# 3D‐Printed Architected Anisotropic Channels for Ultrafast Solar‐Driven Interfacial Evaporation via Localized Thermal Management and Water Layer Structuring

## TL;DR

A 3D-printed solar evaporator uses aligned materials to efficiently manage heat and water flow, achieving fast and long-lasting desalination.

## Contribution

The novel integration of anisotropic architecture with aligned nanomaterials enables ultrafast and durable solar-driven evaporation.

## Key findings

- The a-BTCG evaporator achieves an evaporation rate of 5.43 kg m−2 h−1 under 1 sun.
- Aligned boron nitride enhances thermal conductivity and heat localization for efficient evaporation.
- The system maintains performance for over 200 hours in 20 wt.% NaCl solution.

## Abstract

Efficient solar‐driven interfacial evaporation requires coordinated photon absorption, heat confinement, and directional water delivery, yet current directional evaporators rarely achieve materials‐level anisotropy to regulate photon‐phonon‐water coupling. Here, we report a 3D‐printed anisotropic channel architecture (a‐BTCG) that co‐engineers directional geometry with preferential alignment of Ti3O5 nanoparticles, boron nitride (BN) nanosheets, and chitosan to form an integrated transport framework. The a‐BTCG delivers a high evaporation rate of 5.43 kg m−2 h−1 under 1 sun and maintains stable performance for over 200 h in 20 wt.% NaCl, enabled by fast water flux (1.13 × 10−2 µm3 s−1) and enhanced in‐plane thermal conductivity (2.73 W m−1 K−1). Mechanistic investigations reveal that aligned BN establishes continuous phonon‐guided thermal pathways for heat localization, while the Ti3O5–BN hybrids enhance broadband absorption via reduced reflectance and multireflection in oriented channels. Chitosan mediates interfacial water structuring, lowers effective evaporation enthalpy, and sustains salt‐resistant replenishment. The combined structural and materials‐level anisotropy, therefore, overcomes conventional trade‐offs in light absorption, heat dissipation, and water supply. This work demonstrates the potential of 3D printing–assisted alignment engineering for high‐performance solar evaporators and provides a generalizable platform for advanced desalination and environmental thermal‐management technologies.

A 3D‐printed anisotropic channel evaporator integrates directional geometry with aligned titanium oxide, boron nitride, and chitosan networks to coordinate photon absorption, heat localization, and water transport. Phonon‐guided thermal pathways and interfacial water structuring enable ultrahigh evaporation rates and long‐term salt‐resistant solar desalination.