TY - JOUR
T1 - Cobalt-doped cerium oxide nanoparticles
T2 - Enhanced photocatalytic activity under UV and visible light irradiation
AU - Saranya, Jayapalan
AU - Ranjith, Kugalur Shanmugam
AU - Saravanan, Padmanaban
AU - Mangalaraj, Devanesan
AU - Rajendra Kumar, Ramasamy Thangavelu
PY - 2014/10
Y1 - 2014/10
N2 - CeO2 nanoparticles (NPs) were synthesized by coprecipitation using cerium(III) nitrate hexahydrate as the precursor and ethanol as the solvent. Different concentration of cobalt-doped cerium oxide NPs (3mol % and 6 mol %) were prepared by adding various concentrations of cobalt chloride to cerium nitrate. The as-synthesized NPs were characterized through X-ray diffraction (XRD) measurements, ultraviolet (UV)-visible spectroscopy, Photoluminescence (PL) spectroscopy, and transmission electron microscopy (TEM). XRD results reveal that the as-prepared CeO2 NPs had a face-centered cubic structure with crystallite size in the range of 5-8 nm. TEM analyses showed that the CeO2 NPs and Co-doped CeO2 NPs had a homogenous size distribution (sizes were within 5-12 nm). Band-edge absorption of CeO2 NPs redshifted upon increasing the Co concentration as compared to undoped CeO2 NPs. PL spectra reveal a peak shift of CeO2 emission upon cobalt doping, which were due to an increase in oxygen defects localized between the Ce4f and O2p energy levels (i.e., via formation of Ce3+ states). Photocatalytic degradation of methylene blue in aqueous solution under UV and visible (sunlight) irradiation in the presence of pure CeO2 NPs and of Co-doped CeO2 NPs was investigated. The efficiency of photocatalytic degradation of CeO2 NPs increased with the Co concentration both under UV irradiation and under visible light. Co-doped CeO2 NPs (6 mol%) showed degradation efficiencies of 98% and 89% at 420 min of exposure to UV irradiation and to visible light, respectively.
AB - CeO2 nanoparticles (NPs) were synthesized by coprecipitation using cerium(III) nitrate hexahydrate as the precursor and ethanol as the solvent. Different concentration of cobalt-doped cerium oxide NPs (3mol % and 6 mol %) were prepared by adding various concentrations of cobalt chloride to cerium nitrate. The as-synthesized NPs were characterized through X-ray diffraction (XRD) measurements, ultraviolet (UV)-visible spectroscopy, Photoluminescence (PL) spectroscopy, and transmission electron microscopy (TEM). XRD results reveal that the as-prepared CeO2 NPs had a face-centered cubic structure with crystallite size in the range of 5-8 nm. TEM analyses showed that the CeO2 NPs and Co-doped CeO2 NPs had a homogenous size distribution (sizes were within 5-12 nm). Band-edge absorption of CeO2 NPs redshifted upon increasing the Co concentration as compared to undoped CeO2 NPs. PL spectra reveal a peak shift of CeO2 emission upon cobalt doping, which were due to an increase in oxygen defects localized between the Ce4f and O2p energy levels (i.e., via formation of Ce3+ states). Photocatalytic degradation of methylene blue in aqueous solution under UV and visible (sunlight) irradiation in the presence of pure CeO2 NPs and of Co-doped CeO2 NPs was investigated. The efficiency of photocatalytic degradation of CeO2 NPs increased with the Co concentration both under UV irradiation and under visible light. Co-doped CeO2 NPs (6 mol%) showed degradation efficiencies of 98% and 89% at 420 min of exposure to UV irradiation and to visible light, respectively.
KW - Cerium oxide
KW - Cobalt-doped cerium oxide
KW - Methylene blue
KW - Photocatalytic activity
UR - http://www.scopus.com/inward/record.url?scp=84901030624&partnerID=8YFLogxK
U2 - 10.1016/j.mssp.2014.03.054
DO - 10.1016/j.mssp.2014.03.054
M3 - Article
AN - SCOPUS:84901030624
SN - 1369-8001
VL - 26
SP - 218
EP - 224
JO - Materials Science in Semiconductor Processing
JF - Materials Science in Semiconductor Processing
IS - 1
ER -