Reactive and morphological trends on porous anodic TiO2 substrates obtained at different annealing temperatures

Syrek, Karolina; Sennik-Kubiec, Aneta; Rodríguez‐López, Joaquín; Rutkowska, Małgorzata; Żmudzki, Paweł; Hnida-Gut, Katarzyna E.; Grudzień, Joanna; Chmielarz, Lucjan; Sulka, Grzegorz D.

doi:10.1016/j.ijhydene.2019.11.213

Cited by 17 publications

(25 citation statements)

References 64 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Slight differences in the estimated values may result from the porosity and non-homogeneity of the tested surfaces. This effect is often observed for crystalline porous materials [35,40]. The donor densities were also calculated for all tested materials, and the obtained values are collected in Table 3.…”

Section: Resultsmentioning

confidence: 89%

“…As can be seen in Figure 5, planes that can be assigned to the metallic substrate ((200) and (211)) and monoclinic tungsten trioxide ((020), (200), (120), (112), (022), (220), (222), (040), (400), and (042)) can be clearly distinguished in the XRD patterns of anodic oxides. Semiconducting properties of the obtained anodic tungsten oxide layers were studied using Mott-Schottky analysis (1) [35][36][37]:…”

Section: Resultsmentioning

confidence: 99%

“…where Csc is the capacitance of the space charge region (F cm −2 ), Nd is donor density (cm −3 ), ε is the dielectric constant of porous tungsten oxide (20) [36,38], ε0 is permittivity of free space (8.85 × 10 −14 F cm −1 ), q is the electron charge (1.602 × 10 −19 C), E is the applied potential (V), Efb is a flat band potential (V), T is the absolute temperature (K), and k is the Boltzmann constant (1.38 × 10 −23 J K −1 ). The Semiconducting properties of the obtained anodic tungsten oxide layers were studied using Mott-Schottky analysis (1) [35][36][37]:…”

Section: Resultsmentioning

confidence: 99%

“…Semiconducting properties of the obtained anodic tungsten oxide layers were studied using Mott-Schottky analysis (1) [ 35 , 36 , 37 ]:

where C sc is the capacitance of the space charge region (F cm −2 ), N d is donor density (cm −3 ), ε is the dielectric constant of porous tungsten oxide (20) [ 36 , 38 ], ε 0 is permittivity of free space (8.85 × 10 −14 F cm −1 ), q is the electron charge (1.602 × 10 −19 C), E is the applied potential (V), E fb is a flat band potential (V), T is the absolute temperature (K), and k is the Boltzmann constant (1.38 × 10 −23 J K −1 ). The Mott−Schottky analysis allows probing the semiconductor/electrolyte interface by capacitance-voltage measurements, and estimates the donor density and flat band potential of semiconducting material.…”

Section: Resultsmentioning

confidence: 99%

See 3 more Smart Citations

Improving Photoelectrochemical Properties of Anodic WO3 Layers by Optimizing Electrosynthesis Conditions

2020

Self Cite

View full text Add to dashboard Cite

Although anodic tungsten oxide has attracted increasing attention in recent years, there is still a lack of detailed studies on the photoelectrochemical (PEC) properties of such kind of materials grown in different electrolytes under various sets of conditions. In addition, the morphology of photoanode is not a single factor responsible for its PEC performance. Therefore, the attempt was to correlate different anodizing conditions (especially electrolyte composition) with the surface morphology, oxide thickness, semiconducting, and photoelectrochemical properties of anodized oxide layers. As expected, the surface morphology of WO3 depends strongly on anodizing conditions. Annealing of as-synthesized tungsten oxide layers at 500 °C for 2 h leads to obtaining a monoclinic WO3 phase in all cases. From the Mott-Schottky analysis, it has been confirmed that all as prepared anodic oxide samples are n-type semiconductors. Band gap energy values estimated from incident photon−to−current efficiency (IPCE) measurements neither differ significantly for as−synthesized WO3 layers nor depend on anodizing conditions such as electrolyte composition, time and applied potential. Although the estimated band gaps are similar, photoelectrochemical properties are different because of many different reasons, including the layer morphology (homogeneity, porosity, pore size, active surface area), oxide layer thickness, and semiconducting properties of the material, which depend on the electrolyte composition used for anodization.

show abstract

Section: Resultsmentioning

confidence: 89%

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

“…Semiconducting properties of the obtained anodic tungsten oxide layers were studied using Mott-Schottky analysis (1) [ 35 , 36 , 37 ]:

Section: Resultsmentioning

confidence: 99%

See 2 more Smart Citations

Improving Photoelectrochemical Properties of Anodic WO3 Layers by Optimizing Electrosynthesis Conditions

2020

Self Cite

View full text Add to dashboard Cite

show abstract

“…It is worth highlighting that the comprehensive characterization of semiconducting properties (such as band gap energy, flat band potential, charge density, and conduction band potential) is an important aspect of the study of photoanode materials. What is more, it should be emphasized that those properties (e.g., donor density and flat band potential [ 19 ]) of the anodic TiO 2 substrate itself are affected by different oxide thicknesses, pore sizes, wall thicknesses [ 20 ], and post-heat-treatment conditions [ 21 , 22 ] due to changes in the oxide morphology, crystallinity, and composition [ 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 ]. For this reason, a particular emphasis should be put on the systematic study of the semiconducting properties of Fe 2 O 3 –TiO 2 materials.…”

Section: Introductionmentioning

confidence: 99%

Photoelectrochemical Performance of Nanotubular Fe2O3–TiO2 Electrodes under Solar Radiation

et al. 2022

Self Cite

View full text Add to dashboard Cite

Fe2O3–TiO2 materials were obtained by the cathodic electrochemical deposition of Fe on anodic TiO2 at different deposition times (5–180 s), followed by annealing at 450 °C. The effect of the hematite content on the photoelectrochemical (PEC) activity of the received materials was studied. The synthesized electrodes were characterized by field emission scanning electron microscopy (FE-SEM), energy dispersive spectroscopy (EDS), X-ray diffraction (XRD), Raman spectroscopy, diffuse reflectance spectroscopy (DRS), Mott–Schottky analysis, and PEC measurements. It was shown that the amount of deposited iron (ca. 0.5 at.%–30 at.%) and, consequently, hematite after a final annealing increased with the extension of deposition time and directly affected the semiconducting properties of the hybrid material. It was observed that the flat band potential shifted towards more positive values, facilitating photoelectrochemical water oxidation. In addition, the optical band gap decreased from 3.18 eV to 2.77 eV, which resulted in enhanced PEC visible-light response. Moreover, the Fe2O3–TiO2 electrodes were sensitive to the addition of glucose, which indicates that such materials may be considered as potential PEC sensors for the detection of glucose.

show abstract

Band gap engineering of nanotubular Fe2O3-TiO2 photoanodes by wet impregnation

Sołtys-Mróz

Syrek

Pierzchała

et al. 2020

Applied Surface Science

View full text Add to dashboard Cite

Reactive and morphological trends on porous anodic TiO2 substrates obtained at different annealing temperatures

Cited by 17 publications

References 64 publications

Improving Photoelectrochemical Properties of Anodic WO3 Layers by Optimizing Electrosynthesis Conditions

Improving Photoelectrochemical Properties of Anodic WO3 Layers by Optimizing Electrosynthesis Conditions

Photoelectrochemical Performance of Nanotubular Fe2O3–TiO2 Electrodes under Solar Radiation

Band gap engineering of nanotubular Fe2O3-TiO2 photoanodes by wet impregnation

Contact Info

Product

Resources

About