1,2-Diolates of titanium as suitable precursors for the preparation of photoactive high surface titania

Saadoun, L.; Ayllón, José A.; Jiménez-Becerril, J.; Peral, José; Domènech, Xavier; Rodrı́guez-Clemente, R.

doi:10.1016/s0926-3373(99)00031-4

Cited by 54 publications

(33 citation statements)

References 29 publications

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“…However, TiO 2 -87 presented the highest COD reduction, which made it the best photocatalyst. Such efficiency can be attributed to the lower rutile phase content of the catalyst (Ding, Lu, & Greenfield, 2000;Saadoun et al, 1999) because the reduction of the rutile content is related to the increase of the number of water and hydroxyl groups adsorbed onto the surface, which are crucial for photocatalytic reaction (Saadoun et al, 1999). These results indicate that the use of a catalyst with more than 13% of rutile may be promising for the photocatalytic treatment of vinasse, as it may replace TiO 2 P25 (TiO 2 -87), including in the treatment of other types of industrial effluents.…”

Section: Photocatalytic Degradation Of Vinassementioning

confidence: 99%

Photodegradation of sugarcane vinasse: evaluation of the effect of vinasse pre-treatment and the crystalline phase of TiO2

Souza¹,

Lima

Pezoti

et al. 2016

Acta Sci. Technol.

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ABSTRACT. In this work, the effect of vinasse pre-treatment and anatase content in the photocatalytic degradation of sugarcane vinasse was evaluated. The in nature vinasse was pretreated by coagulation/flocculation using vegetal tannin as coagulant and diluted 1: 2 with deionized water. The photocatalytic tests with in nature, pretreated and diluted vinasse were performed for 48 hours under UV radiation using 1 g of catalyst: TiO 2 Kronos calcined at 300 o C (100% anatase) and 1000 o C (34% anatase) and TiO 2 P25 (87% anatase). The process of coagulation/flocculation removed about 50, 85 and 97% of COD, color and turbidity of in nature vinasse, respectively. The results showed that despite the slight COD decrease of in nature vinasse, its toxicity was significantly reduced after photocatalytic treatment, especially when TiO 2 -34 and TiO 2 -87 were used. This behavior shows that the mixture of anatase and rutile phases showed a positive synergistic effect. Regarding pre-treatment of vinasse, the coagulation/flocculation process was more efficient, promoting the greatest reductions of COD (67%) and toxicity (up to 10 times).Keywords: vinasse, coagulation/flocculation, photocatalysis, toxicity.Fotodegradação da vinhaça: avaliação do efeito do pré-tratamento da vinhaça e da fase cristalina do TiO 2 RESUMO. Neste trabalho, foi avaliado o efeito do pré-tratamento da vinhaça e do teor de anatase na degradação fotocatalítica da vinhaça. A vinhaça in natura foi pré-tratada por coagulação/floculação usando tanino vegetal como coagulante e diluição 1:2 com água deionizada. Os testes fotocatalíticos com a vinhaça in natura, pré-tratada e diluída foram realizados durante 48h sob radiação UV utilizando 1 g de catalisador: TiO 2 Kronos calcinado a 300 o C (100% anatase) e a 1000 o C (34% anatase) e TiO 2 P25 (87% anatase). O processo de coagulação/floculação removeu cerca de 50, 85 e 97% de DQO, cor e turbidez da vinhaça in natura, respectivamente. Os resultados mostraram que apesar da pequena redução de DQO da vinhaça in natura, sua toxicidade foi reduzida significativamente após tratamento fotocatalítico, principalmente quando TiO 2 -34 e TiO 2 -87 foram utilizados. Esse comportamento evidencia que a mistura das fases anatase e rutile apresentou efeito sinérgico positivo. Em relação ao pré-tratamento da vinhaça, o processo de coagulação/floculação se mostrou mais eficiente, promovendo as maiores reduções de DQO (67%) e toxicidade (até 10 vezes).Palavras-chave: vinhaça, coagulação/floculação, fotocatálise, toxicidade.

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Section: Photocatalytic Degradation Of Vinassementioning

confidence: 99%

Photodegradation of sugarcane vinasse: evaluation of the effect of vinasse pre-treatment and the crystalline phase of TiO2

Souza¹,

Lima

Pezoti

et al. 2016

Acta Sci. Technol.

