Facile synthesis of two clay minerals supported graphitic carbon nitride composites as highly efficient visible-light-driven photocatalysts.

To overcome rapid electron-hole recombination and low adsorption capacity of single g-C3N4 photocatalyst, the present work reports on the fabrication of two kinds of visible-light-driven composite photocatalysts (g-C3N4/kaolinite and g-C3N4/illite composites). 2D/2D assembly was successfully achieved in this work. Furthermore, the as-synthesized composites exhibited significantly enhanced photocatalytic activity under visible-light irradiation, whose reaction rate constants were almost 4.13 times (g-C3N4/kaolinite) and 3.18 times (g-C3N4/illite) that of pure g-C3N4. A plausible reaction mechanism over the as-prepared composite photocatalysts was also proposed based on the experimental results obtained. The photocatalytic enhancement of synthesized composites should be attributed to the intimate interface contact between g-C3N4 and layered minerals, resulting in better dispersion performance, higher charge separation efficiency as well as stronger adsorption ability.