Nanjing University

About: Nanjing University is a education organization based out in Nanjing, China. It is known for research contribution in the topics: Catalysis & Adsorption. The organization has 85961 authors who have published 105504 publications receiving 2289036 citations. The organization is also known as: NJU & Nanking University.

Scalable and hierarchically designed polymer film as a selective thermal emitter for high-performance all-day radiative cooling.

Abstract: Traditional cooling systems consume tremendous amounts of energy and thus aggravate the greenhouse effect1,2. Passive radiative cooling, dissipating an object’s heat through an atmospheric transparency window (8–13 μm) to outer space without any energy consumption, has attracted much attention3–9. The unique feature of radiative cooling lies in the high emissivity in the atmospheric transparency window through which heat can be dissipated to the universe. Therefore, for achieving high cooling performance, the design and fabrication of selective emitters, with emission strongly dominant in the transparency window, is of essential importance, as such spectral selection suppresses parasitic absorption from the surrounding thermal radiation. Recently, various materials and structures with tailored spectrum responses have been investigated to achieve the effect of daytime radiative cooling6–8,10–15. However, most of the radiative cooling materials reported possess broad-band absorption/emission covering the whole mid-infrared wavelength11–15. Here we demonstrate that a hierarchically designed polymer nanofibre-based film, produced by a scalable electrostatic spinning process, enables selective mid-infrared emission, effective sunlight reflection and therefore excellent all-day radiative cooling performance. Specifically, the C–O–C (1,260–1,110 cm−1) and C–OH (1,239–1,030 cm−1) bonding endows the selective emissivity of 78% in 8–13 μm wavelength range, and the design of nanofibres with a controlled diameter allows for a high reflectivity of 96.3% in 0.3–2.5 μm wavelength range. As a result, we observe ~3 °C cooling improvement of this selective thermal emitter as compared to that of a non-selective emitter at night, and 5 °C sub-ambient cooling under sunlight. The impact of this hierarchically designed selective thermal emitter on alleviating global warming and temperature regulating an Earth-like planet is also analysed, with a significant advantage demonstrated. With its excellent cooling performance and a scalable process, this hierarchically designed selective thermal emitter opens a new pathway towards large-scale applications of all-day radiative cooling materials. A hierarchically designed polymer nanofibre-based film produced by a scalable electrospinning process enables selective mid-infrared emission and effective sunlight reflection, and thus realizes an excellent all-day radiative cooling performance.

A water lily-inspired hierarchical design for stable and efficient solar evaporation of high-salinity brine.

Abstract: In recent years, interfacial solar vapor generation has shown great potential in realizing desalination and wastewater treatment with high energy conversion efficiency. However, high evaporation rate cannot be maintained because of the seemingly unavoidable fouling or salt accumulation on the solar absorbers. The degradation accelerates as the solute concentration increases. Here, we demonstrate a water lily–inspired hierarchical structure that enables efficient evaporation (~80% solar-to-vapor efficiency) out of high-salinity brine [10 weight % (wt %)] and wastewater containing heavy metal ions (30 wt %). More notably, neither decrease in evaporation rate nor fouling on absorbers was observed during the entire evaporation process until water and solute were completely separated. With the capabilities of stable and high-rate evaporation out of high-salinity brine and the effective separation of solute from water, it is expected that this technology can have direct implications in various fields such as wastewater treatment, sea-salt production, and metal recycling.

Rise to modern levels of ocean oxygenation coincided with the Cambrian radiation of animals

Abstract: The early diversification of animals (∼ 630 Ma), and their development into both motile and macroscopic forms (∼ 575-565 Ma), has been linked to stepwise increases in the oxygenation of Earth's surface environment. However, establishing such a linkage between oxygen and evolution for the later Cambrian 'explosion' (540-520 Ma) of new, energy-sapping body plans and behaviours has proved more elusive. Here we present new molybdenum isotope data, which demonstrate that the areal extent of oxygenated bottom waters increased in step with the early Cambrian bioradiation of animals and eukaryotic phytoplankton. Modern-like oxygen levels characterized the ocean at ∼ 521 Ma for the first time in Earth history. This marks the first establishment of a key environmental factor in modern-like ecosystems, where animals benefit from, and also contribute to, the 'homeostasis' of marine redox conditions.

Metal-complex chromophores for solar hydrogen generation

Abstract: Solar H2 generation from water has been intensively investigated as a clean method to convert solar energy into hydrogen fuel. During the past few decades, many studies have demonstrated that metal complexes can act as efficient photoactive materials for photocatalytic H2 production. Here, we review the recent progress in the application of metal-complex chromophores to solar-to-H2 conversion, including metal-complex photosensitizers and supramolecular photocatalysts. A brief overview of the fundamental principles of photocatalytic H2 production is given. Then, different metal-complex photosensitizers and supramolecular photocatalysts are introduced in detail, and the most important factors that strictly determine their photocatalytic performance are also discussed. Finally, we illustrate some challenges and opportunities for future research in this promising area.

Two-dimensional quasi-freestanding molecular crystals for high-performance organic field-effect transistors

Abstract: Inorganic two-dimensional atomic crystals exhibit a variety of unusual but practically useful properties. Here, the authors produce an organic counterpart, atomically smooth monolayers of a molecular crystal, and use this organic analogue of graphene in high-performance organic field-effect transistors.