Rational construction of defect-enriched α-Fe2O3/Bi2S3 composites for high-effective photocatalytic degradation of p-nitrophenol

Herein, the high-activity α-Fe2O3 (PSNF) was obtained first, and defect-enriched PSNF/Bi2S3 composites were prepared via a one-step hydrothermal process. The obtained PSNF had abundant oxygen vacancies (OV) and low bandgap energy, showing enhanced visible-light catalytic activity. Compared with PSNF and Bi2S3, the PSNF/Bi2S3 composites presented superior adsorption capacity and photocatalytic degradation activity for p-nitrophenol (p-NP). The p-NP degradation process followed the BMG model. The PSNF/Bi2S3-2 exhibited the highest photocatalytic activity, as 90.5% of the p-NP was degraded within 30 min. A tight heterojunction was formed between PSNF and Bi2S3 by the S–O bond, which effectively inhibited the recombination of photoproduced carriers and promoted the generation of OV defects. Under the synergistic effect of OV detects, photo-Fenton, and heterojunction, the generation of active species was promoted in the composite degradation system, thereby resulting in the rapid degradation of p-NP. •The OV-rich α-Fe2O3 (PSNF) nanoring was obtained.•The PSNF/Bi2S3 composites with improved catalytic activity were prepared.•The PSNF/Bi2S3 system could produce more active species.•The PSNF/Bi2S3-2 exhibited the highest visible-light photocatalytic activity.