent photocatalytic and photoelectrochemical activities under visible light irradiation. Moreover, the simultaneous application of ultrasound-induced mechanical waves can further improve its photocatalytic activities through reinforcing the built-in piezoelectric field. This work proposes a widely applicable strategy for the fabrication of high-performance ferroelectric based photocatalysts and also provides some new ideas for developing the understanding of ferroelectric photocatalysis. (C) 2021 Published by Elsevier Ltd on behalf of The editorial office of Journal of Materials Science & Technology.

Automated summary

Graphitic carbon nitride (g-C3N4) is considered a promising photocatalyst, but its high recombination rate of charge carriers is a challenge. This study successfully optimized the photocatalytic and photoelectrochemical activities by constructing a PbTiO3/g-C3N4 heterostructure, utilizing the ferroelectric properties of PbTiO3 for efficient charge separation.