Comparing potentiostatic and galvanostatic anodization of titanium membranes for hybrid photocatalytic/microfiltration processes

Casado, Cintia; Mesones, Sandra; Adán, Cristina; Marugán, Javier

doi:10.1016/j.apcata.2019.03.024

Cited by 10 publications

(6 citation statements)

References 45 publications

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“…The film's thickness under potentiostatic conditions depends linearly on the applied potential (strength of the applied electric field), and a better-defined porous morphology depending on the electrolyte is obtained under intermediate applied voltage e.g., 50 V (Lai and Sreekantan, 2013;Syrek et al, 2018). On the other hand, galvanostatic anodization may be considered when it is desirable to control the rate of the occurring electrochemical processes (Casado et al, 2019), and may result in increased growth rate of the oxide film (Manovah David et al, 2014). It is known that under galvanostatic conditions the voltage reaches a peak, and the following drop indicates pore formation by field-induced oxide dissolution (Parkhutik and Shershulsky, 1992;Mukherjee et al, 2003).…”

Section: Introductionmentioning

confidence: 99%

Improved Photocatalytic Water Splitting Activity of Highly Porous WO3 Photoanodes by Electrochemical H+ Intercalation

Levinas¹,

Цынцару

Murauskas³

et al. 2021

Front. Chem. Eng.

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WO3 photoanodes are widely used in photoelectrochemical catalysis, but typically the as-synthesized material is annealed before application. It is therefore desirable to explore less energy-intensive treatments. In this study, WO3 films of up to 3.9 μm thickness were obtained by galvanostatic anodization of tungsten foil in a neutral-pH Na2SO4 and NaF electrolyte, also containing a NaH2PO2 additive (to suppress O2 accumulation on the pore walls). Additionally, the WO3 photoanodes were modified by applying a cathodic reduction (H+ intercalation) and anodic activation treatment in-situ. XPS spectra revealed that intercalation modifies WO3 films; the amount of W5+-O and O-vacancy bonds was increased. Furthermore, subsequent activation leads to a decrease of the W5+ signal, but the amount of O-vacancy bonds remains elevated. The as-prepared and reduced (intercalated & activated) films were tested as OER photoanodes in acidic 0.1 M Na2SO4 media, under illumination with a 365 nm wavelength LED. It was observed that thinner films generated larger photocurrents. The peculiarities detected by XPS for reduced films correlate well with their improved photocatalytic activity. Photo-electrochemical impedance and intensity modulated photocurrent spectroscopies were combined with steady-state measurements in order to elucidate the effects of H+ intercalation on photoelectrochemical performance. The reduction results in films with enhanced photoexcited charge carrier generation/separation, improved conductivity, and possibly even suppressed bulk recombination. Thus, the intercalation & activation adopted in this study can be reliably used to improve the overall activity of as-synthesized WO3 photoanodes, and particularly of those that are initially poorly photoactive.

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Section: Introductionmentioning

confidence: 99%

Improved Photocatalytic Water Splitting Activity of Highly Porous WO3 Photoanodes by Electrochemical H+ Intercalation

Levinas¹,

Цынцару

Murauskas³

et al. 2021

Front. Chem. Eng.

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“…On the other hand, in the galvanostatic anodization, voltage varies with current density being constant. [146][147][148] The V-t plot of galvanostatic anodization is presented in Fig- ure 43a. The galvanostatic mode is characterized by the static application of current density constantly which controls the course of the reaction.…”

Section: Conventional Galvanostatic Anodizationmentioning

confidence: 99%

A critical review on the variations in anodization parameters toward microstructural formation of TiO₂ nanotubes

