利用理論計算研究水在non-polar的GaN表面上分解產生氫氣的反應過程和反應路徑，探討整個過程中的能障以及反應的可能性，另外也加入輔助催化劑Pt和Rh，加入輔助催化劑有助於反應能障降低和氫氣的生成，並探討兩種輔助催化劑的差異和效能，可以幫助我們日後在實驗上輔助催化劑的選擇。
輔助催化劑用兩種不同方式進行探討，一種是吸附在GaN表面的情況，另一種則是鑲嵌在GaN表面上，且Pt和Rh催化方式也有差別，Pt是和H先形成鍵結，H在和Pt上的H形成氫氣；Rh則是直接進行催化生成氫氣，且鑲嵌式的Rh生成氫氣的能障最低，且兩種輔助催化劑具有不同的催化效果，可能涉及了熱力學或是動力學催化。
水分解第一個H的能障0.042eV，反應容易進行，但要分解第二個H產生氫氣的能障就非常高，因此，反應途經可能不是直接將水的兩個H直接分解，而是過程中會先形成O-O鍵來穩定氧原子，進而幫助H容易和O斷鍵，將H分離，探討了另一種不同的反應路徑，且和輔助催化劑一起加入探討，有助於我們更瞭解整個水分解產生氫氣的反應過程。

A theoretical study is carried out to investigate hydrogen generation on non-polar GaN surface through water molecules decomposition. The various catalytic pathways are explored and the corresponding reaction barriers are calculated. Co-catalysts, Pt and Rh, are also taken into account in the computational models in order to understand the subsequent effect in hydrogen molecule formation and catalytic reaction barriers resulted from the presence of metal elements. The theoretical insights collected through the analysis on both transition metal elements could be helpful for the further co-catalyst development.
Two types of models for the description of co-catalyst are introduced in the current study. The first model is metal atoms being physically absorbed on surface while the other one is embedding the metal atoms in the vacant sites of GaN materials. The catalytic mechanisms of Pt and Rh were also different. Hydrogen atom favored to bond with Pt with the additional hydrogen atom interacting with PtH intermediate. Rh element played more significant role of catalyzing the H-H bond formation especially the embedded Rh was found to have a lowest reaction barrier. However, the current study could not clarify if the bottleneck step happens at a thermodynamic step or kinetic step.
The first barrier of splitting water is 0.042eV however the second barrier is quite high as more than 6 eV. The direct generation of breaking water into H2 and O2 is inaccessible without the external assistance, e.g. photon or applied voltage. Interestedly, the coupling of two OH radicals absorbed on the surface may lead to the formation O-O bond and formed HOOH. The breaking HO bond in HOOH may be another potential pathway for the source of H atoms.

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