Note: at the end of the paper, there is a brief introduction of the research team and an analysis of the research ideas in this paper
Photocatalytic technology has been widely concerned because it can utilize the inexhaustible solar energy to decompose water to prepare clean and high energy density renewable hydrogen to alleviate the energy crisis. However, the lower quantum efficiency limits the application of photocatalysis, which is mainly due to the lower solar light efficiency and carrier separation efficiency. So, how to improve the efficiency of solar light utilization and carrier separation at the same time to significantly improve the performance of photocatalytic decomposition of water for hydrogen production? Recently, Professor Lu Chunhua, Professor Kou Jiahui of Nanjing University of technology and Professor Zhao Yuanjin (co corresponding author) of Southeast University introduced the built-in electric field of infrared photoresponse pyroelectricity into the photocatalytic reaction for the first time and significantly improved the photocatalytic performance by effectively constructing the pyroelectric photothermal photocatalytic composite micro fiber.
Infrared light, which accounts for about 50% of the solar spectrum, is not paid attention because of its low photon energy and can't directly stimulate the catalytic reaction of luminescence, while photothermal technology can convert infrared light into heat energy, and the conversion rate is as high as 85%. Ferroelectric materials can form a positive and negative pyroelectric field on their surface depending on the temperature change, and the electric field can be used as a driving force to effectively regulate the transport behavior of carriers. Then, if the pyroelectric materials and pyroelectric materials are combined with photocatalyst to construct the pyroelectric photothermal photocatalytic composite system, the infrared light will be effectively utilized and the pyroelectric built-in electric field will be generated to promote the performance of photocatalytic decomposition of aquatic hydrogen. Based on this, the research team creatively designed and constructed the pyroelectric photothermal photocatalytic composite micro fiber PVDF-HFP / CNT / CDs, realized the construction of infrared photoresponsive pyroelectric field and significantly improved the hydrogen production efficiency of photocatalytic decomposition water by more than 5 times, and the corresponding average apparent quantum efficiency was about 16.9%. The research team explored the relationship between pyroelectric substrate, content of photothermal materials and pyroelectric potential output and photocatalytic performance, and explored the photocatalytic stability of composite spiral fiber.
Through the pyroelectric output test, temperature dependent electrochemical test and temperature dependent fluorescence characterization, the direct experimental evidence is provided that the pyroelectric field can enhance the photocatalytic performance by effectively promoting carrier separation, accelerating carrier migration speed and prolonging carrier life. The results show that the aging of the built-in electric field increases with the increase of the temperature change rate. This work provides a new strategy to improve the performance of photocatalysis by using infrared light to construct pyroelectric field, and promotes the application of photocatalysis technology in solving energy crisis and environmental pollution.
This achievement was recently published on advanced materials. The first author is Dai Baoying, a doctoral candidate of Nanjing University of technology.
Construction of infrared light responsive photoinduced carriers driver for enhanced photocatalytic hydrogen evolution BAOYING Dai, Jiujiang Fang, Yunru Yu, Menglong sun, hengming Huang, Chunhua Lu, Jiahui Kou, Yuanjin Zhao, zhongzi xuadv. mater., 2020, 32, 1906361, DOI: 10.1002/adma.201906361
Prof. Lu Chunhua
Lu Chunhua, professor and doctoral director of School of materials science and engineering, Nanjing University of technology, and vice minister of scientific research department, Nanjing University of technology. He obtained his doctorate from Nanjing University of technology in 2001, lecturer and associate professor of Nanjing University of technology from 2002 to 2010, senior visiting scholar of University of Arizona from June to December 2010, and professor of Nanjing University of technology in January 2011.
He is mainly engaged in the research of selective absorption and energy conversion of light electromagnetic wave such as laser and sunlight, especially focusing on the interaction between light wave and nano materials and controllable preparation technology of materials. He has successively undertaken more than 10 scientific research projects such as national "973", General Assembly pre research, National Natural Science Fund, and key project of natural science fund of Jiangsu University. He directed and trained more than 30 doctoral and postgraduate students, published more than 100 academic papers in nano lett., adv. funct. Mater., appl. Catalyst. B-environ., crystal engcomm and other academic journals, applied for 32 national patents, and obtained 14 authorizations.
https://www.x-mol.com/university/faculty/27874
About Professor Kou Jiahui
Kou Jiahui, professor and master director, School of materials science and engineering, Nanjing University of technology. In 2008, he obtained a Ph.D. in engineering from the Department of materials of Nanjing University, worked in the Department of physics of Nanjing University from 2008 to 2010, and carried out postdoctoral work in the U.S. National Environmental Protection Administration from 2010 to 2013, with the support of the American orise postdoctoral fund. In October 2013, I worked in the school of materials, Nanjing University of technology until now.
