Microwave-assisted construction of AgIO3/BaTiO3 heterostructure with excellent photocatalytic activity for tetracycline and methyl blue degradation

Abstract

A series of AgIO3/BaTiO3 composite photocatalysts were synthesized by a microwave-assisted hydrothermal method. Among obtained samples, ABO-2 exhibited superior catalytic performance toward the photocatalytic degradation of TC (30 mg/L) with a degradation rate reaching 76.2% within 40 min. Scanning electron microscopy and transmission electron microscopy demonstrated the formation of smaller spherical particles of BaTiO3 on the AgIO3 surface with a direct Z-type heterojunction. Photoluminescence indicated weaker fluorescence response intensity of the composite ABO-2, suggesting effectively suppressed recombination of electron-hole pairs. The impact of pH and inorganic anions on the removal of pollutants by ABO-2 was discussed in detail by degradation experiments. Experimental evidence obtained from free radical active species capture experiments and electron spin resonance (ESR) spectroscopy tests revealed that h+ and •O2− are the primary active species. The intermediates of the TC degradation process analyzed by liquid chromatograph mass spectrometer (LC-MS), as well as the potential degradation pathways and mechanisms were all studied. The photodegradation experiments under sunlight demonstrated ABO-2 achieving a degradation rate of 74.4% toward MB (10 mg/L) within 75 min, indicating a promising composite catalyst for practical applications.