The photocatalytic activities of the as-synthesized PtAu bimetallic alloy NPs-integrated g-C3N4 toward H2 production through water splitting were investigated in aqueous solution of sulfide/ sulfite mixture as hole scavenger. The average photocatalytic H2 evolution rate over the different alloy NPs-integrated gC3N4 was compared not only with the monometallic Pt/gC3N4 and Au/g-C3N4 but also with the pure g-C3N4 as shown in Figure 6a.