近年來，全球暖化是非常值得關心且熱門的議題。其中可能的解決方案是有效地利用取之不盡且非常乾淨的天然資源，如太陽光與水資源。光催化水解產氫為人工光合作用，可以將水轉化成氫氣，是一種有潛力的發展方向。學者致力找尋可應用於太陽光波段之光催化劑，其必要條件包括低電子電洞對再結合速率及良好的光催化活性。為減少電子電洞對的再結合機率，可利用具異質結構的半導體光催化劑。對於異質結構之半導體光催化劑，其電子電洞對被光源激發後，載子會分別連續傳遞到另一光催化劑，進而分離電子及電洞。要成為良好的異質結構半導體之光催化劑，其前提是這兩種光催化劑必須具備合適的價帶、導帶與費米能階位置。
本研究係利用磷酸銀-二氧化鈦異質結構，在太陽光照射下進行光催化水解產氫。研究分為兩個部分，第一部分為材料製備與性質分析，另一部分則為光催化效率之探討。
首先利用溶膠凝膠法及原子層沉積法製備不同形貌之二氧化鈦，後者係以四氯化鈦與水為前驅物，將二氧化鈦薄膜鍍在具中空多孔結構之聚碸纖維板模上，再經過高溫退火將聚碸移除。其次，將磷酸銀成長在此二種不同形貌之二氧化鈦上，形成磷酸銀-二氧化鈦異質結構。為進一步提升此異質結構之光催化活性，再沉積適量金奈米晶粒作為助催化劑，以增進其催化效率。
以X光繞射判別材料的結晶相，並以比表面積與孔隙度分析儀測量此兩種不同製程的二氧化鈦之比表面積。從掃描式電子顯微鏡及穿透式電子顯微鏡之觀察，可得知材料表面形貌、顆粒尺度及分布，再進一步利用球面像差穿透式電子顯微鏡觀測晶面間距與晶格，並使用電子能譜儀分析其元素組成及分布。二氧化鈦及磷酸銀之能隙、能帶位置及費米能階，可由紫外光-可見光分光光譜與紫外光電子能譜推知，而載子再結合速率則可由光激發螢光光譜之結果得知，進而與產氫結果對照。
第二部分研究光催化產氫，材料對象包括二氧化鈦、磷酸銀-二氧化鈦異質結構及鍍覆金奈米晶粒之磷酸銀-二氧化鈦異質結構。藉由調整磷酸銀之比例，可以提升該異質結構之產氫效率，高於二氧化鈦，並達到最佳的產氫量；而以金奈米晶粒作為異質結構之光觸媒，則可進一步增加產氫能力。實驗發現以下兩種比例之異質結構，磷酸銀(12 wt%)-二氧化鈦(溶膠凝膠法)及磷酸銀(6 wt%)-二氧化鈦(原子層沉積法)經四小時太陽光照射，分別產生178和444 μmolg-1之氫氣。若再加上金奈米晶粒，則其產氫量可分別提升至1812和2346 μmolg-1。此外，磷酸銀的顆粒尺度亦會影響異質結構之表現，如果顆粒變小，電子、電洞移動到表面上的反應部位之距離會縮短，可減少載子再結合之機率，電子也比較容易從磷酸銀遷移到二氧化鈦上與溶液反應，產生氫氣。此可解釋為何磷酸銀(6 wt%)-二氧化鈦(原子層沉積法)之效率比磷酸銀(12 wt%)-二氧化鈦(溶膠凝膠法)高；而加入金奈米晶粒後，其結果亦是如此。
綜上所述，磷酸銀-二氧化鈦異質結構與鍍覆金奈米晶粒之異質結構，在太陽光照射下，皆具有良好的光催化活性。

Global warming has become hot issues in recent years. Making good use of sufficient and clean resources, like sun light and water, has been one of the important strategies. Photocatalytic water splitting, an artificial photosynthesis process, is a potential candidate for producing hydrogen from water. Searching for good solar light-driven photocatalysts which have low recombination rate and high photocatalytic activity efficiency is a tough task. The creation of a heterojunction, whereby charge carriers are generated in one semiconductor-based photocatalyst and directly transferred to the other photocatalyst, may reduce the recombination rate of electron and hole pairs. In such a system, two semiconductor-based photocatalysts with relatively suitable band positions and Fermi levels are chosen.
