Potential of Piper betle@Co3O4 nanoparticles as high-performance photocatalysts for the removal of industrial dyes

In this study, cobalt oxide (Co 3 O 4 ) NPs were bio-synthesized for photocatalytic application through the reduction of cobalt chloride hexahydrate using extract of Piper betle (e.g., polyphenols). The as-prepared Co 3 O 4 NPs exhibited the face-centered cubic structure of Co 3 O 4 with the crystallite sizes ranging from 20 to 30 nm with an energy band gap of 3.86 eV. FTIR spectra revealed that Piper betle extracts were present on the surface of the resulting Co 3 O 4 . HRTEM confirmed the dispersion of non-agglomerated uniformly spherical particles over a large area. The photocatalytic activity of the Co 3 O 4 NPs was investigated for the degradation of the industrial dye, Eriochrome Black T (EBT). The degradation efficiency of EBT could exceed 94% within 80 min under UV light. The Piper betle@ Co 3 O 4 NPs recorded superior performance (quantum yield of 1.98 × 10 −4 Φ and figure-of-merit of 1.59 × 10 −9 mol L J −1 g −1 h −1 ) with a low energy requirement of 2.35 × 10 9 J mol −1 . As such, the Piper betle @Co 3 O 4 NPs are recognized as a high-efficiency photocatalyst for efficient degradation of industrial dyes. • The pollution of industrial dyes poses a significant threat to human and ecological systems. • A biogenic photocatalyst (Piper betle@Co 3 O 4 ) was prepared to treat industrial dyes. • The biogenic photocatalyst was used for the first time in the study of EBT dye removal. • Its enhanced removal potential for EBT dyes is validated in terms of performance evaluation.