Two-Dimensional\nLayered Co(OH)₂/g‑C₃N₄/Ni(OH)₂ Ternary Nanocomposites for\nEnhanced Visible-Light Photocatalytic H₂‑Production\nActivity

Abstract

Two-dimensional\n(2D) layered nanocomposite provides a surface-to-surface\nheterojunction, which is an effective way to improve the photocatalytic\nperformance because larger contact areas can promote the separation\nrate of interfacial charge carriers. In this study, Co­(OH)₂/g-C₃N₄/Ni­(OH)₂ 2D layered photocatalysts\nhave been successfully synthesized through a simple precipitation–hydrothermal\nmethod. The composite achieves a high H₂-production rate\nof 899 μmol·h^–1·g^–1, which exceeds the rate of samples only coupled with Co­(OH)₂ and Ni­(OH)₂ by 4.0 and 1.9 times, respectively.\nIn addition, the activity is even higher than that of the optimized\nPt-g-C₃N₄ sample (1 wt. % Pt–C). The\ncharacterization results reveal the close contact of g-C₃N₄ and Ni/Co hydroxides, and such a face-to-face contact\ncan greatly improve the interfacial charge-transfer rate, resulting\nin a high photocatalytic performance. This work demonstrates a simple\nway to enhance the photocatalytic H₂ production of g-C₃N₄ under the cooperative effect of Co­(OH)₂ and Ni­(OH)₂ and provides novel insights into constructing\nother 2D ternary heterostructure nanocomposites.