Mainly engaged in the research and teaching of material physics and chemistry. The main research fields are: photocatalytic materials, environmental materials, nano materials. At present, as the project leader, he has undertaken the general projects of the National Natural Science Foundation of China, the general projects of the natural science foundation of Jiangsu Province, and the cooperation projects of production, education and research in Jiangsu Province. More than 50 research papers have been published in SCI journals such as chemical rev, nano let., adv. funct. Mater., nano energy.
https://www.x-mol.com/university/faculty/27881
Prof. Zhao Yuanjin
Zhao Yuanjin, professor and doctoral director of School of biological science and medical engineering, Southeast University, science and technology leader of national "ten thousand talents plan", national Youqing, Jiangsu Province outstanding youth, RSC follow. He obtained his bachelor's degree in medicine from Southeast University in 2006, CO trained with Professor David A. Weitz (academician of the three academies of the United States) from Harvard University from 2009 to 2010, graduated from Southeast University in 2011, obtained his doctor's degree in engineering, and stayed in the University for work, and was promoted to associate researcher and researcher in 2012 and 2015 respectively.
Now the main research directions are biomimetic materials and tissue engineering, microfluidics and organ chips. More than 150 SCI papers have been published, of which more than 50 have more than 10 influencing factors, and more than 4800 papers have been cited (H factor is 39). There are 110 papers by the first author and corresponding author, the sum of influencing factors is more than 1100, including SCI. Robot., SCI. Adv., NAT. Protoc., PNAs, adv. mater., JACS, angel. Chem., adv. funct. Mater., mater. Horiz., ACS Nano, Chem. Rev., chem. SOC. Rev., acc. chem. Res., mater. Today, etc., and 75 patents have been applied for the research results (U.S. patent 1 32 authorized, including 2 converted.
https://www.x-mol.com/university/faculty/41619
Analysis of scientific research ideas
Q: What was the initial purpose of the study? Or how do ideas come about? A: As mentioned above, we want to improve the utilization of light and the separation efficiency of carriers by designing the materials under natural conditions, so as to achieve a significant improvement in the performance of photocatalytic hydrogen production. We know that pyroelectric materials can efficiently convert infrared light into heat energy, while ferroelectric materials can generate pyroelectric field depending on the temperature change. If we composite the pyroelectric matrix with the pyroelectric materials and photocatalysts to prepare micro fibers and localize the photocatalytic decomposition of water reaction on the fiber surface to make the pyroelectric effect and the pyroelectric effect play to the extreme, it is possible to realize it Now, the construction of the infrared photoresponsive pyroelectric field can effectively promote the carrier separation and improve the photocatalytic performance. So we started the work.
Q: What are the biggest challenges in the research process? A: The biggest challenge in this work is to characterize the effect of the built-in pyroelectric field generated by composite materials on the photocatalysis behavior, to provide direct experimental evidence for the enhancement of photocatalysis performance by the corresponding infrared light built-in pyroelectric field, and to reveal the essential relationship between the built-in electric field and the carrier behavior. In this process, our team played a key role in the theoretical background of photocatalytic mechanism and reaction process. In the process of experimental testing, we actively play our subjective initiative to explore effective characterization techniques and means, so that the work can be successfully completed.
Q: What are the most likely important applications of the research results? Which areas of business or research institutions are most likely to benefit from this outcome? A: In addition to the pyroelectric, pyroelectric and photocatalysis properties, the pyroelectric photocatalysis composite micro fiber has good flexibility. Therefore, it can be widely used in the fields of energy conversion and photocatalytic application under natural conditions, including solar energy, water flow energy and wind energy conversion, photocatalytic decomposition of water to hydrogen, photocatalytic purification of air, photocatalytic degradation of pollutants and other fields. In this work, the multi-functional composite micron fiber is constructed to realize the establishment of infrared photoresponsive pyroelectric field and significantly enhance the photocatalytic performance, which provides new research ideas and strategies for the development of photocatalytic technology, and has great application prospects in further solving the energy crisis and environmental pollution problems.
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