近年來由於電漿子材料與其組合而成的異質奈米結構優異的電漿子特性，引起許多關注。近期的研究也顯示透過加入電漿子材料，半導體的光催化效率可以藉由電漿子光敏化和電漿子引發的光吸收增強而提高。
本研究驗證了以陽極氧化鋁為模板之TiO2/TiN孔洞陣列在光催化水解產氫的優異表現，並利用掃描式與穿透式電子顯微鏡以及能量分辨X光能譜儀的分析顯示其結構的均勻性與符合預期的孔洞尺寸。在300瓦的氙燈照射下以氣相層析法量測產氫量測結果，顯示單位試片面積的產氫量可以藉由加深孔洞或是縮減孔洞寬度而提升；而每公克TiO2產氫量則與孔洞深度無關，僅能藉由縮減孔洞寬度來提升單位效率。
為了更深入了解TiN薄膜和此結構中之奈米孔洞尺寸所產生的電漿子增益效果，也進一步以有限時域差分法模擬了近場電場的分布，其孔洞內壁越接近時電場越強的結果與光水解產氫測試中的增益程度吻合。

Due to their fascinating plasmonic features, hybrid nanostructures consisting of plasmonic materials have attracted a great deal of attention recently. Recent studies have also demonstrated that by the addition of plasmonic materials, the photocatalytic efficiency of semiconductors can be enhanced owing to plasmonic sensitization and plasmon-enhanced light absorption.
In the present study, excellent photocatalytic properties for hydrogen production in water splitting have been demonstrated by utilizing the ALD-deposited TiO2/TiN layers on porous anodic aluminum oxide (AAO) template. The as-fabricated structures were analyzed by scanning electron microscopy, transmission electron microscopy and energy-dispersive x-ray spectroscopy to show their high uniformity and pore sizes of desire. The hydrogen production rate was measured by gas chromatography under the irradiation of a 300 W Xe lamp. It is seen that by deepening the pores, the hydrogen production rate per sample area can be increased due to the increased surface area. On the other hand, by reducing the pore widths, both the hydrogen production rate per sample area and per gram of TiO2 can be significantly enhanced due to the LSPR effect.
To further investigate the plasmon-enhancing effect of the addition of the TiN thin layer and the size of the nanopores on the structure, the finite difference time domain (FDTD) method was also used to simulate the near-field electric field distribution. It indicates that enhanced electric field with more proximate pore sidewalls is consistent with the further improvement of photocatalytic water splitting efficiency.

1.Turner, J. A., A realizable renewable energy future. Science 1999, 285 (5428), 687-689.
2.Warren, S. C.; Thimsen, E., Plasmonic solar water splitting. Energy & Environmental Science 2012, 5 (1), 5133-5146.
3.Gomes Silva, C. u.; Juárez, R.; Marino, T.; Molinari, R.; García, H., Influence of excitation wavelength (UV or visible light) on the photocatalytic activity of titania containing gold nanoparticles for the generation of hydrogen or oxygen from water. Journal of the American Chemical Society 2011, 133 (3), 595-602.
4.Mubeen, S.; Lee, J.; Singh, N.; Krämer, S.; Stucky, G. D.; Moskovits, M., An autonomous photosynthetic device in which all charge carriers derive from surface plasmons. Nature Nanotechnology 2013, 8 (4), 247-251.
5.Babu, V. J.; Vempati, S.; Uyar, T.; Ramakrishna, S., Review of one-dimensional and two-dimensional nanostructured materials for hydrogen generation. Physical Chemistry Chemical Physics 2015, 17 (5), 2960-2986.
6.Boriskina, S. V.; Ghasemi, H.; Chen, G., Plasmonic materials for energy: From physics to applications. Materials Today 2013, 16 (10), 375-386.
7.Schuller, J. A.; Barnard, E. S.; Cai, W.; Jun, Y. C.; White, J. S.; Brongersma, M. L., Plasmonics for extreme light concentration and manipulation. Nature Materials 2010, 9 (3), 193-204.
8.Stockman, M. I., Nanoplasmonics: past, present, and glimpse into future. Optics Express 2011, 19 (22), 22029-22106.
9.Barnes, W. L.; Dereux, A.; Ebbesen, T. W., Surface plasmon subwavelength optics. Nature 2003, 424 (6950), 824-830.
