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以KOH和La(NO3)3·6H2O为前驱体,柠檬酸为保护剂,采用一步水热法合成三维La(OH)3纳米球光催化剂.通过XRD、SEM、PL和UV-vis DRS等对样品进行结构表征.结果表明,柠檬酸的加入量对La(OH)3的形貌均匀性和催化活性均有较大影响.柠檬酸和La(NO3)3·6H2O的物质的量的比为2∶1时,得到的样品为形貌均匀的纳米球,光催化活性最佳且稳定性好.这是因为三维的纳米球结构更容易促进光生载流子的分离;此外,形貌均匀无团聚,增加了催化剂表面的活性位点,使反应过程中反应物和中间产物迅速扩散,从而光催化活性最高.在光催化过程中,羟基自由基(·OH)和超氧自由基(·O-2)是最主要的氧化物种.NO可以和产生的·OH和·O-2反应生成HNO2和HNO3,从而去除NO.本文研究结果充实了La(OH)3光催化材料的合成基础理论,探讨了La(OH)3光催化活性机理,为La(OH)3应用打开了新的视野.
The three-dimensional La (OH) 3 nanospheres photocatalyst was synthesized by one-step hydrothermal method using KOH and La (NO3) 3 · 6H2O as precursors and citric acid as the protective agent. By XRD, SEM, PL and UV- The results showed that the addition of citric acid had a great influence on the morphology and catalytic activity of La (OH) 3.The ratio of the amount of citric acid and La (NO3) 3 · 6H2O was 2: 1, the sample obtained is a homogeneous nanosphere with the best photocatalytic activity and good stability, because the three-dimensional nanosphere structure is easier to promote the separation of photo-generated carriers. In addition, The photocatalytic activities of hydroxyl radicals (· OH) and superoxide radicals (· O -2) is the most important oxide species. NO can react with · OH and · O-2 to form HNO2 and HNO3 to remove NO. The results of this paper enrich the basic theory of synthesis of La (OH) 3 photocatalyst, The mechanism of La (OH) 3 photocatalytic activity was discussed, which opened up a new field of vision for La (OH) 3 application.