隨著溫室效應日益嚴重，發展可替換石化燃料的能源越發重要，如太陽能、氫能等。其中利用太陽能催化水解產氫有巨大的潛能，因為地球富含水分，而氫氣燃燒不會生成溫室氣體，因此氫能具有極高的開發價值。為了達到此目的，發展效能優秀的光催化元件便是此研究的主要目標。此光催化元件能有效利用光能激發光生電子，並運用光生電流進行水解，已產生氫氣作為能源利用。
此研究將開發利用葉綠素修飾金屬氧化物半導體異質材料的光催化元件，並作為光電化學系統的光陽極。葉綠素將從小球藻中萃取出來，並利用有機溶劑溶解製成溶液。葉綠素為常見的光敏化材料，能捕捉更多可見光範圍的光能，並激發更大光電流。金屬氧化物半導體氧化亞銅為p型半導體，具有很好的光催化產氫效果，其能帶位置包含HER和OER的電位，其寬能隙能有效避免電子電動再結合，此外，容易合成、無毒、成本低廉以及運用廣泛皆是其作為元件開發的優勢。葉綠素主要捕捉Soret Band(紫外可見光區域420奈米範圍內)和Q band(紫外可見光區域700奈米範圍內)，相比氧化亞銅多了Q band的區域，因此利用葉綠素修飾氧化亞銅可以捕捉更大範圍的可見光並激發更多光生電子。此外葉綠素提前吸收部分可見光，並將氧化亞銅和電解液隔開，避免了光致腐蝕產生空缺的機會，顯著提升了氧化亞銅的耐受度。 透過葉綠素附著在氧化亞銅上，其形成的接合面展現出Z-type的異質結合現象，在施加超過0.6伏特的偏壓後便展現type II的異質接合，使得光電流密度最大值達3.26 mA/??2，最大外加偏壓光-電轉化效率(ABPE)達最大值1.37%。

Hydrogen energy possesses substantial potential for energy development, as its combustion does not produce greenhouse gases. In the realm of photo electrochemistry, the Hydrogen Evolution Reaction (HER) entails the dissociation of water to generate hydrogen gas. Initially, under illumination, the photocatalyst absorbs light energy, prompting electrons to be excited to the conduction band, leaving corresponding holes in the valence band. The excited electrons then react with water molecules, producing hydrogen gas. To enhance the efficiency of this reaction, the development of effective catalysts is a critical area of research. Therefore, developing high-efficiency photocatalytic components is a primary objective of this research. This study aims to develop photocatalytic components using chlorophyll-modified metal oxide semiconductor heterogeneous materials, serving as the photoanode in a photoelectrochemical (PEC) system. Chlorophyll will be extracted from Chlorella and dissolved in organic solvents to create a solution. The presence of chlorophyll monomers in the solution is confirmed by LC-MS analysis. As a common photosensitizer, chlorophyll captures a broader range of visible light, stimulating increased photocurrent. Cuprous oxide, a p-type semiconductor, exhibits excellent photocatalytic hydrogen production capabilities; its band structure encompasses the potentials for HER and OER, and its wide bandgap effectively prevents electron-hole recombination. From UV-Vis absorption spectra, it is observed that chlorophyll primarily captures the Soret Band and Q band, absorbing visible light in the 400-500 nm range, thus allowing chlorophyll-modified cuprous oxide to capture a broader spectrum of visible light, stimulate more photogenerated electrons, and exhibit reduced resistance and extended carrier lifetime as detected in EIS analysis. Additionally, chlorophyll absorbs some visible light beforehand, isolating the cuprous oxide from the electrolyte, thereby preventing photo corrosion and significantly enhancing the durability of cuprous oxide. By adhering chlorophyll onto cuprous oxide, the interface formed displays a Z-type heterojunction phenomenon. Upon applying a bias exceeding 0.6 V, a type II heterojunction is demonstrated, significantly enhancing the photocurrent density, and achieving the maximum bias-enhanced photovoltaic efficiency (ABPE) at a bias of 0.9 V, showcasing the potential of chlorophyll/Cu2O as a future PEC cell.

