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A simple and mildly rapid preparation strategy is developed to accelerate polymerization by UV-induced excitation of ferric phytate ligands and generation of free radicals by electron transfer. The introduction of phytic acid provides a synergy between excellent electrical conductivity and anti-freezing the hydrogel through ionization and hydrogen bonding, which enables hydrogel-based strain sensors to show great potential for stable detection of physiological activities in low-temperature environments. [Display omitted] • Anti-freezing, ion-conducting and stretchable hydrogels are developed. • A rapid gelation process in 90s with UV induced iron phytate. • The hydrogel shows good sensing properties at −30℃ with 97% gauge factor retention. • A novel hydrogel-based temperature control switch is demonstrated. Conductive hydrogels have great potential in flexible electronics due to their flexibility, excellent biocompatibility and diverse functionalities. However, most rapid-gelation hydrogels tend to manifest weak and fragile due to vigorous reaction process and poor adaptability in cryogenic environment, which severely impede their practical applications. Herein, a facile and mild strategy for rapid gelation is proposed that accelerates polymerization by generating reactive oxygen radicals via electron transfer based on the excitation of ferric phytate ligands under UV irradiation, which takes only 17 s to initiate. Interestingly, the introduced phytic acid imparts the hydrogel excellent electrical conductivity (12 ms/cm), frost resistance (−31℃) and improves tensile properties (elongation at break 1299 %). The hydrogel that combines the above merits inspires the construction of strain sensor for monitoring physiological activity of low-temperature environments. This study provides a simple and universal approach for the rapid preparation of antifreeze hydrogels and reinforces the focus on sustainable and high-value utilization of phytic acid in advanced applications. [ABSTRACT FROM AUTHOR]

A vertically oriented porous PVA hydrogel and PDA/CB modified 3D raised-fabric are innovatively designed as an solar evaporator to enhance the evaporation rate, conversion efficiency and self-desalting performance. [Display omitted] • A super water transport PVA hydrogel and PDA/CB modified 3D raised-fabric are innovatively designed as solar evaporators. • It exhibits high water evaporability (1.73 kg m-2h−1, 1 sun) and conversion efficiency (91.9 %). • The 3D raised-fabric solar evaporator system can be readily fabricated for scalable production. • The collected water is in full compliance with the drinking requirements of WHO and EPA. A solar evaporator with simple fabrication process, exceptional photothermal conversion efficiency and dependable continuous water evaporation holds significant potential for seawater desalination and wastewater treatment. Despite the substantial research dedicated to developing high-efficiency solar evaporators, there remains a need for additional exploration to tackle concerns such as salt crystallization, low evaporation efficiency, poor durability and stability. Here, an efficient water transport PVA hydrogel (water transport layer) and polydopamine/carbon black modified 3D raised-fabric (photothermal layer) are innovatively designed as solar evaporators. The synergistic effect between the periodic raised structure and polydopamine/carbon black results in outstanding photothermal conversion capabilities of PDA/CB@RF. Meanwhile, the porous structure of PVA hydrogel and its vertically aligned channels facilitate ion exchange and ensure a consistent water supply to the photothermal layer. This phenomenon serves to prevent the accumulation of salt in the photothermal layer, thereby markedly enhance the water evaporation capability of the PDA/CB@RF evaporator. The results demonstrate that the PDA/CB@RF evaporator system exhibits excellent photothermal conversion performance with its surface temperature rapidly ascending to 73.3 ℃ under 1 sun light intensity, and effectively boost the water evaporation rate (1.73 kg m-2h−1, 1 sun). Furthermore, the PDA/CB@RF evaporator exhibits excellent conversion efficiency (91.9 %) and self-desalting capability. Overall, this solar evaporator system with a 3D raised fabric design integrates light and thermal energy, consistent water evaporation and self-desalting functionalities, which makes it hold the potential to solve the pressing challenge of water shortage. [ABSTRACT FROM AUTHOR]