A reconfigurable and magnetically responsive assembly for dynamic solar steam generation

Abstract

Interfacial solar vapor generation is a promising technique to efficiently get fresh water from seawater or effluent. However, for the traditional static evaporation models, further performance improvement has encountered bottlenecks due to the lack of dynamic management and self-regulation on the evolving water movement and phase change in the evaporation process. Here, a reconfigurable and magnetically responsive evaporator with conic arrays is developed through the controllable and reversible assembly of graphene wrapped Fe3O4 nanoparticles. Different from the traditional structure-rigid evaporation architecture, the deformable and dynamic assemblies could reconfigure themselves both at macroscopic and microscopic scales in response to the variable magnetic field. Thus, the internal water transportation and external vapor diffusion are greatly promoted simultaneously, leading to a 23% higher evaporation rate than that of static counterparts. Further, well-designed hierarchical assembly and dynamic evaporation system can boost the evaporation rate to a record high level of 5.9 kg m−2 h−1. This proof-of-concept work demonstrates a new direction for development of high performance water evaporation system with the ability of dynamic reconfiguration and reassembly.

Magnetically Assembled Ultrablack Surface with Omnidirectional and Broadband Light Absorption

“…Figure c shows the magnetic hysteresis loops of Fe 3 O 4 nanoparticles and the PDMS@Fe 3 O 4 composite. Misaligned hysteresis loops were obtained for both materials (Figure c), implying that both are ferromagnetic . As a result of the ferromagnetism, deposited PDMS@Fe 3 O 4 during spraying is magnetized under the external magnetic field .…”

“…Misaligned hysteresis loops were obtained for both materials (Figure 1c), implying that both are ferromagnetic. 22 As a result of the ferromagnetism, deposited PDMS@Fe 3 O 4 during spraying is magnetized under the external magnetic field. 23 The relative permeability of PDMS@Fe 3 O 4 is 1.21, which means that the induced magnetic field strength in the deposited needle-like structure is higher than that of the background, as simulated in Figure 1c and Figure S2 of the Supporting Information.…”

Recent advances in interfacial solar vapor generation: clean water production and beyond

“…189 Recently, Qu's group developed hybrid graphene-wrapped Fe 3 O 4 nanoparticles to further fabricate a reconfigurable and magnetically responsive conic-array evaporator. 190 Under the applied variable magnetic field, the evaporator could achieve a dynamic evaporation process with a 23% higher evaporation rate than that of the static evaporation process, stemming from improved water vapor diffusion. It was demonstrated that the synergistic effect of hybrid graphene and Fe 3 O 4 materials endowed the evaporator with distinct properties.…”

“One stone two birds” or “you can't have your cake and eat it too”? Effects of device dimensions and position of the thermoelectric module on simultaneous solar-driven water evaporation and thermoelectric generation

“…Therefore, recent research has focused on designing devices with different structures. 9,13–15 For example, the WE area has been increased by introducing a well-designed three-dimensional (3D) evaporator, 16–18 allowing additional energy to be absorbed from the surroundings, thereby effectively increasing the PCE beyond the theoretical limit. 19–23…”