Preparation of Zr-based MOF/PDMS Janus membrane for vacuum membrane distillation and its removal of phenolic pollutants from coal chemical wastewater

The conventional blending method for preparing photocatalytic composite membranes often results in dense polymeric structures that encapsulate photocatalysts, thereby limiting their photocatalytic activity. To address this limitation, we developed an innovative Janus membrane through in-situ growth of polyaniline for hydrophilic modification of polydimethylsiloxane (PDMS), followed by controlled deposition of zirconium-based metal-organic framework (TFMOF) particles via a dip-coating process. The obtained TFMOF/PDMS Janus membrane exhibits significant asymmetric wettability (underwater oil contact angle >140°). In phenol degradation tests, the membrane achieved 93.78 % removal efficiency within 2 h under visible light irradiation. When applied to actual coal chemical wastewater treatment, the Janus membrane demonstrated removal rates of 68.71 % for volatile phenols and 77.22 % for COD in the feed solution, with corresponding values of 79.85 % and 86.18 % in the distillate, respectively. This work provides a robust solution for coal chemical wastewater treatment by synergistically combining asymmetric wettability structure with photocatalytic membrane distillation.