ZnO nanowire-decorated 3D printed pyrolytic carbon for solar light–driven photocatalytic degradation of wastewater contaminants

Abstract

Photocatalytic wastewater treatment offers advantages like improved degradation of organic contaminants and adaptable catalysts that can be optimized for cost-effectiveness. However, challenges are faced when dealing with complex water purification scenarios, such as particle aggregation and the separation of photocatalysts from treated water. This work aims to overcome the limitations of photocatalysts by decorating them on customizable pyrolyzed 3D microlattice architectures for enhanced photocatalytic performance. Here, we first fabricated 3D carbon microlattice architectures by digital light processing (DLP) 3D printing of a precursor resin, followed by carbonization at 900 °C and the hydrothermal growth of zinc oxide (ZnO) nanowires on the 3D pyrolyzed structures (ZnO@PyC). The photocatalytic performance of ZnO@PyC structures was evaluated through the degradation of rhodamine B (RhB) dye under both UV light and direct sunlight irradiation. The ZnO@PyC structures demonstrated an enhanced degradation efficiency, achieving 97.73% and 84.04% for RhB dye after 180 min and 280 min under UV light and direct sunlight irradiations, respectively. This demonstrates the ability of the fabricated ZnO@PyC structures to eliminate the contaminants in the wastewater without the necessity for additional equipment during the degradation process. Furthermore, the ZnO@PyC structures exhibit good reusability only through a facile washing step with water, demonstrating 86.22 ± 2.15% degradation efficiency retention after repeated cycles over 7 days. The inventive combination of ZnO@PyC structure represents a promising pathway for advancing sustainable and effective water purification technologies.

Graphical Abstract