2 research outputs found
Formation of Hierarchical Structure Composed of (Co/Ni)Mn-LDH Nanosheets on MWCNT Backbones for Efficient Electrocatalytic Water Oxidation
Active,
stable, and cost-effective electrocatalysts are attractive
alternatives to the noble metal oxides that have been used in water
splitting. The direct nucleation and growth of electrochemically active
LDH materials on chemically modified MWCNTs exhibit considerable electrocatalytic
activity toward oxygen evolution from water oxidation. CoMn-based
and NiMn-based hybrids were synthesized using a facile chemical bath
deposition method and the as-synthesized materials exhibited three-dimensional
hierarchical configurations with tunable Co/Mn and Ni/Mn ratio. Benefiting
from enhanced electrical conductivity with MWCNT backbones and LDH
lamellar structure, the Co<sub>5</sub>Mn-LDH/MWCNT and Ni<sub>5</sub>Mn-LDH/MWCNT could generated a current density of 10 mA cm<sup>–2</sup> at overpotentials of ∼300 and ∼350 mV, respectively,
in 1 M KOH. In addition, the materials also exhibited outstanding
long-term electrocatalytic stability
Enhanced Performance of Photoelectrochemical Water Splitting with ITO@α-Fe<sub>2</sub>O<sub>3</sub> Core–Shell Nanowire Array as Photoanode
Hematite
(α-Fe<sub>2</sub>O<sub>3</sub>) is one of the most
promising candidates for photoelectrodes in photoelectrochemical water
splitting system. However, the low visible light absorption coefficient
and short hole diffusion length of pure α-Fe<sub>2</sub>O<sub>3</sub> limits the performance of α-Fe<sub>2</sub>O<sub>3</sub> photoelectrodes in water splitting. Herein, to overcome these drawbacks,
single-crystalline tin-doped indium oxide (ITO) nanowire core and
α-Fe<sub>2</sub>O<sub>3</sub> nanocrystal shell (ITO@α-Fe<sub>2</sub>O<sub>3</sub>) electrodes were fabricated by covering the
chemical vapor deposited ITO nanowire array with compact thin α-Fe<sub>2</sub>O<sub>3</sub> nanocrystal film using chemical bath deposition
(CBD) method. The <i>J</i>–<i>V</i> curves
and IPCE of ITO@α-Fe<sub>2</sub>O<sub>3</sub> core–shell
nanowire array electrode showed nearly twice as high performance as
those of the α-Fe<sub>2</sub>O<sub>3</sub> on planar Pt-coated
silicon wafers (Pt/Si) and on planar ITO substrates, which was considered
to be attributed to more efficient hole collection and more loading
of α-Fe<sub>2</sub>O<sub>3</sub> nanocrystals in the core–shell
structure than planar structure. Electrochemical impedance spectra
(EIS) characterization demonstrated a low interface resistance between
α-Fe<sub>2</sub>O<sub>3</sub> and ITO nanowire arrays, which
benefits from the well contact between the core and shell. The stability
test indicated that the prepared ITO@α-Fe<sub>2</sub>O<sub>3</sub> core–shell nanowire array electrode was stable under AM1.5
illumination during the test period of 40 000 s