Synergistic photocatalytic degraded tetracycline upon supported CuO clinoptilolite nanoparticles

CuO was supported on the clinoptilolite nanoparticles (NCP) via a simple, easy ion exchange process followed by calcination at 450 degrees 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.

Automated summary

CuO was successfully supported on clinoptilolite nanoparticles (NCP) via ion exchange and calcination, forming CuO-NCP photocatalysts. CuO-NCP exhibited enhanced photocatalytic activity towards tetracycline (TC), and the best degradation performance was achieved under optimal conditions (25 ppm TC solution, pH 4.8, and 0.5 g/L catalyst).