1. Ahmad, T., et al., Artificial intelligence in sustainable energy industry: Status Quo, challenges and opportunities. Journal of Cleaner Production, 2021. 289.
2. de Vries, A., The growing energy footprint of artificial intelligence. Joule, 2023. 7(10): p. 2191-2194.
3. An, J., W. Ding, and C. Lin, ChatGPT: tackle the growing carbon footprint of generative AI. Nature, 2023. 615(7953): p. 586-586.
4. Li, C., et al., Artificial intelligence, household financial fragility and energy resources consumption: Impacts of digital disruption from a demand-based perspective. Resources Policy, 2024. 88.
5. Rampai, M.M., et al., Hydrogen production, storage, and transportation: recent advances. Rsc Advances, 2024. 14(10): p. 6699-6718.
6. Muhammed, N.S., et al., Hydrogen production, transportation, utilization, and storage: Recent advances towards sustainable energy. Journal of Energy Storage, 2023. 73.
7. Zhou, B., et al., Few-Atomic-Layers Iron for Hydrogen Evolution from Water by Photoelectrocatalysis. iScience, 2020. 23.
8. Fuhrhop, J.H., Porphyrin Assemblies and Their Scaffolds. Langmuir, 2014. 30(1): p. 1-12.
9. Wang, X.F., et al., TiO2- and ZnO-based solar cells using a chlorophyll a derivative sensitizer for light-harvesting and energy conversion. Journal of Photochemistry and Photobiology a-Chemistry, 2010. 210(2-3): p. 145-152.
10. Wang, X.F. and O. Kitao, Natural Chlorophyll-Related Porphyrins and Chlorins for Dye-Sensitized Solar Cells. Molecules, 2012. 17(4): p. 4484-4497.
11. Kumara, G.R.A., et al., Shiso leaf pigments for dye-sensitized solid-state solar cell. Solar Energy Materials and Solar Cells, 2006. 90(9): p. 1220-1226.
12. Zhou, H.Z., et al., Dye-sensitized solar cells using 20 natural dyes as sensitizers. Journal of Photochemistry and Photobiology a-Chemistry, 2011. 219(2-3): p. 188-194.
13. Zhang, R.G., et al., Adsorption and dissociation of H₂ on the Cu₂O(111) surface: A density functional theory study. Applied Surface Science, 2010. 257(4): p. 1175-1180.
14. Lv, Z.Y., et al., Wrapping BiVO4 with chlorophyll for greatly improved photoelectrochemical performance and stability. Science China-Materials, 2022. 65(6): p. 1512-1521.
15. Dawood, F., M. Anda, and G.M. Shafiullah, Hydrogen production for energy: An overview. International Journal of Hydrogen Energy, 2020. 45(7): p. 3847-3869.
16. Ortiz, A.L., M.J.M. Zaragoza, and V. Collins-Martínez, Hydrogen production research in Mexico: A review. International Journal of Hydrogen Energy, 2016. 41(48): p. 23363-23379.
17. Preethi, V. and S. Kanmni, Photocatalytic hydrogen production. Materials Science in Semiconductor Processing, 2013. 16(3): p. 561-575.
18. Dincer, I. and C. Acar, Innovation in hydrogen production. International Journal of Hydrogen Energy, 2017. 42(22): p. 14843-14864.
19. Marwat, M.A., et al., Advanced Catalysts for Photoelectrochemical Water Splitting. Acs Applied Energy Materials, 2021. 4(11): p. 12007-12031.
20. Zhang, B., et al., Designing MOF Nanoarchitectures for Electrochemical Water Splitting. Advanced Materials, 2021. 33(17).
21. Sekimoto, T., et al., Analysis of Products from Photoelectrochemical Reduction of <SUP>13</SUP>CO₂ by GaN-Si Based Tandem Photoelectrode. Journal of Physical Chemistry C, 2016. 120(26): p. 13970-13975.
