Laser‐Induced 3D Arch‐Bridged Solar Evaporator Based on Diradical‐Featured Photothermal Polymers for Highly Efficient Seawater Desalination

Why It Matters

The breakthrough offers a cost‑effective, high‑performance solution for freshwater production in arid and coastal regions, accelerating adoption of solar‑driven desalination technologies.

Key Takeaways

• PSSe‑Se polymer reaches 32% photothermal efficiency
• LIBA‑Se evaporator yields 2.67 kg m⁻² h⁻¹ under 1 sun
• No salt buildup after ten 20% brine cycles
• Effective removal of heavy metals, dyes, extreme pH water
• Laser‑induced 3D arch design enhances Marangoni flow

Pulse Analysis

The emergence of open‑shell organic radicals like PSSe‑Se marks a shift in photothermal material design. By integrating selenium‑enhanced acceptor units with flexible thiophene side chains, the polymer achieves near‑full‑spectrum absorption and suppresses radiative losses, delivering a 32% conversion efficiency that rivals many inorganic counterparts. This molecular strategy not only broadens the light‑harvesting window but also introduces intrinsic non‑radiative pathways through intramolecular rotations, a key factor for scalable solar‑thermal applications.

Building on the polymer's optical prowess, the laser‑induced 3D arch‑bridged evaporator (LIBA‑Se) translates heat into rapid water vaporization. The arched architecture creates uniform surface grooves that trigger Marangoni convection, continuously flushing salt away from the interface. As a result, the system sustains evaporation rates above 2.5 kg m⁻² h⁻¹ even in highly saline (20 wt% NaCl) environments without performance degradation, addressing a long‑standing hurdle of salt accumulation in solar stills.

Beyond desalination, LIBA‑Se demonstrates multifunctional water treatment capabilities, efficiently chelating heavy‑metal ions and extracting organic dyes while withstanding acidic and alkaline extremes. Such versatility positions the technology as a comprehensive water‑purification platform for remote or disaster‑affected regions. By coupling high photothermal conversion with robust salt‑rejection and contaminant removal, this approach could lower the total cost of clean water production and accelerate the transition toward sustainable, off‑grid water infrastructure.