BiVO4 with surface Bi-vacancies enhanced photoelectrocatalytic polyethylene terephthalate oxidation and electrocatalytic nitrate reduction

Bi vacancy efficiently improved charge transport and electron-hole pair separation of BiVO 4 . • Bi vacancy in BiVO 4 enhanced photoelectrocatalytic polyethylene terephthalate oxidation. • After coupling PETOR with NO 3 RR, the performance of PETOR was greatly improved. • The glycolic acid and formate yield was 6.02 mmol h −1 g −1 and 97.32 mmol h −1 g −1 , respectively. Bismuth vanadate (BiVO 4 ) is a promising photoanode material but suffers from severe charge recombination, resulting in unsatisfactory photoelectrocatalysis. Herein, we report the fabrication of a deep-eutectic solvent (DES)-treated BiVO 4 photoanode (BiVO 4 -DES-x) with bismuth vacancies (Bi vac ). The generation of Bi vac in BiVO 4 -DES-x efficiently improved the charge transport properties, electron–hole pair separation of BiVO 4 , and production of hydroxyl radical, boosting its photocatalytic activity and polyethylene terephthalate (PET) oxidation to form value-added glycolic acid (GA) and formate (FA). We designed a coupling system using photoelectrocatalytic oxidation of waste PET and nitrate (NO 3 − ) electrocatalytic reduction. Thus, BiVO 4 -DES-x functions as a photoanode and cathode. In the coupled reaction system, the GA yield rate increased from ∼ 4.20 mmol h −1 g −1 to 6.02 mmol h −1 g −1 and the Faradaic efficiency from ∼ 87.71% to 95.36%, while the FA yield rate was ∼ 97.32 mmol h −1 g −1 . This study provides an efficient solution for microplastic pollution and offers technical support for alleviating white pollution. Download: Download high-res image (108KB) Download: Download full-size image