Heterojunction photoanode of SnO2 and Mo-doped BiVO4 for boosting photoelectrochemical performance and tetracycline hydrochloride degradation.

The photoelectrochemical (PEC) method has a potential to harvest solar energy for sustainable energy and degrade contaminants. Herein, we fabricated cauliflower-like SnO2 and porous Mo-doped BiVO4 (SnO2/Mo:BiVO4) photoelectrodes by a sol-gel spin-coating method for better PEC performance and higher degradability of tetracycline hydrochloride (TC-HCl). The SnO2 layer plays a crucial role in attaining a smooth and uniform surface of the photoanodes for blocking holes to defect trap sites and preventing charge recombination with improved light utilization. Mo dopants serve as nuclei for the crystallization of BiVO4 and for making charge-adjustable porous structures for PEC performance. Thus, the content-optimized SnO2/Mo:BiVO4 photoanode film presents the highest photocurrent density of 0.59 mA cm-2 at 1.23 VRHE of 82.1% TC-HCl decomposition efficiency within 120 min at a rate constant of 1.49 × 10-2 min-1, providing a promising method for green environmental applications.