Z-scheme CaIn2S4/Ag3PO4 nanocomposite with superior photocatalytic NO removal performance: fabrication, characterization and mechanistic study

Abstract

The development of the economy benefits from fossil fuels, but their consumption inevitably results in environmental pollution. For example, nitric oxide (NO) removal from coal-fired flue gas is a significant aspect of atmospheric pollution control. Based on its unique advantages to resolve atmospheric pollution, photocatalytic oxidation (PCO) is regarded as an effective technique to remove NO. Herein, we have first fabricated Z-scheme CaIn₂S₄/Ag₃PO₄ nanocomposites and studied their performance in the PCO of NO (400 ppm) with the assistance of H₂O₂. The results indicate that the CaIn₂S₄/Ag₃PO₄ nanocomposites exhibit superior photocatalytic performance, and the PCO efficiency of NO can reach 83.61%. The excellent photocatalytic ability belongs to the low recombination rate of the photoinduced electron–hole pairs. The production and participation of more active species is another critical factor due to the injected H₂O₂. FTIR and ion chromatography results reveal that NO₃⁻ is the final product. Furthermore, the fluorescence spectra combined with the electron spin resonance and the trapping experiment suggest that ˙OH and ˙O₂⁻ might play a predominant role in NO removal.