Hierarchical Porous Carbonized Lotus Seedpods for Highly Efficient

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Hierarchical porous carbonized lotus seedpods for highly efficient solar steam generation Jing Fang, Jie Liu, Jiajun Gu, Qinglei Liu, Wang Zhang, Huilan Su, and Di Zhang Chem. Mater., Just Accepted Manuscript • DOI: 10.1021/acs.chemmater.8b01702 • Publication Date (Web): 08 Sep 2018 Downloaded from http://pubs.acs.org on September 9, 2018

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Chemistry of Materials

oHierarchical porous carbonized lotus seedpods for highly efficient ssolar steam generation Jing Fang‡, Jie Liu‡, Jiajun Gu*, Qinglei Liu*, Wang Zhang, Huilan Su, and Di Zhang State Key Laboratory of Metal Matrix Composites, School of Materials Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, China ABSTRACT: Efficient solar steam generation under 1 sun illumination is of great importance towards the worldwide problems of water resource scarcity. Researchers have found that the evaporation efficiency could be effectively improved with the assistance of thermally insulating layer, e.g. a polystyrene foam for reducing heat loss. However, the use of polystyrene foam is not environmental friendly, and may increase plastic pollution. In this work, hierarchical porous carbonized lotus seedpods are found to be highly efficient solar steam generator under 1 sun illumination at room temperature (25.0 ºC) for the first time. The carbonized lotus seedpods could achieve ~86.5% conversion efficiencies under 1 sun illumination. To the best of our knowledge, this value outperforms most of solar steam generation performance that was reported by other researchers without any thermally insulating layer or container until now. The excellent performance of carbonized lotus seedpods was attributed to the unique macroscopic cone shape and hierarchical meso/macropore structures, which benefit in three aspects: (1) effective solar light absorption and heat generation ability; (2) good water absorption ability; and (3) excellent thermal insulation property with significant reduced thermal loss. This work provides inspirations for the design and development of high performance photothermal conversion devices. Low-cost and efficient technologies for the conversion and utilization of solar energy are of great importance towards various environmental pollution and resource shortage nowadays.1, 2 Meanwhile, water scarcity along with water treatment as well as water recycle are major challenges all over the world. It has been estimated that salty water take up ~97% of the earth's water,3 and by 2025, nearly two thirds of the world’s population will be pressured by water resource scarcity.2 Seawater desalination is recognized as a prospective method towards relieving this problem, among which efficient seawater desalination under normal 1 sun irradiation (the light intensity 1 kW/m2) without complicated systems is widely expected.46 There is broad agreement that two aspects play key roles in solar desalination process: (1) effective solar light absorption and heat generation ability, and (2) efficient heat management with minimized thermal loss.5, 7 First, noble metal nanoparticles (e.g., Au8-10 and Ag11, 12) have been utilized, owing to the localized surface plasmon resonance (LSPR) effect, which can absorb solar energy and efficiently generate heat. However, the applications are deeply limited by the cost of noble metals and the stability of nanoparticles.13, 14 Besides, various carbon materials (e.g., graphene oxide aerogels,6 graphene oxide foam,5, 15 graphene foam,16 graphene sheets,17 exfoliated graphite,18 carbon nanotube composites,19, 20 and carbon black21 ) have been investigated for solar steam generation, in virtue of their strong light absorption ability. However, the evaporation efficiency of individual materials without any thermally insulating layer or container is usually indeed low (e.g., 30–45%),3 because of large amount of thermal conduction to bulk water (thermal conductivity ~0.5 W/mK) or thermal side losses.22

