Carbon quantum dots/BiVO4 S-scheme piezo-photocatalysts improved carrier separation for efficient antibiotic removal.

• A CQDs/BiVO 4 S-scheme piezo-photocatalyst was successfully constructed. • CQDs/BiVO 4 displayed efficient piezo-photocatalytic degradation of TC. • C–O–Bi bonds provided an atomic-level interfacial channel for facilitating charge separation. • The possible piezo-photocatalytic degradation mechanism of CQDs/BiVO 4 was proposed. Reasonable design of an efficient S-scheme photocatalyst remains an ongoing challenge due to the limitation of interfacial charge separation efficiency. Herein, CQDs/BiVO 4 S-scheme heterojunction with Bi–O–C bond was synthesized by introducing carbon quantum dots (CQDs) growth on BiVO 4 piezo-photocatalyst and absorbed visible light up to 750 nm. Under light + ultrasonic conditions, the reaction rate constant (k) of BVO/C-0.10 reached 0.0517 min⁻¹ on tetracycline (TC) degradation, which was 2.24 and 4.04 times higher than those of BiVO 4 and CQDs, respectively. The enhanced performance was attributed to the improved efficiency of the photogenerated carrier separation, originating from the combination of piezoelectric effect and S-scheme heterojunction with Bi–O–C bond. The Bi–O–C bond at the CQDs (3–8 nm) and BiVO 4 interfaces connected the two semiconductor materials and provided an atomic-level interface channel for carrier migration. The piezoelectric properties of the composites were investigated by piezo−response force microscopy (PFM). Based on Mott−Schottky curves, X-ray photoelectron spectroscopy (XPS), and scavenging experiments, the possible piezo-photocatalytic mechanism was proposed in combination with the band structures and characteristics of CQDs and BiVO 4. This work furnishes unique insights into developing efficient S-scheme piezo-photocatalysts for purifying wastewater. [Display omitted] [ABSTRACT FROM AUTHOR]