Synthesis of novel flower-like Bi4Ti3O12/BiOCl heterojunctions with excellent piezoelectric photocatalytic performance.

Photocatalysis technology can not only degrade pollutants by renewable solar energy, but also has enormous promise for resolving environmental issues. The piezoelectric field inside the piezoelectric material can be used as the driving force of charge separation to improve the photocatalytic activity. In order to study the catalytic effect of piezoelectric materials on photocatalysis, a flower-like Bi 4 Ti 3 O 12 /BiOCl (BTO/BOC) composite catalyst is prepared in this paper. The photogenerated carrier separation efficiency is characterized by electrochemical, PL and ESR tests. BOC's built-in electric field helps to facilitate the separation of photogenerated carrier, reducing the recombination rate and improving photocatalytic efficiency. The piezoelectric effect caused by ultrasonic vibration is coupled with the photocatalysis, which realizes the high efficiency co-catalysis of BTO/BOC piezoelectric photocatalyst. The polarized BTO/BOC heterojunction catalysts achieved a very high degradation efficiency (99.15 %) under piezo-photocatalysis. The degradation rates (k = 0.7494 min−1) are 1.74 and 8.19 times higher than photocatalysis (k = 0.4304 min−1) and piezoelectric catalysis (k = 0.0915 min−1), respectively. The investigation of the piezoelectric effect and photocatalysis's synergistic relationship is very significant. [Display omitted] • Bi 4 Ti 3 O 12 /BiOCl heterojunctions are successfully synthesized using hydrothermal method. • The degradation rate of catalyst is greatly improved through the coupling of piezoelectric effect and photocatalysis. • The internal electric field of ferroelectric materials promotes the separation of photogenerated electrons and holes. [ABSTRACT FROM AUTHOR]