A multi-institute team led by Professors Tian Liu, Alicia Kyoungjin An and Wen-Wei Li has unveiled a binder-free “surface self-bounded photocatalytic membrane” (SSPM) that simultaneously produces green H₂O₂ and annihilates antibiotics in water. Published in Nano-Micro Letters , the work converts a simple PVDF nanofiber sheet into a high-activity reactor—no glue, no embedding, no energy-intensive steps.
Why Binder-Free Wins
Instant Catalyst Fixation : A 2-minute dimethylformamide (DMF) bath softens PVDF fibers, allowing 1.6-μm CoO x /Mo:BiVO 4 /Pd particles to slip into freshly opened micropores; solvent evaporation then shrinks the fibers, mechanically clamping the catalyst with <5 % loss after 20 cycles.
Mass-Transfer Leap : Surface-bound particles enjoy 4.2× faster O 2 access and 19× higher H 2 O 2 diffusion than matrix-embedded controls, pushing production to 7,700 μmol g -1 h -1 —outpacing 90 % of reported catalysts.
Hydrophobic Shield : The 120.9° water-contact-angle surface limits H 2 O 2 back-decomposition, yielding 0.53 mM in 2 h versus 0.12 mM for embedded designs.
Universal Toolkit : The same stretch-shrink protocol immobilized 800 nm RF523 spheres and hydrophilic variants, cutting fabrication cost by 39 %.
Real-World Validation
Micropollutant Blitz : Under 254 nm UV (1.08 mW cm -2 ), the membrane erased 95 % of 10 mg L -1 tetracycline or bisphenol A in 60 min—10× faster than UV alone—while mineralizing 70 % of total organic carbon.
Lake-to-Tap Resilience : Tests on lake water, tap water and secondary effluent all exceeded 90 % pollutant removal, with negligible activity loss in 5 mM Cl - , NO 3 - or humic acid.
Continuous-Flow Ready : A flow-by reactor (0.2 mL min -1 ) sustained 82 % tetracycline and 93 % BPA removal for 10 h with self-cleaning antifouling action.
Mechanistic Insights
Multi-Physics Modeling : Oxygen concentration profiles show severe starvation inside embedded catalyst layers, whereas SSPM maintains >0.8 mM O 2 at the surface—critical for sustaining the 2-electron O 2 reduction pathway.
ROS Mapping : Scavenger tests reveal ·OH and 1 O 2 dominate degradation; LC-MS identified 10 BPA and 9 TC intermediates, all eventually mineralized to CO 2 and H 2 O.
Self-Defouling : In situ H 2 O 2 continuously oxidizes membrane foulants, maintaining 95 % flux after 40 h of operation.
Economic & Regulatory Edge
Cost Model : At 10,000 m 2 yr -1 production, SSPM is projected at $9.95 m -2 —39 % cheaper than matrix-embedded equivalents and competitive with commercial PVDF.
Dry-Storage Advantage : Unlike embedded membranes that lose 40 % activity after 30 days dry storage, SSPM retains >95 % performance, simplifying logistics.
Regulatory Alignment : All materials are REACH-compliant, and the process uses only DMF and ethanol—solvents already approved for membrane manufacturing.
Scale-Up & Next Steps
Roll-to-Roll Pilot : A 1 m 2 module under construction will integrate SSPM into a skid-mounted UV/H 2 O 2 reactor for 10 m 3 day -1 municipal pilot trials in Suzhou.
Hybrid AOPs : Coupling SSPM with low-pressure UV lamps enables on-site H 2 O 2 generation + micropollutant destruction, eliminating chemical dosing and storage hazards.
Beyond Water : The stretch-shrink concept is being adapted for gas-phase VOC filters and self-sterilizing air-conditioning meshes.
By transforming passive membranes into active, self-armored reactors, the Li team delivers a plug-and-play upgrade for next-generation UV/H 2 O 2 plants—cleaner water, lower cost, zero binders.
Nano-Micro Letters
Experimental study
Binder-Free Immobilization of Photocatalyst on Membrane Surface for Efficient Photocatalytic H2O2 Production and Water Decontamination
18-Jun-2025