Design,Synthesis And Photo/Electrocatalytic Properties Of Multi-metal Compound Micro/Nano Structures

Bi-based photocatalyst materials usually have suitable valence band positions and strong hole oxidation properties,and have shown potential application value in the field of photocatalytic degradation of organic pollutants.Compared with the traditional one-component bismuth-based photocatalytic material,the three-component material has faster photo-generated charge separation efficiency,and thus shows significantly improved photocatalytic activity.On the other hand,multi-component transition metal phosphides have good electrical conductivity,high mechanical strength,unique electronic structure,rich and variable valence states,and well-known synergistic catalytic effects.Both show excellent HER and OER activity and are considered to be the most promising electrocatalytic materials to replace precious metals.The main work of this paper are as follows:1.Under the high temperature and high pressure environments by solvothermal method,partially released Bi3+ ions derived from the Bi2WO6 nanosheets could react with Ge source,leading to the formation of Bi12GeO20 tetrahedrons.Meanwhile,the remaining Bi2WO6 nanosheets were also anchored in situ onto the surface of the Bi12GeO20 tetrahedrons,thus forming Bi12GeO20-Bi2WO6 heterojunction with“face-to-face" heterogeneous interface.The Ag-Bi12GeO20-Bi2WO6 heterogeneous was obtained after loading of Ag nanoparticles.Due to the structural and compositional features such as matching band structure,intimate interfacial contacts,and "schottky barriers",the photo-generated charges of the resulting ternary composite photocatalyst was efciently separated and thus exhibited improved catalytic activity of RhB.2.Composite photocatalytic system based on interface structure design is deemed to be a feasible method to improve the photocatalytic efficiency of sillenite-type photocatalytic material.Therefore,we reported the successful construction of novel tetrahedron-like Ag-Bi25GaO39-Bi2WO6 heterostructure through a partial chemical conversion strategy coupling with the photo-reduction method.Experiment indicated that when the Ag nanoparticals was loaded of 6 wt%,the as-prepared Ag-Bi25GaO39-Bi2WO6 heterogeneous structure possessed the best activity for the decomposition of RhB and 95%of RhB molecules could be decomposed after 20 min of UV-vis light irradiation.Moreover,the resulted Ag-Bi25GaO39-Bi2WO6 product also exhibited outstanding photocatalytic activity for the decomposition of other pollutant such as phenol and toxic Cr(VI)solutions.3.The rational design of two-dimensional(2D)heterogeneous photocatalysts is considered to be one of the effective methods to achieve high-efciency migration and separation of photo-excited electrons and holes.Nevertheless,if these separated photo-excited electrons fail to be removed as soon as possible,they tend to recombine with photo-generated holes due to their own instability,losing its excellent photocatalytic activity.Therefore,we reported the preparation of novel 2D Ag-Bi7O9I3-Bi25VO40 composite photocatalyst,employing the pre-prepared Bi25VO40 microcubes as starting materials.The resulted Ag-Bi7O9I3-Bi25VO40 ternary heterostructure exhibited outstanding photo-degradation ability of RhB by comparison of pure Bi7O9I3,Bi25VO40 as well as Bi7O9I3-Bi25VO40.4.Uniform Ni3[Co(CN)6]2·12H2O nanocubes were taken as the starting material to fabricate the bifunctional catalysts through ammonia carving,conformal polydopamine coating,precursor metal ion coordination,and thermal phosphorization to create efficient bifunctional electrocatalysts for electrochemical overall water splitting.Holes located at the eight vertices allow easy access of the electrolyte to and fast rejection of evolving gas bubbles from the interior of the cube.The N-doped carbon nanocubes,providing fast charge transport pathway,and the positive synergistic effects arising from the mixed metal phosphides,significantly enhanced catalytic performances of the product catalyst.When achieving 10 mA/cm2,the overpotentials of OER and HER are only 251 and 142 mV,respectively and a working cell voltage of 1.63 V for the overall water splitting all.5.The microporous cubic ZIF-67 was used as a start material,and reacted with five-membered heterocylic compound,1H-1,2,3-triazole,in methanol solution employing solvent-assistant-linker-exchange method.The Nitrogen-rich EZIF-67-C eletrocatalyst was obtained by high temperature carbonization,and the appearance of cubic was still maintains.Expriment shows that EZIF-67-C exhibit excellent performance in electrolysis of water.Figure[72]table[3]reference[207]...