A preferential precursor for photocatalytically active titanium dioxide thin films: Titanium bis-ammonium lactato dihydroxide as an alternative to titanium tetra iso-propoxide

Anderson, Ann-Louise; Binions, Russell

doi:10.1016/j.poly.2016.07.020

Cited by 15 publications

(4 citation statements)

References 43 publications

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“…Photocatalyst activity indicator inks, in particular the Rz paii , have proved popular for assessing the photocatalytic activity of new materials. Table provides some examples of the reported uses of the Rz ink. − One of the more innovative uses of the Rz ink comes from the group of Parkin at University College London, in their studies of photocatalyst films generated by CVD . These workers used combinatorial atmospheric chemical vapor deposition to generate a graduating substitutional/interstitial N-doped anatase TiO 2 thin film on a 50 mm × 225 mm × 3.2 mm standard float glass plate.…”

Section: Applications Of Paiismentioning

confidence: 99%

Photocatalyst Activity Indicator Inks, paiis, for Assessing Self-Cleaning Films

2021

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Conspectus Semiconductor photocatalysis, usually referred to simply as “photocatalysis” is a relatively new and yet still a growing subject area, which has led to a billion-dollar industry, mostly focused on the production of self-cleaning architectural materials, such as glass, paint, tiles, fabric, plastic and concrete. All such materials need to be tested for activity, but for self-cleaning activity there are few appropriate tests; the International Standards Organization, ISO, for example, have at present only two, both of which are slow and largely ineffective for most commercial self-cleaning products. The photocatalyst community in general, and the manufacturers of self-cleaning photocatalytic products in particular, need a fast, simple, easy to use method of assessing photocatalytic activity, which can also be used to demonstrate the efficacy of self-cleaning materials in minutes, i.e., a quantitative and qualitative test. In this account we highlight our work on photocatalyst activity indicator inks, i.e., paiis, which address the above need and work via the photocatalyzed reduction of a dye, usually resazurin, Rz, and concomitant oxidation of an organic, almost always glycerol. We describe our early work on the Rz ink which showed that, when used to assess photocatalytic film activity, the measured rate of change in color is directly proportional to the measured rate of photocatalyzed mineralization of the popular test pollutants stearic acid, SA, and methylene blue, MB, by O2. We show that photography, coupled with digital color analysis, is just as effective and much less expensive at measuring the rate of color change exhibited by paiis as UV/vis spectrophotometry and also can be used for testing clear and opaque photocatalytic samples in the laboratory and in situ. We demonstrate how the Rz ink can be used to assess the activities of both UV and Visible light absorbing photocatalytic powders and thin films, and highly colored samples. The kinetics of the photocatalyzed color change are outlined, which are zero-order with respect to the initial dye concentration and ink film thickness. We describe the basic features of the recently published Rz-ink based ISO for the qualitative and quantitative assessment of activity of nonporous, flat photocatalytic films. Although the Rz ink is best suited for assessing films of moderate photocatalytic activity, such as found in most examples of commercial self-cleaning glass, other paiis are described which can be used to assess commercial products that have much higher or lower, activities, such as photocatalytic paints and tiles, respectively. Examples of how paiis have been used in research over recent years are given, a highlight of which is their use in the search for a suitable, visible light absorbing photocatalyst alternative to TiO2, that can compete with the latter in terms of cost, durability, stability, and activity. Finally, the novel, photocatalyst-based inks that have been developed as a consequence of the works on paiis are discussed briefly, inclu...

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Section: Applications Of Paiismentioning

confidence: 99%

Photocatalyst Activity Indicator Inks, paiis, for Assessing Self-Cleaning Films

2021

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“…Photocatalytic reactions are advanced reduction and oxidation process widely used in water and cleansing systems, self-cleaning of surfaces, hydrogen production, and photoelectrochemical reactions [ 1 , 2 , 3 ]. TiO 2, a heterogeneous photocatalyst, has been demonstrated to effectively degrade organic pollutants in the environment into products such as CO 2 and H 2 O.…”

Section: Introductionmentioning

confidence: 99%

Preparation of TiO2/WO3/C/N Composite Nanofibers by Electrospinning Using Precursors Soluble in Water and Their Photocatalytic Activity in Visible Light

