Ni Co1-S as an effective noble metal-free cocatalyst for enhanced photocatalytic activity of g-C3N4

Abstract Solar photocatalysis, as a method of green energy production and sustainable technology, has been regarded as one of the most effective strategies to resolve environmental issues and the current energy crisis. In this work, intimate contact hollow NixCo1-xS polyhedron/g-C3N4 nanosheet composites were prepared in-situ through a facile one-step hydrothermal method. The as-prepared NixCo1-xS/g-C3N4 composites showed superior photocatalytic activity and high stability for H2 generation and methyl orange (MO) degradation under visible light irradiation. The optimized 4 wt.% NixCo1-xS/g-C3N4 composite attained a maximum H2 evolution rate of 1420 μmol g–1 h–1, which was about 157 times higher than that of pure g-C3N4. In addition, the NixCo1-xS/g-C3N4 composite also exhibited greatly improved photocatalytic activity for dye degradation, which for MO was at 98.14 % in 9 min. The outstanding photocatalytic performance was predominantly attributed to the unique architecture of hollow NixCo1-xS polyhedrons, which not only provided more active sites at the edges and surface as convenient charge transfer channels, but also promoted the separation and transport of electron-hole pairs. This work provides some novel ideas for the design and development of highly efficient noble metal-free cocatalyst/semiconductor systems for photocatalytic H2 generation and dye degradation.