Large Area Honeycomb-Structured TiO₂ Film for Photocatalytic Water Splitting

Abstract

We demonstrate the fabrication of a large area 2-dimensional (2-D) binary colloidal assembly of polymeric microspheres (μ-spheres) and TiO2 nanoparticles (NPs). TiO2 NPs near the surface of poly­(methyl methacrylate) (PMMA) μ-spheres in aqueous dispersion exerted attractive depletion force between μ-spheres, allowing the formation of the well-ordered composite monolayer having hexagonal close-packed (hcp) structure on the air–water interface which can be transferred to a solid substrate. Subsequent drying and calcination of the composite film resulted in an “egg plate” structured TiO2 film. When additional TiO2 dispersion was spin-coated on the composite monolayer, an interesting honeycomb structured TiO2 film was obtained. After the photodeposition of Au NPs on the honeycomb structured TiO2 film for an enhanced absorptivity of visible light, the film was tested as a photoelectrode for photocatalytic water splitting. Owing to the large surface area of the well-ordered 2-D porous structure, a photoanode with the honeycomb-structured TiO2 thin film exhibited a 67 times higher photocurrent density (PCD) for water splitting compared to the value from nanoporous TiO2 photoanode with the same thickness.

Shape Deformation in Ion Beam Irradiated Colloidal Monolayers: An AFM Investigation

“…Interfacial self-assembly has been used for the fabrication of colloidal monolayers due to its effectiveness and versatility for the assembly of very diverse materials and has been widely investigated theoretically [1,3,[45][46][47][48][49][50][51][52][53][54][55][56]. In particular, air/water interface self-assembly based on surface confinement and water discharge has been adopted [45].…”

Toward Atomic-Scale Inorganic Double Helices via Carbon Nanotube Matrices—Induction of Chirality to Carbon Nanotubes

“…SnIP, as a 1.8 eV semiconductor, was successfully used to fabricate composites in inorganic matrices and 2D materials. Electrochemically etched nanotubular TiO 2 membranes, being a prominent photocatalyst, − and layered C 3 N 4 were used as effective matrices to accommodate SnIP. Heterojunction formation occurred in such hybrid systems resulting in effective water splitting catalysts. − Motivated by the heterostructure formation we therefore decided to evaluate if the formation of SnIP@CNT heterostructures might be possible.…”

“…TiO2 was used as a matrix to create effective photochemical materials for various catalytic applications. [23][24][25][26][27][28][29] Here, in some cases nano-sized arrays are formed by electrochemical etching, which are modified by semiconductors afterwards. The nanotube approach was first adopted by Üzer et al to SnIP to form an effective photocatalytic hybrid 30,31 for water splitting.…”

Superhydrophobic Surface and Lubricant‐Infused Surface: Implementing Two Extremes on Electrodeposited NiTiO2 Surface to Drive Optimal Wettability Regimes for Droplets’ Multifunctional Behaviors

“…[8] TiO 2 nanocomposites have many advantages to be widely used in many applications due to their unique chemical, physical, and electro-optical characteristics: including solar cells, electronic devices, paint pigments, water splitting, photocatalysis, spintronics, optics, and medicines. [9][10][11][12][13] It is well known that the electrical and mechanical properties of TiO 2 films depend on their surface morphology, composition, total surface area, and crystallinity. In addition, TiO 2 can also be used as a protective coating material to improve the corrosion resistance of metals, such as nickel (Ni), and composite coatings containing TiO 2 nanoparticles (NPs) could exhibit the exceptional characteristics, such as corrosion resistance and higher hardness.…”