David

Dev

Wilson

et al. 2021

Electrochemical Science Adv

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Over the past couple of decades (2001)(2002)(2003)(2004)(2005)(2006)(2007)(2008)(2009)(2010)(2011)(2012)(2013)(2014)(2015)(2016)(2017)(2018)(2019)(2020), titania (TiO 2 ) nanotubes (NTs) have been prepared by anodization techniques. The architecture of TiO 2 NTs is predominantly dependent on the potential, current density, electrolyte and time, in addition to other few minor factors. This review is about the state-of-the-art formation of TiO 2 NTs involving anodization technique. In fact, the principal motive is to briefly discuss the slight variations involved within the anodization technique in terms of applied potential and/or applied current density and the resultant outcome. An initial overview of the technique is given so as to understand the beauty of the reactions when variations are incorporated. A minute alteration in the conventional anodization technique results in the formation of highly different morphological features. There are about 30 different miniscule modifications in the anodization processes that have been reported, thus, far. The review primarily introduces and outlines the various anodization techniques involved in growing TiO 2 NTs and the consequent variations arising from these introduced variations. This review is a tribute to the bountiful and fruitful researches based on modifying anodization that was conducted in the recently passed bi-decades.

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“…Due to the ability of photocatalysis to work with solar energy, it is considered a promising simultaneous eco-safe water treatment and hydrogen production technology in terms of protecting environmental resources. Photocatalytic technology has been developed over the past decades and studied on environmental application areas, such as water treatment [16][17][18][19][20], air purification [21], disinfection [22][23][24][25], hazardous chemical treatment [20,26,27], hydrogen production [28][29][30][31], environmental remediation [32], CO 2 photoreduction to fuels [33][34][35][36], suitable organic syntheses [37][38][39][40], and renewable energy [41][42][43]. The basic principle of utilizing sunlight energy is the absorption of light and the creation of electron-hole pairs by spatial separation.…”

Section: Introductionmentioning

confidence: 99%

Desalination and Detoxification of Textile Wastewater by Novel Photocatalytic Electrolysis Membrane Reactor for Ecosafe Hydroponic Farming

et al. 2021

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In this study, a novel photoelectrocatalytic membrane (PECM) reactor was tested as an option for the desalination, disinfection, and detoxification of biologically treated textile wastewater (BTTWW), with the aim to reuse it in hydroponic farming. The anionic ion exchange (IEX) process was used before PECM treatment to remove toxic residual dyes. The toxicity evaluation for every effluent was carried out using the Vibrio fischeri, Microtox® test protocol. The disinfection effect of the PECM reactor was studied against E. coli. After PECM treatment, the 78.7% toxicity level of the BTTWW was reduced to 14.6%. However, photocatalytic desalination during treatment was found to be slow (2.5 mg L−1 min−1 at 1 V potential). The reactor demonstrated approximately 52% COD and 63% TOC removal efficiency. The effects of wastewater reuse on hydroponic production were comparatively investigated by following the growth of the lettuce plant. A detrimental effect was observed on the lettuce plant by the reuse of BTTWW, while no negative impact was reported using the PECM treated textile wastewater. In addition, all macro/micronutrient elements in the PECM treated textile wastewater were recovered by hydroponic farming, and the PECM treatment may be an eco-safe wastewater reuse method for crop irrigation.

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Comparing potentiostatic and galvanostatic anodization of titanium membranes for hybrid photocatalytic/microfiltration processes

Cited by 10 publications

References 45 publications

Improved Photocatalytic Water Splitting Activity of Highly Porous WO3 Photoanodes by Electrochemical H+ Intercalation

Improved Photocatalytic Water Splitting Activity of Highly Porous WO3 Photoanodes by Electrochemical H+ Intercalation

A critical review on the variations in anodization parameters toward microstructural formation of TiO₂ nanotubes

Desalination and Detoxification of Textile Wastewater by Novel Photocatalytic Electrolysis Membrane Reactor for Ecosafe Hydroponic Farming

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Comparing potentiostatic and galvanostatic anodization of titanium membranes for hybrid photocatalytic/microfiltration processes

Cited by 10 publications

References 45 publications

Improved Photocatalytic Water Splitting Activity of Highly Porous WO3 Photoanodes by Electrochemical H+ Intercalation

Improved Photocatalytic Water Splitting Activity of Highly Porous WO3 Photoanodes by Electrochemical H+ Intercalation

A critical review on the variations in anodization parameters toward microstructural formation of TiO2 nanotubes

Desalination and Detoxification of Textile Wastewater by Novel Photocatalytic Electrolysis Membrane Reactor for Ecosafe Hydroponic Farming

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A critical review on the variations in anodization parameters toward microstructural formation of TiO₂ nanotubes