Solar steam generation is regarded as a perspective technology, due to its potentials in solar light absorption and photothermal conversion for seawater desalination and water purification. Although lots of steam generation systems have been reported to possess high conversion efficiencies recently, researches of simple, cost-effective, and sustainable materials still need to be done. Here, inspired by natural young sunflower heads’ property increasing the temperature of dish-shaped flowers by tracking the sun, we used 3D-structured carbonized sunflower heads as an effective solar steam generator. The evaporation rate and efficiency of these materials under 1 sun (1 kW m–2) are 1.51 kg m–2 h–1 and 100.4%, respectively, beyond the theoretical limit of 2D materials. This high solar efficiency surpasses all other biomass-based materials ever reported. It is demonstrated that such a high capability is mainly attributed to the 3D-structured top surface, which could reabsorb the lost energy of diffuse reflection and thermal radiation, as well as provide enlarged water/air interface for steam escape. 3D-structured carbonized sunflower heads provide a new method for the future design and fabrication of high-performance photothermal devices.

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Surface plasmon resonance (SPR), a promising technology, is beneficial for various applications, such as photothermal conversion, solar cells, photocatalysts, and sensing. However, the SPR performance may be restricted by the 1D-or 2D-distributed hotspots. The bicontinuous interconnected gyroidstructured materials have emerged in light energy conversion due to a high density of 3D-distributed hotspots, ultrahigh light− matter interactions and large scattering cross-section. Here, a series of bioinspired Au−CuS gyroid-structured materials are fabricated by precisely controlling the deposition time of CuS nanoparticles (NPs) and then adopted for solar steam generation. Specifically, Au−CuS/GMs-80 present the highest evaporation efficiency of 88.8% under normal 1 sun, with a suitable filling rate (57%) and a large inner surface area (∼2.72 × 10 5 nm 2 per unit cell), which simultaneously achieves a dynamic balance between water absorption and evaporation as well as efficient heat conduction with water in nanochannels. Compared with other state-of-the-art devices, Au−CuS/GMs-80 steam generator requires a much lower photothermal component loading (<1 mg cm −2 ) and still guarantees outstanding evaporation performance. This superior evaporation performance is attributed to broadband light absorption, continuous water supply, excellent heat generation and thermal insulation, and good light−heat−water interaction. The combination of 3D interconnected nanostructures with controllable metal− semiconductor deposition could provide a new method for the future design of high-performance plasmonic devices.

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We performed a study of the nonlinear optical properties of chemically purified chitin and insect cuticle using two-photon excited autofluorescence (TPEF) and second-harmonic generation (SHG) microscopy. Excitation spectrum, fluorescence time, polarization sensitivity, and bleaching speed were measured. We have found that the maximum autofluorescence signal requires an excitation wavelength below 850 nm. At longer wavelengths, we were able to penetrate more than 150-um deep into the sample through the chitinous structures. The excitation power was kept below 10 mW (at the sample) in order to diminish bleaching. The SHG from the purified chitin was confirmed by spectral- and time-resolved measurements. Two cave-dwelling, depigmented, insect species were analyzed and three-dimensional images of the cuticular structures were obtained.