Low Iron Switchable Smart Glass Low Iron Switchable Smart Glass,Smart Glass Privacy Film Tempered Glass,Laminated Glass Switchable Pdlc,Switchable Smart Glass For Hotels Shenzhen YuGuang New Material Co.,Ltd , https://www.ygsmartfilm.com
Dr. Lu Wei and Zhu Kaixing, Ph.D. students of the Institute of Physics of the Chinese Academy of Sciences/Beijing National Laboratory for Condensed Matter Physics (Funding) Advanced Materials and Structure Analysis Laboratory (Functional Crystal Research and Application Center) under the guidance of researchers Guo Liwei and Chen Xiaolong A method for preparing a graphene/SiC core-shell heterojunction material (GCSP) based on SiC powder (see Fig. 1). By subjecting the micron-sized 6H-SiC powder to high temperature annealing under vacuum conditions, high quality graphene (as shown in Scheme 1g) completely coated with SiC particles can be grown in situ on the surface of the SiC particles. By controlling the growth process conditions, the number of layers of graphene can be effectively regulated (Fig. 1h). The graphene/SiC heterojunction particle composites prepared in 2012 were studied for degradation of organic pollutants. In 2014, an experimental study on photocatalytic cracking of hydrogen production was carried out. It was found that when the number of graphene layers coated on the surface of SiC particles is 4-9 layers, the particles exhibit the best ability to degrade organic matter and the efficiency of hydrogen production in splitting water. The effect of the 0.5μm particle size graphene/SiC composite particles on the degradation of organic matter is 7 times higher than that of the original SiC particles of the same size; while the hydrogen production efficiency of the 5 μm particle size composite particles reaches 472μmolg-1h-1, which is compatible with some properties. The hydrogen production effect of the excellent nano-sized catalyst is comparable. The outstanding hydrogen degradation efficiency of degraded organic pollutants and splitting water is mainly due to the bipolar carrier transfer channels of heterojunction particles formed by graphene and SiC. The main mechanism for forming the bipolar channel is due to the different Fermi levels of graphene grown in different regions of the same SiC particle surface, resulting in different band bending at the interface between SiC and graphene (as shown in Figure 2). ), resulting in efficient separation and transfer of the two photogenerated carriers, promoting the redox (degradation, hydrogen production) reaction. This bipolar carrier transfer channel allows the composite particles to produce hydrogen under ultraviolet light irradiation even without a sacrificial agent. Related research not only provides a new idea for graphene-based photocatalysis research, but also develops a green, environmentally friendly, stable, low-cost, high-efficiency metal-free photocatalyst system with great potential. This work was recently published on Adv. Mater.
The above research work was funded by the National Natural Science Foundation of China, the “973†project of the Ministry of Science and Technology, and the Chinese Academy of Sciences. 
Figure 1. SEM morphology of (ac) 5 μm and (df) 0.5 μm particle size of raw SiC, GCSP-L (graphene 1-3 layer) and GCSP-M (graphene 4-9 layer) powder; g) is a schematic diagram of the derivatization of the original SiC particles to GCSP; (h) Raman spectra of two different number of graphene/SiC particles.
Figure 2. Schematic diagram of the band structure of graphene self-doping resulting in the formation of a graphene/SiC heterojunction bipolar carrier transfer channel.
Abstract With the advancement of society and the improvement of living standards, environmental pollution and energy shortage have become huge obstacles to sustainable development. Solutions to solve these obstacles include photocatalytic degradation of organic pollutants and photocatalytic cracking of water to produce hydrogen (converting solar energy into chemical energy).
With the advancement of society and the improvement of living standards, environmental pollution and energy shortage have become huge obstacles to sustainable development. Solutions to these obstacles include photocatalytic degradation of organic pollutants and photocatalytic cracking of water to produce hydrogen (which converts solar energy into chemical energy). Therefore, it is the direction of material scientists to explore and develop photocatalytic materials that can achieve the above two functions at the same time, with excellent performance, stable physical and chemical properties, simple preparation process, green environmental protection and low cost. After nearly 50 years of development, the development of photocatalytic materials is changing with each passing day. However, its basic structure is a nanocomposite loaded with precious metals in nano-semiconductor particles, such as metal platinum-modified cadmium sulfide nanocomposites, which are representative of excellent photocatalytic materials. However, such materials contain precious metals and sulfides, which may bring new problems to the environment. Therefore, the development of high-efficiency catalysts without metals has become a research hotspot in this field. Graphene has been chosen to replace precious metals as a highly efficient cocatalyst because of its excellent electrical conductivity and transparency. The discovery and preparation of graphene/semiconductor nanocomposite high-efficiency photocatalytic materials without any metal is expected in the industry.