In this research, we report an advanced composite photocatalyst, Ag3PO4-TiO2 heterojunction, to enhance photocatalytic water splitting for hydrogen evolution under solar light irradiation. The first part deals with the fabrication of the materials. Two types of TiO2 (SG) and TiO2 (ALD) were prepared by sol-gel method and ALD process, respectively. For the ALD process, polysulfone (PSF) hollow fiber with the wall consisting of interconnected nanofibers was chosen as the template. The thickness of TiO2 film was precisely controlled by using TiCl4 and H2O as the precursors. Ag3PO4 was then deposited on TiO2. To have better photocatalytic activity, gold nanoparticles were deposited on the heterojunction to act as a co-catalyst. The crystalline phases were examined by X-ray diffraction (XRD), and the morphologies were observed by scanning electron microscopy (SEM). Brunauer-Emmett-Teller (BET) analysis were conducted to measure the specific surface areas of TiO2 (SG) and TiO2 (ALD). The bio-transmission electron microscopy (Bio-TEM) was employed to observe the morphologies of the Ag3PO4-TiO2 heterojunctions and particle sizes and distributions of Ag3PO4 in the heterojunctions. The d-spacings and crystal lattices of the samples were observed by spherical-aberration corrected field emission transmission electron microscopy. Energy dispersive spectroscopy (EDS) was conducted for elemental mapping. The bandgaps, energy band positions, and the Fermi levels of the anatase phase TiO2 and Ag3PO4 were determined by UV-visible spectrometry and ultraviolet photoelectron spectroscopy (UPS). The charge carrier recombination rates of TiO2, Ag3PO4, Ag3PO4-TiO2 heterojunctions, and Au@Ag3PO4-TiO2 heterojunctions were measured by photoluminescence (PL) spectroscopy to confirm the results of hydrogen production.
The second part is on the application of TiO2, Ag3PO4-TiO2 heterojunction, and Au@Ag3PO4-TiO2 in photocatalytic water splitting for hydrogen evolution. The optimum condition for achieving a maximum hydrogen evolution by this heterojunction photocatalyst was investigated. The results demonstrated that applying the Ag3PO4-TiO2 heterojunction and Au@Ag3PO4-TiO2 with a certain amount of Ag3PO4 exhibited enhanced efficiencies compared with using only one single photocatalyst. Among the samples tested, Ag3PO4(12 wt%)-TiO2 (SG) and Ag3PO4(6 wt%)-TiO2 (ALD) showed the best performance of hydrogen evolution than the other samples prepared in the same process. Under solar light irradiation for 4 h, the amounts of hydrogen produced by Ag3PO4(12 wt%)-TiO2 (SG) and Ag3PO4(6 wt%)-TiO2 (ALD) were 178 and 444 μmolg-1, respectively. When adding Au nanoparticles as the co-catalyst, the values of hydrogen production by Au@Ag3PO4(12 wt%)-TiO2 (SG) and Au@Ag3PO4(6 wt%)-TiO2 (ALD) were raised to 1812 and 2346 μmolg-1, respectively. Therefore, the heterojunctions of Ag3PO4-TiO2 and Au@Ag3PO4-TiO2 with optimal ratios of Ag3PO4 could be promising photocatalysts for hydrogen evolution under solar light. In addition, the particle size of Ag3PO4 could influence the behavior of the heterojunctions. If Ag3PO4 particles become smaller, the distance that photogenerated electrons and holes have to migrate to reaction sites on the surface would become shorter, resulting in reduced recombination probability. The electrons are easier to transport from Ag3PO4 to TiO2. Therefore, the photocatalytic activity of Ag3PO4(6 wt%)-TiO2 (ALD) is even better than that of Ag3PO4(12 wt%)-TiO2 (SG). Similar argument can be applied to the relative performances of Au@Ag3PO4-TiO2 composites.
