Hetero- and homogeneous three-dimensional hierarchical tungsten oxide nanostructures by hot-wire chemical vapor deposition

Rational Design of Branched WO3 Nanorods Decorated with BiVO4 Nanoparticles by All-Solution Processing for Efficient Photoelectrochemical Water Splitting

“…The construction of BiVO 4 /WO 3 heterostructure was reported as one of the most effective ways to improve the electron–hole separation and transport, because of its type II band alignment at the interfaces. ,, For the heterostructure, WO 3 will provide conductive pathway for charge transfer, whereas BiVO 4 could absorb broad visible spectrum to facilitate light harvesting. , Hence, the structural configuration of WO 3 would play an essential role in the PEC performance of BiVO 4 /WO 3 composites. Among various WO 3 nanoarchitectures, the single-crystalline one-dimensional WO 3 nanorod is regarded as a promising candidate which can provide an enlarged surface area to maximize active sites and direct conduction pathways for generated charges with reduced charge recombination. , By integrating abundant branches on nanorods, photocatalytic activity can be further enhanced owing to its maximized redox-active sites and increased light-trapping characteristics, as revealed by previous efforts. − In recent years, various synthetic routes have been employed to prepare branched hierarchical WO 3 nanorods, including thermal evaporation of W powders, hot electrospinning with polystyrene-colloid-template, and hot-wire chemical vapor deposition . Although these methods could provide relatively acceptable control of hierarchical morphology, the demand of high thermal energy and/or vacuum environment hampers the cost-effective synthesis of large photoelectrochemical cells, which are critically important for real applications.…”

“…43 −46 In recent years, various synthetic routes have been employed to prepare branched hierarchical WO 3 nanorods, including thermal evaporation of W powders, 47 hot electrospinning with polystyrene-colloid-template, 48 and hot-wire chemical vapor deposition. 49 Although these methods could provide relatively acceptable control of hierarchical morphology, the demand of high thermal energy and/or vacuum environment hampers the cost-effective synthesis of large photoelectrochemical cells, which are critically important for real applications. In stark contrast, two-step hydrothermal reaction can be a promising and viable alternative that can synthesize highly crystalline branched nanostructures with facile, cost-effective, and scalable manner.…”

Hot metal wires as sinks and sources of B atoms

“…On the other hand, there have been several reports on utilizing such chemical reactions of filament materials. For example, Schropp and coworkers took advantage of the oxidation of W and succeeded in fabricating amorphous as well as nanostructured tungsten oxide films [13,14]. Carburization of the wire surfaces is also effective for suppressing Si accommodation [9].…”

Branched Tungsten Oxide Nanorod Arrays Synthesized by Controlled Phase Transformation for Solar Water Oxidation

“…Recently, synthesis of hierarchical branched WO 3 have been reported, in which three‐dimensional tungsten oxide (WO 3− x ) nanostructures from a hot W filament were prepared on the heated substrate using a hot‐wire chemical vapor method with a flow of ambient air and hydrogen at subatmospheric pressure and novel 3 D hierarchical WO 3 hollow dendrites, spheres, and dumbbells synthesized by calcining acid‐treated PbWO 4 and SrWO 4 . Template‐assisted electrospinning was also used to deposit hierarchical porous WO 3 nanofibers .…”