In this study, we prepare pure WO3 inverse opal(IO) film with a thickness of approximately 3 μm by electrodeposition, and an ultra-thin TiO2 layer having a thickness of 2 nm is deposited on WO3 IO film by atomic layer deposition. Both sets of photoelectrochemical properties are evaluated after developing dye-sensitized solar cells(DSSCs). In addition, morphological, crystalline and optical properties of the developed films are evaluated through field-emission scanning electron microscopy(FE-SEM), High-resolution transmission electron microscopy(HR-TEM), X-ray diffraction(XRD) and UV/ visible/infrared spectrophotometry. In particular, pure WO3 IO based DSSCs show low VOC, JSC and fill factor of 0.25 V, 0.89 mA/cm2 and 18.9 %, achieving an efficiency of 0.04 %, whereas the TiO2/WO3 IO based DSSCs exhibit VOC, JSC and fill factor of 0.57 V, 1.18 mA/cm2 and 50.1 %, revealing an overall conversion efficiency of 0.34 %, probably attributable to the high dye adsorption and suppressed charge recombination reaction.

최근 들어 정렬구조의 나노구조체를 이용한 분리막 응용기술이 큰 관심을 받고 있다. 나노구조체 분리막은 낮은 흐름저항을 통해 높은 투습성을 유지하면서도 매우 균일한 기공크기 특성으로 인해 높은 분리선택비를 가질 수 있다는 장점 을 지닌다. 특히 콜로이드 입자의 자기조립체인 오팔상 및 그 역구조인 역오팔상 구조체를 이용한 분리막 기술이 각광을 받 고 있는데, 기공크기를 자유롭게 제어하면서도 내부에 다양한 기능기의 도입이 가능하여 크기선별 분리 뿐 아니라 반응성 분 리막의 응용에까지 폭넓게 적용이 가능하다. 더불어 다양한 멀티스케일 구조화 기술을 이용하여 기존의 분리막 소재에서는 다룰 수 없었던 다양한 형태의 기공 및 채널구조를 도입할 수 있어, 차세대 고부가가치 분리막 소재기술에 있어 큰 활용이 기대된다. 본 기고에서는 다양한 소재를 활용한 역오팔상 구조체 분리막 기술과 더불어 계층구조화를 통한 기능성 분리막의 개발에 대해 총괄적으로 살펴보고 논의하고자 한다.

We report a facile method for preparing KIT-1 mesoporous silicates with two different macroporous structures by dual templating. As a template for macropores, polystyrene (PS) beads are assembled into uniform three dimensional arrays by ice templating, i.e., by growing ice crystals during the freezing process of the particle suspension. Then, the polymeric templates are directly introduced into the precursor-gel solution with cationic surfactants for templating the mesopores, which is followed by hydrothermal crystallization and calcination. Later, by burning out the PS beads and the surfactants, KIT-1 mesoporous silicates with macropores are produced in a powder form. The macroporous structures of the silicates can be controlled by changing the amount of EDTANa4 salt under the same templating conditions using the PS beads and inverse-opal or hollow structures can be obtained. This strategy to prepare mesoporous powders with controllable macrostructures is potentially useful for various applications especially those dealing with bulky molecules such as, catalysis, separation, drug carriers and environmental adsorbents.

Advances made in membrane technology have to do with either enhancing separation efficiency or improving the permeation flux. Enhancing the separation efficiency, however, inevitably led to reducing the flux, and improving the permeation flux resulted in a loss in the separation efficiency. In this presentation, we suggest multiscale porous membranes with inverse-opal structures that allow for high permeation flux without sacrificing separation efficiency. In order to create the multiscale architectured membranes, primary structure of inverse opal having macropores is first prepared. Then, secondary nanostructures are incorporated to elaborately tune the pore size, tortuosity, and interfacial properties. Finally, the constructed multiscale architectures are utilized for water-treatment or removal or organic molecules.