22. Zhao, G.L., et al., Life cycle cost analysis: A case study of hydrogen energy application on the Orkney Islands. International Journal of Hydrogen Energy, 2019. 44(19): p. 9517-9528.
23. Huang, Q., Q. Li, and X.D. Xiao, Hydrogen Evolution from Pt Nanoparticles Covered p-Type CdS:Cu Photocathode in Scavenger-Free Electrolyte. Journal of Physical Chemistry C, 2014. 118(5): p. 2306-2311.
24. Yang, Y., et al., Cu2O/CuO Bilayered Composite as a High-Efficiency Photocathode for Photoelectrochemical Hydrogen Evolution Reaction. Scientific Reports, 2016. 6(1): p. 35158.
25. Paracchino, A., et al., Highly active oxide photocathode for photoelectrochemical water reduction. Nature Materials, 2011. 10(6): p. 456-461.
26. Paracchino, A., et al., Synthesis and Characterization of High-Photoactivity Electrodeposited Cu₂O Solar Absorber by Photoelectrochemistry and Ultrafast Spectroscopy. Journal of Physical Chemistry C, 2012. 116(13): p. 7341-7350.
27. Son, M.-K. Key Strategies on Cu2O Photocathodes toward Practical Photoelectrochemical Water Splitting. Nanomaterials, 2023. 13, DOI: 10.3390/nano13243142.
28. Wang, Y., et al., Improving the p-type conductivity of Cu2O thin films by Ni doping and their heterojunction with n-ZnO. Applied Surface Science, 2022. 590.
29. Liu, S.H., Y.S. Wei, and J.S. Lu, Visible-light-driven photodegradation of sulfamethoxazole and methylene blue by Cu2O/rGO photocatalysts. Chemosphere, 2016. 154: p. 118-123.
30. Chen, L., et al., Enhanced catalyst activity by decorating of Au on Ag@Cu2O nanoshell. Applied Surface Science, 2018. 435: p. 72-78.
31. Lu, Q., et al., 2D Transition-Metal-Dichalcogenide-Nanosheet-Based Composites for Photocatalytic and Electrocatalytic Hydrogen Evolution Reactions. Advanced materials (Deerfield Beach, Fla.), 2015. 28.
32. Nunes, D., et al., Charging effects and surface potential variations of Cu-based nanowires. Thin Solid Films, 2016. 601: p. 45-53.
33. de Jongh, P.E., D. Vanmaekelbergh, and J.J. Kelly, Photoelectrochemistry of electrodeposited Cu2O. Journal of the Electrochemical Society, 2000. 147(2): p. 486-489.
34. Guo, M.Y., et al., Hydrothermal vs. electrodeposited CuxO for photocatalytic applications under simulated solar illumination. Materials Chemistry and Physics, 2012. 135(2-3): p. 694-698.
35. Zhou, M., Z.G. Guo, and Z.F. Liu, FeOOH as hole transfer layer to retard the photocorrosion of Cu₂O for enhanced photoelctrochemical performance. Applied Catalysis B-Environmental, 2020. 260.
36. Toe, C.Y., et al., Photocorrosion of Cuprous Oxide in Hydrogen Production: Rationalising Self‐Oxidation or Self‐Reduction. Angewandte Chemie, 2018. 130(41): p. 13801-13805.
37. Wang, Q., et al., Photocorrosion behavior of Cu2O nanowires during photoelectrochemical CO2 reduction. Journal of Electroanalytical Chemistry, 2022. 912: p. 116252.
38. Zindrou, A., L. Belles, and Y. Deligiannakis, Cu-Based Materials as Photocatalysts for Solar Light Artificial Photosynthesis: Aspects of Engineering Performance, Stability, Selectivity. Solar, 2023. 3.
39. Li, J., et al., Polyimide stabilized Cu2O photocathode for efficient PEC water reduction. Ionics, 2023. 29(2): p. 685-693.