Second, in the recent two years, researchers have found that the evaporation efficiency could be improved to 7888% in the presence of a bibulous paper/film and a polystyrene foam.3, 5, 17, 21, 23 With air filling inside its porous structures, a polystyrene foam (thermal conductivity ~0.04 W/mK) can act as a thermal insulation, which can reduce thermal conduction to bulk water and thus significantly improve the evaporation efficiency. Similarly, Hu’s group designed a jellyfish-like solar steam generator that consists of the porous carbon black/graphene oxide composite layer (body), aligned GO pillars (tentacles) and expanded polystyrene matrix for both thermal insulation and one-dimensional water transport, achieving a high evaporation efficiency of 87.5%.24 Yu’s group demonstrated a hierarchically nanostructured gel (HNG) as an solar vapour generator based on polyvinyl alcohol and polypyrrole to get a record high rate of 3.2 kg m−2 h−1 via 94% solar energy from 1 sun irradiation.25 Gan’s group adopted an intriguing strategy by operating the temperature of the system below that of the surroundings to get very high rate of the water evaporation (2.20 kg m−2 h−1) under 1 sun which is higher than the upper limit of 1.68 kg m−2 h−1.26 However, the use of organic polystyrene foam and polyvinyl alcohol/polypyrrole is not environmental friendly, and may increase plastic pollution. Thus, more friendly strategies have been attempted using biomass-based structures. For example, Hu et al. demonstrated the natural wood as a high-performance solar steam device which offer an inexpensive and scalable strategy for solar steam generation.27, 28 In summary, there is a broad consensus that good solar evaporation performance depends on four main structure characteristics: good absorbing in the solar spectrum, well thermally insulating, hydrophilic surfaces and interconnected pores for fluid flow.22

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The sacred lotus (Nelumbo nucifera) was reported to heat themselves to maintain warmth in cold weather, and their spongy, cone-shaped lotus receptacle produces most of the heat.29, 30 The exact thermal regulation mechanism of lotus has interested biologists since 1898.31 However, from the perspective of materials science, research on the natural hierarchical micro/nanostructures of lotus receptacle and the exploration of their applications is rare. It is known that lotus receptacle, lotus seeds and petiole make up lotus seedpods, which are usually collected for picking lotus seeds for food, and the rest parts are usually regarded as abandoned waste.32-34 Obviously, lotus seedpods can absorb water for living purpose. Meanwhile, as the supply for rhizome and roots, air can take its way through interconnected caverns and canals inside lotus seedpods.35 Thus, lotus seedpods are exactly perfect natural artworks for solar steam generation. In this work, we investigated the hierarchical porous structures of lotus seedpods and used carbonized lotus seedpods for solar steam generation under normal solar irradiation. The experimental results show that carbonized lotus seedpods possessing hierarchical porous structures exhibited highly efficient solar steam generation performance, owing to their excellent light absorbing and heat generation ability, good thermal insulation, hydrophilic surfaces and interconnected hierarchical pores.

Figure 1. Digital images of (a) a fresh lotus seedpod, (b) top view of a carbonized lotus seedpod, (c) the top surface removed carbonized receptacle, (d) carbonized petiole, and (e) detail view of (c). SEM images of (f) the top surface, (g) the inner walls under the top surface, the inner walls inside (h) carbonized lotus receptacle, and (i) carbonized petiole, respectively. (j) Nitrogen adsorption−desorption isothermals and pore size distributions (inset) of a carbonized lotus receptacle. (k) Schematic of heat management of carbonized lotus seedpods. Scale bars: (a) 1 cm, (b-c) 5 mm, (d) 0.5 mm, (e) 1 mm, and (f-i) 1 μm.

