Halloysite nanotubes supported copper oxide composites used as efficient catalysts for bisphenol A removal

Copper oxide/ halloysite nanotubes (CuO/HNTs) served as excellent catalysts for bisphenol A (BPA) removal were prepared through a hydrothermal method. The influences of catalyst dosage, peroxymonosulfate (PMS) concentration, pH value, initial BPA concentration, temperature, inorganic anions, and humic acid on the degradation efficiency were investigated. The degradation results indicated that the catalyst 70% CuO/HNTs (70% represented the weight ratio of CuO to HNTs) displayed an extraordinary TOC removal efficiency of 96%, which was 1.2 times higher than that of CuO. The mechanism studies suggested that the abundant hydroxyl groups of HNTs mostly contributed to the superior degradation efficiency of CuO/HNTs. The singlet oxygen (1O2) produced in the CuO/HNTs/PMS system acted as the predominant active specie in the degradation process. Moreover, the formed Cu-O-Al bond constrained the growth of CuO and improved the cycle performance of CuO/HNTs. This work provides an efficient catalyst for contaminant removal and contributes an innovative strategy for constructing functional mineral composites with abundant hydroxyl groups.