Dual functional Ag2MoO4/thickness-controlled g-C3N4 composites for enhanced photocatalytic and adsorption activity

Abstract

Background

Nanocomposites have a wide range of applications in the field of energy and environment, especially in the treatment of organic pollutants and radioactive materials in water, so the development of new nanocomposites for the treatment of environmental pollution is urgent.

Methods

The morphology of g-C₃N₄ has a significant impact on its properties. The g-C₃N₄ with different thicknesses were prepared by thermal oxidation exfoliation and etching of bulk g-C₃N₄ (CNB) under air atmosphere, and separately combined with Ag₂MoO₄. The samples were characterized with X-ray diffraction, scanning electron microscopy (SEM), UV–vis diffuse reflectance spectra, X-ray photoelectron spectroscopy.

Significant findings

The results showed that the composite of Ag₂MoO₄ formed of g-C₃N₄ with a thickness of 24.7 nm exhibited excellent photocatalytic degradation property. The photo-degradation rate of methylene blue (MB), rhodamine B (RhB) and methyl orange (MO) were 97.9 % (30 min), 94.2 % (40 min) and 91.3 % (40 min), respectively. Differently, when Ag₂MoO₄ is combined with g-C₃N₄ with a thickness of 10.0 nm, which show excellent adsorption performance. The adsorption amount of I₂ can reach 4.487 g/g under 75 °C of saturated I₂ vapor. And the nanocomposite manifested splendid adsorption efficiency of MB (95.8 %, 6 min), RhB (93.2 %, 6 min) and MO (94.3 %, 6 min), respectively. The nanocomposite achieved the bifunctional characteristics of degradation of organic pollutants and efficient adsorption.