A robust Ti3C2Tx/alginate hydrogel reinforced with wheat straw cellulose microfibers (CMFs) for highly durable solar-driven water evaporation and desalination

Solar-driven interfacial water evaporation offers a transformative and sustainable route to alleviate the global freshwater crises through localized photothermal conversion. Cellulose microfibers (CMFs), derived from abundant agricultural waste such as wheat straw, serve as a renewable and valuable reinforcing material in Ti 3 C 2 T x /alginate/CMFs hydrogel, enhancing its porous structure and water transport properties for efficient solar-driven water evaporation and desalination. A highly hydrophilic Ti 3 C 2 T x /alginate/CMFs hydrogel, optimized via a unique one-layer and two-layer freeze casting strategy, features a porous architecture with interconnected CMFs networks, enabling ultrafast water transport, broadband solar absorption, and high photothermal conversion for water evaporation. Under one-sun irradiation (1 kW m −2 ), the optimized hydrogel evaporator (MACMF-8) achieved an evaporation rate of 1.66 kg m −2  h −1 with an evaporation efficiency of 85.41%. The hydrogel exhibited excellent salt rejection, maintaining a high evaporation rate of 1.57 kg m −2  h −1 in 5 wt% NaCl solution with only a minor 3.13% decrease over a 10-day desalination period. Using a simple device under one-sun irradiation for 12 h, 18.48, 19.33, 19.83, and 19.81 kg m −2 of purified water were obtained from 5 wt% NaCl solution, simulated seawater, ponceau S, and crystal violet dye solution, respectively. Combining scalability, durability, and solar-driven operation, the Ti 3 C 2 T x /alginate/CMFs hydrogel represents a highly promising platform for sustainable water purification and desalination.