40. Li, W.W., et al., Si-doped Cu₂O/SiOx composites for efficient photoelectrochemical water reduction. Journal of Power Sources, 2021. 492.
41. Zheng, G.W., et al., WO₃/Cu₂O heterojunction for the efficient photoelectrochemical property without external bias. Applied Catalysis B-Environmental, 2020. 265.
42. Chen, I.W.P., Y.M. Lai, and W.S. Liao, One-Pot Synthesis of Chlorophyll-Assisted Exfoliated MoS₂/WS₂ Heterostructures via Liquid-Phase Exfoliation Method for Photocatalytic Hydrogen Production. Nanomaterials, 2021. 11(9).
43. Cheng, J., L. Wu, and J. Luo, Improving the photovoltage of Cu2O photocathodes with dual buffer layers. Nature Communications, 2023. 14(1): p. 7228.
44. Dentuto, P.L., et al., Photophysical and electrochemical properties of chlorophyll a-cyclodextrins complexes. Bioelectrochemistry, 2004. 63(1-2): p. 117-120.
45. Watanabe, H., Y. Kamatani, and H. Tamiaki, Coordination-Driven Dimerization of Zinc Chlorophyll Derivatives Possessing a Dialkylamino Group. Chemistry-an Asian Journal, 2017. 12(7): p. 759-767.
46. Jiang, X.K., et al., Asymmetry induces Q-band split in the electronic excitations of magnesium porphyrin. Molecular Physics, 2018. 116(13): p. 1697-1705.
47. Montforts, F.P., et al., Long-lived photoinduced charge transfer state of synthetically affable porphyrin-fullerene dyads. Journal of Porphyrins and Phthalocyanines, 2003. 7(9-10): p. 651-666.
48. Pai, A. and B. Nair, Synthesis and characterization of a binary oxide ZrO2–TiO2 and its application in chlorophyll dye-sensitized solar cell with reduced graphene oxide as counter electrodes. Bulletin of Materials Science, 2015. 38: p. 1129-1133.
49. Fagadar-Cosma, E., et al., UV-VIS and fluorescence spectra of meso-tetraphenylporphyrin and meso-tetrakis-(4-methoxyphenyl) porphyrin in THF and THF-water systems. The influence of pH. Revista de Chimie, 2007. 58: p. 451-455.
50. Yang, C.H., et al., Morphology Observation and J-Aggregation Characteristics of Merocyanine Dye with Arachidic Acid LB Films. Molecular Crystals and Liquid Crystals, 2008. 491: p. 356-364.
51. Kobayashi, H., T. Kiba, and S. Sato, Enhancement of J Aggregation of Zinc Tetraphenylporphyrin in Water/Ethanol Binary Solution in the Presence of Cyclodextrin. Molecular Crystals and Liquid Crystals, 2010. 520: p. 448-454.
52. Tolbin, A.Y., et al., Aggregation of <i>slipped-cofacial</i> phthalocyanine J-type dimers: Spectroscopic and AFM study. Spectrochimica Acta Part a-Molecular and Biomolecular Spectroscopy, 2018. 205: p. 335-340.
53. Li, Y., et al., Zinc chlorophyll aggregates as hole transporters for biocompatible, natural-photosynthesis-inspired solar cells. Journal of Power Sources, 2015. 297: p. 519-524.
54. Günsel, A., et al., Ag(I) and Pd(II) sensing, H- or J-aggregation and redox properties of metal-free, manganase(III) and gallium(III) phthalocyanines. Dyes and Pigments, 2014. 102: p. 169-179.
55. Zhou, X., S. Lin, and H. Yan, Interfacing DNA nanotechnology and biomimetic photonic complexes: advances and prospects in energy and biomedicine. Journal of Nanobiotechnology, 2022. 20.
