TY - JOUR

T1 - Comparative photocatalytic activity of sol-gel derived rare earth metal (La, Nd, Sm and Dy)-doped ZnO photocatalysts for degradation of dyes

AU - Alam, Umair

AU - Khan, Azam

AU - Ali, Danish

AU - Bahnemann, Detlef

AU - Muneer, M.

N1 - Funding information: The authors gratefully acknowledge the financial support from Ministry of Mines, government of India, New Delhi and Alexander von Humboldt foundation, Germany under research group linkage program. The authors would like to acknowledge the DST and UGC, for research support (DRS II, PURSE& FIST) to the Department of Chemistry, AMU, Aligarh. Umair Alam thanks to CSIR, New Delhi for the Senior Research Fellowship. The authors gratefully acknowledge the nancial support from Ministry of Mines, government of India, New Delhi and Alexander von Humboldt foundation, Germany under research group linkage program. The authors would like to acknowledge the DST and UGC, for research support (DRS II, PURSE& FIST) to the Department of Chemistry, AMU, Aligarh. Umair Alam thanks to CSIR, New Delhi for the Senior Research Fellowship.

PY - 2018

Y1 - 2018

N2 - Rare earth metal doping into semiconductor oxides is considered to be an effective approach to enhance photocatalytic activity due to its ability to retard the electron-hole pair recombination upon excitation. Herein, we report the synthesis of different rare earth metal (La, Nd, Sm and Dy)-doped ZnO nanoparticles using a facile sol-gel route followed by evaluation of their photocatalytic activity by studying the degradation of methylene blue (MB) and Rhodamine B (RhB) under UV-light irradiation. Different standard analytical techniques were employed to investigate the microscopic structure and physiochemical properties of the prepared samples. The formation of the hexagonal wurtzite structure of ZnO was established by XRD and TEM analyses. In addition, the incorporation of rare earth metal into ZnO is confirmed by the shift of XRD planes towards lower theta values. All metal doped ZnO showed improved photocatalytic activity toward the degradation of MB, of which, Nd-doped ZnO showed the best activity with 98% degradation efficiency. In addition, mineralization of the dye was also observed, indicating 68% TOC removal in 180 min with Nd-doped ZnO nanoparticles. The influence of different operational parameters on the photodegradation of MB was also investigated and discussed in detail. Additionally, a possible photocatalytic mechanism for degradation of MB over Nd-doped ZnO nanoparticles has been proposed and involvement of hydroxyl radicals as reactive species is elucidated by radical trapping experiments.

AB - Rare earth metal doping into semiconductor oxides is considered to be an effective approach to enhance photocatalytic activity due to its ability to retard the electron-hole pair recombination upon excitation. Herein, we report the synthesis of different rare earth metal (La, Nd, Sm and Dy)-doped ZnO nanoparticles using a facile sol-gel route followed by evaluation of their photocatalytic activity by studying the degradation of methylene blue (MB) and Rhodamine B (RhB) under UV-light irradiation. Different standard analytical techniques were employed to investigate the microscopic structure and physiochemical properties of the prepared samples. The formation of the hexagonal wurtzite structure of ZnO was established by XRD and TEM analyses. In addition, the incorporation of rare earth metal into ZnO is confirmed by the shift of XRD planes towards lower theta values. All metal doped ZnO showed improved photocatalytic activity toward the degradation of MB, of which, Nd-doped ZnO showed the best activity with 98% degradation efficiency. In addition, mineralization of the dye was also observed, indicating 68% TOC removal in 180 min with Nd-doped ZnO nanoparticles. The influence of different operational parameters on the photodegradation of MB was also investigated and discussed in detail. Additionally, a possible photocatalytic mechanism for degradation of MB over Nd-doped ZnO nanoparticles has been proposed and involvement of hydroxyl radicals as reactive species is elucidated by radical trapping experiments.

UR - http://www.scopus.com/inward/record.url?scp=85047434121&partnerID=8YFLogxK

U2 - 10.1039/c8ra01638k

DO - 10.1039/c8ra01638k

M3 - Article

VL - 8

SP - 17582

EP - 17594

JO - RSC Advances

JF - RSC Advances

SN - 2046-2069

IS - 31

ER -