利用溶劑法合成二硫化鐵奈米晶體並與石墨烯混摻作為析氫觸媒之應用

Abstract

氫能是一乾淨能源，而且為最具有潛力能取代石油，成為一新穎燃料。因此，利用電解水產氫反應也越來越具有一定的重要性，成為重要的可再生能源之一。雖然像是鉑金屬之類的貴重金屬，在析氫反應中具有高效率的產氫能力，但因為貴重金屬其地球含量不多，使其成本相當高昂，難以大規模應用。因此開發新型便宜且地表上含量豐富之析氫觸媒就很重要了。 此研究中，本實驗團隊利用溶劑熱法有效的合成出不同結構之二硫化鐵奈米晶體，並且與還原態氧化石墨烯藉由超音波震盪作混合結合動作。使得二硫化鐵奈米晶體與還原態氧化石墨烯複合材料能做為一新式析氫反應之觸媒。 立方體二硫化鐵奈米晶體與還原態氧化石墨烯之複合材料比起純二硫化鐵奈米晶體與具有更良好的析氫活性。於極化曲線量測中發現，此複合材料之onset potential 約210 mV。而其Tafel slope 值約80 mV/dec。而其立方體二硫化鐵奈米晶體與還原態氧化石墨烯之複合材料之穩定性比球型及立方體二硫化鐵奈米晶體要好。並推測其立方體二硫化鐵奈米晶體與還原態氧化石墨烯之複合材料的反應機制為Volmer-Heyrovsky反應。最後，我們成功利用地球豐富且無毒性之二硫化鐵奈米晶體與還原態氧化石墨烯之複合材料當作析氫觸媒。Hydrogen energy is clean and serves as one of the most promising candidates for replacing petroleum fuels in the future. Although the rare metals, such as platinum, have high efficiency in the hydrogen evolution reaction (HER), their scarcity and high cost inhibit large scale applications. Thus, developing new, inexpensive, and abundant HER catalysts remain challenging. In this study, we developed a new electrocatalyst in the hydrogen evolution reaction (HER) based on hybrid of FeS2 nanocubes and reduced graphene oxide by sonication to form the FeS2 nanocubes-rGO nanocomposites. The FeS2 nanocubes-rGO hybrid exhibited superior electrocatalytic activity in the hydrogen evolution reaction (HER) than the pristine FeS2 nanocubes. The catalytic performance of FeS2 nanocubes-rGO hybrid showed a low overpotential ~ 210mV with a Tafel slope of ~80mV/decade. The ~80 mV/decade Tafel slope suggested the Volmer-Heyrovsky mechanism for the FeS2-catalyzed HER, with electrochemical desorption of hydrogen as the rate-limiting step.