Facile in situ construction of novel hybrid 3D-BiOCl@PDA heterostructures with vacancy induced charge transfer for efficient visible light driven photocatalysis and antibacterial activity

Abstract

Combining a wide band BiOCl semiconductor with organic π-conjugated systems is critical for increasing its light absorption and charge carrier mobility at heterojunction interfaces for efficient photocatalysis. In this study, we described a bioinspired dopamine-assisted one-pot route as an environmentally benign method to construct multifunctional in situ hybrid 3D-BiOCl@PDA heterostructure photocatalysts in an aqueous medium under mild conditions. The versatile role of dopamine was utilized for the controlled integration of 3D-BiOCl (001) hierarchical microspheres while simultaneously modified their surfaces with thin layers of PDA via its in situ polymerization. TGA, UVDRS, and XPS revealed that PDA thickness and its cooperative chelating effect with BiOCl nanosheet at a hybrid interface allowed effective charge transfers, and band-edge shift, induced oxygen defects for extended visible light absorptions. The resulting hybrids exhibited evidently multifunctional photocatalytic performance for complete RhB dye removal (12 times), enhanced selective benzyl alcohol oxidation (>99 benzaldehyde) and excellent antibacterial activity against Staphylococcus aureus (99.9%) than bare BiOCl under identical conditions. Furthermore, the hybrids showed excellent photostability and recyclability for up to five reaction cycles. These highly enhanced results are attributed to their 3D-structural features and close contact between PDA and BiOCl. Based on the results of active species experiments and ESR spectral analysis a possible Z-scheme photocatalytic mechanism has been proposed for the hybrid heterostructure system. Hence, the present work is an effective noble metal-free strategy for creating novel hybrid BiOCl heterostructures with multifunctional properties for visible light photocatalytic applications.