2results about How to "Control growth direction" patented technology

This invention discloses a method for preparing a WO3 photoanode rich in (002) crystal planes. The method employs a hydrothermal process, using sodium tungstate as the tungsten source. Hydrochloric acid is added to precipitate the sodium tungstate aqueous solution, followed by the addition of oxalic acid and hydrochloric acid to form a hydrothermal precursor. A WO3 seed layer is added to the hydrothermal precursor for a hydrothermal reaction, followed by annealing to obtain a WO3 photoanode film rich in (002) crystal planes. This method is simple, and the prepared WO3 rich in (002) crystal planes exhibits higher photocurrent density, more active sites for water oxidation, and superior hydroxyl radical generation compared to WO3 rich in (200) crystal planes. It also demonstrates good stability and highly efficient tetracycline degradation capabilities.

The invention relates to a multi-grain-boundary cerium-based catalyst as well as a preparation method and application thereof. The multi-grain-boundary cerium-based catalyst comprises a multi-grain-boundary cerium dioxide carrier and an active component loaded on the carrier, the active component comprises any one or a combination of at least two of copper oxide, manganese oxide or cobalt oxide. According to the multi-grain-boundary cerium-based catalyst, multi-grain-boundary CeO2 is adopted as a carrier, and compared with a traditional single-crystal Ce-based catalyst, the multi-grain-boundary Ce-based catalyst has rich grain boundary defects, so that generation of an oxygen vacancy active structure is promoted, and higher photochemical reaction activity is achieved. The structural advantages are beneficial to adsorption and activation of reactants and generation of active oxygen species, so that the deep oxidation performance of the catalyst on VOCs is remarkably improved. Compared with the traditional thermocatalysis, the application of the photothermal catalysis technology reduces the energy consumption of external heating. The multi-grain-boundary cerium-based catalyst has excellent low-temperature degradation capability and reaction stability, so that the multi-grain-boundary cerium-based catalyst has a good application prospect in purification of VOCs (Volatile Organic Compounds) in industrial flue gas.