Ni_(x)Co_(1-x)S as an effective noble metal-free cocatalyst for enhanced photocatalytic activity of g-C_(3)N_(4)

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 Ni_(x)Co_(1-x)S polyhedron/g-C3N4 nanosheet composites were prepared in-situ through a facile one-step hydrothermal method.The as-prepared Ni_(x)Co_(1-x)S/g-C_(3)N_(4) composites showed superior photocatalytic activity and high stability for H2 generation and methyl orange(MO)degradation under visible light irradiation.The optimized 4 wt.%Ni_(x)Co_(1-x)S/g-C_(3)N_(4) composite attained a maximum H2 evolution rate of 1420μmol g^–1 h^–1,which was about 157 times higher than that of pure g-C3N4.In addition,the Ni_(x)Co_(1-x)S/g-C_(3)N_(4) 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 Ni_(x)Co_(1-x)S 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.