Photodegradation of N-Methyldiethanolamine over ZnO/SnO2 Coupled Photocatalysts


1 Department of Chemistry,Kuwait University

2 Department of Chemistry,University of Mashad

3 Department of Chemical Processes Developmant and Engineering,British Nuclear Fuels Ltd

4 Department of Chemistry,British Nuclear Fuels Ltd


A photocatalyst semiconductor can be used to remove organic pollutants from wastewater
in the presence of UV light. In this research, coupled ZnO/SnO2 semiconductors with 1:1 and 2:1 ratios
were prepared using the co-precipitation method. The prepared coupled ZnO/SnO2 photocatalyst was
tested towards the photodegradation of simulated N-Methyldiethanolamine (MDEA) under UV-irradiation
( = 365 nm, 100 V, 6 W). The ZnO/SnO2 was characterized using UV di used re
ectance spectroscopy
and X-ray di raction. The band gap energy for ZnO/SnO2 (ZS) catalyst calcined at 200C, 400C,
600C and 900C were 3.22, 3.13, 3.12 and 3.07 eV, respectively, while for Z2S were 3.71, 3.28, 3.16,
and 3.14 eV, respectively. XRD results indicated that ZS and Z2S catalysts possessed mixed phases of ZnO,
SnO2 and Zn2SnO4 at a calcinations temperature above 600C. The ZnO/SnO2 (2:1) catalyst, which was
calcined at 600C for 9 hours, gave the optimum percentage photodegradation of MDEA with 39.18%.
The percentage degradation of MDEA was measured using ion chromatography with retention time at the
measured peak of 4-5 minutes. The optimum system was applied on the photodegradation of MDEA in
petroleum wastewater. The percentage degradation of MDEA in petroleum wastewater was 23.38 %.