Synergistic photocatalytic degraded tetracycline upon supported CuO clinoptilolite nanoparticles

Abstract

CuO was supported on the clinoptilolite nanoparticles (NCP) via a simple, easy ion exchange process followed by calcination at 450 °C. XRD results confirmed both crystallite phases for clinoptilolite and CuO with an estimated crystallite size below 50 nm by the Scherrer formula. DRS results showed a band gap energy of 1.3 eV pHpzc of the catalyst was about 6.3. TEM results showed particles with a nano dimension. The boosted photocatalytic activity of CuO-NCP was obtained concerning micronized clinoptilolite (CP) and its nanoparticles (NCP), and unsupported bulk and nano CuO towards tetracycline (TC) in an aqueous solution. The catalyst containing 5.8 % CuO showed the highest photocatalytic activity. The optimal conditions were 25 ppm TC solution at pH 4.8 and 0.5 g/L of the catalyst. Based on the decreased peak area in HPLC chromatograms, the TC degradation extents of 43 % and 67 % were obtained for the photodegraded solutions after 60 and 300 min. The initial COD of a 25 ppm blank TC solution was decreased from 1048 mg O2/L to 783, 700, 614, 520, and 358 mg O2/L after 60, 120, 180, 240, and 300 min photodegradation periods, respectively. The results correspond to 25.3, 33.2, 41.4, 50.4, and 65.8 % of TC. The kinetics of the process obeyed the Hinshelwood pseudo-first-order rate kinetics.