Enhancement of Water Productivity and Energy Efficiency in Sorption-based Atmospheric Water Harvesting Systems: From Material, Component to System Level.

To address the increasingly serious water scarcity across the world, sorption-based atmospheric water harvesting (SAWH) continues to attract attention among various water production methods, due to it being less dependent on climatic and geographical conditions. Water productivity and energy efficiency are the two most important evaluation indicators. Therefore, this review aims to comprehensively and systematically summarize and discuss the water productivity and energy efficiency enhancement methods for SAWH systems based on three levels, from material to component to system.

Mask-inspired moisture-transmitting and durable thermochromic perovskite smart windows.

Thermochromic perovskite smart windows (TPWs) are a cutting-edge energy-efficient window technology. However, like most perovskite-based devices, humidity-related degradation limits their widespread application. Herein, inspired by the structure of medical masks, a unique triple-layer thermochromic perovskite window (MTPW) that enable sufficient water vapor transmission to trigger the thermochromism but effectively repel detrimental water and moisture to extend its lifespan is developed.

Hierarchically structured passive radiative cooling ceramic with high solar reflectivity.

Passive radiative cooling using nanophotonic structures is limited by its high cost and poor compatibility with existing end uses, whereas polymeric photonic alternatives lack weather resistance and effective solar reflection. We developed a cellular ceramic that can achieve highly efficient light scattering and a near-perfect solar reflectivity of 99.6%.

Perovskite-Coated Thermochromic Transparent Wood: A Novel Material for Smart Windows in Energy-Efficient and Sustainable Buildings.

Transparent wood (TW) has emerged as a sustainable alternative to conventional glass as an energy-efficient window glazing material owing to its exceptional optical transparency and superior mechanical and thermal performances. However, it is challenging to develop the TW-based color-switching smart windows with both high optical performance and mechanical strengths. In this work, an optically switchable and mechanically robust perovskite-coated thermochromic transparent wood (PTTW) is developed for use as smart windows to achieve an effective solar modulation and thermal management.

Investigations on asymmetric transmittivity of optical devices and different diode-like behaviors.

This study theoretically proved that although reciprocal optical devices can show asymmetric transmittivity (AT) under controlled incident modes (i.e., conditional AT), they cannot guarantee AT with arbitrary incident light modes, whereas only nonreciprocal optical devices can possibly guarantee AT.

Perovskite Smart Windows: The Light Manipulator in Energy-Efficient Buildings.

Uncontrolled sunlight entering through windows contributes to substantial heating and cooling demands in buildings, which leads to high energy consumption from the buildings. Recently, perovskite smart windows have emerged as innovative energy-saving technologies, offering the potential to adaptively control indoor solar heat gain through their impressive sunlight modulation capabilities. Moreover, harnessing the high-efficiency photovoltaic properties of perovskite materials, these windows have the potential to generate power, thereby realizing more advanced windows with combined light modulation and energy harvesting capabilities.

Radiative Cooling Nanofabric for Personal Thermal Management.

A wearable textile that is engineered to reflect incoming sunlight and allow the transmission of mid-infrared radiation simultaneously would have a great impact on the human body's thermal regulation in an outdoor environment. However, developing such a textile is a tough challenge. Using nanoparticle-doped polymer (zinc oxide and polyethylene) materials and electrospinning technology, we have developed a nanofabric with the desired optical properties and good applicability.

Near-Infrared-Activated Thermochromic Perovskite Smart Windows.

Perovskite-based thermochromic smart windows that can change color have attracted much interest. However, the high transition temperature (>45 °C in air) hinders their practical application. Herein, a near-infrared (NIR) activated thermochromic perovskite window that enables reversible transition cycles at room temperature is proposed.

A Solution-Processed Inorganic Emitter with High Spectral Selectivity for Efficient Subambient Radiative Cooling in Hot Humid Climates.

Daytime radiative cooling provides an eco-friendly solution to space cooling with zero energy consumption. Despite significant advances, most state-of-the-art radiative coolers show broadband infrared emission with low spectral selectivity, which limits their cooling temperatures, especially in hot humid regions. Here, an all-inorganic narrowband emitter comprising a solution-derived SiO N layer sandwiched between a reflective substrate and a self-assembly monolayer of SiO microspheres is reported.

Biotechnology of Plastic Waste Degradation, Recycling, and Valorization: Current Advances and Future Perspectives.

Invited for this month's cover is the collaborative group of Dr. Carol Sze Ki Lin and Dr. Xiang Wang.

Biotechnology of Plastic Waste Degradation, Recycling, and Valorization: Current Advances and Future Perspectives.

Although fossil-based plastic products have many attractive characteristics, their production has led to severe environmental burdens that require immediate solutions. Despite these plastics being non-natural chemical compounds, they can be degraded and metabolized by some microorganisms, which suggests the potential application of biotechnologies based on the mechanism of plastic biodegradation. In this context, microbe-based strategies for the degradation, recycling, and valorization of plastic waste offer a feasible approach for alleviating environmental challenges created by the accumulation of plastic waste.

Self-Densified Optically Transparent VO Thermochromic Wood Film for Smart Windows.

Optically transparent wood has emerged as a promising glazing material. Thanks to the high optical transmittance, strong mechanical properties, and excellent thermal insulation capability of transparent wood, it offers a potential alternative to glass for window applications. Recently, thermo-, electro-, and photochromic transparent woods that dynamically modulate light transmittance have been investigated to improve building energy efficiency.

Coalescence-Induced Jumping Droplets on Nanostructured Biphilic Surfaces with Contact Electrification Effects.

Benefitting from the coalescence-induced droplet jumping on superhydrophobic surfaces, the condensing droplets on heat exchangers can be removed efficiently, significantly improving the condensation heat-transfer performance of various thermal applications. However, the enhancement of droplet jumping height and self-removal to further improve the condensation heat-transfer performance of the thermal applications remains a challenge due to considerable interfacial adhesion caused by the inevitable partial-Wenzel state condensing droplets on superhydrophobic surfaces. In this study, a biphilic nanostructure is developed to effectively improve the droplet jumping height by decreasing the interfacial adhesion with the formation of Cassie-like droplets.

Solution-Processed All-Ceramic Plasmonic Metamaterials for Efficient Solar-Thermal Conversion over 100-727 °C.

Low-cost and large-area solar-thermal absorbers with superior spectral selectivity and excellent thermal stability are vital for efficient and large-scale solar-thermal conversion applications, such as space heating, desalination, ice mitigation, photothermal catalysis, and concentrating solar power. Few state-of-the-art selective absorbers are qualified for both low- (<200 °C) and high-temperature (>600 °C) applications due to insufficient spectral selectivity or thermal stability over a wide temperature range. Here, a high-performance plasmonic metamaterial selective absorber is developed by facile solution-based processes via assembling an ultrathin (≈120 nm) titanium nitride (TiN) nanoparticle film on a TiN mirror.

Bio-inspired TiO nano-cone antireflection layer for the optical performance improvement of VO thermochromic smart windows.

Vanadium dioxide (VO) is a promising material for thermochromic glazing. However, VO thermochromic smart windows suffer from several problems that prevent commercialization: low luminous transmittance (T) and low solar modulation ability (ΔT). The solution to these problems can be sought from nature where the evolution of various species has enabled them to survive.