氨是在人類社會中很重要化合物之一，而且有許多用途。由於氨的大量需求量以及面對能源短缺和環保等環境問題，在氨的製備過程中減少能源的使用和避免環境的污染並如何提升生產的效率已經是非常熱門的研究。本篇利用光催化的方法進行氮還原反應產生作為氨生產的方式。
鹵氧化鉍是一類鉍為基底的半導體二維材料，由於能隙容易控制的特性，常被用來做光催化應用。材料改良的常見的手法比如缺陷、原子摻雜、異質結等等，經常出現在光催化的應用，同樣也常出現在鹵氧化鉍的催化中。本篇使用系列中的溴氧化鉍進行光催化氮還原反應，該材料的合成方法選擇使用簡單、快速且高產率的水熱法的方式進行合成。氮還原反應是在水的環境下且不使用犧牲劑，並利用模擬太陽光作為光源來進行。得出來的原始溴氧化鉍的產率只有2.5 μmol hr-1 g-1。為了提升效率而對材料進行鐵原子的摻雜，並用EDX、XRD、EPR鑑定有成功在材料內摻雜鐵原子。摻雜後產率為5.5 μmol hr-1 g-1，效率有提升。不過為了更好的效率，在摻雜鐵原子後的材料加上磁場進行反應。其反應後的產率達到15 μmol hr-1 g-1，是原始BiOBr的7到8倍，外加磁場對BiOBr的效率有提升。

Ammonia are one of the important compounds in human society with many uses. Due to the high demand of ammonia and environmental problem such as energy crisis and eco-friendly, decreasing consuming energy, avoiding environment pollution and enhance efficiency in ammonia process are very popular research for nowadays. We use photocatalysis nitrogen reduction reaction method to produce ammonia.
Bismuth oxyhalide is a kind of bismuth-based semi-conductor two- dimensional material. Because of tunable bandgap, it is usually used in photocatalysis process. To improve material efficiency, the method such as defect manufacture, atom doping and heterojunction are the technique often be used in photocatalysis application. Bismuth oxyhalide also can improve efficiency by these methods. In this article, we use bismuth oxybromide for photocatalysis nitrogen reduction reaction, choosing solvothermal method to synthesize bismuth oxybromide, it providing simple, fast and high yield way in synthesis. Nitrogen reduction reaction is conducted in water without hole scavenger, and we use solar simulator as light source. In result, pristine bismuth oxybromide yield rate is 2.5 μmol hr-1 g-1. In order to enhance efficiency, the material is doped with iron atom and characterized by EDX、XRD、EPR, which efficiency enhance to 5.5 μmol hr-1 g-1. To obtain better efficiency from iron-doped bismuth oxybromide, the material process nitrogen reduction reaction under external magnetic field. The yield rate we obtain reach up to 15 μmol hr-1 g-1, which enhance 7-8 fold than pristine bismuth oxybromide. As the result, magnetic field can enhance the efficiency of iron-doped bismuth oxybromide.

1. Qing, G.; Ghazfar, R.; Jackowski, S. T.; Habibzadeh, F.; Ashtiani, M. M.; Chen, C.-P.; Smith III, M. R.; Hamann, T. W., Recent advances and challenges of electrocatalytic N2 reduction to ammonia. Chemical Reviews 2020, 120 (12), 5437-5516.
2. Modak, J. M., Haber process for ammonia synthesis. Resonance 2002, 7 (9), 69-77.
3. Nazemi, M.; Panikkanvalappil, S. R.; El-Sayed, M. A., Enhancing the rate of electrochemical nitrogen reduction reaction for ammonia synthesis under ambient conditions using hollow gold nanocages. Nano Energy 2018, 49, 316-323.
4. Huang, R.; Li, X.; Gao, W.; Zhang, X.; Liang, S.; Luo, M., Recent advances in photocatalytic nitrogen fixation: from active sites to ammonia quantification methods. RSC Advances 2021, 11 (24), 14844-14861.
5. Medford, A. J.; Hatzell, M. C., Photon-Driven Nitrogen Fixation: Current Progress, Thermodynamic Considerations, and Future Outlook. ACS Catalysis 2017, 7 (4), 2624-2643.
6. Choe, S.; Kim, S. M.; Lee, Y.; Seok, J.; Jung, J.; Lee, J. S.; Jang, Y. J., Rational design of photocatalysts for ammonia production from water and nitrogen gas. Nano Convergence 2021, 8 (1), 22.