carbonized lotus seedpods. The volumes were reduced by half, but the original shapes and structures were reserved in carbonized lotus seedpods (Figure 1a-b and Figure S1 in the supporting information). The outside surface of carbonized lotus seedpods could be seen nonporous with the naked eye. However, the inside structures of carbonized lotus seedpods were cribrate and spongy (Figure 1c-e). Air cavities and vascular bundles could be seen in cross section of carbonized lotus petiole and receptacle, and the latter were responsible for transferring water and nutrients. Thus, both of air and water can be absorbed quickly and continuously via the petiole and receptacle. SEM images (Figure 1f-i) reveal the microscopic structures of carbonized lotus seedpods. The top surface of receptacle was rather rough (Figure 1f). The inner walls under the top surface and inside receptacle as well as lotus petiole have rich porous structures forming interconnected porous network (Figure 1g-i). These pores ranging from hundreds of nanometers to several microns can act as transport channels for water, leading to fast fluid supplement to the hot region. The porous structures of carbonized lotus receptacle were further characterized by nitrogen absorption measurements. Before the gas adsorption measurements, the carbonized lotus receptacle was crushes by hand and then degassed at 200 °C for 15 h in vacuum. The isothermals (Figure 1j) exhibited increased adsorbed gas volume at moderate relative pressure and a hysteresis loop, which are typical isothermals of mesopore-rich materials.36, 37 The pore size distributions (inset in Figure 1j) also clearly show hierarchical mesopores (2-50 nm) and macropores ( ＞50 nm) on the ranges of 16−146 nm as illustrated by TEM observation in Figure S2, which can help transport of water. Moreover, the gas conductivity within a pore will fall far below the free gas value (e.g. ~0.025 W/mK) when the pore structure is finer than the mean free path (~70 nm) due to Knudsen effect.38, 39 A fine-scale pore structure will also reduce heat convection and radiation effectively owing to a large internal surface area for local heat exchange. In other words, the hierarchical pore structures leads to excellent thermal insulation property as illustrated in Table S1. However, considering the permeability and fluid flow rate, micropores (＜2 nm) are undesired in the application for solar vapor generation.40 Mesopore and macropore structures are more preponderant and suitable for fast fluid transportation. That is to say the natural hierarchical mesopore and macropore structures of carbonized lotus seedpods can ensure better water absorption ability as well as good thermal insulation property leading to less heat loss (Figure 1k).

The digital images (Figure 1a-e) reveal the macroscopic shape and structures of fresh lotus seedpods and carbonized lotus seedpods. Green fresh lotus seedpods composited of lotus seeds, lotus receptacle and lotus petiole usually grow into the shape of cone. After freeze drying and carbonation process, fresh lotus seedpods turned into black


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Chemistry of Materials (Figure S6). On one hand, water was absorbed quickly from the bottom of petiole to the top surface of the carbonized lotus seedpod. On another hand, the temperature of the carbonized lotus seedpod reduced obviously owing to the endothermic effect produced by rapid evaporation even without incident light. This result indicated that carbonized lotus seedpods possess superior hydrophilicity as well as strong water absorbing ability, which are essential for solar steam generation.

Figure 2. (a) High-resolution XPS spectra of the C 1s peak, (b) UV-vis absorption spectra of carbonized lotus seedpods and fresh lotus seedpods, respectively. (c) The temperature changing course of a fresh lotus seedpod and a carbonized lotus seedpod under 1 sun solar illumination on and off, respectively. (d) Infrared photos respectively corresponding to t = 0, 30, 60, and 90 s after the dried carbonized lotus seedpod was in touch with water. XPS analysis was further conducted to record the surface chemical composition of fresh lotus seedpods and carbonized lotus seedpods. Both were mainly composited of C and O elements (Figure S3). However, the highresolution spectra of C ls peak (Figure 2a) exhibited obvious differences. The C ls peak of fresh lotus seedpods was consisted of three peaks, corresponding to C-C (284.7 eV), C-O (286.4 eV) and COOR (289.1 eV), respectively. For carbonized lotus seedpods, there was only C-C peak located at 284.8 eV, revealing that deoxidation reactions were carried out in carbonized process. UV-vis absorption spectra (Figure 2b and Figure S4) reveals that fresh lotus seedpods had unsatisfactory absorption ability over the wavelength ranges of 740-1300 nm. However, after carbonized process, the carbonized lotus seedpods exhibited 98-99% absorption over the whole wavelength ranges of 250-2000 nm, demonstrating effective solar light absorption ability. To evaluate the heat generation ability, 1 sun solar irradiation was illuminated upon a fresh lotus seedpod and a carbonized lotus seedpod for 600s. The top surface temperature rose to ~67.2 °C and 80.0 °C, and the side wall temperature rose to ~30.5 °C and 38.5 °C respectively (Figure 2c and Figure S5), demonstrating the outstanding photothermal property of carbonized lotus seedpods. Moreover, water absorbing capacity of carbonized lotus seedpods was investigated (Figure 2d). The wetting process was rapidly completed within 90 s. The temperature of the carbonized lotus seedpod was the same as room temperature (25.0 °C) before in touch with water. However, once in touch with water, the wetting process occurred rapidly, as demonstrated by the water contact angle test

