Two-dimensional (2D) magnets with intrinsic ferromagnetic/antiferromagnetic (FM/AFM) ordering are highly desirable for future spintronic devices. However, the direct growth of their crystals is in its infancy. Here we report a chemical vapor deposition approach to controllably grow layered tetragonal and non-layered hexagonal FeTe nanoplates with their thicknesses down to 3.6 and 2.8 nm, respectively. Moreover, transport measurements reveal these obtained FeTe nanoflakes show a thickness-dependent magnetic transition. Antiferromagnetic tetragonal FeTe with the Néel temperature (TN) gradually decreases from 70 to 45 K as the thickness declines from 32 to 5 nm. And ferromagnetic hexagonal FeTe is accompanied by a drop of the Curie temperature (TC) from 220 K (30 nm) to 170 K (4 nm). Theoretical calculations indicate that the ferromagnetic order in hexagonal FeTe is originated from its concomitant lattice distortion and Stoner instability. This study highlights its potential applications in future spintronic devices.
Interfacial solar steam generation (ISSG) is the main method to get fresh water from seawater or wastewater. The balance between evaporation rate and salt resistance is still a major challenge for ISSG. Herein, a wood aerogel island solar evaporator (WAISE) with tunable surface structure and wettability by synthesizing poly(n‐isopropylacrylamide)‐modified multi‐walled carbon nanotube photothermal layers. Compared to dense surface structure evaporators, interfacial moisture transport, thermal localization, and surface water vapor diffusion of WAISE are greatly promoted, and the evaporation rate of WAISE increased by 87.64%. WAISE allows for record performance of 200 h continuous operation in 20% NaCl solution without salt accumulation. In addition, the photo‐thermal‐electric device is developed based on WAISE with continuous water purification, power generation, and irrigation functions. This work provides a new direction for the development of multifunctional water purification systems.
Freshwater scarcity is a critical global issue, exacerbated by water pollution. Solar-driven interfacial evaporation (SDIE) offers a promising solution due to its energy efficiency and environmental benefits. This study presents a light-driven adaptive interfacial solar steam evaporation system enhanced by dynamic water gating. The system addresses the challenge of balancing high evaporation rates with salt accumulation, a common limitation in SDIE technology. An evaporator is developed using modified spiropyran and inexpensive wood, enabling dynamic salt discharge through light variations. Theoretical calculations reveal that the reversible structural changes in spiropyrans facilitate salt removal. The evaporator features a two-layer design, with a light-control layer and a hydrophilic layer, which enhances evaporation by stabilizing the gas-liquid interface and minimizing heat loss. Experimental results confirm the evaporator’s long-term stable salt-discharge and freshwater production capabilities, demonstrating high evaporation rates, reusability, and pollution resistance. Outdoor experiments and water purification tests further validate its effectiveness in producing freshwater and preventing salt accumulation. This research underscores the potential of light-responsive materials in designing efficient, sustainable evaporators, offering a significant advancement in water purification and desalination technologies.
Large amount of oily wastewater discharged from domestic sources and industrial has caused lots of pollution to our surrounding. Thus, searching effective and eco‐friendly ways for separation of stabilized oil/water emulsions is urgent and highly desirable. Among various methods, membrane with special wettability is an ideal choice for the efficient treatment of oil/water emulsions owing to its low energy consumption and cost. However, it remains a great challenge to develop super‐wettable membranes using green and inexpensive materials to realize durability, easy fabrication and scale‐up. To address this issue, a highly flexible, durable, robust, and super‐hydrophobic polydivinylbenzene (PDVB)‐wood membrane with hydrophobic‐nanopores is developed by the surface coating of cross‐linked PDVB on the porous wood. The as‐produced PDVB‐wood membrane shows excellent flexibility, durability, chemical resistance and possesses above 99.98% separation efficiency for surfactant‐stabilized water‐in‐oil emulsions. Furthermore, the PDVB‐wood membrane also performs excellent recyclability with separation efficiency up to 99.98% after 20 separation cycles. The synergistic effect of the super‐hydrophobicity and nanopores contributes to the high separation performance. With its excellent durability, easy scale up, easy fabrication, inexpensive, and green regeneration, we envision that this functional biomass‐derived membrane could be used as a substitute for filter membrane in environmental restoration. image