Adsorption-photocatalytic degradation of Acid Red 88 by supported TiO2: Effect of activated carbon support and aqueous anions

Bifen Gao*, Pow Seng Yap, Tuti Mariana Lim, Teik Thye Lim

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

238 Citations (Scopus)

Abstract

TiO2 nanoparticles supported on activated carbons (TiO2/AC) were synthesized for the synergistic removal of Acid Red 88 (AR) via photocatalytic degradation and adsorption. Great enhancement of photocatalytic efficiency was achieved by supporting TiO2 on two ACs, Darco-G60 and Norit SA UF. The surface hydrophilic properties and pore size distribution of ACs have significant influences on TiO2 deposition on the supports, resulting in remarkable different performances of the two TiO2/AC composites in the degradation of AR. TiO2 loaded on Norit SA UF (TiO2/AC-N) had a more dispersed coverage on the AC support but lower AR adsorption capacity due to larger degree of pores blockage by the TiO2 nanoparticles which were also shielded from incident UV. In comparison, TiO2 loaded on Darco-G60 (TiO2/AC-D) showed higher photocatalytic activity and better durability in cyclic reuse. The synergistic adsorption-photocatalysis was observed, and the optimal TiO2-to-AC mass ratio was 80-20 for the highest photocatalytic activity. Inorganic anions exhibited varying impacts on the performance of TiO2/AC. In general, the AC support could greatly abate TiO2 deactivation by inorganic anions. Sulfate promoted the AR degradation over both TiO2/AC-D and TiO2/AC-N while chloride and nitrate exhibited no influence on TiO2/AC-D but positive effect on TiO2/AC-N. Phosphate and bicarbonate could deactivate the TiO2/AC composites but to a less extent compared to their effects on the TiO2 without AC support.

Original languageEnglish
Pages (from-to)1098-1107
Number of pages10
JournalChemical Engineering Journal
Volume171
Issue number3
DOIs
Publication statusPublished - 15 Jul 2011
Externally publishedYes

Keywords

  • Activated carbon
  • Anion
  • Bifunctional composite
  • Photocatalysis
  • TiO

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