CAJ | 학술논문

采用恒电压方法,以掺杂氟的SnO2(FTO)导电玻璃为基底,采用不同的聚合时间制备SO42-掺杂的聚苯胺对电极(PANI CEs).利用扫描电子显微镜(SEM)、紫外-可见(UV-Vis)吸收光谱、循环伏安法(CV)和电化学阻抗谱(EIS)等技术详细研究了聚合时间对PANI CEs的表面形貌、结构(如掺杂度、共轭性、氧化态等)和对I-/I3-的催化活性的影响. SEM结果表明PANI在FTO上的生长分两个阶段.适当增加聚合时间可以增加PANI CEs的比表面积,为催化I-/I3-反应提供更多的活性位点,同时聚苯胺链的共轭性、半氧化态聚苯胺(EB)结构的含量和对阴离子SO42-的掺杂度会随着增加,进而PANI的导电率也逐渐增大.然而,聚合时间过长会引起薄膜厚度的增加和氧化结构的过多,使PANI CEs的导电率降低,电子在PANI薄膜中的传输阻抗增加,进而影响其对I-/I3-的催化性能.聚合时间为300 s时制备出的PANI薄膜作为染料敏化太阳能电池(DSSCs)对电极和以D149为染料时,获得的最高电池光电转换效率为5.30%,可达到基于Pt对电极电池效率的88%.因此,通过电化学方法制备的PANI CEs有望代替贵金属Pt CEs用于DSSCs中.
채용항전압방법,이참잡불적SnO2(FTO)도전파리위기저,채용불동적취합시간제비SO42-참잡적취분알대전겁(PANI CEs).이용소묘전자현미경(SEM)、자외-가견(UV-Vis)흡수광보、순배복안법(CV)화전화학조항보(EIS)등기술상세연구료취합시간대PANI CEs적표면형모、결구(여참잡도、공액성、양화태등)화대I-/I3-적최화활성적영향. SEM결과표명PANI재FTO상적생장분량개계단.괄당증가취합시간가이증가PANI CEs적비표면적,위최화I-/I3-반응제공경다적활성위점,동시취분알련적공액성、반양화태취분알(EB)결구적함량화대음리자SO42-적참잡도회수착증가,진이PANI적도전솔야축점증대.연이,취합시간과장회인기박막후도적증가화양화결구적과다,사PANI CEs적도전솔강저,전자재PANI박막중적전수조항증가,진이영향기대I-/I3-적최화성능.취합시간위300 s시제비출적PANI박막작위염료민화태양능전지(DSSCs)대전겁화이D149위염료시,획득적최고전지광전전환효솔위5.30%,가체도기우Pt대전겁전지효솔적88%.인차,통과전화학방법제비적PANI CEs유망대체귀금속Pt CEs용우DSSCs중.
SO42- doped polyaniline (PANI) counter electrodes (CEs) on fluorine-doped tin oxide (FTO) glass substrates were fabricated, using electrochemical method under constant bias for different polymerization time. The effect of polymerization time on surface morphology, structure (such as doping level, conjugation and oxidization state), and electrocatalytic activity for I-/I3-redox reaction of the obtained PANI CEs was investigated by scanning electron microscopy (SEM), UV-Vis absorption spectroscopy, cyclic voltammetry (CV), and electrochemical impedance spectroscopy (EIS). SEM results indicated that the growth of PANI films on FTO substrate occurred in two phases. Properly increasing polymerization time could increase the specific surface area of PANI CEs, affording more electrocatalytic sites for the I-/I3-redox reaction. Meanwhile, the conductivity of the PANI CEs increased gradual y because of enhanced conjugation, emeraldine base (EB) structure, and SO42- doping degree. If the polymerization time was too long, however, the CE conductivity would decrease due to the formation of a thick film and superabundance of oxidized structure, resulting in an increase in the electron transfer resistance and decrease in the electrocatalytic activity of PANI CEs for I-/I3- redox reaction. Dye-sensitized solar cel s (DSSCs) based on PANI CEs with a polymerization time of 300 s and D149 dye showed the best photovoltaic performance, with a solar-to-energy conversion efficiency of 5.30%. This result is approximately 88% of the efficiency of Pt CE based-solar cel s, suggesting that PANI CEs polymerized with electrochemical method may replace Pt CEs in DSSCs.