| 摘要: | 能源議題近年來倍受關注，尤其環保及能源逐年匱乏經常是該議題中最具挑戰的項目，因此發展再生能源成為能源短缺和永續發展最好的解方，能源載體（energy carrier）之一的氫能為一種潔淨能源，可以取代傳統化石燃料且對環境汙染極低，是非常具有潛力的能源。過渡金屬硫化物為現今光催化進行水分解產氫的領域中效能較好的觸媒之一，但其光生載流子快速複合使產氫效率下降是目前面臨的一大挑戰，因此在本研究中，我們嘗試改質過渡金屬硫化物，以提高其光催化效率。
本研究藉由簡易的低溫溶劑熱法合成由有機金屬骨架（MOF）MIL-68-NH2與過渡金屬硫化物ZnIn2S4（ZIS）組成的異質結構複合物，進一步提升ZIS光催化產氫的性能。MIL-68-NH2具有高比表面積和獨特的管狀結構，因此，引入MIL-68-NH2增加的比表面積可以捕獲更多光子，此外，在MIL-68-NH2@ZnIn2S4複合物形成的同時，MIL-68-NH2形成中空結構，進一步提高活性位點的數量，而MIL-68-NH2吸收光波長範圍落在近紅外光處，ZnIn2S4與其複合後可有效地擴展光吸收範圍。為了減少材料成本，本研究於實驗中並無額外加入貴金屬（如：鉑、金等）作為共觸媒來提高產氫效率，並在室溫下以100mW/cm2的光強度照射進行反應，其中MIL10020@ZIS為最佳比例之複合物，以光觸媒總重計算得到之最高產氫效率為1901µmol/g/h。
;Recently, increasing attention has been paid to energy issues, especially in relation to environmental protection and energy scarcity, which are the most challenging aspects of the future. Therefore, the development of renewable energy has become the best solution for addressing energy shortages and promoting sustainable development. Hydrogen energy is one type of renewable and clean energies carrier, whose representative reaction is light-driven water splitting for hydrogen evolution. It can replace fossil fuels without causing environmental pollution. Hence, it’s important to develop efficient photocatalysts that can be used in hydrogen energy. Transition metal sulfides are among the most efficient photocatalysts in the field of photocatalytic hydrogen evolution, but their hydrogen evolution efficiency is hindered by the rapid recombination of photogenerated charge carriers, presenting a major challenge. Therefore, in this study, we attempted to modify transition metal sulfides to improve their photocatalytic efficiency.
We synthesized a heterostructured composite consisting of the organic metal-organic framework (MOF) MIL-68-NH2 and the transition metal sulfide ZnIn2S4 (ZIS) by a simple oil bath method to further enhance the photocatalytic hydrogen evolution performance of ZIS. MIL-68-NH2 possesses a high surface area and a unique tubular structure. Therefore, the introduction of MIL-68-NH2 not only increases the surface area of the photocatalyst for light absorption but also exposes more active sites for reaction. In addition, during the formation of the MIL-68-NH2@ZnIn2S4 composite, MIL-68-NH2 forms a hollow structure, further increasing the number of active sites. Moreover, the heterostructure composite effectively expands the light absorption range.
In order to keep the cost down, t this study didn’t add any additional precious metals, e.g., Pt and Au as co-catalyst in the reaction. The highest hydrogen evolution rate of the optimal ratio sample MIL10020@ZIS reaches up to 1901 µmol/g/h under 100 mW/cm2 of visible light intensity at room temperature. |
