以含硫或金屬鐵氰化合物應用於產能及節能之元件

Abstract

本論文主要研究硫化物(第三章與第四章)及鐵氰化物(第五章與第六章)的光電化學特性，並將其應用於產能及節能系統。為了降低對電極於染料敏化太陽能電池(DSSCs)中之成本，此論文針對兩種過渡金屬硫化物之催化電極-硫銅鋅錫硫(Cu2ZnSnS4)以及氮摻雜石墨烯/二硫化鉬複合材料(NGr/MoS2)進行研究及探討。 此研究將Cu2ZnSnS4四元化合物應用於DSSCs之對電極，並針對其不同元素之莫耳比進行詳細研究及探討，接近化學計量比之Cu2ZnSnS4具有最大之薄膜表面積，且其晶粒均勻地分佈在薄膜中，將最佳化之Cu2ZnSnS4應用於DSSCs對電極，可達到7.94%之其光電轉換效率，此值相當接近以白金當DSSCs對電極之效率(8.55%)。 複合材料的概念可更進一步提升DSSCs之效率，MoS2的催化活性位置只在其材料的邊緣，限制了此材料之應用，而NGr在複合材料中扮演著骨架的角色，此可以幫助MoS2露出活性位置，當最佳化之NGr/MoS2對電極應用於DSSCs可達到7.82%之光電轉換效率，此非常接近於應用白金對電極之8.25%的效率。 於儲能科技中，電致色變元件(ECDs)需具備高光學對比以及低操作電位窗之特性，根據高光學對比之課題，普魯士藍和聚紫精應用於互補式固態電致色變元件，於可見光波545nm下，可達到62.5%之穿透度變化，此元件連續操作1,000圈後，仍可維特原穿透度變化的94%。為了降低操作ECDs的額外施加電壓，此元件提出一個自發電之電致色變系統，此研究提出一個新的複合離子儲存材料結合鐵氰化鎳以及鐵氰化鋅材料之優點，藉由調控鐵氰化鎳以及鐵氰化鋅之重量比以及結合DSSC，製備出一個自發電且不需額外施加偏壓之電致色變系統，於一個太陽光模擬系統照光下，此自發電之普魯士藍元件在690波長下具有48.1%之穿透度變化以及15.6 cm2 min-1 W-1之光著色效率。

In this dissertation, the main purpose is investigation into the photoelectrochemical properties of the sulfide (Chapter 3 & 4), and metal hexacyanoferrate electro-active materials (Chapter 5 & 6), which applied in the energy generation and saving. In order to reduce the cost of the counter electrode (CE) in the DSSCs, two transition metal sulfides, copper zinc tin sulfide (Cu2ZnSnS4) and nitrogen-doped graphene/molybdenum disulfide composite (NGr/MoS2) electrocatalysts were investigated. The quaternary electrocatalysts, Cu2ZnSnS4, was applied as the CEs in the DSSCs, and the photoelectrochemical properties of different molar ratios in CZTS films were investigated in detail. The near-stoichiometric composition of CZTS CE demonstrated larger surface area, and the grains covered on the its surface evenly. The DSSC with the optimized CZTS CE demonstrated the efficiency of 7.94%, which is close to the DSSC with platinum (Pt) CE (8.55%). In order to further increase the efficiency of DSSC, the concept of the composited CEs is introduced. The electroactive sites of MoS2 only located on the edge of their basal-planes, the stacking MoS2 limited its electrocatalytic ability. The NGr acts as the skeleton in the composited film, which could help the MoS2 expose its active site. The DSSC with the optimized NGr/MoS2 CE exhibits efficiency of 7.82%, close to 8.25% of the DSSC with Pt CE. From the view of saving energy technology, the ECDs with high optical contrast and lower applied external bias are important. According to issue of the high optical contrast ECD. A solid-state complementary ECD was prepared based on the (water-dispered Prussian blue) wPB and the poly(butyl viologen) (PBV) thin films, which achieved the transmission change (ΔT) of about 62.5% at 545 nm. After the operation of the device for 1,000 cycles, the transmittance change (ΔT) of the proposed ECD remain 94 % at 545 nm. In order to decrease the applied external bias of the ECD, a self-powered ECD were developed. A new composite ion storage material is prepared by the combination of the advantages of both nickel hexacyanoferrate (NiHCF) and zinc hexacyanoferrate (ZnHCF). The weight ratios of NiHCF and ZnHCF would be optimized and discussed. By incorporated the DSSC, the self-powered wPB-based ECD without external bias could be prepared successfully. Under an AM 1.5 simulated light illumination, the transmittance attenuation and photocoloration efficiency (PhCE) of self-powered all-wPB device showed up to 48.1% and 15.6 cm2 min-1 W-1 at 690 nm, respectively.