Synthesis And Photoelectrochemical Properties Of Composite Carbon Counter Electrode

Dye sensitized solar cell (DSSC) is considered as the most promising new generation of photovoltaic devices, which is due to its low price, simple preparation, environmental friendly materials, relatively high energy conversion efficiency.Dye sensitized solar cell consists of three major components:dye sensitized nanostructured semiconductor electrode, redox electrolyte and counter electrode. The counter electrode has an important role in the catalytic reduction oxidation of redox electrolyte. The performance of the electrode is largely determined by its electrical conductivity, electrocatalytic activity, chemical stability and so on. Traditional counter electrodes were made of platinum (Pt), but Pt was expensive, which limited its development on DSSC. Therefore, it was of great significance for the application of DSSC by the way of high efficiency and low cost. In this paper, Synthesis and photoelectrochemical properties of different types of composite carbon counter electrode materials were discussed.(1) Preparation and photoelectrochemical properties of F doped SnO2/carbon black composite counter electrode materials were discussed. Due to the low cost, high electrical conductivity of carbon black, besides, it had the advantage of excellent catalytic activity of iodine three compounds. F-doped SnO2 was synthesized and applied as binder to fabricate a novel mixed carbon black and F-doped SnO2 counter electrode of DSSCs. Scanning electron microscope (SEM) and X-ray diffraction (XRD) were used to characterize the crystalline phase and morphology of the films. Photoelectrochemical experiment has shown that the open circuit photovoltage of the DSSCs with F doped SnO2/carbon black composite counter electrode increased from 0.693 V to 0.710 V. The photoelectric conversion efficiency was 6.01%, which is expected to replace platinum electrode.(2) Preparation and photoelectrochemical properties of Polyaniline/carbon black composite counter electrode materials were discussed. In view of the conductive polyaniline(PANI) with excellent catalytic activity and its mesh structure, carbon black particles could effectively be adsorbed on the dendritic long-chain of polyaniline, which would greatly improve the catalytic performance of the electrode. The counter electrodes were prepared by mixing polyaniline and carbon black according to different quality at room temperature, to join in the mixture of N methyl pyrrolidone, OP emulsifier, PVP solution. Scanning electron microscope (SEM) showed that polyaniline mesh structure was apparent, a amount of carbon black particles could effectively fill the gap mesh of the polyaniline. Photoelectrochemical experiments showed that when the content of carbon black in the electrode was different, the photoelectric conversion efficiency would be different, when the carbon black fraction was 3%, the photoelectric conversion efficiency was 8.29%. At the same time, the open circuit voltage was 0.694 V.(3) Preparation and photoelectrochemical properties of ZnO(Al)/graphite composite counter electrode materials were discussed. Al doped ZnO water colloid was binder. Firstly, ZnO(Al) gels were synthesized, and we mixed it with graphite powder, pasted this product on the conductive glass. Al doped ZnO/graphite composite materials for electrode were formed after annealing. Photoelectrochemical experiments have shown that compared with platinum counter electrode, the photoelectric conversion efficiency (η) of ZnO(Al)/graphite composite electrode was 8.21%, the open circuit voltage was increased from 0.682 V to 0.690 V.