Odhiambo

Mustafa

et al. 2021

Nanomaterials

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Extending the absorption range of TiO2 nanofibers to visible light is a great improvement of the photocatalytic property of TiO2. In this study, TiO2/WO3/C/N nanofibers were prepared by electrospinning using precursors soluble in water then annealing in argon. Titanium(IV) bis(ammonium lactato)dihydroxide (TiBALDH) and ammonium metatungstate (AMT) were used as the precursor for TiO2 and WO3 respectively. Different volume ratios of the precursors were added to a solution of PVP before electrospinning. The fibers were studied by XPS, SEM-EDX, TEM, FTIR, XRD, Raman spectroscopy and UV–VIS diffuse reflectance spectroscopy (DRS). The photocatalytic degradation of methylene blue by the fibers in visible light was investigated. The fibers had anatase TiO2 and monoclinic WO3. Based on UV–VIS DRS and Kubelka-Munk function the fibers could absorb visible light. Moreover, 100% TiBALDH had an indirect band gap of 2.9 eV, and the band gap decreased with increase in AMT, i.e., for 0% TiBALDH, band gap was 2.4 eV. The fibers degraded methylene blue dye in visible light, and 90% TiBALDH had the highest photocatalytic activity, i.e., it degraded 40% of the dye after 240 min.

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“…To prepare titanium dioxide, the most common precursor generally employed is titanium isopropoxide (Ti(OCH(CH 3 ) 2 ) 4 , TIPP); the main problem associated with its use, however, is its stability. TIPP tends to hydrolyse when in contact with moisture, which may lead to the formation of titanium dioxide crystals without a proper control of their shape and size [8]. Acetyl acetone (a di-ketone with formula C 5 H 8 O 2 , acac) has been reported to stabilise the titanium (IV) ion in solution by forming an acetyl acetonate complex [9]; indeed, acac-stabilised TIPP was employed to prepare TiO 2 both in form of crystals/powder and thin films [10,11].…”

Section: Introductionmentioning

confidence: 99%

Nanostructured titanium dioxide coatings prepared by Aerosol Assisted Chemical Vapour Deposition (AACVD)

Taylor

Pullar

Parkin

et al. 2020

Journal of Photochemistry and Photobiology A: Chemistry

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Titanium dioxide is a compound of great interest, due to its functional properties; one of its most important uses is as a photocatalyst. TiO 2 coatings can be deposited using different techniques. Aerosol Assisted Chemical Vapour Deposition (AACVD) is particularly interesting, as high temperature or pressure are not necessary to generate the gaseous precursors. Furthermore, by carefully choosing the deposition conditions (i.e. deposition temperature, solvent), it is possible to obtain deposits with different morphology and, consequently, different functional properties. In this paper we present the synthesis of titanium dioxide coatings with AACVD using complexes between titanium isopropoxide (TIPP) and acetyl acetone (acac) as precursors. Deposition experiments were performed using different ratios of TIPP to acac, to assess the effect on the composition of the coatings, their morphology and photocatalytic activity. Results showed that the use of acac led to nanostructured titanium dioxide (nanoparticles of about 10−25 nm diameter). Raman analysis showed the presence of both anatase and rutile phases. XPS analysis indicated the presence of residual carbonaceous species in the coatings; despite this, they displayed photocatalytic properties similar or superior to AACVD films without carbon. Photocatalytic tests, performed measuring the Formal Quantum Efficiency (FQE) and the Formal Quantum Yield (FQY) in the degradation of resazurin, showed that a acac:TIPP ratio equal to 1 led to the material with the highest performance, as the FQE value was about three times higher than that for the coating prepared with TIPP alone. Overall the complexes between TIPP and acac are promising precursors for the AACVD technique, leading to nanostructured coatings with enhanced performance.

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A preferential precursor for photocatalytically active titanium dioxide thin films: Titanium bis-ammonium lactato dihydroxide as an alternative to titanium tetra iso-propoxide

Cited by 15 publications

References 43 publications

Photocatalyst Activity Indicator Inks, paiis, for Assessing Self-Cleaning Films

Photocatalyst Activity Indicator Inks, paiis, for Assessing Self-Cleaning Films

Preparation of TiO2/WO3/C/N Composite Nanofibers by Electrospinning Using Precursors Soluble in Water and Their Photocatalytic Activity in Visible Light

Nanostructured titanium dioxide coatings prepared by Aerosol Assisted Chemical Vapour Deposition (AACVD)

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