In conclusion, here we report the fabrication and characterization of advanced photocatalysts of Ag3PO4-TiO2 and Au@Ag3PO4-TiO2 which have good photocatalytic activity under solar light irradiation.

摘要......I
Abstract......IV
誌謝......VII
Chapter I Introduction......1
1.1. Energy Crisis......1
1.2. Motivation of the Research......3
1.3. Framework of the Research......6
Chapter II Literature Review......7
2.1. Principle of Photocatalysis......7
2.2. Improvement of Photoactivity......9
2.2.1. Heterojunction Photocatalysts......9
2.2.2. Co-catalyst......11
2.3. Basic Properties of TiO2 and Ag3PO4......14
2.3.1. TiO2......14
2.3.2. Ag3PO4......20
2.4. Photocatalytic Water Splitting for Hydrogen Evolution......25
2.5. Atomic Layer Deposition (ALD)......32
2.5.1. Principle of ALD......32
2.5.2. Fabrication of TiO2 by ALD......37
Chapter III Experimental Designs......39
3.1. Synthesis of TiO2......39
3.2. Fabrication of Ag3PO4-TiO2 heterojunction......43
3.3. Deposition of Au nanoparticles on Ag3PO4-TiO2 as co-catalyst .......43
3.4. Characterization......44
3.4.1. X-ray diffraction (XRD)......44
3.4.2. Scanning electron microscopy (SEM)......44
3.4.3. Bio-transmission electron microscopy (Bio-TEM)......44
3.4.4. Spherical-aberration corrected field emission transmission electron microscopy......45
3.4.5. Energy dispersive spectroscopy (EDS)......45
3.4.6. Ultraviolet photoelectron spectroscopy (UPS)......45
3.4.7. Brunauer-Emmett-Teller (BET) analysis......45
3.4.8. Photoluminescence (PL) spectroscopy......46
3.4.9. UV-visible spectrometry......46
3.5. Photocatalytic water splitting......46
Chapter IV Results and Discussion......48
4.1. TiO2......48
4.1.1. Characterization......48
4.1.2. Hydrogen generation efficiency for photocatalytic water splitting......61
4.2. Characterization of Ag3PO4......64
4.3. Ag3PO4-TiO2 heterojunction and Au@Ag3PO4-TiO2 (SG)......64
4.3.1. Characterization......64
4.3.2. Hydrogen generation efficiency of photocatalytic water splitting......78
4.4. Ag3PO4-TiO2 heterojunction and Au@Ag3PO4-TiO2 (ALD)......78
4.4.1. Characterization......82
4.4.2. Hydrogen generation efficiency of photocatalytic water splitting ......88
4.5. Factors affecting the photocatalytic performance......92
4.5.1. Ag3PO4-TiO2 heterojunction......92
4.5.2. Comparison of Ag3PO4-TiO2 (SG) and Ag3PO4-TiO2 (ALD)......94
4.5.3. Co-catalyst on photocatalyst......97
4.6. Comparison with previous reported work......97
Chapter V Conclusions......100
Chapter VI Suggested Future Work......101
References......102

1. International Energy Outlook 2017.
2. A.A. Ismail and D.W. Bahnemann, “Photochemical splitting of water for hydrogen production by photocatalysis: A review,” Sol. Energy Mater. Sol. Cells, 128 (2014) 85-101.
3. A. Fujishima and K. Honda, “Electrochemical photolysis of water at a semiconductor electrode,” Nature, 238 (1972) 37-38.
4. Y. Bi, S. Ouyang, N. Umezawa, J. Cao, and J. Ye, “Facet effect of single-crystalline Ag3PO4 sub-microcrystals on photocatalytic properties,” J. Am. Chem. Soc., 133 (2011) 6490-6492.
