Defect Engineered Bi <sub>2</sub> Te <sub>3</sub> Nanosheets with Enhanced Haloperoxidase Activity for Marine Antibiofouling
Sagar Sunil Kulkarni, Dang Khoa Tong, Chien‐Ting Wu, Cheng‐Yen Kao, Surojit Chattopadhyay
Abstract
Abstract Defective bismuth telluride (Bi 2 Te 3 ) nanosheets, an artificial nanozyme mimicking haloperoxidase activity (hPOD), show promise as eco‐friendly, bactericidal, and antimicrofouling materials by enhancing cytotoxic hypohalous acid production from halides and H 2 O 2 . Microscopic and spectroscopic characterization reveals that controlled NaOH (upto X = 250 µL) etching of the nearly inactive non‐transition metal chalcogenide Bi 2 Te 3 nanosheets creates controlled defects (d), such as Bi 3+ species, in d‐Bi 2 Te 3 ‐X that induces enhanced hPOD activity. d‐Bi 2 Te 3 ‐250 exhibits approximately eight‐fold improved hPOD than the as‐grown Bi 2 Te 3 nanosheets. The antibacterial activity of d‐Bi 2 Te 3 ‐250 nanozymes, studied by bacterial viability, show 1, and 45% viability for Staphylococcus aureus and Pseudomonas aeruginosa , respectively, prevalent in marine environments. The hPOD mechanism is confirmed using scavengers, implicating HOBr and singlet oxygen for the effect. The antimicrofouling property of the d‐Bi 2 Te 3 ‐250 nanozyme has been studied on Pseudomonas aeruginosa biofilm in a lab setting by multiple assays, and also on titanium (Ti) plates coated with the nanozyme mixed commercial paint, exposed to seawater in a real setting. All studies, including direct microscopic evidence, exhibit inhibition of microfouling, up to ≈73%, in the presence of nanozymes. This approach showcases that defect engineering can induce antibacterial, and antimicrofouling activity in non‐transition metal chalcogenides, offering an inexpensive alternative to noble metals.