3 research outputs found
Synthesis of CuInS<sub>2</sub> Quantum Dots/In<sub>2</sub>S<sub>3</sub>/ZnO Nanowire Arrays with High Photoelectrochemical Activity
Decoration
of CuInS<sub>2</sub> (CIS) quantum dots (QDs) on ZnO
nanowires (NWs) with an interlayer of In<sub>2</sub>S<sub>3</sub> as
photoelectrode has been successfully fabricated on FTO via the simple
solution routes for photoelectrochemical (PEC) application. Scanning
electron microscopy, transmission electron microscopy, and X-ray diffraction
are utilized to systematically analyze the morphology and structure
of the CIS QD/In<sub>2</sub>S<sub>3</sub>/ZnO NWs heterostructure.
The composition of this multilayer heterostructure and the removal
of QD ligands by a thermal process are confirmed by X-ray photoelectron
spectra. In comparison with CIS QDs/ZnO NWs, the CIS QD/In<sub>2</sub>S<sub>3</sub>/ZnO heterostructural photoelectrode displays an efficient
charge separation and carrier transport path for photocurrent up to
2.4 mA·cm<sup>–2</sup> that is competitive with other
Cd- and Pb-free QD-based materials. In addition, Mott–Schottky
analysis demonstrates the negative shift of the flat band in the CIS
QD/In<sub>2</sub>S<sub>3</sub>/ZnO, which benefits the early onset
potential. Significantly, this hierarchical photoelectrode shows the
improvement the absorption and conversion of solar light in the visible
region obtained using a pristine ZnO structure. Our research paves
the way for exploring lead-free and lead-free sulfide materials in
the new category of solar applications
β‑SnWO<sub>4</sub> Photocatalyst with Controlled Morphological Transition of Cubes to Spikecubes
A distinct morphology of β-SnWO<sub>4</sub> with hierarchically
multiarmed architecture and overall hexahedral symmetry – entitled
as spikecube – is fabricated for the first time via a polyol-mediated
synthesis. The growth of the β-SnWO<sub>4</sub> spikecubes is
investigated and attributed to thermodynamic and kinetic control.
In a sequential reaction, crystalline cubes of β-SnWO<sub>4</sub> enclosed by {100} facets grow in a first Ostwald ripening-based
step. A kinetically controlled growth process to spikecubes follows
under formation of multiarmed spikes on the facets of the cubic seeds.
Such a growth process differs significantly from the literature concerning
highly branched crystals. The synergistic effect of morphological
modification (i.e., introducing more surface reaction sites) and textural
alteration (i.e., incorporation of the <i>p</i>-block Sn<sup>2+</sup> into simple tungsten oxide to reframe its band structure)
leads to an enhanced photocatalytic activity of the β-SnWO<sub>4</sub> spikecubes being 150% higher in comparison to benchmark WO<sub>3</sub> photocatalysts
β‑SnWO<sub>4</sub> Photocatalyst with Controlled Morphological Transition of Cubes to Spikecubes
A distinct morphology of β-SnWO<sub>4</sub> with hierarchically
multiarmed architecture and overall hexahedral symmetry – entitled
as spikecube – is fabricated for the first time via a polyol-mediated
synthesis. The growth of the β-SnWO<sub>4</sub> spikecubes is
investigated and attributed to thermodynamic and kinetic control.
In a sequential reaction, crystalline cubes of β-SnWO<sub>4</sub> enclosed by {100} facets grow in a first Ostwald ripening-based
step. A kinetically controlled growth process to spikecubes follows
under formation of multiarmed spikes on the facets of the cubic seeds.
Such a growth process differs significantly from the literature concerning
highly branched crystals. The synergistic effect of morphological
modification (i.e., introducing more surface reaction sites) and textural
alteration (i.e., incorporation of the <i>p</i>-block Sn<sup>2+</sup> into simple tungsten oxide to reframe its band structure)
leads to an enhanced photocatalytic activity of the β-SnWO<sub>4</sub> spikecubes being 150% higher in comparison to benchmark WO<sub>3</sub> photocatalysts