Biomimetic 3D Membranes with MXene Heterostructures for Superior Solar Steam Generation, Water Treatment, and Electricity Generation

Abstract

2D MXene materials have shown great potential in photothermal conversion, especially for solar steam generation. However, the obvious light losses at the liquid−solid interfaces still limit its broad applications, thereby resulting in a poor light absorption ability. To this end, a facile and general approach is designed for the construction of nanoflower MXene@MoS2 with excellent photothermal conversion ability via one‐step hydrothermal process. Thanks to the multireflective and synergestic effects between MXene and MoS2, the hierarchical MXene@MoS2 heterostructure exhibits broadband light absorption and improved photothermal conversion capacity (69 °C after 10 min solar illumination). Furthermore, inspired by the water vapor process in multiple channels of trees, an ultrathin MXene@MoS2‐based nanofibrous membrane is assembled via directional electrospinning technology. Compared with traditional irregular channels, the controllable and tree‐inspired 3D structure shows competitive advantages in solar absorption and water transport. Thus, the as‐prepared self‐floating membrane presents durable hydrophobicity (contact angle [CA] = 125°) and a high evaporation rate of 1.39 kg/(m2h) (91% efficiency) under 1 sun, which is higher than reported. This 3D MXene‐based device also shows promising electrical generation, solar‐driven sewage, and desalination treatments (99% desalination efficiency). Such high‐performance self‐floating photothermal membranes with multifunctionalities might provide an effective strategy for solving the global problems of freshwater shortage.

Highly Effective Multifunctional Solar Evaporator with Scaffolding Structured Carbonized Wood and Biohydrogel

“…The difference among the performance of the three evaporators indicates the effect of scaffolding structure and MXene on the evaporation efficiency. CMSK shows an excellent evaporation rate and the largest energy efficiency, being superior to most reported ones (Figure g). ,− Based on eqs – for the calculation of evaporation efficiency in Section , the high evaporation efficiency of the evaporator is attributed to the high temperature generated on the evaporator surface and the high evaporation rate.…”

MXenes—An Emerging Class of 2D Materials for Solar Water Desalination: Feasibility and Recent Advances

“…This MXene‐based evaporator showed a water evaporation rate of 1.32 kg m −2 h −1 under 1 sun even with a thinner photothermal material thickness. Recently, an MXene@MoS 2 evaporator was constructed via an electrospun method by Fu et al [ 128 ] Ti 3 C 2 T x MXene and MoS 2 nanosheets were assembled by a one‐step hydrothermal method to build a nanoflower structure that facilitated multiple reflection of incident light inside. In addition, the evaporator also possessed interactive water vapor escape pathway due to the unidirectionally electrospun process.…”

“…b2) Water mass change for different objects (pure water, polylactic acid (PLA), PLA/MXene, and PLA/MXene@MoS 2 ) under 1 sun illumination. Reproduced with permission [128]. Copyright 2021, John Wiley and Sons.…”

Janus Membrane Decorated by MXene Multilayered Nanoflakes for Wet–Thermal Management

“…Apart from wet regulation, thermal management, especially passive thermal comfort, which requires no external energy to operate and adjust the body temperature relying only on the intrinsic properties of the material itself like structure and morphology, is of substantial significance due to the advantages of energy-efficiency and cost-effectiveness. − Briefly, fabrics with thermal management capacity can mainly be categorized as a heating fabric − and a cooling fabric. − Heating fabrics, which keep a constant temperature, save most of the energy used to heat the empty space around the human body, overcome energy consumption and energy wastage, and play a very important role not merely in personal thermal comfort and ameliorating the health conditions but also in improving the work efficiency of pedestrians and outdoor laborers. MXenes (M n +1 X n T x , n = 1∼3), where M is an early transition metal, X is a carbon or nitrogen, and T x represents the surface terminal of −OH, −O, or −F, comprise a large family of two-dimensional (2D) layered nanomaterials. , Owing to the outstanding electrical conductivity, specific capacitance, mechanical property, and photothermal conversion capacity, MXenes have found extensive applications, including catalysis, electromagnetic interference shielding, − energy storage, electrothermal application, water treatment, − wearable devices, and so on. Thereinto, its nearly 100% photothermal conversion efficiency as well as its stability of structure and performance makes it a more suitable candidate for decorating multifunctional textiles.…”