7. Nayak, P. K.; Mahesh, S.; Snaith, H. J.; Cahen, D., Photovoltaic solar cell technologies: analysing the state of the art. Nature Reviews Materials 2019, 4 (4), 269-285.
8. Coronado, J. M.; Fresno, F.; Hernández-Alonso, M. D.; Portela, R., Design of advanced photocatalytic materials for energy and environmental applications. Springer: 2013.
9. Fabbri, E.; Schmidt, T. J., Oxygen Evolution Reaction—The Enigma in Water Electrolysis. ACS Catalysis 2018, 8 (10), 9765-9774.
10. Ithisuphalap, K.; Zhang, H.; Guo, L.; Yang, Q.; Yang, H.; Wu, G., Photocatalysis and photoelectrocatalysis methods of nitrogen reduction for sustainable ammonia synthesis. Small Methods 2019, 3 (6), 1800352.
11. Ye, K.; Li, K.; Lu, Y.; Guo, Z.; Ni, N.; Liu, H.; Huang, Y.; Ji, H.; Wang, P., An overview of advanced methods for the characterization of oxygen vacancies in materials. TrAC Trends in Analytical Chemistry 2019, 116, 102-108.
12. Niu, P.; Liu, G.; Cheng, H.-M., Nitrogen Vacancy-Promoted Photocatalytic Activity of Graphitic Carbon Nitride. The Journal of Physical Chemistry C 2012, 116 (20), 11013-11018.
13. Chen, F.; Huang, H.; Guo, L.; Zhang, Y.; Ma, T., The role of polarization in photocatalysis. Angewandte Chemie International Edition 2019, 58 (30), 10061-10073.
14. Asadi, K.; van der Veen, M. A., Ferroelectricity in metal–organic frameworks: characterization and mechanisms. European Journal of Inorganic Chemistry 2016, 2016 (27), 4332-4344.
15. Cui, Y.; Briscoe, J.; Dunn, S., Effect of Ferroelectricity on Solar-Light-Driven Photocatalytic Activity of BaTiO3—Influence on the Carrier Separation and Stern Layer Formation. Chemistry of Materials 2013, 25 (21), 4215-4223.
16. Huang, H.; Tu, S.; Du, X.; Zhang, Y., Ferroelectric spontaneous polarization steering charge carriers migration for promoting photocatalysis and molecular oxygen activation. Journal of Colloid and Interface Science 2018, 509, 113-122.
17. Li, S.; Bai, L.; Ji, N.; Yu, S.; Lin, S.; Tian, N.; Huang, H., Ferroelectric polarization and thin-layered structure synergistically promoting CO 2 photoreduction of Bi 2 MoO 6. Journal of Materials Chemistry A 2020, 8 (18), 9268-9277.
18. Tsymbal, E. Y., Two-dimensional ferroelectricity by design. Science 2021, 372 (6549), 1389-1390.
19. Shirodkar, S. N.; Waghmare, U. V., Emergence of Ferroelectricity at a Metal-Semiconductor Transition in a 1T Monolayer of MoS2. Physical Review Letters 2014, 112 (15), 157601.
20. Cui, C.; Xue, F.; Hu, W.-J.; Li, L.-J., Two-dimensional materials with piezoelectric and ferroelectric functionalities. npj 2D Materials and Applications 2018, 2 (1), 1-14.
21. Wei, X.; Akbar, M. U.; Raza, A.; Li, G., A review on bismuth oxyhalide based materials for photocatalysis. Nanoscale Advances 2021, 3 (12), 3353-3372.
22. Li, P.; Gao, S.; Liu, Q.; Ding, P.; Wu, Y.; Wang, C.; Yu, S.; Liu, W.; Wang, Q.; Chen, S., Recent Progress of the Design and Engineering of Bismuth Oxyhalides for Photocatalytic Nitrogen Fixation. Advanced Energy and Sustainability Research 2021, 2 (5), 2000097.
23. Li, J.; Li, H.; Zhan, G.; Zhang, L., Solar Water Splitting and Nitrogen Fixation with Layered Bismuth Oxyhalides. Accounts of Chemical Research 2017, 50 (1), 112-121.
