Recently, top journals on energy, material and engineering thermophysics, including Adv. Funct. Mater., Nano Energy and Carbon, devoted pages to the research progress in the cross-disciplinary research of bionic energy materials and energy&mass transfer and conversion made by the research group led by Associate Professor Li Meng of the School of Energy and Power Engineering, Chongqing University.
Science published 125 scientific problems crying out for solutions in the incoming 25 years at its 125th Anniversary. In particular, "new energy utilization" and "greenhouse effect" are the most prominent energy and environment problems. At the same time, in the face of increasingly severe problems including freshwater shortage and water pollution, the realization of ultra-low energy consumption to obtain freshwater has become an important research topic related to water resources and energy security in China. The research focus in this area is to realize high-efficiency seawater interface evaporation with the help of green solar energy photo-thermal conversion materials. Nature itself is a skillful designer. The materials, assembly, interface and evolution formed by the long-term evolution of various ecological monomers and systems provide reference for human research. The excellence of research results based on bionics also shows that learning from nature is a feasible way to solve many problems.
To solve these problems, the research group led by Li Meng of the CQU-NUS Renewable Energy Materials & Devices Joint Laboratory of the School of Energy and Power Engineering (the research group of flexible renewable energy materials and devices) carried out a series of inter-disciplinary research work in bionic energy materials and energy&mass transfer and conversion. For example, knowing the fact that the micro-nano ridge array structure on the surface of black butterfly wings is inseparable from its efficient sunlight absorption, the research group prepared a solar photo-thermal conversion film with light trapping micro-nano structure by using bionic strategy, and applied it to an environment-friendly and low-cost interface solar energy water evaporation system; at the same time, inspired by the selective ion channel of plant root cells, the improvement of membrane salt barrier performance was also studied with the help of ion channel design. The film material has excellent evaporation rate (1.33 kg m-2 h-1) and photo-thermal conversion efficiency (~ 85.2%), and can still maintain an efficiency of 81.4% after repeated use in seawater for 40 times. The research findings were published in a world well-known journal, Nano Energy, under the title “A bio-inspired nanocomposite membrane with improved light-trapping and salt-rejecting performance for solar-driven interfacial evaporation applications” recently. Ying Peijin, a postgraduate student of CQU, is the first author of the paper.
Besides, as for plant bionics, some plants in low light environment evolve into self-similar fractal structures for efficient solar photosynthesis. The inherent micro-porous structure of grapefruit peel, a waste biomass in Southwest China, has attracted the attention of the team researchers. This porous structure is very suitable for preparing fractal structure materials as a substrate. Therefore, the research group developed a new biomass-derived solar thermal conversion material based on bionic fractal structure design, and applied it to the environment-friendly and low-cost interface solar water evaporation system. The research findings were published in a world well-known journal, Advanced Functional Materials, under the title “Bioinspired Fractal Design of Waste Biomass Derived Solar-thermal Materials for Highly Efficient Solar Evaporation” as a cover paper recently. Geng Yang, a postgraduate student of CQU, is the first author of the paper.
The research group also studied the internal relationship and law between the band gap and photo-thermal properties of semiconductor photo-thermal conversion materials, and explored the quantitative relationship between water transport and evaporation rate of one-dimensional water channel in the interface photo-thermal steam generation system, so as to provide a theoretical basis for accurately controlling water transport and improving evaporation rate in the follow-up work. Relevant findings were published in Carbon and ACS Applied Materials & Interfaces. Based on the above series of work, the research group is writing an invited overview of the application of bionic energy materials in the field of photo-thermal seawater desalination on the leading domestic journal, Nano Research, which will be published online in the near future. At the same time, the research project is supported by the general project under the National Natural Science Foundation of China in 2021, "synergistic principle of energy and mass transfer and conversion of photo-thermal evaporation bionic structural materials and construction method of coupling device", and applications for 2 relevant patents have been submitted.
For the full text and more information on related work, please click the following links:
Micro-nano structure of bionic black butterfly wing enhances photothermal seawater desalination:
Bionic fractal structure design assists in solar water evaporation of biomass source efficient interface:
Construction of multi-level carbon network in interface solar water evaporation system and quantitative analysis of system water transport:
Research on band gap engineering of semiconductor photothermal conversion materials and devices: