Arc-melting synthesis of Li-doped λ-Ti3O5 for efficient solar-driven interfacial evaporation

The Magnéli-phase λ-Ti 3 O 5 , characterized by its unique flat-band electronic structure, is a promising photothermal conversion material for solar-driven interfacial evaporation. However, its intrinsic thermodynamic instability at ambient temperature severely constrains large-scale practical application. To overcome this challenge, we developed a scalable synthesis strategy for stabilizing λ-Ti 3 O 5 via arc-melting followed by high-energy ball milling, coupled with Lithium (Li) doping. Structural and surface analyses confirm that Li incorporation effectively stabilizes the λ-phase. Morphological studies reveal particle refinement (∼1–2 μm) with increased surface roughness and oxygen vacancies, further enhancing solar absorption with overall reflectivity < 6% in the range of 250–2500 nm. Incorporating 10 wt.% of Li 0.25 Ti 2.75 O 5 particles into a Polyvinyl alcohol/Polyvinylpyrrolidone (PVA/PVP) porous hydrogel evaporator yielded an evaporation rate of 5.22 kg m −2 h −1 under one sun irradiation. Remarkably, the evaporator demonstrated excellent resistance to salt crystallization, maintaining stable performance during a 24-h continuous operation in 3.5 wt.% saline water. This work not only provides a practical and scalable approach for stabilizing λ-Ti 3 O 5 but also offers valuable insights into the development of efficient, durable photothermal materials for solar desalination technologies.