Microwave assisted in situ decoration of a g-C3N4 surface with CdCO3 nanoparticles for visible light driven photocatalysis

Abstract

Graphitic carbon nitride (g-C₃N₄) supported cadmium carbonate (CdCO₃) as an organic–inorganic hybrid nanophotocatalyst was realised by an in situ microwave heating method. The hybrid composite retains the structure of each component, which was verified by p-XRD, FT-IR and solid state ¹³C-NMR analysis. The as-prepared hybrid g-C₃N₄/CdCO₃ composites were evaluated as a photocatalyst towards the degradation of indigo carmine (IC) dye and inactivation of the Gram negative E. coli pathogen. In this composite, the wide band gap CdCO₃ acts as an electron accepting platform from g-C₃N₄ and facilitates the subsequent photocatalytic reaction. The optimized hybrid g-C₃N₄/CdCO₃-90 photocatalyst exhibits four-fold increase in the degradation of IC dye compared to pristine g-C₃N₄ and almost a complete mineralization of the dye occurs after 180 min of irradiation. Besides, this photocatalyst completely inhibits the growth of E. coli bacteria within 45 min of visible light irradiation. The enrichment in the photoactivity of CdCO₃ decorated g-C₃N₄ is ascribed to the combined effects of improved visible light absorption, enhanced dye adsorption and facile separation of electron–hole pairs as evidenced by electrochemical impedance spectroscopy (EIS) measurements. The present work may provide valuable information and insights into the microwave assisted synthesis of g-C₃N₄ hybrid composites and may permit a better comprehension of future advancements in high performance materials for environmental remediation applications.