Utilization of visible light is of crucial importance for exploiting efficient semiconductor catalysts for solar water splitting. In this study, an advanced ion implantation method was utilized to dope Cu ions into ZnO nanorod arrays for photoelectrochemical water splitting in visible light. X-ray diffraction (XRD) and X-ray photo-electron spectroscopy (XPS) results revealed that Cu+ together with a small amount of Cu2+ were highly dispersed within the ZnO nanorod arrays. The Cu ion doped ZnO nanorod arrays displayed extended optical absorption and enhanced photoelectrochemical performance under visible light illumination (λ > 420 nm). A considerable photocurrent density of 18 μA/cm2 at 0.8 V (vs. a saturated calomel electrode) was achieved, which was about 11 times higher than that of undoped ZnO nanorod arrays. This study proposes that ion implantation could be an effective approach for developing novel visible-light-driven photocatalytic materials for water splitting.
Tian, Z. R.; Voigt, J. A.; Liu, J.; McKenzie, B.; McDermott, M. J.; Rodriguez, M. A.; Konishi, H.; Xu, H. Complex and oriented ZnO nanostructures. Nat. Mater.2003, 2, 821–826.CrossRefGoogle Scholar
[2]
Lakshmi, B. B.; Dorhout, P. K.; Martin, C. R. Sol-gel template synthesis of semiconductor nanostructures. Chem. Mater.1997, 9, 857–862.CrossRefGoogle Scholar
[3]
Sakthivel, S.; Neppolian, B.; Shankar, M. V.; Arabindoo, B.; Palanichamy, M.; Murugesan, V. Solar photocatalytic degradation of azo dye: Comparison of photocatalytic efficiency of ZnO and TiO2. Sol. Energy Mater. Sol. C2003, 77, 65–82.CrossRefGoogle Scholar
[4]
Yang, J. L.; An, S. J.; Park, W. I.; Yi, G. C.; Choi, W. Photocatalysis using ZnO thin films and nanoneedles grown by metal-organic chemical vapor deposition. Adv. Mater.2004, 16, 1661–1664.CrossRefGoogle Scholar
Mansilla, H. D.; Villaseñor, J.; Maturana, G.; Baeza, J.; Freer, J.; Durán, N. ZnO-catalysed photodegradation of kraft black liquor. J. Photoch. Photobio. A1994, 78, 267–273.CrossRefGoogle Scholar
[7]
Gu, L.; Zheng, K.; Zhou, Y.; Li, J.; Mo, X.; Patzke, G. R.; Chen, G. Humidity sensors based on ZnO/TiO2 core/shell nanorod arrays with enhanced sensitivity. Sens. Actuators. B2011, 159, 1–7.CrossRefGoogle Scholar
[8]
Akpan, U. G.; Hameed, B. H. The advancements in sol-gel method of doped-TiO2 photocatalysts. Appl. Catal., A2010, 375, 1–11.CrossRefGoogle Scholar
[9]
Das, S. C.; Green, R. J.; Podder, J.; Regier, T. Z.; Chang, G. S.; Moewes, A. Band gap tuning in ZnO through Ni doping via spray pyrolysis. J. Phys. Chem. C2013, 117, 12745–12753.CrossRefGoogle Scholar
[10]
Yang, X.; Wolcott, A.; Wang, G.; Sobo, A.; Fitzmorris, R. C.; Qian, F.; Zhang, J. Z.; Li, Y. Nitrogen-doped ZnO nanowire arrays for photoelectrochemical water splitting. Nano. Lett.2009, 9, 2331–2336.CrossRefGoogle Scholar
[11]
Law, M.; Greene, L. E.; Johnson, J. C.; Saykally, R.; Yang, P. Nanowire dye-sensitized solar cells. Nat. Mater.2005, 4, 455–459.CrossRefGoogle Scholar
[12]
Huang, K.-C.; Chang, Y.-H.; Chen, C.-Y.; Liu, C.-Y.; Lin, L.-Y.; Vittal, R.; Wu, C.-G.; Lin, K.-F.; Ho, K.-C. Improved exchange reaction in an ionic liquid electrolyte of a quasi-solid-state dye-sensitized solar cell by using 15-crown-5-functionalized MWCNT. J. Mater. Chem.2011, 21, 18467–18474.CrossRefGoogle Scholar
[13]
