Facile and Ecofriendly One‐pot Synthesis of CuO/Cu 2 O/Cu Nanoheterostructures for Environmental Applications

ABSTRACT The present study deals with the one‐pot green synthesis of CuO/Cu2O/Cu nanoheterostructures using an aqueous extract of rose‐petal flowers for the photocatalytic degradation and catalytic reduction of water pollutants. The prepared nanostructures possessed granular and polyhedral morphologies with the crystalline monoclinic phase of CuO and the cubic phase of Cu2O, and exhibited a band gap of 1.65 eV and a mean particle size of 12.71 nm. Photocatalytic degradation studies revealed that the CuO/Cu2O/Cu nanoheterostructures achieved 87.01% and 96.92% degradation of MB and BCB dyes within 80 min of visible‐light exposure at pH 8, with degradation rates of 1.709 × 10 − 2 and 4.157 × 10 − 2 min − 1 , respectively, and retained 81.07% and 90.31% of their degradation capacities for BCB and MB over four consecutive cycles. The scavenger test results confirmed the active contributions of the reactive species •OH for both organic dyes. Furthermore, the catalytic reduction studies of the catalyst against 4‐nitrophenol (4‐NP) and 4‐nitroaniline (4‐NA) demonstrated excellent reduction efficiencies of 98.14% and 94.76%, with corresponding rate constants of 0.6494 min − 1 and 0.5256 min − 1 , respectively.