Construction of a Novel Z-Scheme Heterojunction with Molecular Grafted Carbon Nitride Nanosheets and V₂O₅ for Highly Efficient Photocatalysis

Abstract

Molecular grafted carbon nitride (CN) nanosheets coupled with V2O5 to form a novel Z-scheme heterojunction photocatalyst V2O5/CNX (X is 2-aminobenzonitrile) by a facile in situ growth method was acquired. Its photocatalytic properties were investigated by hydrogen evolution and degradation of rhodamine B under simulated sunlight irradiation. It was found that the assembled heterojunction could remarkably enhance photocatalytic activity in contrast to pure CN, V2O5, and previous reported heterojunctions. The great improvement of photocatalytic activity can be attributed to molecular grafting and the formation of the Z-scheme heterojunction, resulting in a remarkable red shift of the optical absorption, a rapid separation of charge carriers, an increase of specific surface area, and introduction of defects. Moreover, exfoliation of bulk CNX into ultrathin nanosheets increases mobility of charges and specific surface area. Different wt % ratios of V2O5-loaded heterojunctions were prepared, and 2% of V2O5-loaded heterojunctions were found to display optimal catalytic efficiency. The possible activity enhanced mechanism was proposed. This work reveals that the molecular grafted V2O5/CNX Z-scheme heterojunction can be utilized for highly efficient photocatalysis applied in energy conversion and environmental remediation.