Chengyi Song

A Bioinspired, Reusable, Paper‐Based System for High‐Performance Large‐Scale Evaporation

A bioinspired, reusable, paper-based gold-nanoparticle film is fabricated by depositing an as-prepared gold-nanoparticle thin film on airlaid paper. This paper-based system with enhanced surface roughness and low thermal conductivity exhibits increased efficiency of evaporation, scale-up potential, and proven reusability. It is also demonstrated to be potentially useful in seawater desalination.

Bio-Inspired Evaporation Through Plasmonic Film of Nanoparticles at the Air–Water Interface

Plasmonic gold nanoparticles self-assembled at the air-water interface to produce an evaporative surface with local control inspired by skins and plant leaves. Fast and efficient evaporation is realized due to the instant and localized plasmonic heating at the evaporative surface. The bio-inspired evaporation process provides an alternative promising approach for evaporation, and has potential applications in sterilization, distillation, and heat transfer.

Bioinspired Engineering of Thermal Materials

In the development of next-generation materials with enhanced thermal properties, biological systems in nature provide many examples that have exceptional structural designs and unparalleled performance in their thermal or nonthermal functions. Bioinspired engineering thus offers great promise in the synthesis and fabrication of thermal materials that are difficult to engineer through conventional approaches. In this review, recent progress in the emerging area of bioinspired advanced materials for thermal science and technology is summarized. State-of-the-art developments of bioinspired thermal-management materials, including materials for efficient thermal insulation and heat transfer, and bioinspired materials for thermal/infrared detection, are highlighted. The dynamic balance of bioinspiration and practical engineering, the correlation of inspiration approaches with the targeted applications, and the coexistence of molecule-based inspiration and structure-based inspiration are discussed in the overview of the development. The long-term outlook and short-term focus of this critical area of advanced materials engineering are also presented.

Bioinspired Bifunctional Membrane for Efficient Clean Water Generation

Solving the problems of water pollution and water shortage is an urgent need for the sustainable development of modern society. Different approaches, including distillation, filtration, and photocatalytic degradation, have been developed for the purification of contaminated water and the generation of clean water. In this study, we explored a new approach that uses solar light for both water purification and clean water generation. A bifunctional membrane consisting of a top layer of TiO2 nanoparticles (NPs), a middle layer of Au NPs, and a bottom layer of anodized aluminum oxide (AAO) was designed and fabricated through multiple filtration processes. Such a design enables both TiO2 NP-based photocatalytic function and Au NP-based solar-driven plasmonic evaporation. With the integration of these two functions into a single membrane, both the purification of contaminated water through photocatalytic degradation and the generation of clean water through evaporation were demonstrated using simulated solar illumination. Such a demonstration should also help open up a new strategy for maximizing solar energy conversion and utilization.

The impact of surface chemistry on the performance of localized solar-driven evaporation system.

This report investigates the influence of surface chemistry (or wettability) on the evaporation performance of free-standing double-layered thin film on the surface of water. Such newly developed evaporation system is composed of top plasmonic light-to-heat conversion layer and bottom porous supporting layer. Under solar light illumination, the induced plasmonic heat will be localized within the film. By modulating the wettability of such evaporation system through the control of surface chemistry, the evaporation rates are differentiated between hydrophilized and hydrophobized anodic aluminum oxide membrane-based double layered thin films. Additionally, this work demonstrated that the evaporation rate mainly depends on the wettability of bottom supporting layer rather than that of top light-to-heat conversion layer. The findings in this study not only elucidate the role of surface chemistry of each layer of such double-layered evaporation system, but also provide additional design guidelines for such localized evaporation system in applications including desalination, distillation and power generation.

