Reaction mechanism of photocatalytic decomposition of 2,4-dinitrophenol in aqueous suspension of TiO2 fine particles

Rumi Chand, Fumihide Shiraishi

Research output: Contribution to journalArticle

19 Citations (Scopus)

Abstract

The aims of the present study are to propose a mathematical model for photocatalytic decomposition of 2,4-dinitrophenol (DNP) in an aqueous suspension of TiO2 fine particles and to elucidate the reaction mechanism using this model. The following three facts were found experimentally: (i) although a reactant usually decomposes more quickly at higher concentrations, DNP decomposed more slowly; (ii) photocatalytic reaction usually obeys firstorder kinetics when the initial reactant concentration is approximately 10gm-3, although the DNP concentration decreased almost linearly according to zeroorder kinetics; and (iii) the resulting NO3 ion significantly decreased the DNP decomposition rate. A mathematical model constructed by taking into consideration these findings can successfully explain the experimental data, implying that DNP molecules are highly aggregated in the neighborhood of TiO2 particle. The DNP aggregate layer suppresses the generation of active radicals, which leads to reactant inhibition. The photocatalytic decomposition of DNP supplied from the aggregate layer of highly concentrated DNP around TiO2 is observed by zero-order kinetics.

Original languageEnglish
Pages (from-to)369-376
Number of pages8
JournalChemical Engineering Journal
Volume233
DOIs
Publication statusPublished - Nov 1 2013

Fingerprint

Dinitrophenols
2,4-Dinitrophenol
Suspensions
decomposition
Decomposition
kinetics
Kinetics
Mathematical models
Molecules
ion
Ions
particle

All Science Journal Classification (ASJC) codes

  • Chemical Engineering(all)
  • Chemistry(all)
  • Industrial and Manufacturing Engineering
  • Environmental Chemistry

Cite this

@article{d64b6d23b0f14a0b8e264a7b2946f190,
title = "Reaction mechanism of photocatalytic decomposition of 2,4-dinitrophenol in aqueous suspension of TiO2 fine particles",
abstract = "The aims of the present study are to propose a mathematical model for photocatalytic decomposition of 2,4-dinitrophenol (DNP) in an aqueous suspension of TiO2 fine particles and to elucidate the reaction mechanism using this model. The following three facts were found experimentally: (i) although a reactant usually decomposes more quickly at higher concentrations, DNP decomposed more slowly; (ii) photocatalytic reaction usually obeys firstorder kinetics when the initial reactant concentration is approximately 10gm-3, although the DNP concentration decreased almost linearly according to zeroorder kinetics; and (iii) the resulting NO3 ion significantly decreased the DNP decomposition rate. A mathematical model constructed by taking into consideration these findings can successfully explain the experimental data, implying that DNP molecules are highly aggregated in the neighborhood of TiO2 particle. The DNP aggregate layer suppresses the generation of active radicals, which leads to reactant inhibition. The photocatalytic decomposition of DNP supplied from the aggregate layer of highly concentrated DNP around TiO2 is observed by zero-order kinetics.",
author = "Rumi Chand and Fumihide Shiraishi",
year = "2013",
month = "11",
day = "1",
doi = "10.1016/j.cej.2013.08.069",
language = "English",
volume = "233",
pages = "369--376",
journal = "Chemical Engineering Journal",
issn = "1385-8947",
publisher = "Elsevier",

}

TY - JOUR

T1 - Reaction mechanism of photocatalytic decomposition of 2,4-dinitrophenol in aqueous suspension of TiO2 fine particles

AU - Chand, Rumi

AU - Shiraishi, Fumihide

PY - 2013/11/1

Y1 - 2013/11/1

N2 - The aims of the present study are to propose a mathematical model for photocatalytic decomposition of 2,4-dinitrophenol (DNP) in an aqueous suspension of TiO2 fine particles and to elucidate the reaction mechanism using this model. The following three facts were found experimentally: (i) although a reactant usually decomposes more quickly at higher concentrations, DNP decomposed more slowly; (ii) photocatalytic reaction usually obeys firstorder kinetics when the initial reactant concentration is approximately 10gm-3, although the DNP concentration decreased almost linearly according to zeroorder kinetics; and (iii) the resulting NO3 ion significantly decreased the DNP decomposition rate. A mathematical model constructed by taking into consideration these findings can successfully explain the experimental data, implying that DNP molecules are highly aggregated in the neighborhood of TiO2 particle. The DNP aggregate layer suppresses the generation of active radicals, which leads to reactant inhibition. The photocatalytic decomposition of DNP supplied from the aggregate layer of highly concentrated DNP around TiO2 is observed by zero-order kinetics.

AB - The aims of the present study are to propose a mathematical model for photocatalytic decomposition of 2,4-dinitrophenol (DNP) in an aqueous suspension of TiO2 fine particles and to elucidate the reaction mechanism using this model. The following three facts were found experimentally: (i) although a reactant usually decomposes more quickly at higher concentrations, DNP decomposed more slowly; (ii) photocatalytic reaction usually obeys firstorder kinetics when the initial reactant concentration is approximately 10gm-3, although the DNP concentration decreased almost linearly according to zeroorder kinetics; and (iii) the resulting NO3 ion significantly decreased the DNP decomposition rate. A mathematical model constructed by taking into consideration these findings can successfully explain the experimental data, implying that DNP molecules are highly aggregated in the neighborhood of TiO2 particle. The DNP aggregate layer suppresses the generation of active radicals, which leads to reactant inhibition. The photocatalytic decomposition of DNP supplied from the aggregate layer of highly concentrated DNP around TiO2 is observed by zero-order kinetics.

UR - http://www.scopus.com/inward/record.url?scp=84884180707&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84884180707&partnerID=8YFLogxK

U2 - 10.1016/j.cej.2013.08.069

DO - 10.1016/j.cej.2013.08.069

M3 - Article

AN - SCOPUS:84884180707

VL - 233

SP - 369

EP - 376

JO - Chemical Engineering Journal

JF - Chemical Engineering Journal

SN - 1385-8947

ER -