CAJ | 학술논문

通过调节溶液的pH值，在水热条件下合成出长径比为2-45的La(OH)3纳米棒.对水热合成过程中间体的结构演变分析，发现高碱度有利于小尺寸晶核的形成， La(OH)3晶体结构的各向异性导致这些晶种沿着C轴方向生长，进而形成纳米棒结构.将La(OH)3纳米棒前驱体于773 K焙烧可以得到长径比为2-20的La2O2CO3纳米棒.随着长径比的增加， La2O2CO3纳米棒暴露的(110)晶面逐渐增加， La3+-O2-碱性位的数目也从0.08增加到0.24 mmol/g.因此，在Claisen-Schmidt缩合反应中， La2O2CO3纳米棒催化剂上的反应速率随着长径比的增加而逐渐增大.
통과조절용액적pH치，재수열조건하합성출장경비위2-45적La(OH)3납미봉.대수열합성과정중간체적결구연변분석，발현고감도유리우소척촌정핵적형성， La(OH)3정체결구적각향이성도치저사정충연착C축방향생장，진이형성납미봉결구.장La(OH)3납미봉전구체우773 K배소가이득도장경비위2-20적La2O2CO3납미봉.수착장경비적증가， La2O2CO3납미봉폭로적(110)정면축점증가， La3+-O2-감성위적수목야종0.08증가도0.24 mmol/g.인차，재Claisen-Schmidt축합반응중， La2O2CO3납미봉최화제상적반응속솔수착장경비적증가이축점증대.
La(OH)3 nanorods of 15 nm diameter and up to 700 nm long were synthesized using different pH values of the solution used in the hydrothermal synthesis. A more alkaline solution favored the formation of tiny La(OH)3 nuclei, which grew along the c-axis due to their anisotropic nature and led to the formation of rod-shaped crystals. Calcination of the La(OH)3 nanorods at 773 K gave La2O2CO3 nanorods. Their basic properties were correlated with their size. As the aspect ratio increased from 2 to 20, the basic sites increased from 0.08 to 0.24 mmol/g, which was due to a higher exposure of (110) planes. In the catalysis of the condensation reaction of benzaldehyde with acetophenone, the reaction rate was correlated with the number of La3+-O2- pairs on the exposed (110) facets of the La2O2CO3 nanorods.