現今社會存在著能源缺乏以及環境污染的兩大問題，有效率且無汙染地產生能源的方式相當受到關注，光電化學水分解是利用太陽光的能量進行水分解產氫產氧。本研究選用釩酸鉍作為光電極材料，於由此材料能隙小(~2.5 eV)，能有效地吸收可見光，但其缺點為電子傳導性差及與水之間的反應動力學緩慢，本實驗將利用生質柴油的副產物－甘油作為犧牲試劑的角色，以甘油氧化反應取代水氧化，以減少水分解的總耗能，並同時將甘油轉化成其他更具經濟價值的產物。
利用旋轉塗佈法將釩酸鉍沉積在FTO導電玻璃上作為光陽極，在電解液中加入甘油後能使光電流提高且起始電位前移，施加電位1.23 V vs. RHE時，在四硼酸鈉電解液中光電流密度僅有0.33 mA/cm2；而在含有2.0 M甘油的情況下可達1.28 mA/cm2，提高至3.8倍，此時電洞注入電解液的效率達140%，且利用不連續光照射下在0.7 V vs. RHE之電位觀察到甘油的存在能夠減緩電流值的衰減、改善電荷重組的情況。
在含有0.1 M甘油的四硼酸鈉溶液中施加0.7 V vs. RHE的電位，經過三小時後電流值無明顯變化，顯示電極穩定性良好，且在產物分析結果中觀察到陰極的氫氣產量與理論值相近，但光陽極沒有氧氣的生成而是偵測到二羥基丙酮及甲酸(甘油氧化之產物)，產物選擇性分別為15%及85%。

Photoelectrochemical water splitting is using solar energy to convert water into H2 and O2. By doing so, we might be potentially to solve the two major problems, i.e. energy shortage and environmental pollution, at the same time. In this study, we use BiVO4 as photoanode, which has a relatively small band gap (~2.5 eV) and thus it can absorb sun light effectively. However, it has shortcomings of poor electron conductivity and slow water oxidation kinetics. In order to boost the overall efficiency, we use glycerol, a by-product from biodiesel manufacture, as a sacrificial agent to replace water oxidation by glycerol oxidation. As a result, hydrogen can be still produced at the cathode while at the anode, glycerol is converted into other more valuable products.
BiVO4 film grown on FTO via a facile spin-coating method was employed as photoanode. The photocurrent density in the electrolyte with the introduction of glycerol is much higher than that without glycerol. The onset potential shifts towards less positive potentials as glycerol introduced. With 2.0 M glycerol in solution under 1.23 V vs. RHE, the hole injection yield of 140% is observed due to the Current Multiplication effect. The photocurrent density boosts to 1.28 mA/cm2 which is more than 3.8 times higher as that of 0.33 mA/cm2 for water oxidation.
We observed good stability for BiVO4 electrode in 0.1 M glycerol solution after 3 hrs reaction at 0.7 V vs. RHE. The product analysis results show the amount of H2 detected from cathode is close to the theoretical calculation, and the main products from glycerol oxidation are formic acid and dihydroxyacetone with the selectivity of 15% and 85%, respectively.

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