Hydrothermal-assisted synthesis and characterization of MWCNT/copper oxide nanocomposite for the photodegradation of methyl orange under direct sunlight

Abstract

In this study, we report synthesis of a novel MWCNT/copper oxide hybrid nanocomposite and pristine copper oxide using hydrothermal techniques and employed them as a sunlight-driven photocatalyst for the degradation of methyl orange organic (MO) pollutant. The prepared specimens were evaluated using various characterization techniques to analyze the crystallographic, optical, and nanoscale characteristics and the results revealed that the incorporation of MWCNTs significantly altered the crystalline phase, lattice parameters, particle size, shape, and optical band gap when compared with pure copper oxide sample. Pure copper oxide, MWCNT/copper oxide nanocomposite and MWCNT exhibited band gaps of 1.43 eV, 1.90 eV, and 3.8 eV, respectively. After 6 h of exposure to sunlight, pure copper oxide and MWCNT/copper oxide hybrid nanocomposite photodegraded 85 % and 92 % of the MO dye, with pseudo-first-order kinetics and high recyclability up to 5 cycles. The proposed composite shows higher solar radiation-induced photodegradation than pure copper oxide owing to its hybrid heterostructure, making it a promising photocatalyst for wastewater treatment.