Figure 3. (a) Schematic of solar steam generation experiments. (b) The temperature changes of the top surface and side wall of the carbonized lotus seedpod as a function of time during solar steam generation process. (c-h) Infrared photos of the carbonized lotus seedpod in the process of solar vapor generation, respectively corresponding to t = 0, 60, 180, 360, 720 and 3600 s after the light irradiation. Solar steam generation experiments (Figure 3a) were further carried out under 1 sun solar illumination at room temperature (25.0 °C). On one hand, water was absorbed continuously through lotus petiole, along threedimensional hierarchical porous structures and interconnected network inside lotus receptacle and finally up to the top surface. On another hand, the top surface was irradiated by solar light, and the solar energy was effectively converted to heat for steam generation. Moreover, the heat loss to bulk water can be efficiently reduced, owing to the characteristic water transport paths through unique macroscopic cone shape and hierarchical meso/macropore structures as well as excellent thermal insulation property of mesopores of carbonized lotus seedpod. The temperature changes during solar steam generation process were recorded by IR camera (Figure 6b-h). For the carbonized lotus seedpod, the whole temperature decreased from 25.0 °C (room temperature) to ~21.1 °C after the wetting process, owing to the endothermal evaporation of water. However, the temperature of the top surface would rapidly go up from 21.1 °C to 35.1 °C within 60 s after the light irradiation. At the same time, the temperature of the side wall has a slight rise (~1.9 °C). After 180 s and 360 s, the temperatures on the top surface and side wall grew to 40.2 °C /26.5 °C, and 42.5 °C /28.3 °C, respectively. Then, the temperatures tended to be stable, and finally were 44.8 °C and 30.6 °C respectively after the irra-



diation of 3600s. The whole irradiation process clearly demonstrated that carbonized lotus seedpods possess effective solar light absorption and heat generation ability as well as efficient heat management with significant reduced thermal loss to bulk water without any extra insulation measure.

Figure 4. (a) The real-time water mass changes of carbonized lotus seedpod and blank water under dark condition and 1 sun illumination, respectively. (b) Evaporation cycle performance of carbonized lotus seedpod, with each cycle sustained over 3600 s. Solar steam generation performance of the carbonized lotus seedpod was further tested under normal 1 sun illumination. The mass change of blank water within 3600 s was respectively 0.67 g and 0.24g under solar light irradiation and dark condition (Figure 4a). The inner diameter of the beaker was ~42.0 mm. Thus, the evaporation rate of blank water was respectively 0.48 kg·m−2·h−1 and 0.17 kg·m−2·h−1 under light irradiation and dark condition. On another hand, in the stable state, the mass change of water in the presence of carbonized lotus seedpod increased to ~3.28 g under light irradiation (Figure 4a). The diameter of the carbonized lotus seedpod was ~54.0 mm (Figure S7). Thus, the evaporation rate of the carbonized lotus seedpod was 1.30 kg·m−2·h−1 under 1 sun light irradiation. The evaporation rate of the carbonized lotus seedpod under dark condition was 0.13 kg·m−2·h−1 (Figure 4a). After

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the evaporation rate of the dark field subtracted, the evaporation efficiency η was calculated in the form η

(1)

where is the mass flux, hLV is the total enthalpy of liquidsteam phase change, and I is the power density of solar illumination.22 Here, we adopted hLV ≈2394 kJ·kg-1 (45 °C). Thus, the evaporation efficiency of the carbonized lotus seedpod was ~86.5% (Figure 4b), demonstrating excellent photothermal performance under normal 1 sun irradiation. Moreover, the evaporation performance of the carbonized lotus seedpod remained stable for 10 cycles with each cycle sustained over 3600 s (Figure 4b), exhibiting good solar steam generation performance and stability. In conclusion, our work showed that carbonized lotus seedpods possess highly efficient solar steam generation performance. The evaporation rate and the corresponding evaporation efficiency under 1 sun irradiation was 1.30 kg·m−2·h−1 and 86.5%, respectively. To the best of our knowledge, these values outperform most of solar steam generation performances that were reported without any thermally insulating layer or container until now. The excellent performance of carbonized lotus seedpods was attributed to the unique macroscopic cone shape and hierarchical meso/macropore structures forming interconnected porous network, which benefit in three aspects: (1) effective solar light absorption and heat generation ability; (2) good water absorption ability; and (3) efficient thermal insulation property with significant reduced thermal loss. This work explored novel utilization method and promising application for lotus seedpods, of which the main body are usually regarded as abandoned waste. Moreover, our experimental results may also provide inspirations for the design and development of high performance photothermal conversion devices.

