Bovine hide collagen/tannin extract composite: A revelation of the selective structure-activity relationship between phenolic hydroxyls and Cu(II) and study on adsorption properties

In this paper, phenolic compounds are employed to reveal that there is a selective structure-activity relationship between adjacent phenolic hydroxyls in tannin of bovine hide collagen/tannin extract composite (BHC/TE) and Cu(II). Firstly, the morphology and structure of BHC/TE are observed via SEM, TEM and BET. Then, the preparation and adsorption mechanisms of BHC/TE are revealed via XPS, FT-IR and DFT. Meanwhile, four common adsorption models are used to jointly explore the adsorption mechanism. In addition, phenol, resorcinol, hydroquinone, catechol and pyrogallol are employed to investigate the effect of content and location of phenolic hydroxyls on the adsorption of Cu(II) by employing UV-visible spectra, fluorescence spectra and DFT calculation. Finally, the adsorption properties of BHC/TE are also discussed. Therefore, this paper aims to confirm the selective structure-activity relationship between adjacent phenolic hydroxyls and Cu(II), and it also provides a new idea for future research and structure design of related adsorbents.