High-Throughput Electrospinning System| Beam-column structure inspired cellulosenanofiber-based composite aerogel forefficient solar desalination and wastewaterpurification

Associate Professor Zhang Yuanyuan of Qingdao University, Professor Jiang Wei & Professor Yan Jianhua of Donghua University: Cellulose Nanofiber-Based Composite Aerogel for Efficient Solar Desalination and Wastewater Purification

The excessive use of fossil fuels has triggered a dual crisis, leading to non-renewable resource shortages and environmental pollution. The development of cellulose and its derivatives aligns with sustainable development strategies and has attracted significant attention. Cellulose-based biomass aerogels, characterized by high porosity, low density, and abundant porous network structures, have emerged as promising materials for solar-driven clean water supply. However, constrained by weak light absorption capacity and poor mechanical properties, developing efficient and stable cellulose nanofiber aerogel evaporators remains a significant challenge.

Recently, Associate Professor Zhang Yuanyuan and Professor Jiang Wei's team from Qingdao University, in collaboration with Professor Yan Jianhua from Donghua University, published their latest research titled "Beam-Column Structure Inspired Cellulose-Nanofiber-Based Composite Aerogel for Efficient Solar Desalination and Wastewater Purification" in *Chemical Engineering Journal*. Inspired by beam-column load-bearing structures, the researchers prepared a cellulose nanofiber-based composite aerogel (CPCM) with a similar beam-column structure through directional freezing, utilizing physical and chemical entanglement between nanocellulose (CNF) skeletons, amine-functionalized carbon nanotubes (PEI@CNT), and MXene. This structure integrates an interlocked fibrous porous structure with photothermal conversion functional components, demonstrating excellent mechanical properties and high photothermal conversion efficiency. The study provides new insights for developing efficient and environmentally friendly cellulose nanofiber aerogel desalination evaporators capable of long-term stable operation.

Figure 1.CPCM structural design and morphology

Figure 2.Characterization of raw materials and CPCM aerogel  

Figure 3. Morphological structure and formation process characterization of CPCM aerogel  

Using directional freezing technology, the researchers successfully constructed a porous and ordered 3D aerogel structure composed of cellulose nanofibers, amine-functionalized carbon nanotubes, and MXene nanosheets through crosslinking reactions and strong hydrogen bonding. Numerous CNFs are continuously arranged to form a series of lamellar structures, which act as "beams" in the composite aerogel. Additionally, PEI@CNT and MXene, together with some CNF bundles, form "column" structures that support the layers. These "columns" strengthen the connections between layers, creating a continuous and ordered "beam-column" framework for the aerogel, which also provides critical support for the overall stability and unique pore structure of the composite aerogel.

Figure 4. Mechanical properties and solar-driven water evaporation performance of prepared CPCM  

Thanks to the unique beam-column structure, the CPCM aerogel exhibits superior compressive performance. As shown in Figure 4, CPCM-2 demonstrates the highest compressive stress at 50% strain, surpassing unmodified and non-composite cellulose nanofiber aerogels. Furthermore, after substantial compression at 80% strain, the CPCM-2 aerogel reaches a maximum stress of 143.7 kPa and can quickly recover to its initial state with minimal deformation, indicating excellent compressive elastic recovery capability and microstructural stability.Additionally, the CPCM aerogel rapidly generates a temperature response under 1-sun irradiation, effectively converting solar energy into heat, which facilitates solar steam generation. The prepared CPCM aerogel maintains stable and high evaporation efficiency under solar radiation. 

Figure 5. Water purification performance of solar-driven CPCM  

After multiple reuse cycles, the evaporation rate of CPCM remains at a high level, demonstrating its long-term stability and potential for sustainable freshwater production. Moreover, the CPCM aerogel exhibits excellent salt rejection and self-dissolving salt properties. Simultaneously, the ion rejection rate of CPCM exceeds 99%, far below the World Health Organization (WHO) standards for drinking water. It can also purify dye wastewater, showcasing significant potential in water treatment applications.

Original article link: [https://doi.org/10.1016/j.cej.2025.163882](https://doi.org/10.1016/j.cej.2025.163882)