Effect of nonmetal element dopants on photo- and electro-chemistry performance of ultrathin g-C3N4 nanosheets

Increased charge transfer and light absorption as well as large specific surface area are effective ways to improve the catalytic efficiency of photocatalysts . In this paper, barbituric acid , urea and thiourea were separately freeze-dried to form a homogeneous precursor with melamine , followed by thermal polymerization at 750 °C, g-C 3 N 4 was doped successfully with C, N and S. Among them, C-doped g-C 3 N 4 revealed well photocatalytic hydrogen production which reached to 2.45 mmol g −1  h −1 . N-doped g-C 3 N 4 exhibited enhanced photocatalytic degradation properties for organic dye (RhB) which is completely degraded within 8 min while the performance S-doped sample is not satisfied. The introduction of C resulted in planarized sample which has a larger specific surface area and provides more active sites. N doping makes the valence band position moving in the direction of high energy. Thus, holes have stronger oxidizing ability. Accordingly, the effect of C and N ratios in g-C 3 N 4 photocatalysis was fully discussed for more comprehensive understanding of g-C 3 N 4 .