5. Z. Yi, J. Ye, N. Kikugawa, T. Kako, S. Ouyang, H. Stuart-Williams, H. Yang, J. Cao, W. Luo, Z. Li, Y. Liu, and R. L. Withers, “An orthophosphate semiconductor with photooxidation properties under visible-light irradiation,” Nat. Mater., 9 (2010) 559-564.
6. Y. Bi, H. Hu, S. Ouyang, G. Lu, J. Cao, and J. Ye, “Photocatalytic and photoelectric properties of cubic Ag3PO4 sub-microcrystals with sharp corners and edges,” Chem. Commun., 48 (2012) 3748-3750.
7. H. Wang, L. He, L. Wang, P. Hu, L. Guo, X. Han, and J. Li, “Facile synthesis of Ag3PO4 tetrapod microcrystals with an increased percentage of exposed {110} facets and highly efficient photocatalytic properties,” CrystEngComm., 14 (2012) 8342-8344.
8. J. Li and N. Wu, “Semiconductor-based photocatalysts and photoelectrochemical cells for solar fuel generation: a review,” Catal. Sci. Technol., 5 (2015) 1360-1384.
9. X. Li, J. Yu, and M. Jaroniec, “Hierarchical photocatalysts,” Chem. Soc. Rev., 45 (2016) 2603-2636.
10. A.L. Linsebigler, G. Lu, and J.T. Yates, “Photocatalysis on TiO2 surfaces: principles, mechanisms, and selected results,” Chem. Rev., 95 (1995) 735-758.
11. C.C. Nguyen, N.N. Vu, and T.-O. Do, “Recent advances in the development of sunlight-driven hollow structure photocatalysts and their applications,” J. Mater. Chem. A, 3 (2015) 18345-18359.
12. K. Maeda and K. Domen, “New non-oxide photocatalysts designed for overall water splitting under visible light,” J. Phys. Chem. C, 111 (2007) 7851-7861.
13. S.J.A. Moniz, S.A. Shevlin, D.J. Martin, Z.X. Guo, and J.Tang, “Visible-light driven heterojunction photocatalysts for water splitting – a critical review,” Energy Environ. Sci., 8 (2015) 731-759.
14. H. Wang, L. Zhang, Z. Chen, J. Hu, S. Li, Z. Wang, J. Liu, and X. Wang, “Semiconductor heterojunction photocatalysts: design, construction, and photocatalytic performances,” Chem. Soc. Rev., 43 (2014) 5234-5244.
15. S. Yamamoto, T. Sumita, Sugiharuto, A. Miyashita, and H. Naramoto, “Preparation of epitaxial TiO2 films by pulsed laser deposition technique,” Thin Solid Films, 401 (2001) 88-93.
16. D.M. Tobaldi, R. C. Pullar, A. Sever Škapin, M. P. Seabra, and J. A. Labrincha, “Visible light activated photocatalytic behaviour of rare earth modified commercial TiO2,” Mater. Res. Bull., 50 (2014) 183-190.
17. U. Diebold, “The surface science of titanium dioxide,” Surf. Sci. Rep., 48 (2003) 53-229.
18. A. Fujishima, X. Zhang, and D. Tryk, “TiO2 photocatalysis and related surface phenomena,” Surf. Sci. Rep., 63 (2008) 515-582.
19. J.K. Burdett, T. Hughbanks, G.J. Miller, J.W. Richardson, and J.V. Smith, “Structural-electronic relationships in inorganic solids: powder neutron diffraction studies of the rutile and anatase polymorphs of titanium dioxide at 15 and 295 K,” J. Am. Chem. Soc., 109 (1987) 3639-3646.
20. B. Ohtani and S. Nishimoto, “Effect of surface adsorptions of aliphatic alcohols and silver ion on the photocatalytic activity of titania suspended in aqueous solutions,” J. Phys. Chem., 97 (1993) 920-926.
