Three-Dimensionally Printed Zero-Valent Copper with Hierarchically Porous Structures as an Efficient Fenton-like Catalyst for Enhanced Degradation of Tetracycline

Abstract

Three-dimensionally printed materials show great performance and reliable stability in the removal of refractory organic pollutants in Fenton-like reactions. In this work, hierarchically porous zero-valent copper (3DHP-ZVC) was designed and fabricated via 3D printing and applied as a catalyst for the degradation of tetracycline (TC) through heterogeneous Fenton-like processes. It was found that the 3DHP-ZVC/H2O2 system could decompose over 93.2% of TC within 60 min, which is much superior to the homogeneous Cu2+/H2O2 system under similar conditions. The leaching concentration of Cu2+ ions in the 3DHP-ZVC/H2O2 system is 2.14 times lower than that in the Cu powder/H2O2 system in a neutral environment, which could be ascribed to the unique hierarchically porous structure of 3DHP-ZVC. Furthermore, 3DHP-ZVC exhibited compelling stability in 20 consecutive cycles. The effects of co-existing inorganic anions, adaptability, and pH resistance on the degradation of TC were also investigated. A series of experiments and characterizations revealed that Cu0 and superoxide radicals as reducing agents could facilitate the cycling of Cu(II)/Cu(I), thus enhancing the generation of hydroxyl radicals to degrade TC. This study provides new insights into employing promising 3D printing technology to develop high-reactivity, stable, and recycling-friendly components for wastewater treatment.