10.Murray, W. A.; Barnes, W. L., Plasmonic materials. Advanced Materials 2007, 19 (22), 3771-3782.
11.Liu, X.; Swihart, M. T., Heavily-doped colloidal semiconductor and metal oxide nanocrystals: an emerging new class of plasmonic nanomaterials. Chemical Society Reviews 2014, 43 (11), 3908-3920.
12.Peiris, S.; McMurtrie, J.; Zhu, H.-Y., Metal nanoparticle photocatalysts: emerging processes for green organic synthesis. Catalysis Science & Technology 2016, 6 (2), 320-338.
13.Amendola, V.; Pilot, R.; Frasconi, M.; Maragò, O. M.; Iatì, M. A., Surface plasmon resonance in gold nanoparticles: a review. Journal of Physics: Condensed Matter 2017, 29 (20), 203002.
14.Gan, X.; Lei, D.; Ye, R.; Zhao, H.; Wong, K.-Y., Transition metal dichalcogenide-based mixed-dimensional heterostructures for visible-light-driven photocatalysis: Dimensionality and interface engineering. Nano Research 2021, 14 (6), 2003-2022.
15.An, C.; Wang, J.; Jiang, W.; Zhang, M.; Ming, X.; Wang, S.; Zhang, Q., Strongly visible-light responsive plasmonic shaped AgX: Ag (X= Cl, Br) nanoparticles for reduction of CO2 to methanol. Nanoscale 2012, 4 (18), 5646-5650.
16.Tan, J. Z.; Fernández, Y.; Liu, D.; Maroto-Valer, M.; Bian, J.; Zhang, X., Photoreduction of CO2 using copper-decorated TiO2 nanorod films with localized surface plasmon behavior. Chemical Physics Letters 2012, 531, 149-154.
17.Wang, C.; Ranasingha, O.; Natesakhawat, S.; Ohodnicki, P. R.; Andio, M.; Lewis, J. P.; Matranga, C., Visible light plasmonic heating of Au–ZnO for the catalytic reduction of CO2. Nanoscale 2013, 5 (15), 6968-6974.
18.Mankidy, B. D.; Joseph, B.; Gupta, V. K., Photo-conversion of CO2 using titanium dioxide: enhancements by plasmonic and co-catalytic nanoparticles. Nanotechnology 2013, 24 (40), 405402.
19.Liu, Z.; Hou, W.; Pavaskar, P.; Aykol, M.; Cronin, S. B., Plasmon resonant enhancement of photocatalytic water splitting under visible illumination. Nano letters 2011, 11 (3), 1111-1116.
20.Chen, J.-J.; Wu, J. C.; Wu, P. C.; Tsai, D. P., Plasmonic photocatalyst for H2 evolution in photocatalytic water splitting. The Journal of Physical Chemistry C 2011, 115 (1), 210-216.
21.Singh, G.; Shrestha, K.; Nepal, A.; Klabunde, K. J.; Sorensen, C. M., Graphene supported plasmonic photocatalyst for hydrogen evolution in photocatalytic water splitting. Nanotechnology 2014, 25 (26), 265701.
22.Alvaro, M.; Cojocaru, B.; Ismail, A. A.; Petrea, N.; Ferrer, B.; Harraz, F. A.; Parvulescu, V. I.; Garcia, H., Visible-light photocatalytic activity of gold nanoparticles supported on template-synthesized mesoporous titania for the decontamination of the chemical warfare agent Soman. Applied Catalysis B: Environmental 2010, 99 (1-2), 191-197.
23.Fouad, D. M.; Mohamed, M. B., Comparative study of the photocatalytic activity of semiconductor nanostructures and their hybrid metal nanocomposites on the photodegradation of malathion. Journal of Nanomaterials 2012, 2012.
24.Braun, J. H.; Baidins, A.; Marganski, R. E., TiO2 pigment technology: a review. Progress in Organic Coatings 1992, 20 (2), 105-138.
25.Pfaff, G.; Reynders, P., Angle-dependent optical effects deriving from submicron structures of films and pigments. Chemical Reviews 1999, 99 (7), 1963-1981.
26.Salvador, A.; Pascual-Martı, M.; Adell, J.; Requeni, A.; March, J., Analytical methodologies for atomic spectrometric determination of metallic oxides in UV sunscreen creams. Journal of Pharmaceutical and Biomedical Analysis 2000, 22 (2), 301-306.
