Effect of precursors on Cu particle distribution in g-C3N4 nanosheets towards efficient photocatalytic degradation and H2 generation

N-rich precursors govern the thermal polymerization formation of graphitic carbon nitride (g-C3N4) based catalysts towards enhanced photocatalytic performance. In this paper, Cu components were introduced in superior thin g-C3N4 nanosheets using the thermal polymerization copper acetate and bulk g-C3N4 created by different precursors including melamine, dicyandiamide, and thiourea, such as melamine-g-C3N4 (MCN), dicyandiamide-g-C3N4 (DCN), and thiourea-g-C3N4 (TCN). The performance of Cu-g-C3N4 nanosheets depended strongly on the precursors of bulk g-C3N4 samples. The well-developed Cu nanoparticles with clear lattice fringes were observed in the sample prepared using MCN (sample Cu-MCN) while the crystallinity of Cu nanoparticles became worse in the sample prepared using DCN (sample Cu-DCN). Interestingly, Cu clusters were homogeneously distributed in superior thin g-C3N4 nanosheets in the case of using TCN (sample Cu-TCN) because of S components in thiourea affected the thermal polymerization. The photocatalytic activity of Cu-TCN was drastically improved compared with other Cu-g-C3N4 samples. The photocatalytic hydrogen production rate of Cu-TCN with 1% of Cu components was 4035.6 μmol g-1 h-1. Cycle stability test indicated that sample Cu-TCN revealed high stability, in which the H2 generation rate was retained 95% of their initial value after 5 cycles. These results supply efficient approaches for the study and application of g-C3N4 based photocatalysts.