Schölin, R.; Quintana, M.; Johansson, E. M. J.; Hahlin, M.; Marinado, T.; Hagfeldt, A.; Rensmo, H. Preventing dye aggregation on ZnO by adding water in the dye-sensitization process. J. Phys. Chem. C2011, 115, 19274–19279.CrossRefGoogle Scholar
[14]
Leschkies, K. S.; Divakar, R.; Basu, J.; Enache-Pommer, E.; Boercker, J. E.; Carter, C. B.; Kortshagen, U. R.; Norris, D. J.; Aydil, E. S. Photosensitization of ZnO nanowires with CdSe quantum dots for photovoltaic devices. Nano Lett.2007, 7, 1793–1798.CrossRefGoogle Scholar
[15]
Tang, Y.; Hu, X.; Chen, M.; Luo, L.; Li, B.; Zhang, L. CdSe nanocrystal sensitized ZnO core-shell nanorod array films: Preparation and photovoltaic properties. Electrochim. Acta2009, 54, 2742–2747.CrossRefGoogle Scholar
[16]
Bang, J. H.; Kamat, P. V. Quantum dot sensitized solar cells. A tale of two semiconductor nanocrystals: CdSe and CdTe. ACS Nano2009, 3, 1467–1476.CrossRefGoogle Scholar
[17]
Chouhan, N.; Yeh, C. L.; Hu, S. F.; Huang, J. H.; Tsai, C. W.; Liu, R. S.; Chang, W. S.; Chen, K. H. Array of CdSe QD-sensitized ZnO nanorods serves as photoanode for water splitting. J. Electrochem. Soc.2010, 157, B1430–B1433.CrossRefGoogle Scholar
Tanabe, I.; Tatsuma, T. Plasmonic manipulation of color and morphology of single silver nanospheres. Nano. Lett.2012, 12, 5418–5421.CrossRefGoogle Scholar
[20]
Rycenga, M.; Cobley, C. M.; Zeng, J.; Li, W.; Moran, C. H.; Zhang, Q.; Qin, D.; Xia, Y. Controlling the synthesis and assembly of silver nanostructures for plasmonic applications. Chem. Rev.2011, 111, 3669–3712.CrossRefGoogle Scholar
[21]
Burlacov, I.; Jirkovský, J.; Müller, M.; Heimann, R. B. Induction plasma-sprayed photocatalytically active titania coatings and their characterisation by micro-Raman spectroscopy. Surf. Coat. Technol.2006, 201, 255–264.CrossRefGoogle Scholar
[22]
Narayan, H.; Alemu, H.; Macheli, L.; Thakurdesai, M.; Rao, T. K. G. Synthesis and characterization of Y3+-doped TiO2 nanocomposites for photocatalytic applications. Nanotechnology2009, 20, 255601.CrossRefGoogle Scholar
[23]
Jayakumar, O. D.; Salunke, H. G.; Kadam, R. M.; Mohapatra, M.; Yaswant, G.; Kulshreshtha, S. K. Magnetism in Mn-doped ZnO nanoparticles prepared by a co-precipitation method. Nanotechnology2006, 17, 1278–1285.CrossRefGoogle Scholar
[24]
Ba-Abbad, M. M.; Kadhum, A. A. H.; Mohamad, A. B.; Takriff, M. S.; Sopian, K. Visible light photocatalytic activity of Fe3+-doped ZnO nanoparticle prepared via sol-gel technique. Chemosphere2013, 91, 1604–1611.CrossRefGoogle Scholar
[25]
Yates, H. M.; Nolan, M. G.; Sheel, D. W.; Pemble, M. E. The role of nitrogen doping on the development of visible light-induced photocatalytic activity in thin TiO2 films grown on glass by chemical vapour deposition. J. Photoch. Photobio. A2006, 179, 213–223.CrossRefGoogle Scholar
[26]
Fragalà, M. E.; Cacciotti, I.; Aleeva, Y.; Lo Nigro, R. L.; Bianco, A.; Malandrino, G.; Spinella, C.; Pezzotti, G.; Gusmano, G. Core-shell Zn-doped TiO2-ZnO nanofibers fabricated via a combination of electrospinning and metal-organic chemical vapour deposition. CrystEngComm2010, 12, 3858–3865.CrossRefGoogle Scholar
[27]
Bhirud, A. P.; Sathaye, S. D.; Waichal, R. P.; Nikam, L. K.; Kale, B. B. An eco-friendly, highly stable and efficient nanostructured p-type N-doped ZnO photocatalyst for environmentally benign solar hydrogen production. Green Chem.2012, 14, 2790–2798.CrossRefGoogle Scholar
[28]