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“…In heterogeneous catalysis, the specific surface area plays an important role in the adsorption process, and a greater specific surface area can lead to more organic molecules being adsorbed [1], but this increase in specific surface area does not always mean an improvement in photoactivity. The literature reports that photocatalysts with a high specific surface area often have a lot of crystalline defects, which can contribute to electronehole recombination and thus poor photoactivity [7,8,65]. Our data suggests that the improved photoactivity is mainly due to the crystallinity, the crystalline structure of the nanoparticles, and the composition of the phases present.…”

Section: Photocatalytic Activitymentioning

confidence: 52%

“…It is well known that the doping of TiO 2 is one of the possible ways to decrease its band gap energy and to modify its band structure, and the presence of the dopant leads to improvements in some photocatalytic properties. Moreover, many factors affect the improvement in photocatalytic activity of TiO 2 such as its crystalline structure [5,6], crystallinity [7,8], the composition of the phases present [9,10], the average crystallite size and specific surface area [11,12], and electronehole pair recombination [13].…”

Section: Introductionmentioning

confidence: 99%

Study of thulium doping effect and enhancement of photocatalytic activity of rutile TiO2 nanoparticles

Santos

Navas

Aguilar

et al. 2015

Materials Chemistry and Physics

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“…The response to material B was weaker than anticipated, based on its comparatively high BET-measured SSA (274 m 2 /g; Table 1). The high SSA of material B may be attributed in part to the presence of nanometer-sized mesopores [37], but it is not known whether these internal surfaces affect processes leading to the avoidance behavior of earthworms. Although TiO 2 SSA appears to be positively related to reactions causing the earthworm avoidance response, more testing with well-characterized mesoporous TiO 2 nanomaterials is required to evaluate the contribution of internal nanomaterial surfaces to avoidance.…”

Section: Discussionmentioning

confidence: 99%

Reproductive and behavioral responses of earthworms exposed to nano-sized titanium dioxide in soil

McShane¹,

Sarrazin²,

Whalen³

et al. 2011

Environmental Toxicology and Chemistry

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Nanometer-sized titanium dioxide (nano-TiO(2) ) is found in a number of commercial products; however, its effects on soil biota are largely unknown. In the present study, earthworms (Eisenia andrei and Eisenia fetida) were exposed to three types of commercially available, uncoated TiO(2) nanomaterials with nominal diameters of 5, 10, and 21 nm. Nanomaterials were characterized for particle size, agglomeration, surface charge, chemical composition, and purity. Standard lethality, reproduction, and avoidance tests, as well as a juvenile growth test, were conducted in artificial soil or field soil amended with nano-TiO(2) by two methods, liquid dispersion and dry powder mixing. All studies included a micrometer-sized TiO(2) control. Exposure to field and artificial soil containing between 200 and 10,000 mg nano-TiO(2) per kilogram of dry soil (mg/kg) had no significant effect (p > 0.05) on juvenile survival and growth, adult earthworm survival, cocoon production, cocoon viability, or total number of juveniles hatched from these cocoons. However, earthworms avoided artificial soils amended with nano-TiO(2) . The lowest concentration at which avoidance was observed was between 1,000 and 5,000 mg nano-TiO(2) per kilogram of soil, depending on the TiO(2) nanomaterial applied. Furthermore, earthworms differentiated between soils amended with 10,000 mg/kg nano-TiO(2) and micrometer-sized TiO(2) . A positive relationship between earthworm avoidance and TiO(2) specific surface area was observed, but the relationship between avoidance and primary particle size was not determined because of the agglomeration and aggregation of nano-TiO(2) materials. Biological mechanisms that may explain earthworm avoidance of nano-TiO(2) are discussed. Results of the present study indicate that earthworms can detect nano-TiO(2) in soil, although exposure has no apparent effect on survival or standard reproductive parameters.

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1,2-Diolates of titanium as suitable precursors for the preparation of photoactive high surface titania

Cited by 54 publications

References 29 publications

<b>Photodegradation of sugarcane vinasse: evaluation of the effect of vinasse pre-treatment and the crystalline phase of TiO<sub>2</sub>

<b>Photodegradation of sugarcane vinasse: evaluation of the effect of vinasse pre-treatment and the crystalline phase of TiO<sub>2</sub>

Study of thulium doping effect and enhancement of photocatalytic activity of rutile TiO2 nanoparticles

Reproductive and behavioral responses of earthworms exposed to nano-sized titanium dioxide in soil

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