Superhydrophilic ZnO nano-needle decorated over nanofibrous PAN membrane and its application towards oil/water separation

Abstract

Oil spills in the marine environment as well as release of industrial effluent and oily wastewater can pose serious threats to ecosystems and human health. Therefore, designing a filtrating material for treatment of wastewater has been a focus of research. Herein, we employed a simple and low temperature hydrothermal technique to effectively adorn the surface of the electrospun nanofibrous PAN membrane with micro-nano structure of ZnO nano-needles. The proposed membrane integrates a membrane filtration and photodegradation process and has demonstrated improvement in permeability, pollutant eradication, anti-fouling and self-cleaning capabilities. The in-air superhydrophilic NPAN-ZnO nano-needle membrane with micro-nano hierarchal needle architectures captures water and conveys it with underwater superoleophobicity. The substantial amount of pure water flux (7349 ± 200 Lm−2h−1) and separation efficacy (98 ± 1%) justify the membrane's effectiveness in the separation process. The membrane also demonstrated antifouling and self-cleaning characteristics upon UV irradiation after being fouled by BSA and octadecanoic acid, restoring the original flux performance. Furthermore, the membrane has the capability of disintegrating organic and pharmaceutical contaminants found in oily effluent. Given the NPAN-ZnO nano-needle membrane's particular superiority, the technology may inspire the general engineering of multipurpose superwetting polymers materials with intriguing application for complicated oily wastewater treatment.