摘要
Novel 3D flower-like Ag_(2)S/SnS_(2) composites were fabricated by a hydrothermal and ion exchange method.Uniform Ag_(2)S quantum dots were homogeneously interspersed on 3D flower-like SnS_(2).The samples were characterized through X-ray diffraction(XRD),Raman spectroscopy,scanning electron microscopy(SEM),energy-dispersive X-ray spectroscopy(EDS),transmission electron microscopy(TEM),UV-Vis diffuse reflectance spectroscopy(DRS),X-ray photoelectron spectroscopy(XPS)and photoluminescence(PL)analysis.As expected,the as-prepared Ag_(2)S quantum dot modified 3D flower-like SnS_(2) composites exhibited enhanced photoelectrochemical(PEC)performance and photocatalytic activities.The photocurrent density of 3%3D flower-like Ag_(2)S/SnS_(2) at 2.0 V(vs.Ag/AgCl)(0.65 mA cm^(-2))was about 3.25 times higher than that(0.2 mA cm^(-2))of 3D flower-like SnS_(2).The photocatalytic activity of 3D flower-like Ag_(2)S/SnS_(2) composites was assessed through the degradation of methyl orange and the photocatalytic H_(2) evolution performance under visible light irradiation.The coupling of SnS_(2) and Ag_(2)S quantum dots could notably promote the photocatalytic activity.The experimental results indicated that 3%3D flower-like Ag_(2)S/SnS_(2) composites showed the best photocatalytic performance for the degradation of methyl orange.These composites also exhibited a high H_(2) evolution rate of 574.7μmol h^(-1) g^(-1) under visible light irradiation,approximately 5.57 times higher than that of pure 3D flower-like SnS_(2).Based on the calculation,radical trapping tests and ESR,a plausible mechanism for increased photoactivity was proposed.This work provides experimental insight into the design of low-cost photocatalysts for highly efficient photodegradation and photocatalytic H_(2)-production.
基金
supported by the National Natural Science Foundation of China(No.21777063,21407065)
the Natural Science Foundation of Jiangsu Province for Youths(BK20140533)
the China Postdoctoral Science Foundation(2015 T80514)
the Jiangsu University Scientific Research Funding(No.14JDG052)
a project funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions.
