Work

Construction of hollow porous lychee-structured Ni/C/ZnFe2O4 microwave-responsive catalysts with rapid efficiently reduction of Cr(VI) ions

Year: 2025

Type: article

Abstract: Designing catalysts with high reaction efficiency is essential for reducing heavy metal Cr(VI) ions in wastewater via microwave induction. In this paper, a unique microwave-responsive lychee-like Ni/C/ZnFe 2 O 4 composite catalyst with a double-shell hollow porous heterojunction structure was constructed for the efficient reduction of Cr(VI). Benefiting from the novel hollow porous structure and “carbon nanocage” structure of the Ni/C/ZnFe 2 O 4 , coupled with excellent electromagnetic wave absorption ability, the prepared lychee-like Ni/C/ZnFe 2 O 4 composite catalyst could remove up to 98% of Cr(VI) (50 mg L −1 , 50 mL) after 40 min of microwave irradiation, even in nearly neutral water conditions. Additionally, density functional theory calculations indicated that the heterojunction interface between Ni/C and ZnFe 2 O 4 enhances electron transfer from ZnFe 2 O 4 to Ni/C, ultimately facilitating the removal of Cr(VI). Furthermore, the incorporation of Ni/C facilitated the acceleration of H ion transfer to ∗Cr 2 O 7 2− , thereby expediting the conversion kinetics of the latter. This research aims to establish a theoretical and experimental foundation for the effective and stable microwave-assisted catalytic reduction of heavy metal Cr(VI) ions, presenting new insights and methods to combat heavy metal contamination.

Source: Green Energy & Environment

DOI: 10.1016/j.gee.2025.04.008