24. Niu, X.; Shi, A.; Sun, D.; Xiao, S.; Zhang, T.; Zhou, Z.; Li, X. a.; Wang, J., Photocatalytic Ammonia Synthesis: Mechanistic Insights into N2 Activation at Oxygen Vacancies under Visible Light Excitation. ACS Catalysis 2021, 11 (22), 14058-14066.
25. Wang, S.; Hai, X.; Ding, X.; Chang, K.; Xiang, Y.; Meng, X.; Yang, Z.; Chen, H.; Ye, J., Light‐switchable oxygen vacancies in ultrafine Bi5O7Br nanotubes for boosting solar‐driven nitrogen fixation in pure water. Advanced Materials 2017, 29 (31), 1701774.
26. Bai, Y.; Ye, L.; Chen, T.; Wang, L.; Shi, X.; Zhang, X.; Chen, D., Facet-Dependent Photocatalytic N2 Fixation of Bismuth-Rich Bi5O7I Nanosheets. ACS Applied Materials & Interfaces 2016, 8 (41), 27661-27668.
27. Di, J.; Xia, J.; Li, H.; Guo, S.; Dai, S., Bismuth oxyhalide layered materials for energy and environmental applications. Nano Energy 2017, 41, 172-192.
28. Zhang, J.; Lv, J.; Dai, K.; Liang, C.; Liu, Q., One-step growth of nanosheet-assembled BiOCl/BiOBr microspheres for highly efficient visible photocatalytic performance. Applied Surface Science 2018, 430, 639-646.
29. Zhang, A.; Xing, W.; Zhang, D.; Wang, H.; Chen, G.; Xiang, J., A novel low-cost method for Hg0 removal from flue gas by visible-light-driven BiOX (X=Cl, Br, I) photocatalysts. Catalysis Communications 2016, 87, 57-61.
30. Ye, L.; Su, Y.; Jin, X.; Xie, H.; Zhang, C., Recent advances in BiOX (X= Cl, Br and I) photocatalysts: synthesis, modification, facet effects and mechanisms. Environmental Science: Nano 2014, 1 (2), 90-112.
31. Ye, L.; Tian, L.; Peng, T.; Zan, L., Synthesis of highly symmetrical BiOI single-crystal nanosheets and their {001} facet-dependent photoactivity. Journal of Materials Chemistry 2011, 21 (33), 12479-12484.
32. Mohebinia, M.; Wu, C.; Yang, G.; Dai, S.; Hakimian, A.; Tong, T.; Ghasemi, H.; Wang, Z.; Wang, D.; Ren, Z.; Bao, J., Ultrathin bismuth oxyiodide nanosheets for photocatalytic ammonia generation from nitrogen and water under visible to near-infrared light. Materials Today Physics 2021, 16, 100293.
33. Hao, Y.-C.; Guo, Y.; Chen, L.-W.; Shu, M.; Wang, X.-Y.; Bu, T.-A.; Gao, W.-Y.; Zhang, N.; Su, X.; Feng, X.; Zhou, J.-W.; Wang, B.; Hu, C.-W.; Yin, A.-X.; Si, R.; Zhang, Y.-W.; Yan, C.-H., Promoting nitrogen electroreduction to ammonia with bismuth nanocrystals and potassium cations in water. Nature Catalysis 2019, 2 (5), 448-456.
34. Li, H.; Shang, J.; Ai, Z.; Zhang, L., Efficient visible light nitrogen fixation with BiOBr nanosheets of oxygen vacancies on the exposed {001} facets. Journal of the American Chemical Society 2015, 137 (19), 6393-6399.
35. Bai, Y.; Bai, H.; Qu, K.; Wang, F.; Guan, P.; Xu, D.; Fan, W.; Shi, W., In-situ approach to fabricate BiOI photocathode with oxygen vacancies: Understanding the N2 reduced behavior in photoelectrochemical system. Chemical Engineering Journal 2019, 362, 349-356.
36. Wang, X.; Zhou, C.; Yin, L.; Zhang, R.; Liu, G., Iodine-Deficient BiOI Nanosheets with Lowered Valence Band Maximum To Enable Visible Light Photocatalytic Activity. ACS Sustainable Chemistry & Engineering 2019, 7 (8), 7900-7907.
37. Li, Y.; Jiang, H.; Wang, X.; Hong, X.; Liang, B., Recent advances in bismuth oxyhalide photocatalysts for degradation of organic pollutants in wastewater. RSC Advances 2021, 11 (43), 26855-26875.
