Digital 3D Local Growth of Iron Oxide Micro- and Nanorods by Laser-Induced Photothermal Chemical Liquid Growth

Abstract

We introduce laser growth of iron oxide micro and nanorods by the photothermal chemical liquid growth method at low temperature, ambient pressure, and solution environment. By focusing a 532 nm continuous-wave laser on a Pt substrate immersed in iron oxide precursor solution, vertically aligned iron oxide micro- and nanorods are successfully fabricated with the length up to >100 μm, whereas the length can be easily controlled by changing the laser power or the illumination time. It is also found that the direction of the laser ray determines the growth direction of the iron oxide micro- and nanorods, which is the property that makes this process suitable for the fabrication of complex 3D structures as confirmed by making an iron oxide junction and kinked iron oxide microrod structure. Moreover, the resultant iron oxide microrod is applied as a microtemplate for the growth of nanostructure to show that this process can be further integrated to other 3D structures to achieve trans-scale hierarchical structures.

Laser Irradiation of Metal Oxide Films and Nanostructures: Applications and Advances

“…Copyright 2015, American Chemical Society. i,j) Reproduced with permission . Copyright 2014, American Chemical Society.…”

“…Figure g shows the obvious difference in the sensitivity of a typical UV sensor with and without ZnO NWs under UV‐light exposure. The LIHG process has further been employed to grow heterogeneous MO NWs (ZnO and TiO 2 ) on the same substrate (Figure h), trans‐scale hierarchical structures of ZnO NWs on Fe 2 O 3 microrods (Figure i,j), and growth of ZnO NRs decorated with Ag NPs . The fully digital laser‐assisted growth approach discussed above is also promising for nanosensor integration, which requires the highly selective growth of functional nanostructures.…”

“…The large temperature gradients and high diffusion rates during laser processing lead to epitaxial growth rates that are orders of magnitude larger and effective heating times much shorter than that for conventional thermal treatment . Furthermore, the laser irradiation technique has been utilized for processing of complex nanostructures, such as site‐specific growth of nanowires (NWs) (e.g., ZnO, TiO 2 ) and nanorods (NRs) (e.g., Fe 2 O 3 , Ag/ZnO), spatial patterning of nanocrystals (e.g., ZnO) and NWs (e.g., Al 2 O 3 ), fabrication of nanosheets (e.g., Fe 2 O 3 ) and clustered nanostructures (e.g., Ag–ZnS@ZnO, Ag/WO 3− x ), production of oxide nanoparticles (NPs) by laser ablation in liquid (e.g., CuO, MnO x , Y 3 Fe 5 O 12 , Ag/TiO 2 , Y 2 O 3 :Eu 3+ , Gd 2 O 3 :Eu 3+ , Y 3 Al 5 O 12 :Ce 3+ (YAG:Ce), Fe@Fe 2 O 3 , or Fe 3 O 4 ), in situ formation of nanocomposites (e.g., Co 3 O 4 , MoO 2 , and Fe 3 O 4 particles embedded in graphene, ZnO particles embedded in poly(methyl methacrylate)), selective patterning of hybrid electrodes (e.g., Ni/NiO), direct scribing of fine structures (e.g., ITO), and direct writing of microdevices (e.g., TiO 2 , Cu/Cu 2 O).…”

Facile synthesis of anisotropic single crystalline α-Fe2O3 nanoplates and their facet-dependent catalytic performance

“…For instance, high catalytic activity was observed for Pt nanocubes compared to commercial Pt/C due to the exposure of high index facets (211) and (411). Hematite (α-Fe 2 O 3 ), which is most stable iron oxide, with various morphologies such as sphere, 13,14 rod, 15 cube, [16][17][18] nanoribbon, 19 elliptic, 20 cantaloupe, 21 sea-urchin like 22 flower, 23,24 plate, 25 nanodisc, 26 nanoring 27 and polyhedron, [28][29][30] has been explored for several applications, for example solar cells, 31,32 lithium ion batteries, 33 water splitting, 32,34 gas sensors, 35,36 drug delivery, 37 water treatment, 38 magnetic devices, 39 and so on. 11 In addition, enhanced photocatalytic reduction activity was reported for anatase TiO 2 which predominantly exposed (001) and (101) facets.…”

Laser–Material Interactions for Flexible Applications

“…For instance, the fabrication of transparent conductors, crystalline oxide TFTs, and ferroelectric thin films on flexible substrates have been successfully demonstrated using laser–material interaction or laser processing. Absorbed laser energy in the targeted material/substrate allows the formulation of novel materials with enhanced material properties through laser‐induced reactions such as photo‐oxidation, reduction, hydrothermal growth, or phase separation of nanomaterials . Especially, the hydrothermal growth methods by laser heat source enable the local growth on any arbitrary surface, even on a complicated structure as a three‐dimensional structure.…”