Plant photosynthesis in nature can realize the conversion of solar energy to chemical energy, and the photosynthesis of plant leaves II and I are present in the thylakoid membrane of chloroplasts in the form of mosaics, which is an important structural basis for the effective operation of natural photosynthesis. Inspired by this, recently, the research team of Liu Gang of Shenyang National Research Center for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, cooperated with a number of research teams at home and abroad to develop a new technology for embedding semiconductor particles into liquid metal to achieve large-scale film formation, and built a new type of bionic artificial photosynthetic film with both form and spirit, which has the function of similar to leaves and can realize the conversion of solar energy to chemical energy. On February 23, the research results were published in Nature Communications under the title "Liquid Metal-Embraced Photoactive Films for Artificial Photosynthesis".
Embedded semiconductor photoactive films were fabricated based on low-temperature liquid metal embedded semiconductor particles.
Solar photocatalytic water splitting green hydrogen production technology is a cutting-edge and disruptive low-carbon technology, and the key to its application is to construct efficient, stable and low-cost solar driven semiconductor photocatalytic material thin films. At present, the commonly used thin film preparation technology is difficult to meet the practical application needs of solar photocatalytic water splitting to hydrogen due to the harsh preparation environment or poor film formation quality. The researchers used molten low-temperature liquid metal as a conductive current collector and binder to form a film on a large scale on a selected substrate, and combined with rolling technology to embed and integrate semiconductor particles, and realized the large-scale implantation of semiconductor particles. The semiconductor particles are embedded in the liquid metal conductive current collector film to form a three-dimensional strong contact interface, and its structure is like a "cobblestone pavement", which makes it not only have excellent structural stability but also has a very outstanding photogenerated charge collection ability. Taking BiVO4 (bismuth vanadate) as an example, the photoelectrode activity of embedded BiVO4 particles is 2 times higher than that of the traditional non-embedded BiVO4 photoelectrode, and there is almost no activity attenuation after 120 hours of continuous operation for a long time. After the photoelectrode is magnified from 1 square centimeter to 64 square centimeters, the photocurrent density per unit area can still be maintained at about 70%, which is much better than the activity retention rate of the large-area BIVO4 photoelectrode (<30%). Further embedding integrated oxygen-producing and hydrogen-producing photocatalytic materials at the same time can realize the large-scale preparation of photocatalytic water splitting hydrogen production panels, which are nearly 3 times more active than the traditional non-embedded gold thin film supporting photocatalytic material films under visible light irradiation, and work continuously for more than 100 hours without attenuation.
In addition, the technology also has the advantages of good universality and easy raw materials. The large-scale preparation of different semiconductor photoactive films on different matrices can be realized by using commercial semiconductor particles (such as ZNO, WO3 and Cu2O, etc.), and the activity of the obtained granular embedded films is significantly better than that of the control non-embedded samples. Films integrated on flexible substrates retain more than 95% initial activity after 100,000 bends at large curvatures. Semiconductor particles, low-temperature liquid metals, and substrates can be separated and reused using simple hot water ultrasonication, and the reintegration of the resulting artificial photosynthetic film exhibits nearly the same activity as the original film.