Research Of Nickel Suifide Electrode With High Catalytic Activity For Dye-sensitized Solar Cells

Dye-sensitized solar cells?DSSCs?have attracted a large number of researchers for the simple technology,rich raw materials and excellent efficiency.Generally,DSSC devices are composed of semiconductor photoanode,electrolyte and counter electrode.As one of the core components of DSSC,counter electrode is responsible for collecting electrons from external circuit and catalyzing the redox electric pair regeneration in electrolyte.The traditional platinum electrode has excellent electrocatalytic activity and good conductivity,which is widely used in DSSC.However,the geological reserves of platinum are very rare and the price is very expensive.Therefore,it is of great significance to develop new cheap and efficient counter electrode materials for reducing the cost of DSSC and promoting the large-scale application of DSSC.In this paper,three kinds of low-cost and high-efficiency DSSC new-type counter electrode materials are developed,which are porous cotton carbon fiber film?PCC?with Ni S modification,Ni S nanowires material and honeycomb-like Ni S porous film.The preparation technology and related properties of these materials are systematically studied.The specific work is as follows:1.Preparation and properties of porous cotton carbon fiber?PCC?film electrode?Ni S/PCC?modified by Ni S.The flexible porous cotton carbon fiber cloth?PCC?was successfully prepared by high temperature carbonization under the protection of inert gas argon.One dimensional carbon fiber structure makes PCC have good conductivity,and its pore structure makes PCC have huge specific surface area and electrocatalytic activity.In order to improve its electrocatalytic performance,the periodic reverse pulse potentiometry was used to deposit a small amount of Ni S on the surface of PCC,and then the Ni S/PCC composite was obtained.We have studied the properties of these materials systematically.The results show that the electrocatalytic properties of Ni S/PCC are obviously improved due to the addition of a large number of high catalytic activity Ni S sites.Because of its porous structure,Ni S/PCC has a large specific surface area and higher electrocatalytic performance.Its photoelectric conversion efficiency is 6.80%,even slightly higher than that of flat Pt electrode?6.69%?.In addition,this kind of material also has the characteristics of low cost,flexibility and light weight,all of which make it a high-efficiency counter electrode material with large-scale application potential.2.Preparation and properties of Ni S nanowires counter electrode The precursor of Ni?SO4?0.3?OH?1.4 nanobelt was synthesized by hydrothermal method,and then it was vulcanized by ion exchange method.The Ni S nanowire was successfully prepared,and its related properties were studied systematically.The results show that the material not only has a large specific surface area,but also has one-dimensional nanostructure which is conducive to electron transport,and its porous structure is conducive to the diffusion of electrolyte?I₃^-/I^-?.It is proved that the counter electrode formed by this Ni S nanowires has not only good conductivity,but also excellent electrocatalytic performance.It can be used as a cheap and efficient DSSC counter electrode material in dye-sensitized solar cells.3.The preparation and electrocatalytic properties of Ni S film with honeycomb structure.A layer of Ni S was electrodeposited on the template surface of monodisperse polystyrene microspheres by template method.After removing the template,Ni S film with honeycomb porous structure was obtained.The results show that the honeycomb porous Ni S material has a large specific surface area and better electrocatalytic performance compared with the flat Ni S.When it is used as the counter electrode of DSSC,the photoelectric conversion efficiency of the cell can reach 6.77%,even more than 6.67% of the platinum electrode.It is proved that this kind of Ni S film with honeycomb structure has excellent electrocatalytic performance,and can be used as a cheap and efficient counter electrode material in dye-sensitized solar cell.