Showing papers by "Bao Yang published in 2018"
TL;DR: Wang et al. as discussed by the authors designed a novel type of plasmonic material, which is made by uniformly decorating fine metal nanoparticles into the 3D mesoporous matrix of natural wood.
Abstract: Plasmonic metal nanoparticles are a category of plasmonic materials that can efficiently convert light into heat under illumination, which can be applied in the field of solar steam generation. Here, this study designs a novel type of plasmonic material, which is made by uniformly decorating fine metal nanoparticles into the 3D mesoporous matrix of natural wood (plasmonic wood). The plasmonic wood exhibits high light absorption ability (≈99%) over a broad wavelength range from 200 to 2500 nm due to the plasmonic effect of metal nanoparticles and the waveguide effect of microchannels in the wood matrix. The 3D mesoporous wood with numerous low-tortuosity microchannels and nanochannels can transport water up from the bottom of the device effectively due to the capillary effect. As a result, the 3D aligned porous architecture can achieve a high solar conversion efficiency of 85% under ten-sun illumination (10 kW m−2). The plasmonic wood also exhibits superior stability for solar steam generation, without any degradation after being evaluated for 144 h. Its high conversion efficiency and excellent cycling stability demonstrate the potential of newly developed plasmonic wood to solar energy-based water desalination.
623 citations
TL;DR: A facile and effective top-down approach to fabricate an anisotropic wood aerogel directly from natural wood by a simple chemical treatment is reported, representing a promising direction for the fabrication of high-quality aerogels materials.
Abstract: Aerogels can be used in a broad range of applications such as bioscaffolds, energy storage devices, sensors, pollutant treatment, and thermal insulating materials due to their excellent properties including large surface area, low density, low thermal conductivity, and high porosity. Here we report a facile and effective top-down approach to fabricate an anisotropic wood aerogel directly from natural wood by a simple chemical treatment. The wood aerogel has a layered structure with anisotropic structural properties due to the destruction of cell walls by the removal of lignin and hemicellulose. The layered structure results in the anisotropic wood aerogel having good mechanical compressibility and fragility resistance, demonstrated by a high reversible compression of 60% and stress retention of ∼90% after 10 000 compression cycles. Moreover, the anisotropic structure of the wood aerogel with curved layers stacking layer-by-layer and aligned cellulose nanofibers inside each individual layer enables the woo...
312 citations
TL;DR: The nanowood is lightweight yet strong, owing to the effective bonding between the aligned cellulose nanofibrils with a high compressive strength, which exceeds other thermal insulation materials, such as silica and polymer aerogels, Styrofoam, and wool.
Abstract: There has been a growing interest in thermal management materials due to the prevailing energy challenges and unfulfilled needs for thermal insulation applications. We demonstrate the exceptional t ...
298 citations
TL;DR: Li et al. as discussed by the authors developed reduced graphene oxide films that can convert heat up to 3,000 K with high power factors, opening the door for novel applications, which can act as both a radiative receiver and a thermoelectric generator.
Abstract: The development of ultrahigh-temperature thermoelectric materials could enable thermoelectric topping of combustion power cycles as well as extending the range of direct thermoelectric power generation in concentrated solar power. However, thermoelectric operation temperatures have been restricted to under 1,500 K due to the lack of suitable materials. Here, we demonstrate a thermoelectric conversion material based on high-temperature reduced graphene oxide nanosheets that can perform reliably up to 3,000 K. After a reduction treatment at 3,300 K, the nanosheet film exhibits an increased conductivity to ~4,000 S cm−1 at 3,000 K and a high power factor S2σ = 54.5 µW cm−1 K−2. We report measurements characterizing the film’s thermoelectric properties up to 3,000 K. The reduced graphene oxide film also exhibits a high broadband radiation absorbance and can act as both a radiative receiver and a thermoelectric generator. The printable, lightweight and flexible film is attractive for system integration and scalable manufacturing. The Carnot efficiency and the power output of thermoelectric power generation increase with temperature but current thermoelectrics are characterized up to 1,500 K. Here, Li et al. develop reduced graphene oxide films that can convert heat up to 3,000 K with high power factors, opening the door for novel applications.
89 citations
TL;DR: In this paper, a thermally managing boron nitride (BN) separator for Li metal batteries was designed by integrating thermally management BN nanosheets into poly vinylidene fluoride-hexafluoropropene (PVDF-HFP) via an advanced extrusion based 3D printing technique.
80 citations
75 citations
TL;DR: In this article, a sliding-mode triboelectrification system and measurement methods of the charge density on highly porous and deformable materials like textile fabrics with a structural hierarchy were investigated. And the effective charge density of fabrics can be reliably measured when the tribo-electrification process reaches its saturation under the fabric densification pressure.
63 citations
TL;DR: It is demonstrated that an h-BN thin film composed of layer-by-layer laminated hexagonal boron nitride nanosheets can effectively enhance the lateral heat dissipation on the substrate and provide an effective approach to improve the heat Dissipation in integrated circuits and high power devices.
Abstract: The rapid development of high power density devices requires more efficient heat dissipation. Recently, two-dimensional layered materials have attracted significant interest due to their superior thermal conductivity, ease of production and chemical stability. Among them, hexagonal boron nitride (h-BN) is electrically insulating, making it a promising thermal management material for next-generation electronics. In this work, we demonstrated that an h-BN thin film composed of layer-by-layer laminated h-BN nanosheets can effectively enhance the lateral heat dissipation on the substrate. We found that by using the BN-coated glass instead of bare glass as the substrate, the highest operating temperature of a reduced graphene oxide (RGO) based device could increase from 700 °C to 1000 °C, and at the same input power, the operating temperature of the RGO device is effectively decreased. The remarkable performance improvement using the BN coating originates from its anisotropic thermal conductivity: a high in-plane thermal conductivity of 14 W m−1 K−1 for spreading and a low cross-plane thermal conductivity of 0.4 W m−1 K−1 to avoid a hot spot right underneath the device. Our results provide an effective approach to improve the heat dissipation in integrated circuits and high power devices.
49 citations
TL;DR: In this article, a thermoelectric element's thickness and electrical current are optimized to minimize source temperature with respect to ambient, when the thermal and electrical parasitic effects are considered.
Abstract: The continuous rise in heat dissipation of integrated circuits necessitates advanced thermal solutions to ensure system reliability and efficiency Thermoelectric coolers are among the most promising techniques for dealing with localized on-chip hot spots This study focuses on establishing a holistic optimization methodology for such thermoelectric coolers, in which a thermoelectric element’s thickness and the electrical current are optimized to minimize source temperature with respect to ambient, when the thermal and electrical parasitic effects are considered It is found that when element thickness and electrical current are optimized for a given system architecture, a “heat flux vs temperature difference” Pareto frontier curve is obtained, indicating that there is an optimum thickness and a corresponding optimum current that maximize the achievable temperature reduction while removing a particular heat flux This methodology also provides the possible system level ΔT’s that can be achieved for a range of heat fluxes, defining the upper limits of thermoelectric cooling for that architecture In this study, use was made of an extensive analytical model, which was verified using commercially available finite element analysis software Through the optimization process, 3 pairs of master curves were generated, which were then used to compose the Pareto frontier for any given system architecture Finally, a case study was performed to provide an in-depth demonstration of the optimization procedure for an example application
8 citations
4 citations