Bacterial cellulose flakes loaded with Bi2MoO6 nanoparticles and quantum dots for the photodegradation of antibiotic and dye pollutants

Effective strategies to improve charge separation in semiconductor particles are critical for improving the photodegradation of organic pollutants at levels sufficient for environmental applications. Herein, Bi2MoO6 (BMOMOF), comprising both nanoparticles (NPs) and quantum dots (QDs), was synthesized from a bismuth-based metal-organic framework (Bi-MOF) precursor. Surface defects on BMOMOF, the combination of NPs and QDs, and modified energy band edges improved photogenerated charge separation and facilitated redox reactions. When compared to BMO derived from uncoordinated Bi, the BMOMOF photocatalyst (PC) was more efficient at pho-todegrading tetracycline hydrochloride (TCH) and ciprofloxacin (CIP), two widely-used antibiotics ubiquitous in wastewater, as well as the carcinogenic pollutant rhodamine B (RhB). BMOMOF was then loaded on the biopolymer bacterial cellulose (BC) to further enhance photocatalytic performance and facilitate the recovery of the PC after water treatment processes. The novel BMOMOF/BC photocatalytic flakes were significantly larger than pure BMOMOF, and thus easier to recuperate. Furthermore, anchoring BMOMOF on BC flakes augmented significantly the photodegradation of TCH, CIP, and RhB, mainly because hydroxyl groups in BC act as hole traps facilitating photogenerated electron-hole separation. Results obtained with BMOMOF/BC highlight promising approaches to develop optimal PCs for aqueous pollutants degradation.

Automated summary

Effective strategies are critical to improve charge separation in semiconductor particles for enhancing the photodegradation of organic pollutants. In this study, Bi2MoO6 (BMOMOF) nanoparticles and quantum dots were synthesized from a bismuth-based metal-organic framework (Bi-MOF) precursor. The combination of surface defects, NPs and QDs in BMOMOF improved charge separation and facilitated redox reactions. The BMOMOF photocatalyst was more efficient in degrading widely-used antibiotics and carcinogenic pollutants compared to BMO derived from uncoordinated Bi. Loading BMOMOF on biopolymer bacterial cellulose significantly enhanced photocatalytic performance and facilitated material recovery after water treatment processes.