ASSOCIATED CONTENT Supporting Information. This material is available free of charge via the Internet at http://pubs.acs.org. Additional information including experimental details, preparation and characterizations, digital, TEM and IR images, XPS spectra, water contact angle test and thermal conductivity measurement result (PDF).

AUTHOR INFORMATION Corresponding Author *E-mail (J.J. Gu): [email protected] *E-mail (Q.L. Liu): [email protected] Author contribution ‡Authors J.F. and J.L. contributed equally to this work. Notes The authors declare no competing financial interest.

ACKNOWLEDGMENT This work was supported by the National Natural Science Foundation of China (Grant Nos. 51271116, 51772187,


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Chemistry of Materials 51572169, and 51672175), the Shanghai Science and Technology Committee (Grant Nos. 18JC1410500, 17ZR1441400, and 16520710900) and the Key Program for International S&T Cooperation Program of China (2017YFE0113000).

REFERENCES 1. Deng, Z.; Zhou, J.; Miao, L.; Liu, C.; Peng, Y.; Sun, L.; Tanemura, S., The emergence of solar thermal utilization: solar-driven steam generation. J. Mater. Chem. A 2017, 5, 7691-7709. 2. Service, R. F., Desalination Freshens Up. Science 2006, 313, 1088-1090. 3. Durkaieswaran, P.; Murugavel, K. K., Various special designs of single basin passive solar still – A review. Renew. Sust. Energ.y Rev. 2015, 49, 1048-1060. 4. Elimelech, M.; Phillip, W. A., The Future of Seawater Desalination: Energy, Technology, and the Environment. Science 2011, 333, 712-717. 5. Li, X. Q.; Xu, W. C.; Tang, M. Y.; Zhou, L.; Zhu, B.; Zhu, S. N.; Zhu, J., Graphene oxide-based efficient and scalable solar desalination under one sun with a confined 2D water path. P. Nati. Acad. Sci. USA 2016, 113, 13953-13958. 6. Hu, X.; Xu, W.; Zhou, L.; Tan, Y.; Wang, Y.; Zhu, S.; Zhu, J., Tailoring Graphene Oxide-Based Aerogels for Efficient Solar Steam Generation under One Sun. Adv. Mater. 2017, 29, 1604031. 7. Ni, G.; Li, G.; Boriskina, Svetlana V.; Li, H.; Yang, W.; Zhang, T.; Chen, G., Steam generation under one sun enabled by a floating structure with thermal concentration. Nat. Energy 2016, 1, 16126. 8. Zhou, L.; Tan, Y.; Ji, D.; Zhu, B.; Zhang, P.; Xu, J.; Gan, Q.; Yu, Z.; Zhu, J., Self-assembly of highly efficient, broadband plasmonic absorbers for solar steam generation. Sci. Adv. 2016, 2, e1501227. 9. Zhou, L.; Zhuang, S.; He, C.; Tan, Y.; Wang, Z.; Zhu, J., Selfassembled spectrum selective plasmonic absorbers with tunable bandwidth for solar energy conversion. Nano Energy 2017, 32, 195-200. 10. Liu, Y.; Yu, S.; Feng, R.; Bernard, A.; Liu, Y.; Zhang, Y.; Duan, H.; Shang, W.; Tao, P.; Song, C.; Deng, T., A Bioinspired, Reusable, Paper-Based System for High-Performance Large-Scale Evaporation. Adv. Mater. 2015, 27, 2768-2774. 11. Hu, H.; Wang, Z.; Ye, Q.; He, J.; Nie, X.; He, G.; Song, C.; Shang, W.; Wu, J.; Tao, P.; Deng, T., Substrateless Welding of SelfAssembled Silver Nanowires at Air/Water Interface. ACS Appl. Mater. Inter 2016, 8, 20483-20490. 12. Fang, J.; Liu, Q.; Zhang, W.; Gu, J.; Su, Y.; Su, H.; Guo, C.; Zhang, D., Ag/diatomite for highly efficient solar vapor generation under one-sun irradiation. J. Mater. Chem. A 2017, 5, 17817-17821. 13. Cortie, M. B.; McDonagh, A. M., Synthesis and Optical Properties of Hybrid and Alloy Plasmonic Nanoparticles. Chem. Rev. 2011, 111, 3713-3735. 14. Ciriminna, R.; Falletta, E.; Della Pina, C.; Teles, J. H.; Pagliaro, M., Industrial Applications of Gold Catalysis. Angew. Chem. Int. Edit. 2016, 55, 14210-14217. 15. Wang, G.; Fu, Y.; Ma, X.; Pi, W.; Liu, D.; Wang, X., Reusable reduced graphene oxide based double-layer system modified by polyethylenimine for solar steam generation. Carbon 2017, 114, 117-124. 16. Ren, H.; Tang, M.; Guan, B.; Wang, K.; Yang, J.; Wang, F.; Wang, M.; Shan, J.; Chen, Z.; Wei, D.; Peng, H.; Liu, Z., Hierarchical Graphene Foam for Efficient Omnidirectional Solar-Thermal Energy Conversion. Adv. Mater. 2017, 29, 1702590. 17. Zhang, P.; Li, J.; Lv, L.; Zhao, Y.; Qu, L., Vertically Aligned Graphene Sheets Membrane for Highly Efficient Solar Thermal Generation of Clean Water. ACS Nano 2017, 11, 5087-5093. 18. Sajadi, S. M.; Farokhnia, N.; Irajizad, P.; Hasnain, M.; Ghasemi, H., Flexible artificially-networked structure for ambient/high

