Engineering Lateral Heterojunction of Selenium‐Coated Tellurium Nanomaterials toward Highly Efficient Solar Desalination

Herein, a core–shell tellurium–selenium (Te–Se) nanomaterial with polymer‐tailed and lateral heterojunction structures is developed as a photothermal absorber in a bionic solar‐evaporation system. It is further revealed that the amorphous Se shell surrounds the crystalline Te core, which not only protects the Te phase from oxidation but also serves as a natural barrier to life entities. The core (Te)–shell (Se) configuration thus exhibits robust stability enhanced by 0.05 eV per Se atom and excellent biocompatibility. Furthermore, high energy efficiencies of 90.71 ± 0.37% and 86.14 ± 1.02% and evaporation rates of 12.88 ± 0.052 and 1.323 ± 0.015 kg m−2 h−1 are obtained under 10 and 1 sun for simulated seawater, respectively. Importantly, no salting out is observed in salt solutions, and the collected water under natural light irradiation possesses extremely low ion concentrations of Na+, K+, Ca2+, and Mg2+ relative to real seawater. Considering the tunable electronic structures, biocompatibilities, and modifiable broadband absorption of the solar spectrum of lateral heterojunction nanomaterials of Te–Se, the way is paved to engineering 2D semiconductor materials with supporting 3D porous hydrophilic materials for application in solar desalination, wastewater treatment, and biomedical ventures.