56. Matsubara, S. and H. Tamiaki, Supramolecular chlorophyll aggregates inspired from specific light-harvesting antenna “chlorosome”: Static nanostructure, dynamic construction process, and versatile application. Journal of Photochemistry and Photobiology C: Photochemistry Reviews, 2020. 45: p. 100385.
57. Almayyali, A.O.M., H.R. Jappor, and H.O. Muhsen, High hydrogen production in two-dimensional GaTe/ZnI₂ type-II heterostructure for water splitting. Journal of Physics and Chemistry of Solids, 2023. 178.
58. Brillet, J., et al., Highly efficient water splitting by a dual-absorber tandem cell. Nature Photonics, 2012. 6(12): p. 823-827.
59. Chen, J.Y., et al., Efficient Hydrogen Evolution Reaction on Ni3S2 Nanorods with a P/N Bipolar Electrode Prepared by Dealloying Sulfurization of NiW Amorphous Alloys. Acs Applied Energy Materials, 2020. 3(6): p. 5745-5755.
60. Chen, Y.C., et al., Enhancing Low-Bias performance of <i>n</i>-type Cu₂O photoanode for solar water splitting via simultaneously accelerated charge transfer kinetics at back contact and liquid junction. Solar Energy Materials and Solar Cells, 2023. 249.
61. Kaoru, O., et al., A carbon capture and storage technique using gold nanoparticles coupled with Cu-based composited thin film catalysts. Sustainable Energy & Fuels, 2022. 6(20): p. 4765-4778.
62. Li, Y.Y., et al., Interface engineering Z-scheme Ti-Fe2O3/In2O3 photoanode for highly efficient photoelectrochemical water splitting. Applied Catalysis B-Environmental, 2021. 290.
63. Pramod, A.G., et al., Impact of solvents on energy gap, photophysical, photometric properties for a new class of 4-HCM coumarin derivative: Nonlinear optical studies and optoelectronic applications. Journal of Molecular Liquids, 2019. 292.
64. Salari, H. and M. Kohantorabi, Heterogeneous photocatalytic degradation of organic pollutant in aqueous solutions by S-scheme heterojunction in nickel molybdate nanocomposites. Journal of Environmental Chemical Engineering, 2021. 9(5).
65. Xu, P.T., et al., Dye-sensitized photoelectrochemical water oxidation through a buried junction. Proceedings of the National Academy of Sciences of the United States of America, 2018. 115(27): p. 6946-6951.
66. Wang, J., et al., Type-II Heterojunction CdIn2S4/BiVO4 Coupling with CQDs to Improve PEC Water Splitting Performance Synergistically. ACS Applied Materials & Interfaces, 2022. 14(40): p. 45392-45402.
67. Boateng, E., et al., Synthesis and electrochemical studies of WO 3 ‐based nanomaterials for environmental, energy and gas sensing applications. Electrochemical Science Advances, 2021. 2.
68. Ding, M., et al., Advances and Promises of Two‐Dimensional MXenes as Co‐Catalysts for Artificial Photosynthesis. Solar RRL, 2021. 5.
69. Ong, M., et al., First-principles investigation of BiVO₃ for thermochemical water splitting. International Journal of Hydrogen Energy, 2019. 44(3): p. 1425-1430.
70. Cui, W., et al., Silicon/Organic Heterojunction for Photoelectrochemical Energy Conversion Photoanode with a Record Photovoltage. Acs Nano, 2016. 10(10): p. 9411-9419.
71. Termtanun, M., Photocatalytic degradation of pesticides using TiO2 nanoparticles. 2013.
72. Walock, M., Nanocomposite coatings based on quaternary metal-nitrogen and nanocarbon systems. 2012.
73. Baruwati, B., Studies on the Synthesis, Characterization, Surface Modification and Application of Nanocrystalline Nickel Ferrite.
74. Schitter, G., et al., Towards fast AFM-based nanometrology and nanomanufacturing. Int. J. of Nanomanufacturing, 2012. 8: p. 392-418.
