Hierarchical Oriented Anatase TiO2 Nanostructure arrays on Flexible Substrate for Efficient Dye-sensitized Solar Cells

Abstract

The vertically oriented anatase single crystalline TiO2 nanostructure arrays (TNAs) consisting of TiO2 truncated octahedrons with exposed {001} facets or hierarchical TiO2 nanotubes (HNTs) consisting of numerous nanocrystals on Ti-foil substrate were synthesized via a two-step hydrothermal growth process. The first step hydrothermal reaction of Ti foil and NaOH leads to the formation of H-titanate nanowire arrays, which is further performed the second step hydrothermal reaction to obtain the oriented anatase single crystalline TiO2 nanostructures such as TiO2 nanoarrays assembly with truncated octahedral TiO2 nanocrystals in the presence of NH4F aqueous or hierarchical TiO2 nanotubes with walls made of nanocrystals in the presence of pure water. Subsequently, these TiO2 nanostructures were utilized to produce dye-sensitized solar cells in a backside illumination pattern, yielding a significant high power conversion efficiency (PCE) of 4.66% (TNAs, JSC = 7.46 mA cm−2, VOC = 839 mV, FF = 0.75) and 5.84% (HNTs, JSC = 10.02 mA cm−2, VOC = 817 mV, FF = 0.72), respectively.

Anatase TiO2 mesocrystals with exposed (001) surface for enhanced photocatalytic decomposition capability toward gaseous styrene

“…Moreover, hydrofluoric acid (HF), a dangerous and environmentally detrimental fluorine source, was frequently used in water-based method because HF plays a critical role in formation of exposed {0 0 1} crystal facets [9]. In order to avoid directly using HF, less harmful fluorine sources such as NH 4 F [15,16], TiF 4 [17,18] and ion liquid containing F [19,20] have been then applied in the fabrication of anatase TiO 2 with exposed {0 0 1} facets in water-involved system. Recently, solvothermal method without addition of H 2 O and HF has been an environmental benign approach to controllably grow anatase TiO 2 crystals with exposed {0 0 1} facets [7].…”

Maximizing omnidirectional light harvesting in metal oxide hyperbranched array architectures

“…More recently, the synthesis of well-organized nanostructures such as the organized mesoporous TiO 2 films prepared using graft copolymer nanostructural polymers [6][7][8][9][10] , and some wellaligned one-dimensional (1D) nanostructures, such as nanowires (NWs), nanotubes, nanorods (NRs) and nanofibres, have stimulated intense research interest and attention owing to their potential advantages of rapid charge transport and efficient charge collection by means of providing short electrical pathways for rapid transfer and thus efficient collection of photo-generated carriers throughout the device [11][12][13][14][15][16][17] . It is well known that the key to high solar-to-electric efficiency is surface area.…”

Syntheses and Applications of Titanium Compound Nanofiber Thin Films

“…thin films on titanium metal surfaces by the reaction of titanium metal in an alkaline aqueous solution, and their conversions into nanostructured titanium dioxide thin film [5,[8][9][10][11]. For example, known applications of composites that utilize the superior electrical conductivity of titanium include electrode materials of dye-sensitized solar cells [12], lithium-ion batteries [13], and sodium-ion batteries [14]. Superior electrical conductivity can be secured by using titanium dioxide or titanate with one-dimensional morphologies, such as nanorods, nanotubes, or nanofibers, while electrodes can be prepared without using binders or conducting agents.…”