38. Liu, Y.; Hu, Z.; Yu, J. C., Fe Enhanced Visible-Light-Driven Nitrogen Fixation on BiOBr Nanosheets. Chemistry of Materials 2020, 32 (4), 1488-1494.
39. Di, J.; Xia, J.; Yin, S.; Xu, H.; Xu, L.; Xu, Y.; He, M.; Li, H., One-pot solvothermal synthesis of Cu-modified BiOCl via a Cu-containing ionic liquid and its visible-light photocatalytic properties. RSC Advances 2014, 4 (27), 14281-14290.
40. Zeng, L.; Zhe, F.; Wang, Y.; Zhang, Q.; Zhao, X.; Hu, X.; Wu, Y.; He, Y., Preparation of interstitial carbon doped BiOI for enhanced performance in photocatalytic nitrogen fixation and methyl orange degradation. Journal of Colloid and Interface Science 2019, 539, 563-574.
41. Huang, Y.; Zhang, N.; Wu, Z.; Xie, X., Artificial nitrogen fixation over bismuth-based photocatalysts: fundamentals and future perspectives. Journal of Materials Chemistry A 2020, 8 (10), 4978-4995.
42. Li, M.; Lu, Q.; Liu, M.; Yin, P.; Wu, C.; Li, H.; Zhang, Y.; Yao, S., Photoinduced Charge Separation via the Double-Electron Transfer Mechanism in Nitrogen Vacancies g-C3N5/BiOBr for the Photoelectrochemical Nitrogen Reduction. ACS Applied Materials & Interfaces 2020, 12 (34), 38266-38274.
43. Xu, F.; Xu, C.; Wu, D.; Gao, Z.; Ma, X.; Jiang, K., Bi2S3/BiOBr hybrid structure prepared via anion exchange for enhanced photocatalytic nitrogen fixation performance. Materials Letters 2019, 253, 183-186.
44. Dai, Y.; Poidevin, C.; Ochoa‐Hernández, C.; Auer, A. A.; Tüysüz, H., A supported bismuth halide perovskite photocatalyst for selective aliphatic and aromatic C–H bond activation. Angewandte Chemie 2020, 132 (14), 5837-5845.
45. Hsu, C.-L.; Li, Y.-J.; Jian, H.-J.; Harroun, S. G.; Wei, S.-C.; Ravindranath, R.; Lai, J.-Y.; Huang, C.-C.; Chang, H.-T., Green synthesis of catalytic gold/bismuth oxyiodide nanocomposites with oxygen vacancies for treatment of bacterial infections. Nanoscale 2018, 10 (25), 11808-11819.
46. Li, J.; Pei, Q.; Wang, R.; Zhou, Y.; Zhang, Z.; Cao, Q.; Wang, D.; Mi, W.; Du, Y., Enhanced Photocatalytic Performance through Magnetic Field Boosting Carrier Transport. ACS Nano 2018, 12 (4), 3351-3359.
47. Pan, L.; Ai, M.; Huang, C.; Yin, L.; Liu, X.; Zhang, R.; Wang, S.; Jiang, Z.; Zhang, X.; Zou, J.-J.; Mi, W., Manipulating spin polarization of titanium dioxide for efficient photocatalysis. Nature Communications 2020, 11 (1), 418.
48. Li, H.; Zhang, L., Photocatalytic performance of different exposed crystal facets of BiOCl. Current Opinion in Green and Sustainable Chemistry 2017, 6, 48-56.
49. Li, J.; Zhang, L.; Li, Y.; Yu, Y., Synthesis and internal electric field dependent photoreactivity of Bi3O4Cl single-crystalline nanosheets with high {001} facet exposure percentages. Nanoscale 2013, 6 (1), 167-171.
50. Yang, X.; Yang, X.; Peng, Y.; Li, Z.; Yu, J.; Zhang, Y., Regulating the Built-In Electric Field of BiOBr by a Piezoelectric Mineral Tourmaline and the Enhanced Photocatalytic Property. Industrial & Engineering Chemistry Research 2022, 61 (4), 1704-1714.
51. Li, H.; Shang, J.; Shi, J.; Zhao, K.; Zhang, L., Facet-dependent solar ammonia synthesis of BiOCl nanosheets via a proton-assisted electron transfer pathway. Nanoscale 2016, 8 (4), 1986-1993.