Growth And Electrocatalytic Properties Of Two-dimensional Transition Metal Chalcogenides

Energy is important for the development of national economy and the improvement of human living standards.With the decrease of traditional energy resources and the aggravation of environmental pollution,the development and utilization of safe,clean and renewable energy has attracted much attention.Solar energy is undoubtedly one of the most promising energy sources.So dye-sensitized solar cells have been favored by researchers for their low cost and high solar-power conversion efficiency?PCE?.Traditional dye-sensitized solar cells mostly use metal platinum as the electrode material,but its large-scale application is limited by its high cost.Therefore,the search for new non-Pt electrode materials has become a research hotspot,among which transition metal chalcogenides have very important application potential in the field of solar cells due to their special optical,electrical,magnetic and superconducting properties.At the same time,the potential of electrode materials in the process of photoelectric conversion has not been fully exploited.From this point of view,this thesis explores the maximum potential of electrodes photoelectric conversion and looks for materials that can replace traditional Pt pair electrodes to reduce the cost of solar cells.Based on the above objectives,the main work of this thesis includes the following aspects:1.A layer of molybdenum film was deposited on FTO conductive glass by pulsed laser deposition.The coverage of the film was controlled by a mask.Then,by gas phase sulfide method,Mo was converted into MoS₂ which obtaining molybdenum disulfide films with different areas.Through different characterization methods,it was found that under the control of the mask,molybdenum disulfide films did not grow in the areas covered by the mask,but only in the exposed areas.The films have good crystallinity and smooth surface.When using as the counter electrodes of DSSCs,the results shows that the efficiency of dye-sensitized solar cells does not decrease with the proportion of the area of MoS₂ if the coverage is larger than 27%.This indicates that reducing the area of the electrode pair does not affect the photoelectric conversion efficiency of the cells.This provides a new exploration direction and feasible method for effectively exploring the potential of electrodes to save the cost of solar cell manufacturing in the future.2.Pure MnS thin films,NiS₂ thin films and their heterostructures are grown on FTO conductive substrates by pulsed laser deposition and vapor sulfuration.The thickness of the films can be adjusted by controlling the number of pulses and the energy of the laser.The electrochemical test results show that the dye-sensitized solar cells assembled with prepared samples have excellent electrochemical performance and high photoelectric conversion efficiency.Compared with the expensive metal platinum,they are more abundant in resources and cheaper in price.It is helpful for the promotion of dye-sensitized solar cells and makes up for the shortcomings of metal platinum.