在進行電催化產氫及產氧反應會造成相當多的能源消耗，而對於產氧反應具有高催化活性之觸媒多為貴金屬氧化物，如RuOx和IrOx。但是，貴金屬材料成本較高，因此並不適合進行大規模生產。在本研究中，透過光化學金屬有機沉積法(photochemical metal-organic depositions, PMOD)製備對電催化產氧反應具有高催化活性之非晶相金屬氧化物觸媒。由於PMOD法是一種方便、製備及設備成本低且可進行量產的方法。本研究之目標為尋找於地殼中具有高含量且為非貴重金屬之材料，提升其電解水產氧之活性。Molybdenum為電催化產氧反應之活性觸媒且為工業界常用之材料，與其他金屬氧化物進行混合能使其穩定性增加，因此在本研究中，加入molybdenum 與其他金屬混合製備成金屬氧化物電極。

PMOD法能夠製備出與前驅物中比例相同之非晶相金屬氧化物，因此可以藉由此方法來探討金屬氧化物中所含之Fe、Co及Mo比例對於產氧反應的影響，而電極的組成也與EDS測試結果相符。在線性掃描伏安圖可以發現，Fe10Co25Mo65Ox之起始電位為1.52 V，而FeOx與MoOx的起始電位分別為1.64V和1.86V。而當電流密度達到1 mA cm-2時，Fe10Co25Mo65Ox所需電位為1.55 V，而FeOx則為1.70 V。在動力學的部分，Fe10Co25Mo65Ox所具有之Tafel slope為31 mV dec-1，相較於FeOx與CoOx的43 ± 1 mV dec-1和44 ± 2 mV dec-1，證明Fe10Co25Mo65Ox具有良好的產氧反應之催化活性。本研究為了探討金屬氧化物觸媒在進行電催化產氧反應中的穩定性，因此利用定電流(1 mA)進行反應24小時。當反應停止後，Fe10Co25Mo65Ox的反應電位幾乎沒有變化。由以上數據可以證明Fe10Co25Mo65Ox在進行產氧反應時，不論在催化活性或者是穩定性都具有突出的表現，可以作為一個良好的產氧觸媒。

Water splitting reaction costs a lot of energy to produce oxygen and hydrogen. The best catalysts for water oxidation (oxygen evolution reaction, OER) are expensive metal oxides, such as RuO2 and IrO2; however, they cannot be used widely due to their rarity. In this research, we used photochemical metal-organic depositions (PMOD), a convenient, low-cost technique capable of producing highly active amorphous mixed-metal oxide OER catalysts. In this study, trying to find the abundant material on the crust of the earth, and promoting the activity of OER is our main purpose. Molybdenum is a widely used material in industry, and it also can prove the stability when it is mixed with other metal oxides. Therefore, this research will focus on the series of molybdenum oxides for OER.

PMOD method was used to synthesize the amorphous mixed metal oxide films containing specific ratio of iron, cobalt, and molybdenum to figure out how metal affects OER. The compositions were the same and uniform distributed as they were in the precursor solution based on EDS analysis. In order to check the performance of metal oxides, Linear sweep voltammetry, and Tafel slope were plotted. The onset potential of Fe10Co25Mo65Ox was only 1.52 V, but FeOx and MoOx required 1.64 Vand 1.86 V, respectively. When the current density reached 1 mA cm-2, the potential for Fe10Co25Mo65Ox required 1.55 V, and 1.70 V for iron oxides. From Tafel slope, the value of Fe10Co25Mo65Ox was only 31 ± 1 mV dec-1, comparing to 44 ± 2 mV dec-1 for cobalt oxides, that meant Fe10Co25Mo65Ox had better catalytic ability. Stability was also a crucial property for electrodes. In this research, checking the stability by using chronopotentiometry set the current at 1 mA, reacted for 24 hours. The potential of Fe10Co25Mo65Ox almost unchanged. From these results, we can confirm that Fe10Co25Mo65Ox is an outstanding catalyst for OER.

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