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 Cu2+ 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.