pressure solar steam generation. J. Mater. Chem. A 2016, 4, 47004705. 19. Li, Y.; Gao, T.; Yang, Z.; Chen, C.; Luo, W.; Song, J.; Hitz, E.; Jia, C.; Zhou, Y.; Liu, B.; Yang, B.; Hu, L., 3D-Printed, All-in-One Evaporator for High-Efficiency Solar Steam Generation under 1 Sun Illumination. Adv. Mater. 2017, 29, 1700981. 20. Chen, C.; Li, Y.; Song, J.; Yang, Z.; Kuang, Y.; Hitz, E.; Jia, C.; Gong, A.; Jiang, F.; Zhu, J. Y.; Yang, B.; Xie, J.; Hu, L., Highly Flexible and Efficient Solar Steam Generation Device. Adv. Mater. 2017, 29, 1701756. 21. Liu, Z.; Song, H.; Ji, D.; Li, C.; Cheney, A.; Liu, Y.; Zhang, N.; Zeng, X.; Chen, B.; Gao, J.; Li, Y.; Liu, X.; Aga, D.; Jiang, S.; Yu, Z.; Gan, Q., Extremely Cost-Effective and Efficient Solar Vapor Generation under Nonconcentrated Illumination Using Thermally Isolated Black Paper. Global Challenges 2017, 1, 1600003. 22. Ghasemi, H.; Ni, G.; Marconnet, A. M.; Loomis, J.; Yerci, S.; Miljkovic, N.; Chen, G., Solar steam generation by heat localization. Nat. Commun. 2014, 5, 4449. 23. Xu, N.; Hu, X.; Xu, W.; Li, X.; Zhou, L.; Zhu, S.; Zhu, J., Mushrooms as Efficient Solar Steam-Generation Devices. Adv. Mater. 2017, 29, 1606762. 24. Li, Y.; Gao, T.; Yang, Z.; Chen, C.; Kuang, Y.; Song, J.; Jia, C.; Hitz, E. M.; Yang, B.; Hu, L., Graphene oxide-based evaporator with onedimensional water transport enabling high-efficiency solar desalination. Nano Energy 2017, 41, 201-209. 25. Zhao, F.; Zhou, X.; Shi, Y.; Qian, X.; Alexander, M.; Zhao, X.; Mendez, S.; Yang, R.; Qu, L.; Yu, G., Highly efficient solar vapour genera-tion via hierarchically nanostructured gels. Nat. Nanotechnol. 2018, 13, 489-495. 26. Song, H.; Liu, Y.; Liu, Z.; Singer, M. H.; Li, C.; Cheney, A. R.; Ji, D.; Zhou, L.; Zhang, N.; Zeng, X.; Bei, Z.; Yu, Z.; Jiang, S.; Gan, Q., Cold Vapor Generation beyond the Input Solar Energy Limit. Adv. Sci. 2018, 5, 1800222. 27. Zhu, M.; Li, Y.; Chen, G.; Jiang, F.; Yang, Z.; Luo, X.; Wang, Y.; Lacey, S. D.; Dai, J.; Wang, C.; Jia, C.; Wan, J.; Yao, Y.; Gong, A.; Yang, B.; Yu, Z.; Das, S.; Hu, L., Tree-Inspired Design for High-Efficiency Water Extraction. Adv. Mater. 2017, 29, 1704107. 28. Liu, H.; Chen, C.; Chen, G.; Kuang, Y.; Zhao, X.; Song, J.; Jia, C.; Xu, X.; Hitz, E.; Xie, H.; Wang, S.; Jiang, F.; Li, T.; Li, Y.; Gong, A.; Yang, R.; Das, S.; Hu, L., High-Performance Solar Steam Device with Layered Channels: Artificial Tree with a Reversed Design. Adv. Energy Mater. 