With the support of the "Hundred Talents Program" of the Chinese Academy of Sciences and the National Natural Science Foundation of China, the Research Group of Energy and Environmental Nanocatalytic Materials of the Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences has made a series of progress in the structural design and crystal plane control of semiconductor photocatalytic nanomaterials.
The design and synthesis of semiconductor photocatalytic materials and crystal plane control have become hot spots in the field of photocatalysis research. However, currently reported such heterogeneous materials generally have lower photogenerated charge separation efficiency and visible photocatalytic activity due to their morphology and structural defects. . Therefore, how to design and prepare photocatalytic nanomaterials with high-efficiency electron-hole separation structure and realize the controllable synthesis of their highly active crystal planes has become a scientific problem that needs to be solved urgently.
In the early stage, the research team designed and constructed a necklace-shaped heterostructure photocatalyst-metal Ag nanowire / Ag3PO4 cubic heterogeneous photocatalyst, that is, the size, morphology and quantity of selective epitaxial growth on the surface of Ag nanowires are controlled. The Ag3PO4 cube on the {100} plane has high photocatalytic activity due to its high photo-generated carrier separation and conduction efficiency (J. Mater. Chem. 2012, 22, 14847). In the follow-up work, by simply adjusting the concentration of ammonia in the Ag3PO4 cubic solution, the selective reduction growth of glucose on the silver ions at the edge of the Ag3PO4 cube and the {100} crystal plane was achieved, and the growth mechanism and photocatalytic activity were systematically studied. Research (Chem. Eur. J. 2012,18,14272). Based on the preparation of Ag3PO4 cubes with {100} crystal planes (Chem. Commun. 2012, 48, 3748), the research team further synthesized Ag3PO4 with {111} crystal planes by oxidizing silver flakes with hydrogen peroxide Tetrahedron, compared with {100} crystal plane, due to {111} has higher crystal plane energy and more surface defects, so that Ag3PO4 tetrahedron has better visible light catalytic activity than Ag3PO4 cube (J. Mater. Chem . A, 2013, 1, 2387) and (Phys. Chem. Chem. Phys. 2012, 14, 14486-14488).
Recently, researchers have used the method of selective epitaxial growth of Ag3PO4 on the surface of Au @ Ag nanorods to successfully prepare the icosahedral structure of Ag3PO4 with {221} and {332} high-index crystal planes. In addition to the face-centered cubic precious metal icosahedral structure that has been reported so far, this is the first report of a body-centered cubic semiconductor icosahedral heterogeneous photocatalytic material. The researchers also calculated the surface energy of {221} and {332} crystal planes using density functional theory, and found that it has a higher surface energy than low-index crystal planes such as {100}; in addition, high-index crystal planes have more Multiple reactive sites can make Ag3PO4 icosahedral structure have higher visible light catalytic performance. This method has extremely high versatility and practicality in the field of semiconductor photocatalysis, and it opens up a new way for the design and synthesis of heterogeneous semiconductor photocatalytic materials with high index crystal planes. Related research results were published in (Chem. Commun. 2013, 49,636).
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