In-situ growth hierarchical and superhydrophobic flower-like Cu₃(PO₄)₂·2H₂O nanosheets based on copper mesh for efficient oil–water separation

Abstract

Superhydrophobic porous membranes with interconnected open structures for effective treatment oily wastewater have gradually drawn researchers’ attentions owing to frequent occurrence of organics leakage accidents. In this paper, we successfully fabricated superhydrophobic flower-like Cu₃(PO₄)₂·2H₂O nanosheets on copper mesh surface via in-situ growth strategy and silane coupling agent (A151) hydrophobic modification. Specifically speaking, commercial copper mesh served as substrate and Cu could react with (NH₄)₂S₂O₈ and Na₂HPO₄, forming flower-like micro-nanostructure. As-synthesized materials were characterized by scanning electron microscope (SEM), energy dispersive spectrometer (EDS) and X-ray diffractometer (XRD). In addition, chemical, mechanical stability and durability of as-prepared materials were also investigated under different condition. The relevant experiment results demonstrated that flower-like Cu₃(PO₄)₂·2H₂O nanosheets successfully grew on copper mesh surface, resulting in the formation of rough structure. Modified copper mesh showed superhydrophobic and superoleophilic properties simultaneously with water contact angle (CA) of 151.24° and oil contact angle of 0°, respectively. The as-prepared materials could be used to separate oily wastewater with high separation efficiency (above 95.0%). The mechanism of oil–water separation was investigated in detail based on positive and negative capillary effect. High separation efficiency, excellent stability and durability of superhydrophobic copper mesh make it one of best promising separation candidates for wastewater treatment.

KEYWORDS:

• In-situ growth
• flower-like Cu3(PO4)2·2H2O nanosheets
• superhydrophobic and superoleophilic
• capillary effect

Additional information

Funding

This work was financially supported by National Nature Science Foundation of China (Nos. 21706100 and U1507115), Natural Science Foundation of Jiangsu Province (Nos. BK20160500, BK20161362 and BK20160491), the Natural Science Foundation of Hebei Province (No. B2018203393), Qinhuangdao Science and Technology Research and Development Plan, (No. 201701B044) and Hebei Province key research and development projects, (No. 17272402D).