Effect of several commercial rubber as substrates for zinc oxide in the photocatalytic degradation of methylene blue under visible irradiation
R. Nordin, N. Latiff, R. Yusof, W. I. Nawawi, M. Z. Salihin, Z. A. M. Ishak
Vol. 14., No.9., Pages 838-847, 2020
DOI: 10.3144/expresspolymlett.2020.69
DOI: 10.3144/expresspolymlett.2020.69
Corresponding author: R. Nordin 
GRAPHICAL ABSTRACT
ABSTRACT
A new approach of mechanical preparation of photocatalyst zinc oxide (ZnO)/rubbers from four types of rubbers: styrene butadiene rubber (SBR), ethylene propylene diene monomer (EPDM), natural rubber (NR), and epoxidized natural rubber (ENR) with 50% epoxidation is presented. This technique is simple, fast and cost effective as ZnO/rubbers were mechanically mixed using conventional two-roll mill at 27 °C for 10 min and compressed into flat sheet. The characteristics of photocatalyst were studied by X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), ultraviolet-visible spectroscopy (UV-Vis) and field emission scanning electron microscope (FESEM). The photocatalytic activity of ZnO/rubbers was evaluated using methylene blue (MB) as a model pollutant under visible light for 300 min. The photocatalytic degradation efficiency of ZnO/SBR is nearly as good as that of ZnO powder (87.32%) compared to ZnO/NR, ZnO/EPDM and ZnO/ENR. This is due to the highest index of conjugated carbon-carbon bond of SBR and hydrogen bonding between ZnO and SBR. The formation of hydrogen bonding was confirmed by FTIR and reduction of energy band gap of ZnO/SBR. The photocatalytic degradation of MB with ZnO/SBR was could be fitted by pseudo-first-order kinetics of the Langmuir-Hinshelwood model.