2018, 8, 1701616. 29. Seymour, R. S., Plants that warm themselves. Sci. Am. 1997, 276, 104-109. 30. Lamprecht, I.; Seymour, R. S.; Schultze-Motel, P., Direct and indirect calorimetry of thermogenic flowers of the sacred lotus, Nelumbo nucifera. Thermochim. Acta 1998, 309, 5-16. 31. Miyake, K., Some Physiological Observations on Nelumbo nucifera, Gærtn. Shokubutsugaku Zasshi 1898, 12, 112-117. 32. Zang, D.; Zhu, R.; Zhang, W.; Yu, X.; Lin, L.; Guo, X.; Liu, M.; Jiang, L., Corrosion-Resistant Superhydrophobic Coatings on Mg Alloy Surfaces Inspired by Lotus Seedpod. Adv. Funct. Mater. 2017, 27, 1605446. 33. Chen, M.; Jiang, S.; Cai, S.; Wang, X.; Xiang, K.; Ma, Z.; Song, P.; Fisher, A. C., Hierarchical porous carbon modified with ionic surfactants as efficient sulfur hosts for the high-performance lithiumsulfur batteries. Chem. Eng. J. 2017, 313, 404-414. 34. Liu, B.; Zhou, X.; Chen, H.; Liu, Y.; Li, H., Promising porous carbons derived from lotus seedpods with outstanding supercapacitance performance. Electrochim. Acta 2016, 208, 55-63. 35. Vogel, S., Contributions to the functional anatomy and biology of Nelumbo nucifera (Nelumbonaceae) I. Pathways of air circulation. Plant Syst. Evol. 2004, 249, 9-25. 36. Kang, D.; Liu, Q.; Chen, M.; Gu, J.; Zhang, D., Spontaneous Crosslinking for Fabrication of Nanohybrids Embedded with SizeControllable Particles. ACS Nano 2016, 10, 889-898. 37. Kang, D.; Liu, Q.; Gu, J.; Su, Y.; Zhang, W.; Zhang, D., "Egg-Box"Assisted Fabrication of Porous Carbon with Small Mesopores for



High-Rate Electric Double Layer Capacitors. ACS Nano 2015, 9, 11225-11233. 38. Clyne, T. W.; Golosnoy, I. O.; Tan, J. C.; Markaki, A. E., Porous materials for thermal management under extreme conditions. Philos. T. 2006, 364, 125. 39. Pierre, A. C.; Pajonk, G. M., Chemistry of aerogels and their applications. Chem. Rev. 2002, 102, 4243-4265.

40. Rolison, D. R., Catalytic nanoarchitectures - The importance of nothing and the unimportance of periodicity. Science 2003, 299, 1698-1701.

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Hierarchical Porous Carbonized Lotus Seedpods for Highly Efficient

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