75. Guittet, M.J., J.P. Crocombette, and M. Gautier-Soyer, Bonding and XPS chemical shifts in ${mathrm{ZrSiO}}_{4}$ versus ${mathrm{SiO}}_{2}$ and ${mathrm{ZrO}}_{2}:$ Charge transfer and electrostatic effects. Physical Review B, 2001. 63(12): p. 125117.
76. El-desawy, M., Characterization and application of aromatic self-assembled monolayers.
77. Ojeda, J. and M. Dittrich, Fourier Transform Infrared Spectroscopy for Molecular Analysis of Microbial Cells. Methods in molecular biology (Clifton, N.J.), 2012. 881: p. 187-211.
78. Wu, S., G. Lyu, and R. Lou, Applications of Chromatography Hyphenated Techniques in the Field of Lignin Pyrolysis. 2012.
79. Rudrapal, M., Analytical Techniques in Biosciences. 2021.
80. Östman, M., Antimicrobials in sewage treatment plants. 2018.
81. Alshehawy, A.M., et al., Photoluminescence Spectroscopy Measurements for Effective Condition Assessment of Transformer Insulating Oil. Processes, 2021. 9(5): p. 732.
82. Hu, J., et al., Strategies of Anode Materials Design towards Improved Photoelectrochemical Water Splitting Efficiency. Coatings, 2019. 9(5).
83. Shirazizadeh, H.A. and A. Haghtalab, Measurement and modeling of CO₂ solubility in binary aqueous DMSO and MDEA and their ternary mixtures at different temperatures and compositions. Fluid Phase Equilibria, 2021. 528.
84. Luo, Q., et al., Experimental Study on Simultaneous Absorption and Desorption of CO2, SO2, and NOx Using Aqueous N-Methyldiethanolamine and Dimethyl Sulfoxide Solutions. Energy & Fuels, 2018. 32(3): p. 3647-3659.
85. Gao, Y. and V.N. Nemykin, Modeling of the energies and splitting of the Qx and Qy bands in positional isomers of zinc pyridinoporphyrazines by TDDFT approach: Can TDDFT help distinguishing the structural isomers? Journal of Molecular Graphics and Modelling, 2013. 42: p. 73-80.
86. Suponeva, E.P., et al., CYCLIC VOLTAMMETRIC AND SPECTROPHOTOMETRIC STUDY OF MICROCRYSTALLINE CHLOROPHYLL-A ELECTRODEPOSITED ON THE ITO OPTICALLY TRANSPARENT ELECTRODE. Journal of Electroanalytical Chemistry, 1995. 387(1-2): p. 123-126.
87. Kissling, G.P., B. Ruhstaller, and K.P. Pernstich, Measuring frontier orbital energy levels of OLED materials using cyclic voltammetry in solution. Organic Electronics, 2023. 122.
88. Shafiee, A., M.M. Salleh, and M. Yahaya, Determination of HOMO and LUMO of 6,6 -Phenyl C61-butyric Acid 3-ethylthiophene Ester and Poly (3-octyl-thiophene-2, 5-diyl) through Voltametry Characterization. Sains Malaysiana, 2011. 40(2): p. 173-176.
89. Aktar, A., et al., Solution-Processed Synthesis of Copper Oxide (CuxO) Thin Films for Efficient Photocatalytic Solar Water Splitting. Acs Omega, 2020. 5(39): p. 25125-25134.
90. Chen, Y.-C., P.-H. Dong, and Y.-K. Hsu, Defective Indium Tin Oxide Forms an Ohmic Back Contact to an n-Type Cu2O Photoanode to Accelerate Charge-Transfer Kinetics for Enhanced Low-Bias Photoelectrochemical Water Splitting. ACS Applied Materials & Interfaces, 2021. 13(32): p. 38375-38383.
91. Ding, X., L.L. Zhang, and Y. Gao, Insights into electrolyte effects on photoactivities of dye-sensitized photoelectrochemical cells for water splitting. Journal of Energy Chemistry, 2017. 26(3): p. 476-480.