Salt promoted metallic Pt photodeposition on graphitic carbon nitride towards efficiently photocatalytic hydrogen evolution

Abstract

The photocatalytic hydrogen evolution (PHE) activity of pristine graphitic carbon nitride (GCN) and highly crystalline K+-doped GCN can significantly be enhanced under visible light irradiation via adding alkali metal salt into their PHE reaction solution. As manifested in XRD, UVDRS, TEM and XPS measurements, the loading amount of Pt cocatalyst on both GCN and K+-doped GCN, as well as the content of metallic Pt were greatly increased in the presence of 1.0 M KCl solution in the photoreduction solution. More significantly, the proportion of metallic Pt reached around 75 %. As a result, the PHE rate of K+-doped GCN was even as high as 11 mmol h–1g−1 under visible light irradiation. The current work offers a simple and cost-efficient strategy to promote the low depositing efficiency of Pt cocatalyst by traditional photoreduction method, thereby increasing the PHE activity of GCN and GCN based materials.