Efficient visible-light-driven photocatalytic hydrogen production from water by using Eosin Y-sensitized novel g-C3N4/Pt/GO composites

Developing an efficient dye-sensitized photocatalyst for photocatalytic H-2 evolution from water is highly desired. In this study, a novel ternary g-C3N4/Pt/GO composite was synthesized via a facile liquid-phase sonochemical approach. Pt nanoparticles were firstly deposited on the surfaces and/or interlayer of g-C3N4 by chemical reduction, and then, GO was penetrated through ultrasonic treatment. This preparation method is facilitated to prohibit the agglomeration of g-C3N4 and GO because of their pi-pi stacking interaction and enhance electrons transport and the adsorption of dye molecules. The Eosin Y-sensitized ternary g-C3N4/Pt/GO composite shows the highest H-2 production rate of 3.82 mmol center dot g(-1)center dot h(-1) under the optimization conditions, which about 2.1 times and 7.7 times higher than the Eosin Y-sensitized binary g-C3N4/Pt and GO/Pt photocatalysts, respectively. The improved charge separation efficiency is the main reason for the enhancement in H-2 evolution activity. The apparent quantum efficiency of hydrogen evolution for the Eosin Y-sensitized ternary g-C3N4/Pt/GO composite is up to 9.7% at 420 nm. Moreover, the sensitized g-C3N4/Pt/GO composite shows stable photocatalytic activity for H-2 evolution under visible light irradiation. The effect of pH, g-C3N4/GO weight ratios, Pt loading amounts, dye concentrations, and different type dyes on the H-2 evolution activity was also investigated in detail.