氧化銅乃是一種光電化學電池 ( Photo-electrochemical cell, PEC) 的可行材料之一，可吸收光能並分解水產生氫氣。本研究以儀器分析電路板廠的高銅含量廢水，並藉由氨水進行廢水中雜質的去除，希望能使之成為以solution based method合成氧化銅奈米顆粒的可行原料，並調控製程參數，以光學特性及電化學特性探討合成出的成品的PEC表現。

本研究實驗數據表明，在利用氨水去除鐵雜質後，廢水中的鐵去除效果良好。氨水添加莫耳比例應在450：1以上；廢水與氫氧化鈉合成氧化銅時，反應溫度若為55 oC則能得到最佳的光電流表現，這是由於在此反應溫度區間所得到的氧化銅顆粒結晶性最佳。另外，本研究發現由廢水製成的電極表面可能覆蓋有殘餘的硫酸鈉晶體，因此合成顆粒後需要充分的清洗，避免造成電極表面被遮蔽而降低光電流。以反應溫度55 oC及500 oC溫度燒結一小時所製備出的電極，其能隙為1.87 eV；由於電極具有疏鬆的多孔性結構，因此可以有更大的比表面積，而可以得到較大的光電流。在施加偏壓-0.55 V vs. sat. Ag/AgCl，電解液使用1 M NaOH，光源強度為1 sun (AM1.5G) 時，光電流密度可達-1.05 mA/cm2，對應的轉換效率為0.38 %，此值較文獻略低，然而考量廢水處理的環保價值以及雜質去除的優良效率，可以認為以高銅廢水製備氧化銅奈米顆粒乃是具有可行性之製程。

CuO is one of the possible materials of photo-electrochemical cell (PEC). It can be used for splitting water and generation of hydrogen via absorbing light. In this study, I analyzed ingredients of the waste water and removed the impurities, expecting that it can be a possible raw material source of converting CuO nano-particles by solution-based method. I also adjusted the parameters of process and discuss the PEC performance of electrode made from the waste water.

The experiment data shows that the molar ratio of adding ammonium to CuSO4 in the waste water should be 450 to 1 at least. This study found that the surface of electrode made from the waste water could be covered with some Na2SO4 crystal and lower the current density. To remove that, the powder should be washed sufficiently. For powders prepared at 55 oC and sintered at 500 oC for 1 hour, the bandgaps for these electrodes were estimated to be about 1.87 eV, and the porous structure of the nanosized CuO films increased surface area and thus led to a high photocurrent, i.e. 1.05 mA/cm2. These films demonstrated 0.38% solar conversion efficiency at an applied voltage of -0.55 V vs. saturated Ag/AgCl in 1 M NaOH electrolyte with 1 sun (AM1.5G) illumination. The charge carrier density was estimated to be 6.28x1019 cm-3. This relatively high charge carrier density may be due to the high surface area and short transport distance to the electrode/electrolyte interface in the porous nanostructure.

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