Co-optimized membrane design and operating window for TiO₂-MoS₂ photothermal membrane distillation: Localized interfacial heating and enhanced performance
Desalination, vol.636, 2026 (SCI-Expanded, Scopus)
- Publication Type: Article / Article
- Volume: 636
- Publication Date: 2026
- Doi Number: 10.1016/j.desal.2026.120370
- Journal Name: Desalination
- Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Chemical Abstracts Core, Chimica, Compendex, Environment Index, Geobase, INSPEC, Public Affairs Index, Academic Search Ultimate (EBSCO), Engineering Source (EBSCO)
- Keywords: Desalination, Light absorption, Localized interfacial heating, Membrane design, Optimization, Photothermal membrane distillation, TiO2-MoS2
- Ataturk University Affiliated: No
Abstract
Freshwater scarcity, driven by rising pollution and global demand, necessitates efficient and sustainable desalination technologies. Membrane distillation (MD) is attractive but is limited by temperature polarization, membrane wetting, and high energy consumption. Photothermal membrane distillation (PMD) addresses these challenges by localizing heat generation at the membrane–liquid interface rather than relying solely on bulk feed heating. In this study, TiO₂-MoS₂ photothermal layers were deposited onto commercial PVDF hollow fiber membranes via repeated dip-coating (1LTM–5LTM). Crack-free coatings were obtained up to 3 coating cycles (3LTM), whereas excessive thickening led to structural defects. The optimized 3LTM membrane exhibited a high water contact angle (142.1°), preserved porosity (73.06%), and enhanced mechanical strength. Under conventional MD, increasing coating thickness reduced flux due to added mass-transfer resistance. In contrast, under 1 sun irradiation, PMD flux increased systematically with coating thickness, reaching 7.45 kg m−2 h−1 at 30 °C while maintaining '99.9% salt rejection. The photothermal layer reduced specific energy consumption from 172.14 to 63.37 kWh m−3 and increased the temperature polarization coefficient from 1.27 to ∼1.78, confirming effective interfacial heat localization. Response Surface Methodology optimization further enhanced performance under optimized operating conditions, with experimental validation within ±5% deviation. This work clarifies how coating thickness affects the transition from conventional MD to illuminated PMD, confirms effective interfacial heat localization, and combines membrane design with operating optimization to improve flux and energy efficiency. These results provide a clear strategy for developing stable and energy-efficient PMD systems for desalination.