Preparation of Novel n-p gCN-NS/CuBOHeterojunction with Increased Visible Light Photocatalytic Activity for MG Degradation

Recently, industrialization and rapid growth of the population create challenges in terms of energy consumption and water protection. Heterogeneous photocatalysis, as a green, favorable, and feasible technology of the advanced oxidation processes (AOPs) has attracted significant attentions from research communities due to its power to complete degradation of various pollutants under ambient conditions. Between different semiconductor photocatalysts, metal-free polymeric n-type graphitic carbon nitride (g-C3N4) is taken into consideration due to its interesting properties such as unique electrical, structural, physicochemical, optical, and thermal stability, high biocompatibility, abundant, medium bandgap of 2.7 eV, and facile preparation. But, bare gCN suffers from shortcomings such as low absorption of visible light, rapid recombination of charge carriers, and low specific surface area. Various strategies have been used to overcome these limits like morphology controls, coupling with other semiconductors, and doping with metal or nonmetal elements. In this work, we used two improvement strategies: exfoliation of g-C3N4 (gCN-NS) to increase the specific surface area, and coupling of the CuBi2O4 nanoparticles with the g-C3N4-nanosheet (gCN-NS/CuBO) to increase the visible light absorption and improve the charges separation. The photocatalysts were studied by XRD, and FESEM analysis. Then, the as-prepared samples were used as visible-light-driven photocatalysts for degradation of malachite green (MG) as a dye pollutant. The kinetic study results proved that the binary gCN-NS/CuBO (20%) heterostructure has excellent photocatalytic ability in degradation of MG, which was about 18.4 and 10.5-times as high as the bare gCN and gCN-NS, respectively. The enhanced photodegradation ability was attributed to the more absorption of visible light and the construction of n-p heterojunctions at the interface of n-gCN-NS and p-CuBi2O4 semiconductors. This research suggests that the gCN-NS/CuBO nanocomposites can be genuinely used as heterogeneous visible-light-driven photocatalysts for the water purification from the different organic pollutants.

کلیدواژه ها:

gCN-NS/CuBO ، n-p heterojunction photocatalyst ، Visible-light-induced ، Electron–hole separation