3results about How to "Mild preparation method" patented technology

The present application relates to the technical field of porphyrin-based covalent organic framework material preparation, in particular to a mild preparation method of acetaldehyde-based porphyrin covalent organic framework and application thereof, which comprises the following steps: step one: dispersing ligand 2', 5'-bis((ethyl sulfide) methyl)-[1,1':4',1''-triphenyl]-4,4''-diamine in acetonitrile solution to obtain solution A, and dissolving acetaldehyde-based porphyrin in dichloromethane to obtain solution B; step two: mixing solution A and solution B; step three: adding ferric chloride and acetic acid as catalysts to react under mild conditions to obtain acetaldehyde-based porphyrin covalent organic framework material, which has excellent gaseous iodine adsorption performance. The synthesis method provided by the present application has mild conditions, simplifies the high-temperature time-consuming shortcomings of traditional porphyrin-based covalent organic framework material synthesis, and realizes the synthesis of special ligand covalent organic framework.

The invention discloses a titanium dioxide-quantum dot-silicon dioxide composite material with a multilayer core-shell structure as well as a preparation method and application of the titanium dioxide-quantum dot-silicon dioxide composite material. The core layer is composed of titanium dioxide nano-particles, the quantum dot middle layer is adsorbed to the surface of the core layer in a bridging mode through a silane coupling agent, and the compact silicon dioxide shell layer wraps the quantum dot middle layer. The method comprises the following steps: titanium dioxide nanoparticles are subjected to silanization modification to introduce sulfydryl, quantum dots are subjected to ligand exchange to obtain water-soluble sulfhydrylated quantum dots, the water-soluble sulfhydrylated quantum dots and the titanium dioxide nanoparticles form a quantum dot-titanium dioxide compound through interaction of the sulfydryl, and finally, a silicon dioxide shell is formed through silicon source hydrolytic condensation under a weak alkaline condition. Through core-functional layer-shell collaborative design, the problems that a traditional quantum dot composite material is weak in binding force, the quantum dots are prone to falling off and the stability is poor are solved, and the quantum dot composite material can be widely applied to the fields of photoelectric devices, photocatalytic materials and biological fluorescent markers.

The invention discloses a method for preparing pure beta-phase molybdenum carbide particles through one-step carbonization and application of the pure beta-phase molybdenum carbide particles. The preparation method comprises the following steps: (1) preparing molybdenum oxide powder by adopting a method for thermally decomposing a molybdenum metal compound; (2) dividing an organic matter precursor and the molybdenum oxide powder obtained in the step (1) into two stacks, and respectively placing the two stacks on the ventilation side and the exhaust side of a tubular furnace; and (3) introducing carrier gas into the tubular furnace, and carbonizing the molybdenum oxide powder through a temperature programming process. According to the method, the carrier gas is utilized to deliver the gas-phase carbon source produced by thermal decomposition of the organic matter precursor to directly react with the solid-phase molybdenum oxide powder, the carbonization process can be efficiently achieved, high-purity beta-phase molybdenum carbide is obtained through one-step carbonization, high-value and high-risk hydrocarbon gas such as methane and propyl alcohol or alcohol steam is avoided, and the method is suitable for industrial production. The problems of carbon deposition on the surface of the molybdenum carbide caused by using the carrier gas as a carbon source and the like can be avoided, and the preparation method is simple, relatively mild in reaction condition, low in raw material cost, simple and easy to obtain and suitable for large-scale production, popularization and application.