Silver oxide decorated graphitic carbon nitride for the realization of photocatalytic degradation over the full solar spectrum: From UV to NIR region

Abstract

To achieve fully utilization of solar energy, development of an efficient full solar spectrum light responsive photocatalyst is strongly needed. Besides, the smaller particle sizes, better dispersion and more heterojunction interfaces can enhance the photocatalytic performance of photocatalysts. Assembling graphite-like carbon nitride (g-C3N4) with a narrow bandgap semiconductor to form a heterostructure which can increase the charge-separation efficiency and harvest the light from UV to near-infrared (NIR) region would be ideal for photocatalysis. Here, we report a facile synthesis of Ag2O/g-C3N4 heterostructures by in-situ growth Ag2O nanoparticles (NPs) onto surface of g-C3N4 nanosheets (NSs) to display superior UV–visible-NIR full spectrum photocatalytic activities and favorable stability. TEM results show that the obtained Ag2O NPs with the size of 8nm are uniformly dispersed on the surface of g-C3N4 NSs, which reveals that g-C3N4 is probably a promising support template for in-situ growth of nano-sized materials. The mechanism for improving the photocatalytic performance of the Ag2O/g-C3N4 heterostructures is proposed. It is demonstrated that the Ag2O/g-C3N4 heterostructures not only enhance the production of photogenerated electron-hole pairs by extending the visible and NIR light absorption region due to the visible and NIR harvesting of highly dispersed smaller Ag2O NPs on the surface of g-C3N4 NSs, but also facilitate electron-hole separation by the heterojunction formed by intimate contact between Ag2O and g-C3N4. Moreover, the formation of a certain amount of metal Ag0 on the surface of Ag2O under illumination contribute to the high stability and charge transfer of Ag2O/g-C3N4 heterostructures.