【作者】 赵艳；

【导师】 赵敬哲； 王子忱；

【作者基本信息】 吉林大学 ， 物理化学， 2012， 博士

【摘要】 在本论文工作中，我们利用低温液相合成法实现了铜系金属及其氧化物纳米材料的简单制备，对反应机理及内在规律进行了探讨。分别从纳米材料的制备、形成机理、性质表征和应用研究等方面进行论述，内容涉及CuO纳米叶、不同结构Cu纳米材料、Ni催化还原Cu纳米材料、多足状Cu₂O微晶及SiO₂保护Cu纳米粒子等材料的制备、反应机理及催化性能研究。首先，我们以CuSO₄和NaOH为原料，在简单的室温水溶液条件下由Cu（OH）₂制备出了CuO纳米叶。根据转化机理Cu（OH）₂→Cu（OH）42–→CuO中OH^–的作用方式可知整个转化反应的速度受NaOH的用量或浓度影响较大，调节合适的NaOH用量和浓度，可以使反应在30⁶0min内转化完全。通过向体系中引入表面活性剂可以有效地改善样品的形貌及分散性，得到稳定悬浮性很好的CuO纳米叶。然后，我们以室温下水溶液中制备的CuO纳米叶为起始物，还原制备出了不同结构的Cu纳米材料。反应速度较快时，CuO纳米叶被迅速还原到Cu₂O并在几分钟内还原到Cu纳米粒子，Cu纳米粒子发生聚集生长并随着生长时间的延长形成花状Cu；通过适当调节还原剂的用量和反应时间，经Cu₂O八面体形貌遗传机理可以得到八面体笼状Cu。TG–DTA分析表明八面体笼状Cu具有相对较好的热稳定性。将纳米Cu组装成电化学无酶传感器用于葡萄糖检测，具有响应快速、稳定，选择性好，抗干扰能力强等优点，花状Cu的检测灵敏度优于八面体笼状Cu。我们还对油酸钠（SOA）在室温合成CuO纳米叶过程中的作用方式进行了考察研究。SOA对Cu（OH）₂向CuO的转化具有抑制作用，且当体系中OA–含量足够多时，会导致CuO纳米叶顶端分叉并分裂为1D棒状产物。以SOA修饰的CuO为起始物还原制备Cu时，其抑制作用仍然存在，通过向体系中引入少量Ni2+可以催化还原反应快速进行。TG–DTA分析显示，与无Ni催化的八面体笼状Cu相比，加Ni催化制备的八面体笼状Cu具有更好的稳定性。SOA修饰的CuO和Cu纳米材料组装成的电化学无酶传感器对葡萄糖检测均有很好的响应效果，检测灵敏度分别为：CuO：26.6μAmmol^-1L，Cu：39.04μA mmol^–1L。另外，我们还利用NaH₂PO₂在不同环境中的还原性差别，分别在碱性条件和酸性条件下还原制备出了多足状Cu₂O微晶和Cu纳米粒子。在碱性条件下，从Cu（OH）42–出发制备出了多足状的Cu₂O晶体，随着CuSO₄浓度的增大，在相同反应时间内所得样品的形貌呈现出连续变化的过程：八面体、面心带洞八面体、分裂八面体、六足花和箭头。利用NaH₂PO₂在酸性环境中发生键价结构转变的机理，适当调节溶液pH=5⁶制备出了Cu纳米粒子，通过后步SiO₂包覆处理对其进行抗氧化保护，TG–DTA分析表明随着SiO₂引入量的增大，样品的抗氧化性能得到明显提高。且SiO₂的引入可以抑制Cu纳米粒子聚集，改善样品的分散性。最后，我们利用低温液相法制备出来的CuO纳米叶、Cu纳米材料及多足状Cu₂O微晶催化AP热分解，考察了不同催化剂添加量、催化次数对AP热分解性能的影响。用CuO进行催化时，可将AP的主要分解温度由472.7oC降低到300oC，热分解的单位焓变提高(CuO用量为1%时，AP热分解单位焓变由20.33Jg^–1s^–1提高到了36.32J g^–1s^–1)，且表现出很好的重复可利用性。纳米Cu由于其更加活泼的催化性能，添加量为0.05%时就有很好的催化效果，纳米Cu用量为2%时，AP的主要分解温度降低了150oC，热分解单位焓变达到79.07J g^–1s^–1，约为纯AP的3.9倍，实现了AP在低温区的快速高效分解放热。综上所述，本论文的工作很好地涵盖了铜系金属及其氧化物纳米材料的合成、表征和应用性能研究。整个论文工作所选用的材料合成方法简单易行，所制得的材料在电化学无酶传感器及催化高氯酸铵热分解领域具有广阔的应用前景。更多还原

