Modification of structured bio-carbon derived from spongin-based scaffolds with nickel compounds to produce a functional catalyst for reduction and oxidation reactions: Potential for use in environmental protection

Three different 3D fibrous-like NiO/Ni(OH)(2)/Ni-carbonized spongin-based materials were prepared via a simple sorption-reduction method. Depending on the support used, the catalysts were composed of carbon, nickel oxide, nickel hydroxide and zero-valent nickel, with the surface content of the nickel-containing phase in the range 15.2-26.0 wt%. Catalytic studies showed promising activity in the oxidation of phenolic compounds in water and in the reduction of 4-nitrophenol. The oxidation efficiency depends on the substrate used and ranges from 80% for phenol at pH 2 to 99% for 4-chlorophenoxyacetic acid (4-CPA) and methylchlorophenoxypropionic acid (MCPP). In the reduction reaction, all catalysts exhibited superior activity, with rate constants in the range 0.648-1.022 min(-1). The work also includes a detailed investigation of reusability and kinetic studies. (C) 2021 The Author(s). Published by Elsevier B.V.

Automated summary

Three different 3D fibrous-like NiO/Ni(OH)(2)/Ni-carbonized spongin-based materials were prepared using a sorption-reduction method, showing promising catalytic activity in oxidation and reduction reactions. The oxidation efficiency varied depending on the substrate, with superior activity observed in reduction reactions. The catalysts also exhibited good reusability and kinetic properties.