Ethanol Solvothermal Treatment on Graphitic Carbon Nitride Materials for Enhancing Photocatalytic Hydrogen Evolution Performance

Recently, Pt-loaded graphic carbon nitride (g-C3N4) materials have attracted great attention as a photocatalyst for hydrogen evolution from water. The simple surface modification of g-C3N4 by hydrothermal methods improves photocatalytic performance. In this study, ethanol is used as a solvothermal solvent to modify the surface properties of g-C3N4 for the first time. The g-C3N4 is thermally treated in ethanol at different temperatures (T = 140 degrees C, 160 degrees C, 180 degrees C, and 220 degrees C), and the Pt co-catalyst is subsequently deposited on the g-C3N4 via a photodeposition method. Elemental analysis and XPS O 1s data confirm that the ethanol solvothermal treatment increased the contents of the oxygen-containing functional groups on the g-C3N4 and were proportional to the treatment temperatures. However, the XPS Pt 4f data show that the Pt2+/Pt-0 value for the Pt/g-C3N4 treated at ethanol solvothermal temperature of 160 degrees C (Pt/CN-160) is the highest at 7.03, implying the highest hydrogen production rate of Pt/CN-160 is at 492.3 mu mol g(-1) h(-1) because the PtO phase is favorable for the water adsorption and hydrogen desorption in the hydrogen evolution process. In addition, the electrochemical impedance spectroscopy data and the photoluminescence spectra emission peak intensify reflect that the Pt/CN-160 had a more efficient charge separation process that also enhanced the photocatalytic activity.

Automated summary

In this study, g-C3N4 was modified using ethanol as a solvothermal solvent and the resulting material showed improved photocatalytic performance. The ethanol solvothermal treatment increased the oxygen-containing functional groups on g-C3N4, and the Pt/g-C3N4 treated at 160℃ exhibited the highest Pt2+/Pt0 value and hydrogen production rate. The study also found that the modified g-C3N4 had a more efficient charge separation process, which enhanced its photocatalytic activity.