The core–shell nature of nanostructured WO3 photoelectrodes demonstrated in spectroelectrochemical studies

Defects in Porous Networks of WO3 Particle Aggregates

“…For mesoporous semiconductor electrodes, reversible capacitive currents are associated with the population and depopulation of electrochemically active states near the conduction band edge . For thin films of comparable composition and morphology, the accumulated charge is proportional to the electrochemically active surface area . The capacitive currents on WO 3 (450) and WO 3 (550) electrodes differ only slightly, in line with the above conclusion based on SEM results that the particle morphology and thus the electrochemically active surface area of the two thin films do not change significantly upon sintering at T <550 °C.…”

“…The spectral range between 1000 and 750 cm −1 features lattice vibrations and thus contains information on structural changes associated with the electrochemical doping of the oxide (Figure ) . After prolonged polarization at −0.20 V, bands at 900, 860, 815, and 790 cm −1 appear in the IR difference spectrum (Figure a).…”

“…Depending on the amount of injected charge, this process involves major structural changes of the material, leading, ultimately, to the formation of tungsten bronze (i.e. H x WO 3 ) in a near‐surface layer …”

Electrochemically synthesized tungsten trioxide nanostructures for photoelectrochemical water splitting: Influence of heat treatment on physicochemical properties, photocurrent densities and electron shuttling

“…It is a steady-state method used to measure the current response to the application of an AC voltage as a function of frequency. EIS has previously been used to study the charge-transport kinetics in PEC-assisted water splitting processes [25][26][27]. We have performed EIS measurements on the nanostructured WO 3 thin films annealed at temperatures ranging from 100°C to 600°C.…”

Quasi-1D hyperbranched WO3 nanostructures for low-voltage photoelectrochemical water splitting

“…This path includes experimenting with new materials, as well as modifying already known materials through doping [6][7][8][9][10] in order to change their inherent opto-electrical properties. Mesoporous materials [16][17][18][19][20] with high surface area and internal scattering are characterized by higher optical density than their compact counterparts and high chemical reactivity thanks to extended interfaces with the electrolytic solution. Mesoporous materials [16][17][18][19][20] with high surface area and internal scattering are characterized by higher optical density than their compact counterparts and high chemical reactivity thanks to extended interfaces with the electrolytic solution.…”