21. S.T. Martin, H. Herrmann, W. Choi, and M.R. Hoffmann, “Time-resolved microwave conductivity. Part 1.-TiO2 photoreactivity and size quantization,” J. Chem. Soc. Faraday Trans., 90 (1994) 3315-3322.
22. Q. Wang, J. Lian, Y. Bai, J. Hui, J. Zhong, J. Li, N. An, J. Yu, and F. Wang, “Photocatalytic activity of hydrogen production from water over TiO2 with different crystal structures,” Mater. Sci. Semicond. Process., 40 (2015) 418-423.
23. R. Pandiyan, N. Delegan, A. Dirany, P. Drogui, and M. A. E. Khakani, “Probing the electronic surface properties and bandgap narrowing of in situ N, W, and (W, N) doped magnetron-sputtered TiO2 films intended for electro-photocatalytic applications,” J. Phys. Chem. C., 8 (2016) 631−638.
24. A. Kudo and Y. Miseki, “Heterogeneous photocatalyst materials for water splitting,” Chem. Soc. Rev., 38 (2009) 253-278.
25. H. Wang, Y. Bai, J. Yang, X. Lang, J. Li, and L. Guo, “A facile way to rejuvenate Ag3PO4 as a recyclable highly efficient photocatalyst,” Chem. Eur. J., 18 (2012) 5524-5529.
26. X. Ma, B. Lu, D. Li, R. Shi, C. Pan, and Y. Zhu, “Origin of photocatalytic activation of silver orthophosphate from first-principles,” J. Phys. Chem. C, 115 (2011) 4680-4687.
27. J.J. Liu, X.L. Fu, S.F. Chen, and Y.F. Zhu “Electronic structure and optical properties of Ag3PO4 photocatalyst calculated by hybrid density functional method,” Appl. Phys. Lett., 99 (2011) 191903.
28. D.J. Martin, N. Umezawa, X. Chen, J. Ye, and J. Tang, “Facet engineered Ag3PO4 for efficient water photooxidation,” Energy Environ. Sci., 6 (2013) 3380-3386.
29. X. Chen, Y. Dai, and X. Wang, “Methods and mechanism for improvement of photocatalytic activity and stability of Ag3PO4: A review,” J. Alloys Compd., 649 (2015) 910-932.
30. M. Ge, N. Zhu, Y. Zhao, J. Li, and L. Liu, “Sunlight-assisted degradation of dye pollutants in Ag3PO4 suspension,” Ind. Eng. Chem. Res., 51 (2012) 5167-5173.
31. H. Huang, Y. Feng, J. Zhou, G. Li, and K.Dai, “Visible light photocatalytic reduction of Cr(VI) on Ag3PO4 nanoparticles,” Desalin. Water Treat., 51 (2013) 7236-7240.
32. G. Ming, “Photodegradation of rhodamine B and methyl orange by Ag3PO4 catalyst under visible light irradiation,” Chin. J. Catal., 35 (2014) 1410-1417.
33. M. Qamar, R. B. Elsayed, K. R. Alhooshani, M. I. Ahmed, and D. W. Bahnemann, “Chemoselective and highly efficient conversion of aromatic alcohols into aldehydes photo-catalyzed by Ag3PO4 in aqueous suspension under simulated sunlight,” Catal. Commun., 58 (2015) 34-39.
34. K. Hatakeyama, M. Okuda, T. Kuki, and T. Esaka, “Removal of dissolved humic acid from water by photocatalytic oxidation using a silver orthophosphate semiconductor,” Mater. Res. Bull., 47 (2012) 4478-4482.
35. A. Khan, M. Qamar, and M. Muneer, “Synthesis of highly active visible-light-driven colloidal silver orthophosphate,” Chem. Phys. Lett., 519-520 (2012) 54-58.
36. T.A. Vu, C.D. Dao, T.T.T. Hoang, K.T. Nguyen, G.H. Le, P.T. Dang, H.T.K. Tran, and T.V. Nguyen, “Highly photocatalytic activity of novel nano-sized Ag3PO4 for Rhodamine B degradation under visible light irradiation,” Mater. Lett., 92 (2013) 57-60.
