本文選題：核殼結(jié)構(gòu)　切入點(diǎn)：微納材料　出處：《大連理工大學(xué)》2015年碩士論文

【摘要】：核殼結(jié)構(gòu)微納材料具有很多優(yōu)于單組份材料和傳統(tǒng)復(fù)合材料的性質(zhì),在多相催化等領(lǐng)域有廣泛的應(yīng)用,其結(jié)構(gòu)設(shè)計(jì)、制備和性能優(yōu)化是當(dāng)今材料科學(xué)和化學(xué)工程領(lǐng)域的研究熱點(diǎn)。目前,核殼結(jié)構(gòu)微納材料的結(jié)構(gòu)和尺寸可以得到很好地控制,但有關(guān)其形貌控制的研究相對(duì)較少,且存在難以連續(xù)化制備的問題。鑒于此,本文以實(shí)現(xiàn)材料的連續(xù)化和形貌可控制備為研究目標(biāo),采用氣溶膠噴霧干燥法、硬模板法和水熱法制備了一系列核殼結(jié)構(gòu)微納材料,并研究了它們的催化和電化學(xué)性能,為進(jìn)一步研究核殼材料可控制備方法、拓展其應(yīng)用領(lǐng)域打下了基礎(chǔ)。主要內(nèi)容如下。使用氣溶膠噴霧干燥法一步合成了Au@TiO2/SiO2核殼材料,實(shí)現(xiàn)了核殼結(jié)構(gòu)材料的連續(xù)化簡(jiǎn)單制備,并將其應(yīng)用于對(duì)硝基苯酚(4-NP)催化還原反應(yīng)。材料呈球形,表面具有纖維狀TiO2,納米金顆粒被包裹在TiO2/SiO2空心微球骨架之中；當(dāng)反應(yīng)溫度為20℃, NaBH4與4-NP的物質(zhì)的量之比為500：1,催化劑用量為0.15mg/mL時(shí),材料催化4-NP反應(yīng)轉(zhuǎn)化率可達(dá)95%；材料催化性能不隨使用次數(shù)增加而降低,重復(fù)使用八次4-NP轉(zhuǎn)化率均在90%以上。為進(jìn)一步控制材料的形貌和結(jié)構(gòu),并使材料在液相反應(yīng)中有更好的分離回收性能,在上述球形催化材料的基礎(chǔ)上,使用硬模板法制備了立方體、橢球和花生形貌的超順磁性氧化鐵@SiO2-Au@C核殼材料,優(yōu)化了材料的煅燒溫度和Au擔(dān)載量,并將其應(yīng)用于4-NP催化還原反應(yīng)。材料形貌特征明顯,粒徑均勻,具有清晰完整的核殼結(jié)構(gòu),高度單分散、粒徑約為6nm的金顆粒均勻分布在Si02層和炭層之間,其超順磁性來自于煅燒過程中α-Fe2O3原位轉(zhuǎn)化為由α-Fe2O3和Fe304組成的磁性氧化鐵；當(dāng)反應(yīng)溫度為20℃,NaBH4與4-NP的物質(zhì)的量之比為500：1,催化劑用量為0.15mg/mL時(shí),材料催化4-NP反應(yīng)轉(zhuǎn)化率可達(dá)90%以上；材料可利用外加磁場(chǎng)回收,重復(fù)使用7次催化活性沒有明顯降低,且700℃煅燒后仍然保持良好的磁性和催化活性。為了拓展形貌可控硬模板法的應(yīng)用,以不同形貌Si02空殼為基礎(chǔ),使用水熱法制備了立方體、橢球和花生形貌的雙層空心NiS電極材料,并測(cè)試了材料的本征電化學(xué)性能。材料具有均勻的粒徑和明顯的雙層空心結(jié)構(gòu),同時(shí)存在硅酸鎳物相和硫化鎳物相；材料具有明顯的贗電容特性,有很好的可逆性,在低掃描速率(10mV/s)下,氧化、還原峰的峰電勢(shì)分別為0.27和0.15V左右,橢球形貌的電極材料在電流密度為1A/g時(shí)具有最高的比電容,達(dá)206F/g。
[Abstract]:Core-shell structure micronanomaterials have many advantages over single component materials and traditional composite materials. They are widely used in many fields such as heterogeneous catalysis.Preparation and performance optimization are hot topics in the field of material science and chemical engineering.At present, the structure and size of core-shell micro-nano materials can be well controlled, but the research on morphology control is relatively few, and it is difficult to be prepared continuously.In view of this, a series of core-shell microstructures were prepared by aerosol spray drying method, hard template method and hydrothermal method.Their catalytic and electrochemical properties were studied, which laid a foundation for the further study of controllable preparation methods of core-shell materials and the expansion of their application fields.The main contents are as follows.The Au@TiO2/SiO2 core-shell materials were synthesized by aerosol spray drying method. The continuous preparation of core-shell materials was realized, and it was applied to the catalytic reduction of p-nitrophenol.The material was spherical with fibrous TIO _ 2 on the surface, and the gold nanoparticles were encapsulated in the framework of TiO2/SiO2 hollow microspheres. When the reaction temperature was 20 鈩，

本文編號(hào)：1725463