Z-Scheme Ag3PO4/g-C3N4 Nanocomposites for Robust Cocatalyst-Free Photocatalytic H2 Evolution Under Visible Light Irradiation

Ag3PO4/g-C3N4 nanocomposite photocatalysts were synthesized by calcining the mixture of urea and trace amount of Ag3PO4 microcrystals at 600 degrees C, in which Ag3PO4 nanoparticles with size of 20-30nm were wrapped with g-C3N4 layers. The obtained Ag3PO4/g-C3N4 composites exhibited efficient utilization of visible light and separation of photoinduced electron-hole pairs, resulting in enhanced photocatalytic activity for H-2 evolution. The optimum photocatalytic H-2 evolution rate under visible light without Pt co-catalyst for 0.04AP-CN composite was 89.4 mu mol/h, which is 3.34 times of that of g-C3N4 (26.7 mu mol/h). The H-2 evolution rate for 0.04AP-CN with 3 wt% Pt co-catalyst was up to 273.6 mu mol/h, which is 2.39 times of that g-C3N4 (114.4 mu mol/h). The performance of Ag3PO4/g-C3N4 composite was enhanced significantly due to the synergistic effect of the interface formed between Ag3PO4 and g-C3N4. [GRAPHICS] .