Dye-sensitized solar cells based on flower-shaped α-Fe2O3 as a photoanode and reduced graphene oxide–polyaniline composite as a counter electrode

Influence of anodization time on the surface modifications on α-Fe2O3photoanode upon anodization

“…Although a significant improvement has been made on conductivity of a-Fe 2 O 3 by elemental doping 5,[22][23][24][25] and nanostructuring, [26][27][28][29] the influence of the anodizing process on the photocatalytic performance of a-Fe 2 O 3 photoanode in a PEC cell has not been extensively studied. However, a detailed research on the surface molecular structure of anodized a-Fe 2 O 3 photoanode has been conducted and reported transformation of Fe 21 to Fe 31 states at the surface upon subject to anodizing conditions and the findings were attributed to filling of oxygen vacancies due to increasing oxygen content at the surface.…”

Temperature controlled shape evolution of iron oxide nanostructures in HMTA media

“…Iron oxide nanoower structures are approximately 10 times larger in size than hollow iron oxide nanospheres, thereby presenting signicant challenges in obtaining both structures using the same precursor and reactant ratios. 4,6,7,10,13,14 Mild alkali media such as hexamethylenetetramine (HMTA) has previously been used in the synthesis of porous ZnO hollow spheres, 18 ower-like NiO 19 and CuO 20 assemblies, highlighting HMTA as a more suitable media for the synthesis of unique morphologies in the same synthetic route, relative to urea and aqueous ammonia. 4,6,7,17 Hence, in this work we highlight the benets of using HMTA as the key reactant in the synthesis of multiple iron oxide (alkoxide) nanostructures.…”

“…4,6,7,10,13,14 Mild alkali media such as hexamethylenetetramine (HMTA) has previously been used in the synthesis of porous ZnO hollow spheres, 18 ower-like NiO 19 and CuO 20 assemblies, highlighting HMTA as a more suitable media for the synthesis of unique morphologies in the same synthetic route, relative to urea and aqueous ammonia. 4,6,7,17 Hence, in this work we highlight the benets of using HMTA as the key reactant in the synthesis of multiple iron oxide (alkoxide) nanostructures. Iron alkoxide nanosheets, iron alkoxide nanoowers (assembled by nanosheets), mesoporous Fe 3 O 4 hollow nanospheres, Fe 3 O 4 hollow nanospheres and solid Fe 3 O 4 spheres can be obtained in the same experimental system by simply tuning the overall reaction temperature from 160 to 240 C. The resulting structures are characterized by XRD, SEM, TEM and HRTEM and the effect of altering reaction temperatures on subsequent nanostructure morphology is investigated.…”

“…Due to their large specic surface areas, iron oxide nanosheets and ower-like assemblies have been reported as high performance anode materials for lithium-ion batteries and dye-sensitized solar cells. 3,4 In addition mesoporous iron oxide hollow micro/nanospheres have been investigated as vehicles for controlled drug delivery, 5,6 microwave absorption, 7,8 sensing platforms 9 and waste water treatment. 10,11 Synthesis of iron oxide nanomaterials typically follows one of two synthetic pathways resulting in different nanostructure morphologies, namely nanosheets and ower-like assemblies 3,4,7,13,14,17 and hollow nanospheres and solid nanospheres.…”

“…3,4 In addition mesoporous iron oxide hollow micro/nanospheres have been investigated as vehicles for controlled drug delivery, 5,6 microwave absorption, 7,8 sensing platforms 9 and waste water treatment. 10,11 Synthesis of iron oxide nanomaterials typically follows one of two synthetic pathways resulting in different nanostructure morphologies, namely nanosheets and ower-like assemblies 3,4,7,13,14,17 and hollow nanospheres and solid nanospheres. 2,9,11,15,16 Differing synthetic routes are obtained by adjusting experimental parameters such as type of precursor, nucleator, surfactant and solvent ratios in addition to reaction time and temperature.…”