本實驗採用碘離子氧化反應 (Iodide oxidation reaction, IOR) 取代傳統水電解陽極的產氧反應 (Oxygen evolution reaction, OER)。利用IOR 氧化電位比 OER 相對較低的優勢，整體氫氣的生產具有產氫能耗降低的優勢，還生產更具經濟價值的碘。
本實驗中使用的觸媒是源自葡萄糖的非金屬碳球 (Carbon spheres, CS)。 此外，經由摻雜或改變碳化溫度開發了一系列碳基無金屬觸媒 (Carbon-based metal-free catalysts, CMFCs)。我們發展出了一種用於 IOR 的碳基電觸媒，具有出色的酸性條件耐受性、結構穩定性和可持續性，最重要的是在沒有金屬觸媒的應用下，具有相當優異的催化活性，為一種綠色、高實用性的觸媒。
通過掃描電子顯微鏡 (SEM)、拉曼光譜 (Raman)、軟X射線吸收光譜 (XAS)、X射線光電子能譜 (XPS) 等對材料進行了鑑定。在拉曼光譜結果中，可以發現元素摻雜 (包含氮、氧、磷、硫) 可以有效改變 ID/IG。從 FTIR、XPS 和 XAS 的結果可以發現，當C=O的鍵結較多且該鍵結上碳原子的電子密度較低時，可以有效提高 IOR 的活性。這意味著在材料中製造更多的碳陽離子 (Cδ+) 可以更有效地吸引電解液中的碘離子，促進 IOR 反應。
從元素分析也可以看出，只要摻雜少量的硫，就可以有效地提高活性。在電化學性能方面，1 wt% 硫摻雜的觸媒 (2SCS/TF) 活性性能最好，起始電位為0.61 V，電流密度10 mA/cm2時的電位低至0.64 V，明顯優於 OER。在72小時的穩定性測試中，硫摻雜碳球可以在10 mA/cm2的恆電流下穩定且持續地操作，電壓提高僅為8.9%。

In this thesis, the iodide oxidation reaction (IOR) was used to replace the oxygen evolution reaction (OER) at the anode of the traditional water electrolysis. Through the relatively low oxidation potential of IOR than OER, the overall hydrogen production has the advantage of lower energy consumption and the process produces more economically valuable iodine in addition to hydrogen.
The catalysts used in this experiment are non-metallic carbon spheres (CS) are derived from glucose. Further, a series of carbon-based metal-free catalysts (CMFCs) are developed by doping or changing the carbonization temperature. We demonstrate a carbon-based electrocatalysts for IOR with excellent tolerance to acidic conditions, structural stability, and sustainability. The most important thing is that it has excellent electrocatalytic activity and can be a green and viable catalyst.
The materials were examined by scanning electron microscope (SEM), Raman spectroscopy, soft X-ray absorption spectroscopy (XAS), X-ray photoelectron spectroscopy (XPS), etc. In the Raman spectroscopic results, it can be found that the elemental doping (including N, O, P, S) was found to change the ID/IG effectively. From the results of FTIR, XPS, and XAS, it is found that the IOR activity can be further improved when there are more C=O bonds, where the electron density of the carbon atoms is low. This indicate that more carbocations (Cδ+) in CMFCs can attract more iodide ions in the electrolyte and promote the IOR reaction.
It is interesting to note that a small amount of sulfur doping can effectively increase the activity. In terms of electrochemical performance, the carbon catalyst with 1 wt% sulfur doping (2SCS/TF) on titanium foam has the best activity performance, exhibiting an onset potential of 0.61 V and a potential as low as 0.64 V at 10 mA/cm2, which is significantly more energy-efficient than a typical OER. In a 72-hour chronopotential stability test, the sulfur-doped carbon spheres can operate continuously at a constant current of 10 mA/cm2, and the voltage varies only 8.9%.

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