Abstract
Cu2O/TiO2 (1–10 wt% Cu2O) and 2.5% Cu2O/TiO2-AC (2.5–20 wt% AC) photocatalyst composites were synthesised by an ethanol reduction method. The materials were characterised by a number of techniques which confirmed the presence of Cu2O in contact with the TiO2. Pure TiO2 alone was not active for the simultaneous photocatalytic removal of nitrate and oxalic acid under conditions employed, however, photocatalytic activity was observed for TiO2 and TiO2/AC in the presence of Cu2O. This may have resulted from suppression of charge recombination via creation of a p-n heterojunction between Cu2O and TiO2. Within the series, 2.5% Cu2O/TiO2 exhibited the best photocatalytic performance with 57.6 and 99.8% removal of nitrate and oxalic acid, respectively, with selectivities of 45.7, 12.4 and 41.9% to NH4 +, NO2 − and N2, respectively after 3 h. For the carbon containing photocatalysts, 2.5% Cu2O/TiO2-2·5AC displayed the highest activity with 42.5 and 96.6% removal of nitrate and oxalic acid, respectively, with 32.7, 11.6 and 55.7% selectivities to NH4 +, NO2 − and N2, respectively. The highest AC loading tested resulted in selectivity to NH4 + of 21.6 with no NO2 − detected, together with an improved N2 selectivity (78.4%) albeit at lower (12.7%) nitrate conversion. Data suggests that Cu2O/TiO2 can be used in the photocatalytic reduction of nitrate and improved selectivity towards N2 can be attained by influencing factors which control the relative rate of oxalic acid consumption.
| Original language | English |
|---|---|
| Pages (from-to) | 181-191 |
| Number of pages | 11 |
| Journal | Applied Catalysis B: Environmental |
| Volume | 217 |
| Early online date | 3 Jun 2017 |
| DOIs | |
| Publication status | Published - 15 Nov 2017 |
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Keywords
- Activated carbon
- Composites
- Nitrate
- Oxalic acid
- Photocatalysis
- Titania
ASJC Scopus subject areas
- Catalysis
- Environmental Science(all)
- Process Chemistry and Technology
Cite this
Simultaneous photocatalytic removal of nitrate and oxalic acid over Cu2O/TiO2 and Cu2O/TiO2-AC composites. / Adamu, Haruna; McCue, Alan J.; Taylor, Rebecca S.F.; Manyar, Haresh G.; Anderson, James A.
In: Applied Catalysis B: Environmental, Vol. 217, 15.11.2017, p. 181-191.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Simultaneous photocatalytic removal of nitrate and oxalic acid over Cu2O/TiO2 and Cu2O/TiO2-AC composites
AU - Adamu, Haruna
AU - McCue, Alan J.
AU - Taylor, Rebecca S.F.
AU - Manyar, Haresh G.
AU - Anderson, James A.
N1 - This research supported by the Petroleum Technology Development Fund (PTDF) of Nigeria. We are grateful to Abubakar Tafawa Balewa University, Bauchi-Nigeria for the award of a studentship (to HA).
PY - 2017/11/15
Y1 - 2017/11/15
N2 - Cu2O/TiO2 (1–10 wt% Cu2O) and 2.5% Cu2O/TiO2-AC (2.5–20 wt% AC) photocatalyst composites were synthesised by an ethanol reduction method. The materials were characterised by a number of techniques which confirmed the presence of Cu2O in contact with the TiO2. Pure TiO2 alone was not active for the simultaneous photocatalytic removal of nitrate and oxalic acid under conditions employed, however, photocatalytic activity was observed for TiO2 and TiO2/AC in the presence of Cu2O. This may have resulted from suppression of charge recombination via creation of a p-n heterojunction between Cu2O and TiO2. Within the series, 2.5% Cu2O/TiO2 exhibited the best photocatalytic performance with 57.6 and 99.8% removal of nitrate and oxalic acid, respectively, with selectivities of 45.7, 12.4 and 41.9% to NH4 +, NO2 − and N2, respectively after 3 h. For the carbon containing photocatalysts, 2.5% Cu2O/TiO2-2·5AC displayed the highest activity with 42.5 and 96.6% removal of nitrate and oxalic acid, respectively, with 32.7, 11.6 and 55.7% selectivities to NH4 +, NO2 − and N2, respectively. The highest AC loading tested resulted in selectivity to NH4 + of 21.6 with no NO2 − detected, together with an improved N2 selectivity (78.4%) albeit at lower (12.7%) nitrate conversion. Data suggests that Cu2O/TiO2 can be used in the photocatalytic reduction of nitrate and improved selectivity towards N2 can be attained by influencing factors which control the relative rate of oxalic acid consumption.
AB - Cu2O/TiO2 (1–10 wt% Cu2O) and 2.5% Cu2O/TiO2-AC (2.5–20 wt% AC) photocatalyst composites were synthesised by an ethanol reduction method. The materials were characterised by a number of techniques which confirmed the presence of Cu2O in contact with the TiO2. Pure TiO2 alone was not active for the simultaneous photocatalytic removal of nitrate and oxalic acid under conditions employed, however, photocatalytic activity was observed for TiO2 and TiO2/AC in the presence of Cu2O. This may have resulted from suppression of charge recombination via creation of a p-n heterojunction between Cu2O and TiO2. Within the series, 2.5% Cu2O/TiO2 exhibited the best photocatalytic performance with 57.6 and 99.8% removal of nitrate and oxalic acid, respectively, with selectivities of 45.7, 12.4 and 41.9% to NH4 +, NO2 − and N2, respectively after 3 h. For the carbon containing photocatalysts, 2.5% Cu2O/TiO2-2·5AC displayed the highest activity with 42.5 and 96.6% removal of nitrate and oxalic acid, respectively, with 32.7, 11.6 and 55.7% selectivities to NH4 +, NO2 − and N2, respectively. The highest AC loading tested resulted in selectivity to NH4 + of 21.6 with no NO2 − detected, together with an improved N2 selectivity (78.4%) albeit at lower (12.7%) nitrate conversion. Data suggests that Cu2O/TiO2 can be used in the photocatalytic reduction of nitrate and improved selectivity towards N2 can be attained by influencing factors which control the relative rate of oxalic acid consumption.
KW - Activated carbon
KW - Composites
KW - Nitrate
KW - Oxalic acid
KW - Photocatalysis
KW - Titania
UR - http://www.scopus.com/inward/record.url?scp=85020249413&partnerID=8YFLogxK
U2 - 10.1016/j.apcatb.2017.05.091
DO - 10.1016/j.apcatb.2017.05.091
M3 - Article
AN - SCOPUS:85020249413
VL - 217
SP - 181
EP - 191
JO - Applied Catalysis B: Environmental
JF - Applied Catalysis B: Environmental
SN - 0926-3373
ER -