27.Yuan, S.; Chen, W.; Hu, S., Fabrication of TiO2 nanoparticles/surfactant polymer complex film on glassy carbon electrode and its application to sensing trace dopamine. Materials Science and Engineering: C 2005, 25 (4), 479-485.
28.Fujishima, A.; Honda, K., Electrochemical photolysis of water at a semiconductor electrode. Nature 1972, 238 (5358), 37-38.
29.Hagfeldt, A.; Graetzel, M., Light-induced redox reactions in nanocrystalline systems. Chemical Reviews 1995, 95 (1), 49-68.
30.Mills, A.; Le Hunte, S., An overview of semiconductor photocatalysis. Journal of Photochemistry and Photobiology A: Chemistry 1997, 108 (1), 1-35.
31.Jang, J. S.; Kim, H. G.; Joshi, U. A.; Jang, J. W.; Lee, J. S., Fabrication of CdS nanowires decorated with TiO2 nanoparticles for photocatalytic hydrogen production under visible light irradiation. International Journal of Hydrogen Energy 2008, 33 (21), 5975-5980.
32.Wei, R.-B.; Huang, Z.-L.; Gu, G.-H.; Wang, Z.; Zeng, L.; Chen, Y.; Liu, Z.-Q., Dual-cocatalysts decorated rimous CdS spheres advancing highly-efficient visible-light photocatalytic hydrogen production. Applied Catalysis B: Environmental 2018, 231, 101-107.
33.Bao, N.; Shen, L.; Takata, T.; Domen, K., Self-templated synthesis of nanoporous CdS nanostructures for highly efficient photocatalytic hydrogen production under visible light. Chemistry of Materials 2008, 20 (1), 110-117.
34.Kumaravel, V.; Mathew, S.; Bartlett, J.; Pillai, S. C., Photocatalytic hydrogen production using metal doped TiO2: A review of recent advances. Applied Catalysis B: Environmental 2019, 244, 1021-1064.
35.Chiarello, G. L.; Dozzi, M. V.; Selli, E., TiO2-based materials for photocatalytic hydrogen production. Journal of Energy Chemistry 2017, 26 (2), 250-258.
36.Ni, M.; Leung, M. K.; Leung, D. Y.; Sumathy, K., A review and recent developments in photocatalytic water-splitting using TiO2 for hydrogen production. Renewable and Sustainable Energy Reviews 2007, 11 (3), 401-425.
37.Hao, J.-Y.; Wang, Y.-Y.; Tong, X.-L.; Jin, G.-Q.; Guo, X.-Y., Photocatalytic hydrogen production over modified SiC nanowires under visible light irradiation. International Journal of Hydrogen Energy 2012, 37 (20), 15038-15044.
38.Hao, J.-Y.; Wang, Y.-Y.; Tong, X.-L.; Jin, G.-Q.; Guo, X.-Y., SiC nanomaterials with different morphologies for photocatalytic hydrogen production under visible light irradiation. Catalysis Today 2013, 212, 220-224.
39.Yang, J.; Zeng, X.; Chen, L.; Yuan, W., Photocatalytic water splitting to hydrogen production of reduced graphene oxide/SiC under visible light. Applied Physics Letters 2013, 102 (8), 083101.
40.Jeyachandran, Y.; Narayandass, S. K.; Mangalaraj, D.; Areva, S.; Mielczarski, J., Properties of titanium nitride films prepared by direct current magnetron sputtering. Materials Science and Engineering: A 2007, 445, 223-236.
41.Lee, K.-S.; El-Sayed, M. A., Gold and silver nanoparticles in sensing and imaging: sensitivity of plasmon response to size, shape, and metal composition. The Journal of Physical Chemistry B 2006, 110 (39), 19220-19225.
42.Solovan, M.; Brus, V.; Maistruk, E.; Maryanchuk, P., Electrical and optical properties of TiN thin films. Inorganic Materials 2014, 50 (1), 40-45.
43.Naik, G. V.; Schroeder, J. L.; Ni, X.; Kildishev, A. V.; Sands, T. D.; Boltasseva, A., Titanium nitride as a plasmonic material for visible and near-infrared wavelengths. Optical Materials Express 2012, 2 (4), 478-489.
