過渡金屬摻雜磷化鈷之合成與應用於電催化水分解之研究

由於全球能源的需求量日益增加且為了達到維護環境與永續利用的概念，科學家們正積極努力地找尋可替代石化燃料之能源，由於氫氣為一乾淨且具高能量密度之燃料，因此電催化水分解產氫被視為具有解決能源危機與環境汙染的最佳方法，而一般具有高催化活性的物質都為貴重金屬居多，基於成本過高與不易取得之問題，限制其大規模的應用，因此找尋可替代貴重金屬之催化劑被視為近年來研究重點。然而在進行電催化水分解時不僅僅只有陰極的產氫反應，同時也包含了陽極的析氧反應，要是能夠發展出可運用在兩極上的材料的話，更是一舉兩得。在本研究中，我們利用水熱法合成鈷之前驅物與鈷鐵混合之前驅物，然後再搭配化學氣相沈積法將其在充滿磷的氣體下轉變為磷化物，分別應用於水分解之陰極析氫與陽極析氧反應，由於磷化物本身具有金屬的特性，電子較易傳遞，因此在進行陽極產氧反應時，相對於氧化物而言會更加有利。我們再利用添加不同含量的鐵來修飾其形貌與優化其效能，最後再將磷化物附載於碳布上，結合碳布優異的性能，具有可饒性和良好的導電性，使得在進行電催化時，讓電子能夠快速地從碳布傳導至觸媒上，而且又是三維的立體基材，不僅能夠大幅的增加活性表面積，電催化時氣體更容易能夠脫附於電極表面，大幅降低氣泡窒礙活性的問題。經由整體性能的改善後，我們研究出能夠運用於兩極的材料，且性能能夠媲美貴重金屬，對於取代貴重金屬有了更進一步的發展。

關鍵字

水分解；雙功能；過渡金屬磷化物

並列摘要

Because the global demand for energy rapidly increased in the past decades, scientists are looking for renewable and clean energy with the aim of substituting for fossil fuels. Hydrogen has been considered as a high density energy and clean fuel, so that the electrolysis of water for hydrogen production may be a promising way to solve the energy crisis and environment pollution. However, most of highly active electrocatalysts are commonly precious metal, their major drawbacks are high cost and insufficient reserve that restricts practical application. As a result, developing earth-abundant, active and stable catalysts which can operate in the same electrolyte for water-splitting is important for many renewable energy conversion processes. In this research, we utilized the gas-solid reaction to synthesize the cobalt phosphide with dopant of iron. Because the transition metal phosphides (TMPs) are characteristic of metallic properties, which can facilitate the water-splitting reaction owing to an effective charge-transfer. The morphology and catalytic capability can be further modified via doping various amount of iron. Finally, combination of the iron doping and carbon cloth as a hybrid material with flexible and conductive properties can facilitate the charge transfer from substrate to catalyst and lead to an enhanced performance. Besides, bubble releasing problem during the reaction can be remarkably suppressed owing to 3D structure of carbon cloth. Consequently, we successfully synthesized the hybrid material that can perform excellent activities toward both the oxygen and hydrogen evolution reaction. These strategies of TMPs are instructive for designing non-noble metal catalysts for future applications.

並列關鍵字

water splitting ； bifuntional ； transition metal phosphides

參考文獻

4. Fujishima, A.; Honda, K. Electrochemical photolysis of water at a semiconductor electrode. Nature. 1972, 238, 37-38.

5. Kudo, A.; Miseki, Y., Heterogeneous photocatalyst materials for water splitting. Chem. Soc. Rev. 2009, 38, 253-278.

6. Navarro, R. M.; Alvarez-Galvan, M. C.; Villoria de la Mano, J. A.; Al-Zahrani, S. M.; Fierro, J. L. G. A framework for visible-light water splitting. Energy Environ. Sci. 2010, 3 , 1865-1882.

7. Morales-Guio, C. G.; Stern, L. A.; Hu, X. Nanostructured hydrotreating catalysts for electrochemical hydrogen evolution. Chem. Soc. Rev. 2014, 43, 6555-6569.

8. N?rskov, J. K.; Bligaard, T.; Logadottir, A.; Kitchin, J. R.; Chen, J. G.; Pandelov, S.; Stimming, U. Trends in the exchange current for hydrogen evolution. J. Electrochem. Soc. 2005, 152 , J23-J26.

國際替代計量

過渡金屬摻雜磷化鈷之合成與應用於電催化水分解之研究

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