Study on the piezo-photocatalytic synergy in Ba0.66 Sr0.34TiO3-CuO heterojunction for enhanced visible-light catalytic performance

FAN Baoyan; YANG Shuang; ZHAO Yan; LIU Haibo; GUO Xiaoyu; WANG Zonghua

doi:10.19728/j.issn1672-6634.2025090001

Abstract：To address the issues of low piezoelectric catalytic activity and visible light nonresponse of tradi-tional piezoelectric materials,a type III heterostructure was constructed between the piezoelectric Ba0.66Sr0.34TiO3(BST)and the narrow-bandgap semiconductor CuO.This structure utilizes the dynamic built-in electric fields generated by BST under mechanical stress to effectively drive separation of photo-generated charge carriers.Meanwhile,the CuO with narrow-bandgap broaden the photoabsorption range of the piezoelectric material into the visible spectrum,thereby achieving synergistic effects between the pi-ezoelectric response and photocatalytic activity.The BST-CuO photocatalysts were fabricated using a com-bination of hydrothermal and wet chemical methods.Phase structure and microstructure characterization reveal that CuO nanosheets agglomerated on the BST surface with the increase of CuO loading.Under the synergistic action of ultrasound and visible light,the BST-CuO2 heterojunction achieves 59%rhodamine B degradation in 150 min,which was 1.6 times higher than that of pure BST.Notably,this efficiency was 3.3 times and 2.7 times higher than the degradation rates obtained under ultrasonication in the dark and stirring with light irradiation,respectively.Based on the comprehensive analysis of the active species,photocurrent spectroscopy and electrochemical impedance spectroscopy,the incorporation of CuO with a relatively narrow bandgap extends the optical absorption edge to the full-spectrum solar spectrum(200～800 nm).The ultrasound-activated dynamic built-in electric field induced by BST sustainably drives photo-induced charge carrier separation,thereby achieving optimized photocatalytic performance in BST-CuO.This study provides a novel approach for understanding the synergy mechanism of piezoelectricity and pho-tocatalysis.