The term photonic crystals appears because of the analogy between electron waves in crystals and the light waves in artificial periodic dielectric structures. During the recent years the investigation of one-, two-and three-dimensional periodic structures has attracted a widespread attention of the world optics community because of great potentiality of such structures in advanced applied optical fields. The interest in periodic structures has been stimulated by the fast development of semiconductor technology that now allows the fabrication of artificial structures, whose period is comparable with the wavelength of light in the visible and infrared ranges.

http://ieeexplore.ieee.org/iel5/6354/16969/00781867.pdf

Photonic crystals

Self-assembling aluminium nanoparticles are used to make a plasmon-enhanced device for desalination. Plasmonics has generated tremendous excitement because of its unique capability to focus light into subwavelength volumes1, beneficial for various applications such as light harvesting2,3, photodetection4, sensing5, catalysis6 and so on. Here we demonstrate a plasmon-enhanced solar desalination device, fabricated by the self–assembly of aluminium nanoparticles into a three-dimensional porous membrane. The formed porous plasmonic absorber can float naturally on water surface, efficiently absorb a broad solar spectrum (>96%) and focus the absorbed energy at the surface of the water to enable efficient (∼90%) and effective desalination (a decrease of four orders of magnitude). The durability of the devices has also been examined, indicating a stable performance over 25 cycles under various illumination conditions. The combination of the significant desalination effect, the abundance and low cost of the materials, and the scalable production processes suggest that this type of plasmon-enhanced solar desalination device could provide a portable desalination solution.

3D self-assembly of aluminium nanoparticles for plasmon-enhanced solar desalination

Hydrogen fuel is considered as the cleanest renewable resource and the primary alternative to fossil fuels for future energy supply. Sustainable hydrogen generation is the major prerequisite to realize future hydrogen economy. The electrocatalytic hydrogen evolution reaction (HER), as the vital step of water electrolysis to H2 production, has been the subject of extensive study over the past decades. In this comprehensive review, we first summarize the fundamentals of HER and review the recent state-of-the-art advances in the low-cost and high-performance catalysts based on noble and non-noble metals, as well as metal-free HER electrocatalysts. We systemically discuss the insights into the relationship among the catalytic activity, morphology, structure, composition, and synthetic method. Strategies for developing an effective catalyst, including increasing the intrinsic activity of active sites and/or increasing the number of active sites, are summarized and highlighted. Finally, the challenges, perspectives, and research directions of HER electrocatalysis are featured.

Recent Advances in Electrocatalytic Hydrogen Evolution Using Nanoparticles.

Design, and Applications Shutao Wang,†,‡ Kesong Liu, Xi Yao, and Lei Jiang*,†,‡,§ †Laboratory of Bio-inspired Smart Interface Science, Technical Institute of Physics and Chemistry, and ‡Beijing National Laboratory for Molecular Science, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, People’s Republic of China Key Laboratory of Bio-Inspired Smart Interfacial Science and Technology of Ministry of Education, School of Chemistry and Environment, BeiHang University, Beijing 100191, People’s Republic of China Department of Biomedical Sciences, City University of Hong Kong, Hong Kong P6903, People’s Republic of China

Bioinspired Surfaces with Superwettability: New Insight on Theory, Design, and Applications

Transition metal carbides and nitrides (MXenes), a family of two-dimensional (2D) inorganic compounds, are materials composed of a few atomic layers of transition metal carbides, nitrides, or carbonitrides. Ti3C2, the first 2D layered MXene, was isolated in 2011. This material, which is a layered bulk material analogous to graphite, was derived from its 3D phase, Ti3AlC2 MAX. Since then, material scientists have either determined or predicted the stable phases of >200 different MXenes based on combinations of various transition metals such as Ti, Mo, V, Cr, and their alloys with C and N. Extensive experimental and theoretical studies have shown their exciting potential for energy conversion and electrochemical storage. To this end, we comprehensively summarize the current advances in MXene research. We begin by reviewing the structure types and morphologies and their fabrication routes. The review then discusses the mechanical, electrical, optical, and electrochemical properties of MXenes. The focus then turns to their exciting potential in energy storage and conversion. Energy storage applications include electrodes in rechargeable lithium- and sodium-ion batteries, lithium-sulfur batteries, and supercapacitors. In terms of energy conversion, photocatalytic fuel production, such as hydrogen evolution from water splitting, and carbon dioxide reduction are presented. The potential of MXenes for the photocatalytic degradation of organic pollutants in water, such as dye waste, is also addressed, along with their promise as catalysts for ammonium synthesis from nitrogen. Finally, their application potential is summarized.

Applications of 2D MXenes in energy conversion and storage systems

As a ubiquitous solar-thermal energy conversion process, solar-driven evaporation has attracted tremendous research attention owing to its high conversion efficiency of solar energy and transformative industrial potential. In recent years, solar-driven interfacial evaporation by localization of solar-thermal energy conversion to the air/liquid interface has been proposed as a promising alternative to conventional bulk heating-based evaporation, potentially reducing thermal losses and improving energy conversion efficiency. In this Review, we discuss the development of the key components for achieving high-performance evaporation, including solar absorbers, evaporation structures, thermal insulators and thermal concentrators, and discuss how they improve the performance of the solar-driven interfacial evaporation system. We describe the possibilities for applying this efficient solar-driven interfacial evaporation process for energy conversion applications. The exciting opportunities and challenges in both fundamental research and practical implementation of the solar-driven interfacial evaporation process are also discussed. The thermal properties of solar energy can be exploited for many applications, including evaporation. Tao et al. review recent developments in the field of solar-driven interfacial evaporation, which have enabled higher-performance structures by localizing energy conversion to the air/liquid interface.

Solar-driven interfacial 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.

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

We study frost formation and its impact on icephobic properties of superhydrophobic surfaces. Using an environmental scanning electron microscope, we show that frost nucleation occurs indiscriminately on superhydrophobic textures without any particular spatial preference. Ice adhesion measurements on superhydrophobic surfaces susceptible to frost formation show increased adhesion over smooth surfaces with a strong linear trend with the total surface area. These studies indicate that frost formation significantly compromises the icephobic properties of superhydrophobic surfaces and poses serious limitations to the use of superhydrophobic surfaces as icephobic surface treatments for both on-ground and in-flight applications.

/pdf/frost-formation-and-ice-adhesion-on-superhydrophobic-18w2wougr8.pdf

Frost formation and ice adhesion on superhydrophobic surfaces

Temperature effect and thermal impact in lithium-ion batteries: A review

Heterogeneous nucleation of water plays an important role in a wide range of natural and industrial processes. Though heterogeneous nucleation of water is ubiquitous and an everyday experience, spatial control of this important phenomenon is extremely difficult. Here we show for the first time that spatial control in the heterogeneous nucleation of water can be achieved by manipulating the local nucleation energy barrier and nucleation rate via the modification of the local intrinsic wettability of a surface. Such ability to control water nucleation could address the condensation-related limitations of superhydrophobic surfaces and has implications for efficiency enhancements in energy and desalination systems.

/pdf/spatial-control-in-the-heterogeneous-nucleation-of-water-wuhwag0inp.pdf

Tao Deng

Papers

Solar-driven interfacial evaporation

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

Frost formation and ice adhesion on superhydrophobic surfaces

Temperature effect and thermal impact in lithium-ion batteries: A review

Spatial control in the heterogeneous nucleation of water