Preparation, Characterization and Photocatalytic Activity of N doped TiO2

T.P, Dhanya T.P Dhanya

doi:10.9790/5736-0432733

Cited by 6 publications

(9 citation statements)

References 20 publications

(27 reference statements)

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“…On the other hand, an increase in particle diameter (lower specific area), formation of TiN (non‐transparent), and the number of oxygen vacancies (electron–hole recombination sites) are related to high N doping photocatalysts . In any case, this subject is controversial: some authors claim that N doping decreases particle size while electron–hole recombination is prevented by oxygen vacancies (photoluminescence intensity minimization) An increase in BET surface area as N percentage reaches a determined value has been reported, values above the optimum lead to a BET area decrease …”

Section: Resultsmentioning

confidence: 99%

Photocatalytic ozonation of pyridine‐based herbicides by N‐doped titania

Solís

Rivas

Gimeno

et al. 2015

J of Chemical Tech & Biotech

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BACKGROUND A mixture of three pyridine herbicides in water (clopyralid, triclopyr and picloram) has been treated with photocatalytic processes, involving oxygen or ozone. Nitrogen doped and undoped titania were used in the process. Toxicity evolution during photocatalytic ozonation was monitored considering BOD, Daphnia parvula and fitotoxicity trials. RESULTS N doped titania with an optimized photoactivity was tested in photocatalytic ozonation, leading to nearly 95% mineralization in 180 min. This catalyst was characterized by SEM, TEM, XRD and XPS techniques (13.5 nm crystal size, anatase phase, 1% N, and formation of O‐Ti‐N linkage). No loss of photocatalytic activity was observed after five consecutive runs. Although no toxicity from the parent compounds was observed, this parameter increased during the early stages of the oxidation process. When parent compounds were totally degraded and dechlorination was completed, toxicity decayed again to negligible values. CONCLUSION N doping improves bare titania photoactivity through an optimum amount of N. Photocatalysis/ozone showed better behavior than photocatalysis/oxygen in herbicide removal and mineralization, and no significant loss of activity was observed after five runs. Toxicity initially increased due to toxic byproducts formation; however, it decreased after their abatement. © 2015 Society of Chemical Industry

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Section: Resultsmentioning

confidence: 99%

Photocatalytic ozonation of pyridine‐based herbicides by N‐doped titania

Solís

Rivas

Gimeno

et al. 2015

J of Chemical Tech & Biotech

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“…Therefore, electron can also be stimulated when irradiated with visible light and moves between nanotubes and titania. It should be noted that extending the absorption edge of TiO 2 to the visible region is considered as one of the main objectives to have active photocatalyst in the visible light region [7,10,14,15,17].…”

Section: Characterization Of the Optimized Samplementioning

confidence: 99%

“…In thiophenic compound removal, advanced oxidation processes, which begin with oxygen radicals, may take 3 forms: chemical, bio-, and photooxidation [8][9][10]. The great advantage of photocatalytic removal compared to the previous two processes is that it occurs under ambient temperature and pressure, so after a reasonable time, an acceptable amount of pollutant is eliminated [6,10].…”

Section: Introductionmentioning

confidence: 99%

“…Recombination of electrons and generated holes is considered as the most important factor limiting semiconductors' photocatalytic power [5,9,10]. In this case, the stimulated electron returns to the valence band without entering into reaction with the adsorbed component on the surface of the semiconductor and releases its energy as light or heat [9,11].…”

Section: Introductionmentioning

confidence: 99%

“…There are various methods for increasing photocatalytic strength and reducing recombination rate. Some methods increase photocatalytic power by improving structural properties, such as increasing the surface area and porosity, while some others increase the potential to remove contaminants by chemical modification and addition of another component to semiconductor structure [5,7,[9][10][11]. One way to increase efficiency is to perform a photocatalytic process using carbon nanotubes and combine it with semiconductor [5,9,[14][15][16][17][18][19].…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Modeling and Optimization of BT and DBT Photooxidation over Multiwall Carbon Nanotube-Titania Composite by Response Surface Methodology

Barmala

Behnood

2018

International Journal of Photoenergy

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This study investigates optimization of benzothiophene (BT) and dibenzothiophene (DBT) removal via a photocatalytic process by using central composite design (CCD) method. Temperature, pH, and p-25 to MWCNT ratio (g/g) in the composite structure are considered as design factors. According to the results, temperature has the greatest impact on removal rate. In optimal condition, after being exposed to UV lamps (9 W) for 20 min, 59.8% of the solutions' BT was removed, while DBT was completely removed. Although the generated structure band gap is 3.4, but due to the presence of MWCNTs in the structure, it is capable of absorbing visible light, and this leads to complete removal of DBT and 42% removal of BT under visible light radiation (in similar circumstances). Kinetics analysis of thiophene's reaction showed that, in the presence of visible light, first order removal rate constants for DBT and BT are 7.98 and 0.953 1/h, respectively.

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