能源一直是人類所重視的議題，較為熟悉的能源包含煤礦、石油以及天然氣，這些能源在人類的工業發展時期中是非常重要的。可是這些能源皆屬於消耗性能源，而且在使用這些能源的過程中會產生溫室氣體，導致全球暖化、海平面上升以及影響動植物的生態環境。氫能不屬於上述的消耗性能源，而且使用氫能的過程中只會產生水的副產物，因此也被視為對環境友善的能源之一。氫大約占宇宙質量的75%，是相當普遍存在的元素之一，通常是以化合物的形態儲存於水中。氫能所帶動的相關產業相當廣泛，其中可分類為產氫、儲氫以及運氫三大部分。本文著重於產氫的研究項目之中。如果可以透過再生能源獲得氫氣，就能夠使用真正的乾淨能源，而且降低人類對於消耗性能源的依賴。本研究主要探討的材料是氮化鎵半導體，將氮化鎵半導體作為光電解水的光電極。本文將會討論不同的光電極於光電化學反應中。此外，氯化鈉以及海水做為本研究的電解液。期許往後能夠邁入實用階段。

Energy has always been one of the issues that humans have valued. The more familiar energy sources include coal, oil and natural gas, which were important in the industrial development of mankind. However, these energy sources are consumable energy sources, and greenhouse gases are generated during use, leading to global warming, rising sea levels and the ecological environment affecting animals and plants. Hydrogen energy is not a waste energy source as described above, and the use of hydrogen energy source only produces water by-products and is therefore considered one of the environmentally friendly energy sources. Hydrogen, which accounts for about 75% of the mass of the universe, is one of the most ubiquitous elements and is usually stored in water in the form of a compound. The related industries driven by hydrogen energy are quite extensive, and that can be classified into three parts: hydrogen production, hydrogen storage and hydrogen transportation. This article focuses on research projects that produce hydrogen. If we can get hydrogen through renewable energy, we can use real clean energy and reduce human dependence on consumable energy. The material studied in this study is gallium nitride (GaN), that was used as a photoelectrode for photoelectrolysis. This article will discuss the different photoelectrodes in photoelectrochemical reaction. In addition, sodium chloride (NaCl) and seawater were used as electrolytes for this study. It is expected to be able to enter the practical stage in the future.

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