Hexylresorcinol calix[4]arene-assisted synthesis of ZnO-Au micro-nano materials with enhanced photodegradation performance to degrade harmful organic compounds

In this study, hexylresorcinol calix[4]arene-ZnO-Au (HRCA-ZnO-Au) micro-nano materials are synthesized by a simple atmospheric reflux. AuCl4- ions are in situ reduced to Au by the phenolic hydroxyl groups of amphiphilic HRCA and deposited on the primarily formed ZnO sheets, which prevents Zn2+ ions in the solution from depositing at this position. Finally, the flake sample is obtained. HRCA and chloroauric acid effectively shape the morphology of ZnO from micron-sized flowers to nanometer sheets, and they significantly increase the specific surface area of the sample. Low temperature calcination of the HRCA-ZnO-Au composite micro-nano materials partially removes calixarene molecules and exposes the surface of ZnO-Au. Thus, the photocatalytic activity of ZnO-Au is significantly improved due to the synergistic effect between ZnO and Au.