Bioinspired Multifunctional Paper-Based rGO Composites for Solar-Driven Clean Water Generation

Reusing polluted water through various decontamination techniques has appeared as one of the most practical approaches to address the global shortage of clean water. Rather than relying on single decontamination mechanism, herein we report the preparation and utilization of paper-based composites for multifunctional solar-driven clean water generation that is inspired by the multiple water purification approaches in biological systems. The reduced graphene oxide (rGO) sheets within such composites can efficiently remove organic contaminants through physical adsorption mechanism. Under solar irradiation, the floating rGO composites can instantly generate localized heating, which not only can directly generate clean water through distillation mechanism but also significantly enhance adsorption removal performance with the assistance of upward vapor flow. Such porous-structured paper-based composites allow for facile incorporation of photocatalysts to regenerate clean water out of contaminated water with combined adsorption, photodegradation, and interfacial heat-assisted distillation mechanisms. Within a homemade all-in-one water treatment device, the practical applicability of the composites for multifunctional clean water generation has been demonstrated.

Infrared Detection Based on Localized Modification of Morpho Butterfly Wings

Inspired by butterflies an advanced detection and sensing system is developed. The hierarchical nanoarchitecture of Morpho butterfly wings is shown to facilitate the selective modification of such a structure, which results in a sensitive infrared response. These findings offer a new path both for detecting infrared photons and for generating nanostructured bimaterial systems for high-performance sensing platforms.

In Situ Environmental TEM in Imaging Gas and Liquid Phase Chemical Reactions for Materials Research

Gas and liquid phase chemical reactions cover a broad range of research areas in materials science and engineering, including the synthesis of nanomaterials and application of nanomaterials, for example, in the areas of sensing, energy storage and conversion, catalysis, and bio-related applications. Environmental transmission electron microscopy (ETEM) provides a unique opportunity for monitoring gas and liquid phase reactions because it enables the observation of those reactions at the ultra-high spatial resolution, which is not achievable through other techniques. Here, the fundamental science and technology developments of gas and liquid phase TEM that facilitate the mechanistic study of the gas and liquid phase chemical reactions are discussed. Combined with other characterization tools integrated in TEM, unprecedented material behaviors and reaction mechanisms are observed through the use of the in situ gas and liquid phase TEM. These observations and also the recent applications in this emerging area are described. The current challenges in the imaging process are also discussed, including the imaging speed, imaging resolution, and data management.

Rapid charging of thermal energy storage materials through plasmonic heating.

Direct collection, conversion and storage of solar radiation as thermal energy are crucial to the efficient utilization of renewable solar energy and the reduction of global carbon footprint. This work reports a facile approach for rapid and efficient charging of thermal energy storage materials by the instant and intense photothermal effect of uniformly distributed plasmonic nanoparticles. Upon illumination with both green laser light and sunlight, the prepared plasmonic nanocomposites with volumetric ppm level of filler concentration demonstrated a faster heating rate, a higher heating temperature and a larger heating area than the conventional thermal diffusion based approach. With controlled dispersion, we further demonstrated that the light-to-heat conversion and thermal storage properties of the plasmonic nanocomposites can be fine-tuned by engineering the composition of the nanocomposites.

Enhancing Localized Evaporation through Separated Light Absorbing Centers and Scattering Centers.

This report investigates the enhancement of localized evaporation via separated light absorbing particles (plasmonic absorbers) and scattering particles (polystyrene nanoparticles). Evaporation has been considered as one of the most important phase-change processes in modern industries. To improve the efficiency of evaporation, one of the most feasible methods is to localize heat at the top water layer rather than heating the bulk water. In this work, the mixture of purely light absorptive plasmonic nanostructures such as gold nanoparticles and purely scattering particles (polystyrene nanoparticles) are employed to confine the incident light at the top of the solution and convert light to heat. Different concentrations of both the light absorbing centers and the light scattering centers were evaluated and the evaporation performance can be largely enhanced with the balance between absorbing centers and scattering centers. The findings in this study not only provide a new way to improve evaporation efficiency in plasmonic particle-based solution, but also shed lights on the design of new solar-driven localized evaporation systems.