Boosting piezo-photocatalytic activity of BiVO4/BiFeO3 heterojunctions through built-in polarization field tailoring carrier transfer performances
Qinfang Jing, Zhiyong Liu, Xian Cheng, Cichun Li, Pengrong Ren, Kun Guo, Haojie Yue, Bing Xie, Ting Li, Zhiguo Wang, Longlong Shu
Abstract
The greatest challenge that limits the application of piezo-photocatalytic materials is the low separation efficiency of the generated electron-hole pairs, resulting in poor catalytic activity. Here, the semiconductor n -p heterojunctions BiVO 4 /BiFeO 3 (BVO/BFO) were designed to enhance its piezo-photocatalytic processes. Under the excitation of piezo-vibration and the irradiation of visible light, the BVO/BFO heterojunctions exhibited ultra-high and stable piezo-photocatalytic performance with the degradation rate of Rhodamine B (RhB) solution up to 98 %, and its k value was 6.12 times than that of photocatalysis and 4.36 times than that of piezoelectric catalysis. Thanks to the n -type BVO nanoparticles with good crystallinity were uniformly distributed on the surface of the p-type piezoelectric material BFO, the built-in polarization field was formed and be advantageous to improve the carrier transport performances. A large electron diffusion coefficient (27.44 × 10 3 cm 2 ·s −1 ), effective diffusion length (14.49 cm), and long electron lifetime (7.66 × 10 -3 s) were achieved in the BVO/BFO heterojunctions, which played important roles to boost the piezo-photocatalytic activity. The preparation of BVO/BFO heterojunctions and their remarkable photo-piezoelectric properties provides a theoretical and practical reference for the development of efficient piezo-photocatalysis to apply in environmental remediation.