鋯基及銅基金屬有機骨架之光催化劑複合材料在硼烷氨水解中應用

Application of Photocatalyst Composite with Zr-type and Cu-type MOFs in AB Hydrolysis

張景評(Jing-Ping Chang)

指導教授 ： 王誠佑

國立交通大學/工學院/材料科學與工程系所/碩士(2020年)

摘要

硼烷氨(ammonia borane, AB)為具有19.6wt%高儲氫量的化學氫化物，因此被視為一個具潛力的材料。雖然氧化亞銅對於AB脫氫有很好的光催化活性，但是其不穩定性及載子複合是在應用端上的主要缺點。因此我們將氧化亞銅與UiO-66-NH2混合，並利用其異質結構的特性，提升其水解效果。此外，由於此複合材料能帶位置，他們會形成Z-scheme結構。Z-scheme結構可以使複合材料有更好的載子分離及氧化還原反應。根據實驗結果，複合材料有較好的穩定性，較低的活化能及較高的產氫量。在所有樣品中，CU-50有最好的產氫效率。另外，在銅基金屬有機骨架應用於AB脫氫的實驗中，我們比較CuBDC及CuBDC-DMF在不同溶劑下對於AB脫氫的影響。結果表示，由於立體效應，甲醇為最有效之溶劑，依序為甲醇>乙醇>丙醇。而因為CuBDC及CuBDC-DMF本身結構差異，導致在產氫後Cu的價電數產生差異。

關鍵字

光觸媒 ； 產氫 ； 金屬有機骨架 ； 硼烷氨

並列摘要

Ammonia borane (NH3BH3, AB) has a high hydrogen capacity of 19.6wt%, which makes it a promising hydrogen carrier. Cu2O nanoparticles are ones of the active photocatalysts for AB dehydrogenation at ambient conditions. However, cuprous oxide instability and charge recombination are the main drawbacks of practical application. To overcome the obstacles, we have applied Cu2O with MOF as a hybrid photocatalyst Cu2O/UiO-66-NH2, which demonstrates a better photocatalytic performance because of its heterojunction configuration. Furthermore, Cu2O and UiO-66-NH2 can form Z-scheme heterojunction with their band gap positions. The composite can enhance charge separation and hydrogen production efficiency. Besides, this hybrid photocatalyst has better stability and lower activation energy. The results show that this hybrid photocatalyst has higher hydrogen evolution yield than that of Cu2O or UiO-66-NH2 alone. The optimum hybrid with 50 wt% Cu2O loading has the best amount of hydrogen from AB hydrolysis. Besides, for CuBDC used in AB methanolysis, it could produce almost three equivalents of hydrogen in a very short time. Thus, we discussed the effect of different solvents on AB hydrolysis by using CuBDC and CuBDC coordinated DMF. Because of the structure, CuBDC coordinated DMF could have better durability and had more Cu+ ions.

並列關鍵字

photocatalyst ； hydrogen production ； metal-organic frameworks ； ammonia borane

參考文獻

[1] L.Finegold andJ. L.Cude, “Biological sciences: One and two-dimensional structure of alpha-helix and beta-sheet forms of poly(L-Alanine) shown by specific heat measurements at low temperatures (1.5-20 K),” Nature, vol. 238, no. 5358, pp. 38–40, 1972, doi: 10.1038/238038a0.

[2] K.Maeda, K.Teramura, D.Lu, N.Saito, Y.Inoue, and K.Domen, “Roles of Rh/Cr2O3 (core/shell) nanoparticles photodeposited on visible-light-responsive (Ga1-xZn x)(N1-xOx) solid solutions in photocatalytic overall water splitting,” J. Phys. Chem. C, vol. 111, no. 20, pp. 7554–7560, 2007, doi: 10.1021/jp071056j.

[3] A.Kudo andY.Miseki, “Heterogeneous photocatalyst materials for water splitting,” Chem. Soc. Rev., vol. 38, no. 1, pp. 253–278, 2009, doi: 10.1039/b800489g.

[4] R.Dholam, N.Patel, M.Adami, andA.Miotello, “Hydrogen production by photocatalytic water-splitting using Cr- or Fe-doped TiO2 composite thin films photocatalyst,” Int. J. Hydrogen Energy, vol. 34, no. 13, pp. 5337–5346, 2009, doi: 10.1016/j.ijhydene.2009.05.011.

[5] Q.Xu andM.Chandra, “A portable hydrogen generation system: Catalytic hydrolysis of ammonia-borane,” J. Alloys Compd., vol. 446–447, pp. 729–732, 2007, doi: 10.1016/j.jallcom.2007.01.040.