37. T.L.R. Hewer, B.C. Machado, R.S. Freire, and R. Guardani, “Ag3PO4 sunlight-induced photocatalyst for degradation of phenol,” RSC Adv., 4 (2014) 34674-34680.
38. M. Zayat, P. Garcia-Parejo, and D. Levy, “Preventing UV-light damage of light sensitive materials using a highly protective UV-absorbing coating,” Chem. Soc. Rev., 36 (2007) 1270-1281.
39. X. Li, J. Yu, J. Low, Y. Fang, J. Xiao, and X. Chen, “Engineering heterogeneous semiconductors for solar water splitting,” J. Mater. Chem. A, 3 (2015) 2485-2534.
40. X. Chen, C. Li, M. Gratzel, R. Kostecki, and S. S. Mao, “Nanomaterials for renewable energy production and storage,” Chem. Soc. Rev., 41 (2012) 7909-7937.
41. S. Chen and L.W. Wang, “Thermodynamic oxidation and reduction potentials of photocatalytic semiconductors in aqueous solution,” Chem. Mater., 24 (2012) 3659-3666.
42. W. Fan, Q. Zhang, and Y. Wang, “Semiconductor-based nanocomposites for photocatalytic H2 production and CO2 conversion,” Phys. Chem. Chem. Phys., 15 (2013) 2632-2649.
43. Y. Park, K.J. McDonald, and K.S. Choi, “Progress in bismuth vanadate photoanodes for use in solar water oxidation,” Chem. Soc. Rev., 42 (2013) 2321-2337.
44. L.A. Dobrzański, D. Pakuła, A. Křiž, M. Soković, and J. Kopač, “Tribological properties of the PVD and CVD coatings deposited onto the nitride tool ceramics,” J. Mater. Process. Technol., 175 (2006) 179-185.
45. L.A. Dobrzański and D. Pakuła, “Comparison of the structure and properties of the PVD and CVD coatings deposited on nitride tool ceramics,” J. Mater. Process. Technol., 164-165 (2005) 832-842.
46. I.Y. Konyashin, “PVD/CVD technology for coating cemented carbides,” Surf. Coat. Technol., 71 (1995) 277-283.
47. J.E. Crowell, “Chemical methods of thin film deposition: chemical vapor deposition, atomic layer deposition, and related technologies,” J. Vac. Sci. Technol., A, 21 (2003) S88-S95.
48. H. Kim, H.B.R. Lee, and W.J. Maeng, “Applications of atomic layer deposition to nanofabrication and emerging nanodevices,” Thin Solid Films, 517 (2009) 2563-2580.
49. D. Riihelä, M. Ritala, R. Matero, and M. Leskelä, “Introducing atomic layer epitaxy for the deposition of optical thin films,” Thin Solid Films, 289 (1996) 250-255.
50. M. Ahonen, M. Pessa, and T. Suntola, “A study of ZnTe films grown on glass substrates using an atomic layer evaporation method,” Thin Solid Films, 65 (1980) 301-307.
51. D. Vogler and P. Doe, “Where's the metal?” Solid State Technol., 46 (2003) 35-39.
52. V. Miikkulainen, M. Leskelä, M. Ritala, and R.L. Puurunen, “Crystallinity of inorganic films grown by atomic layer deposition: Overview and general trends,” s J. Appl. Phys., 113 (2013) 021301.
53. R.L. Puurunen and W. Vandervorst, “Island growth as a growth mode in atomic layer deposition: a phenomenological model,” J. Appl. Phys., 96 (2004) 7686-7695.
54. S.M. George, “Atomic layer deposition: an overview,” Chem. Rev., 110 (2010) 111-131.
55. E. Granneman, P. Fischer, D. Pierreux, H. Terhorst, and P. Zagwijn, “Batch ALD: characteristics, comparison with single wafer ALD, and examples,” Surf. Coat. Technol., 201 (2007) 8899-8907.
