PHOTOELECTROCHEMICAL ANALYSIS OF TITANIUM DIOXIDE BY USING OXALIC ACID AS A SACRIFICIAL DONOR

Photoelectrochemical (PEC) water splitting is a very promising green method to produce solar fuel. Titanium dioxide (TiO2) has been widely used as photocatalyst for this type of reaction. Improving the performance of TiO2 for PEC water splitting has been ongoing and addition of sacrificial donor especially from waste is an attractive option to achieve this. Oxalic acid is one component in organic waste stream that can be used as sacrificial donor. The TiO2 thin films has been fabricated by coating TiO2 paste on Fluorine Tin oxide (FTO) glass surface. The morphology of the TiO2 thin films were porous and rough with uniform particles size with crystallite size of about 20 nm and dominant anatase peak. The TiO2 photoelectrode undergo PEC testing to measure its photolectroactivity by using oxalic acid as a sacrificial donor in two different type of electrolytes which are distilled water and sodium sulfate (NA2SO4) aqueous solution. The photocurrent produced without addition of oxalic acid is much lower than with the acid. The saturation photocurrent for aqueous NA2SO4 solution and water electrolyte is 0.1 mA/cm2 and negligible respectively. While the photocurrent for addition of oxalic acid in NA2SO4 aqueous solution is 0.5 mA/cm2 and the photocurrent for oxalic acid in water only is 0.9 mA/cm2, which is almost double compared to in NA2SO4 and tenfold in water only. The highest photocurrent produced by TiO2 photoelectrode is by addition of oxalic acid in aqueous (H2O) electrolyte.

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Use of Nanopillars-TiO2 Thin Films in the Photocatalytic Degradation of Bromophenol Blue from Aqueous Solution

Science & Technology Journal ◽

10.22232/stj.2018.06.01.03 ◽

2018 ◽

Vol 6 (1) ◽

pp. 22-30

Author(s):

C. Lalhriatpuia ◽

◽

Thanhming liana ◽

K. Vanlaldinpuia

Keyword(s):

Thin Films ◽

Aqueous Solution ◽

Photocatalytic Activity ◽

Photocatalytic Degradation ◽

Batch Reactor ◽

Bromophenol Blue ◽

Tio2 Thin Films ◽

Initial Concentration ◽

Bet Specific Surface Area ◽

Interfering Ions

The photocatalytic activity of Nanopillars-TiO2 thin films was assessed in the degradation of Bromophenol blue (BPB) dye from aqueous solution under batch reactor operations. The thin films were characterized by the XRD, SEM and AFM analytical methods. BET specific surface area and pore sizes were also obtained. The XRD data showed anatase phase of TiO2 particles with average particle size of 25.4 and 21.9 nm, for S1 and S2 catalysts respectively. The SEM and AFM images indicated the catalyst composed with Nanosized pillars of TiO2, evenly distributed on the surface of the substrate. The average height of the pillars was found to be 180 and 40 nm respectively for the S1 and S2 catalyst. The BET specific surface area and pore sizes of S1 and S2 catalyst were found to be 5.217 and 1.420 m2/g and 7.77 and 4.16 nm respectively. The photocatalytic degradation of BPB using the UV light was studied at wide range of physico-chemical parametric studies to determine the mechanism of degradation as well as the practical applicability of the technique. The batch reactor operations were conducted at varied pH (pH 4.0 to 10.0), BPB initial concentration (1.0 to 20.0 mg/L) and presence of several interfering ions, i.e., cadmium nitrate, copper sulfate, zinc chloride, sodium chloride, sodium nitrate, sodium nitrite, glycine, oxalic acid and EDTA in the photocatalytic degradation of BPB. The maximum percent removal of BPB was observed at pH 6.0 and a low initial concentration of the pollutant highly favours the photocatalytic degradation using thin films. The presence of several interfering ions suppressed the photocatalytic activity of thin films to some extent. The time dependence photocatalytic degradation of BPB was demonstrated with the pseudo-first-order rate kinetics. Study was further extended with total organic carbon measurement using the TOC (Total Organic Carbon) analysis. This demonstrated an apparent mineralization of BPB from aqueous solutions.

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Deposition behaviors and patterning of TiO2 thin films on different SAMs surfaces from titanium sulfate aqueous solution

Colloids and Surfaces A Physicochemical and Engineering Aspects ◽

10.1016/j.colsurfa.2008.04.032 ◽

2008 ◽

Vol 324 (1-3) ◽

pp. 137-142 ◽

Cited By ~ 6

Author(s):

Shan Liang ◽

Miao Chen ◽

Qunji Xue

Keyword(s):

Thin Films ◽

Aqueous Solution ◽

Tio2 Thin Films ◽

Titanium Sulfate

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Effect of nitrogen doped titanium dioxide (N-TiO2) thin films by jet nebulizer spray technique suitable for photoconductive study

Journal of Materials Science Materials in Electronics ◽

10.1007/s10854-015-2871-0 ◽

2015 ◽

Vol 26 (6) ◽

pp. 3573-3582 ◽

Cited By ~ 21

Author(s):

C. Ravidhas ◽

B. Anitha ◽

A. Moses Ezhil Raj ◽

K. Ravichandran ◽

T. C. Sabari Girisun ◽

...

Keyword(s):

Thin Films ◽

Titanium Dioxide ◽

Tio2 Thin Films ◽

Nitrogen Doped ◽

Spray Technique ◽

Jet Nebulizer ◽

Doped Titanium Dioxide ◽

Nebulizer Spray ◽

Nitrogen Doped Titanium Dioxide

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Synthesis, Properties, and Applications of Special Substrates Coated by Titanium Dioxide Nanostructured Thin Films via Sol-Gel Process

Advanced Methods and Applications in Chemoinformatics ◽

10.4018/978-1-60960-860-6.ch012 ◽

2011 ◽

pp. 246-279

Author(s):

Hamid Dadvar ◽

Farhad E. Ghodsi ◽

Saeed Dadvar

Keyword(s):

Thin Films ◽

Titanium Dioxide ◽

Sol Gel ◽

Precursor Solution ◽

Tio2 Thin Films ◽

Simple Method ◽

Nanostructured Thin Films ◽

Precursor Material ◽

Synthesis Properties ◽

Antibacterial Surfaces

In this chapter, the sol-gel made titanium dioxide nanostructured thin films deposited on special substrates such as glasses, mica, steels, textiles, fibers, and other organic/inorganic substrates were reviewed. Through this review, several distinctive properties such as optical, electrical, photocatalytic, morphological, and mechanical properties of TiO2 nanostructured thin films were described. Also, a wide range of practical application of TiO2 nanostructured thin films such as dye-sensitised solar cells, optical coatings, humidity and gas sensors, selfcleaning, dielectric, and antibacterial surfaces were discussed in details. Dip and spin coating techniques were demonstrated as suitable methods for deposition of thin films. It has been shown that properties of such films can be affected by type of coating technique, stabilizer, precursor material, solvents, pH and viscosity of precursor solution, aging, and etc. Finally, Successive Interference Fringes Method (SIFM) was presented as a simple method for the determination of optical constants and thickness of TiO2 thin films from single transmission measurements.

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