Dual-driven interfacial synthesis of PB/PmPD mixed matrix membranes via soft spraying for water treatment

Fe 3+ -dual-driven interfacial synthesis grows PB and PmPD simultaneously • Soft spraying enables one-step and eco-friendly MMM fabrication • PB/PmPD MMM combines photothermal evaporation and membrane separation • MMM realizes molecular-level integration for scalable fabrication A strategy combining soft spraying with Fe 3+ -dual-driven interfacial synthesis is developed to fabricate PB/PmPD mixed matrix membranes (MMMs). Fe 3+ serves dual roles as a coordination center for Prussian blue formation and an oxidant to initiate m -phenylenediamine polymerization (mPD), enabling synchronous generation and in-situ compositing of PB nanoparticles and PmPD matrix at the gas–liquid interface. This synergy enhances structural integrity and interfacial compatibility. The PB/PmPD MMM exhibits excellent performance in both photothermal evaporation and permeation separation. Under solar irradiation, it achieves an evaporation rate of 2.16 kg·m −2 ·h −1 and effectively purifies seawater and wastewater with removal rates exceeding 99%. In terms of membrane separation, it demonstrates over 98% rejection for various dyes, along with water permeance ranging from 89.41 to 117.17 LMH/bar, while exhibiting excellent antifouling and antibacterial properties. This work offers a versatile strategy for constructing multifunctional MMMs integrating evaporation and separation. Download: Download high-res image (153KB) Download: Download full-size image