【Abstract】 In this paper, the copper and copper oxide nanomaterials were synthesized at lowtemperature in aqueous solution. Reaction mechanism and properties characterizationswere also conducted. Investigations are based on several aspects including synthesis,mechanism, properties and applications. The content mainly involve preparation,reaction mechanism and properties study of CuO nanoleaves, Cu flowers, Cuoctahedral cages, Ni-catalyzed Cu nanocrystals, multi-rods Cu₂O crystals andSiO₂-protected Cu nanoparticles.Firstly, CuO nanoleaves were successfully synthesized from Cu（OH）₂precipitation at room temperature in aqueous solution. According to thetransformation mechanism, Cu（OH）₂→Cu（OH）₄^2–→CuO, amounts orconcentrations of NaOH in the system plays an important role in controlling thereaction velocity. Transformation can be accomplished in15³0min by adjustingNaOH solution in a appropriate amount and concentration. Morphologies anddispersibility of samples were improved by introducing surfactants into the system.The obtained CuO nanoleaves were stably suspended in ethanol.Then, CuO nanoleaves synthesized at room temperature were reduced to Cunanostructures by adding reducing agent into the system. Cu nanocrystals withdifferent structures were obtained by adjusting the reducing agent quantity andreduction time. When the reducing reaction took place fast, CuO nanoleaves werereduced to Cu₂O and then to Cu nanoparticles. Cu particles aggregated togetherforming Cu spheres, and Cu flowers were finally obtained with further growth.Accurate controlling the reducing agent quantity and reduction time, Cu octahedralcages were obtained through the morphology heredity from Cu₂O octahedra.TG–DTA analysis illuminated that Cu octahedral cages had higher stability than Cuflowers. The as-prepared Cu nanostructures were used to construct non-enzymaticglucose sensor, which has a well-defined, stable and fast amperometric response.We also studied the behavior of oleic sodium （SOA） in preparation of CuO nanoleaces at room temperature. It was found that adding SOA could not only slowdown the transformation velocity from Cu（OH）₂to CuO, but also effect themorphology of CuO nanoleaves. When the amount of OA–is sufficient in the system,top of the CuO nanoleaf would be branched and separated into nanorod finally. Theinhibited effect of SOA also existed when reducing the SOA-decorated CuOnanoleaves to Cu nanocrystals. By introducing Ni²⁺into the system, reducing reactionwas catalyzed and could accomplish in a short time. TG–DTA results implied that theNi-assisted Cu octahedral cages had higher stability than Cu octahedral cages withoutNi.Otherwise, reducing behavior of NaH2PO₂was studied under different conditions.Multi-rods Cu₂O crystals were obtained from Cu（OH）₄^2–under alkaline condition.Increasing the concentration of CuSO₄, morphologies of Cu₂O crystals change asoctahedron, divided octahedron, six-rods and arrow. According to the bond-valencestructure transformation of NaH₂PO₂in acidic condition, Cu nanoparticles weresuccessfully synthesized by adjusting the solution pH to5⁶. SiO₂were introducedto protect the Cu nanoparticles from oxidation. TG–DTA characteration informed thatas the SiO₂content increased, the stability of Cu nanopaticles was improved.Moreover, introducing SiO₂could also improve the morphologies and dispersibility ofCu nanoparticles.Finally, the as-prepared CuO nanoleaves, Cu nanoparticles and multi-rods Cu₂Ocrystals were used as catalysts for the thermal decomposition of AP. The hightemperature of AP decomposition decreased from472.7oC to308oC when CuO1%was used, and the unit enthalpy of AP decomposition increased. Moreover, CuOnanoleaves were recyclable for AP decomposition. Thank to its higher catalyticactivity, nano-Cu showed good catalytic effect for AP decomposition. The maindecomposition temperature of AP was decreased to319oC when nano-Cu2%wasused. The unit enthalpy was improved to79.07J g^–1s^–1, which is about3.9times ofpure AP. Fast heat release of AP decomposition with high exothermic is realized atlow temperature under Cu nanoparticles’ catalysis.In summary, our research invoved the synthesis, characteration ang propertiesstudy of copper and copper oxide nanomaterials. The preparation method is facil andsimple, the as-prepared samples have widely use in non-enzymatic glucose sensor anddecomposition of AP.更多还原