Copper and iodine co-modified TiO 2 nanoparticles for improved activity of CO 2 photoreduction with water vapor

Qianyi Zhang, Tingting Gao, Jean Andino, Ying Li

Research output: Contribution to journalArticle

95 Citations (Scopus)

Abstract

Copper and iodine co-modified TiO 2 nanoparticles (Cu-I-TiO 2) were synthesized through a combined hydrothermal and wet-impregnation process. The structures and properties of the catalysts were characterized by XRD, BET, SEM/EDX, XPS, and UV-vis diffuse reflectance spectroscopy. Iodine ions were doped in the TiO 2 lattice by replacing Ti 4+ and, consequently, Ti 3+ was generated to balance the charge. Iodine doping reduced the TiO 2 crystal size and was responsible for visible light absorption. Cu species were found to deposit on the surface of TiO 2 and resulted in a slightly increased particle size. The activity of the Cu-I-TiO 2 catalyst was investigated by the photocatalytic reduction of CO 2 with water vapor, and CO was found to be the major reduction product with trace amounts of CH 4 generated. Under UV-vis irradiation, the activity of the co-modified catalyst (Cu-I-TiO 2) was higher than that of the single ion-modified catalysts (Cu-TiO 2 or I-TiO 2). Under visible light irradiation, the addition of Cu to I-TiO 2 did not lead to significant improvements in CO 2 reduction. Methyl chloride (CH 3Cl) was detected as a reaction product when CuCl 2 was used as the precursor in the synthesis, thus suggesting that methyl radicals are reaction intermediates. When CuCl 2 was used as the Cu precursor, a three-fold increase in CO 2 photoreduction activity was observed, as compared to when Cu(NO 3) 2 was used as the Cu precursor. These differences in activities were probably due to enhanced Cu dispersion and the hole-scavenging effects of the Cl ions. However, the formation of by-products (e.g., CH 3Cl) may be undesirable.

Original languageEnglish (US)
Pages (from-to)257-264
Number of pages8
JournalApplied Catalysis B: Environmental
Volume123-124
DOIs
StatePublished - Jul 23 2012

Fingerprint

Steam
Carbon Monoxide
iodine
Iodine
Water vapor
Copper
water vapor
catalyst
Nanoparticles
copper
Catalysts
Ions
ion
irradiation
Methyl Chloride
Irradiation
methyl chloride
Reaction intermediates
Scavenging
Reaction products

Keywords

  • CO reduction
  • Copper
  • Iodine
  • Photocatalysis
  • Solar energy
  • TiO

ASJC Scopus subject areas

  • Catalysis
  • Process Chemistry and Technology
  • Environmental Science(all)

Cite this

Copper and iodine co-modified TiO 2 nanoparticles for improved activity of CO 2 photoreduction with water vapor. / Zhang, Qianyi; Gao, Tingting; Andino, Jean; Li, Ying.

In: Applied Catalysis B: Environmental, Vol. 123-124, 23.07.2012, p. 257-264.

Research output: Contribution to journalArticle

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