Ni, M.; Leung, M. K. H.; Leung, D. Y. C.; Sumathy, K. A review and recent developments in photocatalytic water-splitting using TiO2 for hydrogen production. Renew. Sust. Energ. Rev.2007, 11, 401–425.CrossRefGoogle Scholar
[29]
Ghicov, A.; Macak, J. M.; Tsuchiya, H.; Kunze, J.; Haeublein, V.; Frey, L.; Schmuki, P. Ion implantation and annealing for an efficient N-doping of TiO2 nanotubes. Nano Lett.2006, 6, 1080–1082.CrossRefGoogle Scholar
[30]
Ghicov, A.; Macak, J. M.; Tsuchiya, H.; Kunze, J.; Haeublein, V.; Kleber, S.; Schmuki, P. TiO2 nanotube layers: Dose effects during nitrogen doping by ion implantation. Chem. Phys. Lett.2006, 419, 426–429.CrossRefGoogle Scholar
[31]
Zhou, J.; Takeuchi, M.; Ray, A. K.; Anpo, M.; Zhao, X. S. Enhancement of photocatalytic activity of P25 TiO2 by vanadium-ion implantation under visible light irradiation. J. Colloid Interf. Sci.2007, 311, 497–501.CrossRefGoogle Scholar
[32]
Anpo, M.; Takeuchi, M. The design and development of highly reactive titanium oxide photocatalysts operating under visible light irradiation. J. Catal.2003, 216, 505–516.CrossRefGoogle Scholar
[33]
Takeuchi, M.; Sakai, S.; Matsuoka, M.; Anpo, M. Preparation of the visible light responsive TiO2 thin film photocatalysts by the RF magnetron sputtering deposition method. Res. Chem. Intermediat.2009, 35, 973–983.CrossRefGoogle Scholar
[34]
Greene, L. E.; Law, M.; Goldberger, J.; Kim, F.; Johnson, J. C.; Zhang, Y.; Saykally, R. J.; Yang, P. Low-temperature wafer-scale production of ZnO nanowire arrays. Angew. Chem. Int. Ed.2003, 42, 3031–3034.CrossRefGoogle Scholar
[35]
Wang, M.; Jiang, J.; Liu, G.; Shi, J.; Guo, L. Controllable synthesis of double layered tubular CdSe/ZnO arrays and their photoelectrochemical performance for hydrogen production. Appl. Catal. B2013, 138–139, 304–310.CrossRefGoogle Scholar
[36]
Ren, F.; Zhou, X. D.; Liu, Y. C.; Wang, Y. Q.; Cai, G. X.; Xiao, X. H.; Dai, Z. G.; Li, W. Q.; Yan, S. J.; Wu, W.; et al. Fabrication and properties of TiO2 nanofilms on different substrates by a novel and universal method of Ti-ion implantation and subsequent annealing. Nanotechnology2013, 24, 255603.CrossRefGoogle Scholar
[37]
Ren, F.; Jiang, C.; Liu, C.; Wang, J.; Oku, T. Controlling the morphology of Ag nanoclusters by ion implantation to different doses and subsequent annealing. Phys. Rev. Lett.2006, 97, 165501.CrossRefGoogle Scholar
[38]
Yang, F.; Ma, S.; Zhang, X.; Zhang, M.; Li, F.; Liu, J.; Zhao, Q. Blue-green and red luminescence from ZnO/porous silicon and ZnO:Cu/porous silicon nanocomposite films. Superlattice. Microst.2012, 52, 210–220.CrossRefGoogle Scholar
[39]
Shen, S.; Kronawitter, C. X.; Jiang, J.; Guo, P.; Guo, L.; Mao, S. S. A ZnO/ZnO:Cr isostructural nanojunction electrode for photoelectrochemical water splitting. Nano Energy2013, 2, 958–965.CrossRefGoogle Scholar
[40]
Manjón, F. J.; Marí, B.; Serrano, J.; Romero, A. H. Silent Raman modes in zinc oxide and related nitrides. J. Appl. Phys.2005, 97, 053516.CrossRefGoogle Scholar
[41]
Serrano, J.; Manjón, F. J.; Romero, A. H.; Widulle, F.; Lauck, R.; Cardona, M. Dispersive phonon linewidths: The E2 phonons of ZnO. Phys. Rev. Lett.2003, 90, 055510.CrossRefGoogle Scholar
[42]
Kaschner, A.; Haboeck, U.; Strassburg, M.; Strassburg, M.; Kaczmarczyk, G.; Hoffmann, A.; Thomsen, C.; Zeuner, A.; Alves, H. R.; Hofmann, D. M.; et al. Nitrogen-related local vibrational modes in ZnO:N. Appl. Phys. Lett.2002, 80, 1909–1911.CrossRefGoogle Scholar
[43]
