Hydrogen activity tuning of Pt-doped WO3 photonic crystal

A photonic crystal responsive to H₂ has been fabricated by replicating polystyrene colloidal crystal template with WO₃ sol-gel, followed with subsequent Pt sputter-deposition. Under H₂ stimulation, the reflection peak of the photonic crystal rapidly shifted to short wavelength and its intensity declined accordingly. The reflection peak returned to its original location after exposure to oxygen atmosphere. The Pt-WO₃ photonic crystal also exhibited excellent, tunable optical performance with high sensitivity to hydrogen in the range of 100% to 0.1%.     

SnO2反opal光子晶体的制备及表征

以PS opal膜为模板制得了SnO2反opal光子晶体膜。采用浸渍提拉法和Sol-LPD法对PS opal模板进行填充,450℃焙烧除去PS模板得到SnO2反opal光子晶体。SEM和UV-Vis透射表征显示,两种填充方式都能得到三维有序的SnO2反opal光子晶体;以相同的PS opal膜为模板,通过Sol-LPD填充法得到的SnO2反opal膜的禁带位置向长波移动(以浸渍提拉法制得的光子晶体的禁带位置为基准)。这证实Sol-LPD填充法比浸渍提拉法有更高的填充率。通过Sol-LPD填充法还能够制备具有多重禁带的SnO2反opal异质复合膜。     

B2O3对氟化物乳浊玻璃微结构和性能的影响

以钠钙硅系统玻璃为基体,以氟硅酸钠作为乳浊剂,利用传统熔融法制备乳浊玻璃。采用SEM、XRD和透过率测试分别对其微结构、析晶及乳浊性能进行表征,分析讨论了B2O3对乳浊玻璃微结构和性能的影响。研究结果表明:添加适量的B2O3可有效控制玻璃的析晶尺寸和析晶密度,有利于制备出微结构均匀、乳浊程度可控的乳浊玻璃,其主晶相为CaF2。B2O3的引入可降低玻璃的析晶倾向,且随着B2O3引入量的增加乳浊玻璃的晶粒密度、尺寸相应减小,乳浊程度下降。     

Concept of Templated Lattices of Semiconductor Nanostructures

Design of ordered nanostructured solids by template approach is reviewed. A variety of lattices of semiconductor nanoparticles was formed in the synthetic opal. The impact of an ensemble periodicity upon the electron and photon transport in opal-based lattices has been demonstrated. The conductivity of such lattices is the product of individual transmission characteristics of nanostructures, whereas specific collective properties can be seen as the small additives. In contrast, the photon transport shows strong collective behaviour and the photonic energy band structure is formed in addition to the electronic band structure. If the optical range photonic bandgap is tuned in the resonance with the fundamental electronic gap of a composite, their interference leads to the conjugated equilibrium state of the system.     

Effect of the combination of inverse opal photon superficial areaic crystal and heterojunction on active free radicals and its effect on the mechanism of photocatalytic removal of organic pollutants

For the inverse opal photocatalyst, hydraulic pressure and other problems caused by the ordered structure of the inverse opal photocatalyst make it difficult for the pollutants to enter the structure quickly and effectively, so the effective control of its structure has become an urgent problem to be solved. Here, multi-heterojunction inverse opal structure catalyst with multi-level branched pore structure is prepared by the sol-gel method. The special three-dimensional dendritic porous structure solves the problem that a pollutant solution is difficult to effectively enter a skeleton with the traditional ordered inverse opal photocatalyst. This structure can also lead to the nanocrystallization of TZS powders, thus promoting the formation of the intermediate product ZrTiO₄ and optimizing the heterogeneous interface in the TiO₂–ZrO₂ heterojunction, thereby successfully constructing the multi-heterostructure and effectively improving the redox ability. Furthermore, by adjusting the loading amount of TZS, the matching of the heterojunction and the inverse opal structure can be effectively controlled, the matching of the photonic band gap and the forbidden bandwidth can be effectively adjusted, and the degradation efficiency is greatly improved. This study provides a new idea for effective collaboration between multi-heterogeneous interfaces and 3D branch fractal structures.     

Solution processed thin films of non-aggregated TiO2 nanoparticles prepared by mild solvothermal treatment

In this report, non-aggregated anatase TiO₂ nanoparticles were synthesized by mild solvothermal process in 1-butanol. By varying solvothermal reaction temperature and time, TiO₂ particle size was controlled from 5.3 to 9.0 nm, while maintaining pure anatase phase and optical clearance in the concentrated dispersion (5 wt%). Spin coating of TiO₂ dispersions resulted in transparent thin films with thickness controllability, and it was confirmed that the mild solvothermal reaction significantly increased the refractive index of the thin films without post-thermal treatment. In addition to the fabrication of low-temperature processed thin films, the inverse opal TiO₂ films were also fabricated by the colloidal templating method followed by thermal calcination to reveal the improved volume shrinkage of the mesoporous TiO₂ films.     

在乙醇介质中制备SiO2光子晶体及其表征

以乙醇为介质,用二氧化硅球沉降法制备有序性较好的人工欧泊(Opal),并对二氧化硅球排布进行了显微形貌及透射谱表征.结果显示二氧化硅微球有序堆积,其结构为类面心立方晶型,与目前的理论研究结果符合得很好.     

新型乳白石英玻璃材料生产线的研制

论述了新型乳白石英玻璃材料生产工艺基础,工艺改进原理,生产线改进措施和效果.     

Significant reduction of upconversion emission in CaTiO3: Yb, Er inverse opals

Inverse opal photonic crystals of Yb³⁺, Er³⁺ co-doped CaTiO₃ (CaTiO₃: Yb, Er) were prepared using self-assembled polystyrene templates combined with the infiltration of sol-gel precursor. The influence of the photonic band gap on upconversion emission of Er³⁺ has been investigated in the CaTiO₃: Yb, Er inverse opals. Significant reduction of the upconversion emission was detected if the photonic band-gap overlaps with the Er³⁺ ions emission band.