Interaction between copper and carbon nanotubes triggers their mutual role in the enhanced photodegradation of p-chloroaniline

Copper (Cu, 1-5 wt%) was loaded onto carbon nanotubes (CNTs) by a simple electrochemical method. The physicochemical properties of catalysts (Cu/CNTs) were characterized by using X-ray diffraction (XRD), transmission electron microscopy (TEM), nitrogen (N2) adsorption-desorption, Fourier transform infra-red spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), and electron spinning resonance (ESR). The results showed that the Cu was distributed well on the CNT surface by the interaction of Cu(2+) ions with -OH and -COOH groups on the CNT surface, which preferentially occurred at the defect sites along the CNT backbone. The Cu-O-C bonds formed were found to play an important role in enhancing the photoactivity of the catalysts. The highest number of Cu-O-C bonds possessed by 3 wt% Cu/CNTs demonstrated the best performance in the degradation of p-chloroaniline (96%) under UV light irradiation within 5 h of reaction at 27 °C and under neutral pH conditions. Kinetic studies showed that the degradation followed the pseudo-first order model and the surface reaction was the controlling step. It is believed that these results could contribute to the synthesis of various supported catalysts for various applications.