能源短缺及環境污染是全球高度關注且急需解決的兩大議題，故找出能無汙染地產生能源且同時具有高效益的方法是此類研究者的共同目標。利用太陽能進行光電化學水分解可得氫與氧的產物，故為產生替代能源的有效方法之一。光陽極材料BiVO4(釩酸鉍)具有許多光電化學電池(PEC)的優良特性，例如:符合水分解所需的價帶位置、能隙小(~2.4 eV)，能有效地吸收可見光。儘管如此，BiVO4仍有缺點使其發展受限，例如:電子傳導性能差、電洞擴散距離較短(~70 nm)及與水反應動力學緩慢等，而本研究致力於改善與水反應的動力學問題以提升產氧效率。
利用光沉積法將乙酸鈷錯合物(Co-Ac)沉積於BiVO4上，其中光沉積法的優點在於能將觸媒沉積於半導體之光活性位置上，且不需額外供電即可完成樣品製備。中性磷酸緩衝溶液(phosphate buffer)作為電解液，在1.23 V vs. RHE時BiVO4電流表現約為0.68 mA/cm2，而添加Co-Ac後電流表現提升至2.14 mA/cm2，可知添加助產氧催化劑Co-Ac後的電流表現提升的幅度高達三倍。在電解液中加入電洞犧牲劑的方法可以了解半導體表面之電洞注入電解液的效率，在1.23 V vs. RHE時BiVO4大約有20%的電洞能真正注入電解液中，而添加Co-Ac後可以提升至約65%，藉此證明添加助產氧催化劑Co-Ac確實能有效地幫助BiVO4克服與水反應動力學緩慢之缺點以提升產氧效率。

Energy shortage and environmental pollution are the issues that are highly concerned and urgently needed to be resolved. So the common goal of such researchers is to find ways to generate energy without pollution. The use of solar energy for photoelectrochemical water splitting is one of the effective methods to generate alternative energy sources. BiVO4 is selected as the photoanode material because it has many excellent properties as photoelectrochemical cells (PEC), such as valence band boundary range required for water splitting, narrow energy gap (~2.4 eV), and effective absorption of visible light. However, BiVO4 still has short comings that limit its development, such as poor electron mobility, short hole diffusion length (~70 nm), and slow kinetics of reaction with water. In this research, we dedicated to improving the kinetics of reaction with water to enhance oxygen evolution efficiency.
We use photochemical deposition to deposit Co-Ac on BiVO4, it can deposit the catalyst on the photoactive site of the semiconductor without additional power supply. BiVO4 photocurrent showed about 0.68 mA/cm2 in phosphate buffer (pH 7) at 1.23 V vs. RHE, and after adding Co-Ac is about 2.14 mA/cm2, which shows that the performance after adding Co-Ac is up to three times. The method of adding a hole sacrificial agent to the electrolyte can understand the ratio of the hole actually injected into the electrolyte. In this experiment, about 20% of the holes in BiVO4 at 1.23 V vs. RHE can be actually injected into the electrolyte, and after adding Co-Ac can be increased to about 65%, it can be proved that Co-Ac can help BiVO4 overcome the slow kinetics problem to achieve the purpose of improving oxygen evolution efficiency.

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