56. R.W. Johnson, A. Hultqvist, and S.F. Bent, “A brief review of atomic layer deposition: from fundamentals to applications,” Mater. Today, 17 (2014) 236-246.
57. R.L. Puurunen, “Surface chemistry of atomic layer deposition: a case study for the trimethylaluminum/water process,” J. Appl. Phys., 97 (2005) 121301.
58. M.R. Saleem, R. Ali, M.B. Khan, S. Honkanen, and J. Turunen, “Impact of atomic layer deposition to nanophotonic structures and devices,” Front. Mater., 1 (2014) 1-15.
59. E. Marin, A. Lanzutti, F. Andreatta, M. Lekka, L. Guzman, and L. Fedrizzi, “Atomic layer deposition: state-of-the-art and research/industrial perspectives,” Corros. Rev., 29 (2011) 191-208.
60. H. Hu, B. Dong, H. Hu, F. Chen, M. Kong, Q. Zhang, T. Luo, L. Zhao, Z. Guo, J. Li, Z. Xu, S. Wang, D. Eder, and L. Wan, “Atomic layer deposition of TiO2 for a high-efficiency hole-blocking layer in hole-conductor-free perovskite solar cells processed in ambient air,” ACS Appl. Mater. Interfaces, 8 (2016) 17999-18007.
61. A. Rahtu and M. Ritala, “Reaction mechanism studies on titanium isopropoxide–water atomic layer deposition process,” Chem. Vap. Deposition, 8 (2002) 21-28.
62. J. L. Gunjakara, Y. K. Joa, I. Y. Kima, J. M. Leea, S. B. Patila, J. C. Pyunb, and S. J. Hwang “A chemical bath deposition route to facet-controlled Ag3PO4 thin films with improved visible light photocatalytic activity,” J. Solid State Chem., 240 (2016) 115-121.
63. Z. W. Tong, D. Yang, Y. Y. Sun, Y. Tian, and Z. Y. Jiang, “In situ fabrication of Ag3PO4/TiO2 nanotube heterojunctions with enhanced visible-light photocatalytic activity,” Phys. Chem. Chem. Phys., 17 (2015) 12199-12206.
64. J. C. S. Wu, J. J. Chen, P. C. Wu, and D. P. Tsai, “Plasmon-enhanced photolysis of water for hydrogen production,” SPIENewsroom, 2012.
65. Y. Di, X. A. Thomas, and M. Antonietti, “Making metal-carbon nitride heterojunctions for improved photocatalytic hydrogen evolution with visible light,” ChemCatChem, 2 (2010) 834–838.
66. F. J. Sheu, C. P. Cho, Y. T. Liao, and C. T. Yu, “Ag3PO4-TiO2-graphene oxide ternary composites with efficient photodegradation, hydrogen evolution, and antibacterial properties,” Catalysts, 8 (2018) 57.
67. J. Yan, H. Wu, H. Chen, Y. Zhang, F. Zhang, and S. F. Liu, “Fabrication of TiO2/C3N4 heterostructure for enhanced photocatalytic Z-scheme overall water splitting,” Appl. Catal. B, 191 (2016) 130-137.
68. Q. Xiang, J. Yu, and M. Jaroniec, “Synergetic effect of MoS2 and graphene as cocatalysts for enhanced photocatalytic H2 production activity of TiO2 nanoparticles,” J. Am. Chem. Soc., 134 (2012) 6575-6578.
69. X. Y. Zhang, H. P. Li, X. L. Cui, and Y. Lin, “Graphene/TiO2 nanocomposites: synthesis, characterization and application in hydrogen evolution from water photocatalytic splitting,” J. Mater. Chem., 20 (2010) 2801-2806.
70. P. Khemthong, P. Photai, and N. Grisdanurak, “Structural properties of CuO/TiO2 nanorod in relation to their catalytic activity for simultaneous hydrogen production under solar light,” Int. J. Hydrogen Energy, 38 (2013) 15992-16001.