Anchoring 3D hydrangea-like ZnIn2S4/C3N5 heterojunction onto poly(arylene ether nitrile) membrane via one-step co-deposition for enhanced photocatalytic self-cleaning and oil-repellence capacity

Membrane separation technology demonstrates preeminent advantages in the field of oily wastewater treatment. However, the coexistence of oily emulsions and soluble organic pollutants in oily wastewater poses stringent challenge to the performance of membrane materials. To address this issue, this study employed an biomimetic co-deposition technique to construct a 3D hydrangea-like ZnIn 2 S 4 /C 3 N 5 heterojunction structure on the surface of poly(arylene ether nitrile)(PEN) porous support, conferring the superior permeability and photocatalytic self-cleaning capacity. The free deposition and arrangement of the 3D hydrangea-like ZnIn 2 S 4 /C 3 N 5 heterojunction effectively broke through the limitation of separation flux. Benefiting from its superhydrophilic/underwater oleophobic property, low oil adhesion, and precisely regulated water channel structure, the ZnIn 2 S 4 /C 3 N 5 @PEN composite membrane exhibited outstanding permeation performance (with a flux reaching 784–946 L m −2  h −1 ) while maintaining a stable rejection efficiency of over 99 % when treating various stable water-in-oil emulsions. The cross-linking network formed by the 3D hydrangea-like ZnIn 2 S 4 /C 3 N 5 heterojunction, sodium alginate, and dopamine effectively enhanced the structural stability and anti-fouling performance of the membrane's functional layer. Notably, the synergy between ZnIn 2 S 4 and C 3 N 5 endowed the membrane with efficient photocatalytic degradation capability for soluble organic compounds. Under visible light irradiation, the degradation rate of MeB reached as high as 95.93 % within 2 h.