Fabrication And Photoelectric Performance Of Metal Sulfide Nanostructured Films In Energy Devices

With the rapid development of global economy and population,the demand of renewable energy is continuously increasing,and then how to efficiently transform and store renewable energy has become a hot spot of research.Transition metal sulfides,which are non-toxic and abundant in nature,have aroused much attention due to their excellent conductivity,stability and photoelectrochemical performance.In this dissertation,a series of binary/ternary and hierarchical nanostructured metal sulfide films are fabricated on different substrates,such as conducted FTO glass,carbon cloth,Ti mesh and Ni foam,and then applied in energy devices.The synthetic methods and the growth mechanism of the nanostructured materials are investigated as well.In addition,the corresponding electrochemical ability,photocatalytic activity and energy storage performance of the nanostructured metal sulfide materials have also been studied in the fields of quantum dot-sensitized solar cells(QDSCs),photocatalysis and supercapacitors.The main novelty and achievements of this dissertation are outlined as follows:1.Various methods have been used to fabricate CuS nanosheet films on FTO substrates.The obtained samples are characterized and then served as counter electrodes in QDSCs.The QDSC based on the optimized CuS counter electrode exhibits a considerable power conversion efficiency(PCE)value of 3.82%as compared to the traditional noble metal Pt counter electrode(1.56%).2.A general approach has been developed to produce hierarchical hybrid metal sulfide nanomaterials.The novel coralloid Co9S8-CuS hierarchical films are firstly fabricated on different substrates(conducted FTO glass,carbon cloth,Ti mesh,and Ni foam),and act as electrode materials in QDSCs and supercapacitors.According to electrochemical measurements,they show superior electrochemical ability and stability compared to the single material(Co9S8 and CuS).Besides,the hierarchical Co9S8-NiS2 and Co9S8-MoS2 nanostructure films are also successfully synthesized in the similar way,which implies the universality of the method.3.Ternary sulfide Cu2Mo6S8 films with needle-leaf-like structures are firstly grown on copper plates via a facile two-step route.Interestingly,the Cu2Mo6S8 films exhibit significantly photocatalytic performance in degradation of MB dye under visible light,owing to their unique needle-leaf-like structures and suitable energy level.