44.Guler, U.; Naik, G. V.; Boltasseva, A.; Shalaev, V. M.; Kildishev, A. V., Performance analysis of nitride alternative plasmonic materials for localized surface plasmon applications. Applied Physics B 2012, 107 (2), 285-291.
45.Naik, G. V.; Shalaev, V. M.; Boltasseva, A., Alternative plasmonic materials: beyond gold and silver. Advanced Materials 2013, 25 (24), 3264-3294.
46.Ishii, S.; Sugavaneshwar, R. P.; Nagao, T., Titanium nitride nanoparticles as plasmonic solar heat transducers. The Journal of Physical Chemistry C 2016, 120 (4), 2343-2348.
47.Chang, C.-C.; Kuo, S.-C.; Cheng, H.-E.; Chen, H.-T.; Yang, Z.-P., Broadband titanium nitride disordered metasurface absorbers. Optics Express 2021, 29 (26), 42813-42826.
48.Yu, M.-J.; Chang, C.-L.; Lan, H.-Y.; Chiao, Z.-Y.; Chen, Y.-C.; Howard Lee, H. W.; Chang, Y.-C.; Chang, S.-W.; Tanaka, T.; Tung, V., Plasmon-enhanced solar-driven hydrogen evolution using titanium nitride metasurface broadband absorbers. ACS Photonics 2021, 8 (11), 3125-3132.
49.Sheasby, P. G.; Pinner, R.; Wernick, S., The surface treatment and finishing of aluminium and its alloys. ASM international Materials Park, OH: 2001; Vol. 1. 5-8
50.Lee, W.; Park, S.-J., Porous anodic aluminum oxide: anodization and templated synthesis of functional nanostructures. Chemical Reviews 2014, 114 (15), 7487-7556.
51.Stupp, S. I.; Braun, P. V., Molecular manipulation of microstructures: biomaterials, ceramics, and semiconductors. Science 1997, 277 (5330), 1242-1248.
52.Wehrspohn, R. B., Ordered Porous Nanostructures and Applications. Springer: 2005. 37-53
53.Jani, A. M. M.; Losic, D.; Voelcker, N. H., Nanoporous anodic aluminium oxide: Advances in surface engineering and emerging applications. Progress in Materials Science 2013, 58 (5), 636-704.
54.Elam, J.; Routkevitch, D.; Mardilovich, P.; George, S., Conformal coating on ultrahigh-aspect-ratio nanopores of anodic alumina by atomic layer deposition. Chemistry of Materials 2003, 15 (18), 3507-3517.
55.Detavernier, C.; Dendooven, J.; Sree, S. P.; Ludwig, K. F.; Martens, J. A., Tailoring nanoporous materials by atomic layer deposition. Chemical Society Reviews 2011, 40 (11), 5242-5253.
56.Veenkamp, R.; Ye, W. N., Plasmonic metal nanocubes for broadband light absorption enhancement in thin-film a-Si solar cells. Journal of Applied Physics 2014, 115 (12), 124317.
57.Hassan, N. A.; Hashim, A. M., The effect of size of Au nanodisc on the localized surface plasmon resonance simulated using finite-difference time-domain (FDTD) method. Materials Today: Proceedings 2019, 7, 607-611.
58.Lesina, A. C.; Vaccari, A.; Berini, P.; Ramunno, L., On the convergence and accuracy of the FDTD method for nanoplasmonics. Optics Express 2015, 23 (8), 10481-10497.
59.Cao, Y.; Manjavacas, A.; Large, N.; Nordlander, P., Electron energy-loss spectroscopy calculation in finite-difference time-domain package. ACS Photonics 2015, 2 (3), 369-375.
60.Belwalkar, A.; Grasing, E.; Van Geertruyden, W.; Huang, Z.; Misiolek, W., Effect of processing parameters on pore structure and thickness of anodic aluminum oxide (AAO) tubular membranes. Journal of Membrane Science 2008, 319 (1-2), 192-198.
61.Bakke, J. R.; Jung, H. J.; Tanskanen, J. T.; Sinclair, R.; Bent, S. F., Atomic layer deposition of CdS films. Chemistry of Materials 2010, 22 (16), 4669-4678.
62.Liu, Y.-T.; Lu, M.-Y.; Perng, T.-P.; Chen, L.-J., Plasmonic enhancement of hydrogen production by water splitting with CdS nanowires protected by metallic TiN overlayers as highly efficient photocatalysts. Nano Energy 2021, 89, 106407.