Enhanced sonocatalytic performance of PEG-modified hierarchical Cu 2 ZnSnS 4 microspheres in Methylene Blue degradation

Abstract

Abstract In this work, hierarchical Cu2ZnSnS4 microspheres were synthesized via a hydrothermal method with the utilization of PEG as surfactant. The as-prepared CZTS samples were systemically characterized by XRD, Raman, TEM, XPS, UV-Vis, PL and BET techniques. The sonocatalytic activity of as-prepared Cu2ZnSnS4 was evaluated by the degradation of methylene blue. The results displayed that the PEG-modified Cu2ZnSnS4 microspheres with smaller optical band gap and lower recombination rate of electrons and holes lead to rapid removal of methylene blue. Over 95.0% methylene blue was snonocatalytic degraded by PEG-modified Cu2ZnSnS4 microspheres after 20 min, while only about 82.1% of methylene blue was degraded over Cu2ZnSnS4 without PEG modification. The effect of radical scavengers on methylene blue degradation process was investigated and clarified that the sonogenerated holes and hydroxyl radicals are the main active oxidative species in sonocatalytic process.