Graphene foam-carbon nitride based composites as photoelectrocatalysts for overall water splitting in acidic and neutral media

The generation of significant amounts of H-2 and O-2 from water splitting utilizing nonprecious metal photoelectrocatalysts within the electrolysis pathway is targeted. Accordingly, black titanium/carbon nitride (BT) is first synthesized using a simple method, then it is mixed with various weight percentages of graphene foam (GF; 5-20%). The catalyst 10% GF/BT demonstrates superior HER performance under neutral conditions (1.0 M KCl) at an overpotential of -0.02 V at 10 mA cm(-2) exceeding that of Pt/C values (0.53 V). An overpotential of -0.75 and -1.22 V at 50 and 100 mA cm(- 2), respectively, was also exhibited. However, oxygen evolution reaction (OER) displays an overpotential of 0.67 V at ?10. Additionally, the 10% GF/BT bifunctional electrode displayed perfect water splitting with 1.5 V at 10 mA cm(-2) current density. The correlations of the activity in different media, besides texturing, morphology, and structural characteristics examined by XRD, HRTEM-SAED-FFT, FTIR, and XPS, were assessed and discussed.

Automated summary

This study aims to generate significant amounts of H-2 and O-2 through water splitting using nonprecious metal photoelectrocatalysts. A black titanium/carbon nitride (BT) material is synthesized and mixed with graphene foam (GF) at different weight percentages. The 10% GF/BT catalyst demonstrates superior performance in the hydrogen evolution reaction (HER) and displays perfect water splitting. The activity of the catalyst in different media is assessed and discussed based on its structural characteristics.