Tütüncü, H. M.; Srivastava, G. P.; Duman, S. Lattice dynamics of the zinc-blende and wurtzite phases of nitrides. Physica B2002, 316–317, 190–194.CrossRefGoogle Scholar
[44]
Demangeot, F.; Groenen, J.; Frandon, J.; Renucci, M. A.; Briot, O.; Clur, S.; Aulombard, R. L. Coupling of GaN- and AlN-like longitudinal optic phonons in Ga1−xAlxN solid solutions. Appl. Phys. Lett.1998, 72, 2674–2676.CrossRefGoogle Scholar
[45]
Wang, L. S.; Tripathy, S.; Sun, W. H.; Chua, S. J. Micro-Raman spectroscopy of Si-, C-, Mg- and Be-implanted GaN layers. J. Raman Spectrosc.2004, 35, 73–77.CrossRefGoogle Scholar
[46]
Shuai, M.; Liao, L.; Lu, H. B.; Zhang, L.; Li, J. C.; Fu, D. J. Room-temperature ferromagnetism in Cu+ implanted ZnO nanowires. J. Phys. D2008, 41, 135010.CrossRefGoogle Scholar
[47]
Kulkarni, G. U.; Rao, C. N. R. EXAFS and XPS investigations of Cu/ZnO catalysts and their interaction with Co and methanol. J. Phys. D: Appl. Phys.2003, 22, 183–189.Google Scholar
[48]
Jing, L. Q.; Qu, Y. C.; Wang, B. Q.; Li, S. D.; Jiang, B. J.; Yang, L. B.; Fu, W.; Fu, H. G.; Sun, J. Z. Review of photoluminescence performance of nano-sized semiconductor materials and its relationships with photocatalytic activity. Sol. Energ. Mat. Sol. C2006, 90, 1773–1787.CrossRefGoogle Scholar
[49]
Guo, P.; Jiang, J.; Shen, S.; Guo, L. ZnS/ZnO heterojunction as photoelectrode: Type II band alignment towards enhanced photoelectrochemical performance. Int. J. Hydrogen Energy2013, 38, 13097–13103.CrossRefGoogle Scholar
[50]
Wang, X. B.; Song, C.; Geng, K. W.; Zeng, F.; Pan, F. Photoluminescence and Raman scattering of Cu-doped ZnO films prepared by magnetron sputtering. Appl. Surf. Sci.2007, 253, 6905–6909.CrossRefGoogle Scholar
[51]
Shen, S.; Jiang, J.; Guo, P.; Kronawitter, C. X.; Mao, S. S.; Guo, L. Effect of Cr doping on the photoelectrochemical performance of hematite nanorod photoanodes. Nano Energy2012, 1, 732–741.CrossRefGoogle Scholar
[52]
Shen, S.; Kronawitter, C. X.; Jiang, J.; Mao, S. S.; Guo, L. Surface tuning for promoted charge transfer in hematite nanorod arrays as water-splitting photoanodes. Nano Res.2012, 5, 327–336.CrossRefGoogle Scholar
[53]
Kouklin, N. Cu-doped ZnO nanowires for efficient and multispectral photodetection applications. Adv. Mater.2008, 20, 2190–2194.CrossRefGoogle Scholar
[54]
Garces, N. Y.; Wang, L.; Bai, L.; Giles, N. C.; Halliburton, L. E.; Cantwell, G. Role of copper in the green luminescence from ZnO crystals. Appl. Phys. Lett.2002, 81, 622–624.CrossRefGoogle Scholar
[55]
Samanta, K.; Arora, A. K.; Katiyar, R. S. Impurity induced bond-softening and defect states in ZnO:Cu. J. Appl. Phys.2011, 110, 043523.CrossRefGoogle Scholar
[56]
Ghosh, A.; Ghule, A.; Sharma, R. Effect of Cu doping on LPG sensing properties of soft chemically grown nano-structured ZnO thin film. J. Phys. Conf. Ser.2012, 365, 012022.CrossRefGoogle Scholar
[57]
Song, D. M.; Wang, T. H.; Li, J. C. First principles study of periodic size dependent band gap variation of Cu doped ZnO single-wall nanotube. J. Mol. Model.2012, 18, 5035–5040.CrossRefGoogle Scholar
[58]
Mora-Seró, I.; Fabregat-Santiago, F.; Denier, B.; Bisquert, J.; Tena-Zaera, R.; Elias, J.; Lévy-Clément, C. Determination of carrier density of ZnO nanowires by electrochemical techniques. Appl. Phys. Lett.2006, 89, 203117.CrossRefGoogle Scholar
[59]
Xing, G. Z.; Yi, J. B.; Tao, J. G.; Liu, T.; Wong, L. M.; Zhang, Z.; Li, G. P.; Wang, S. J.; Ding, J.; Sum, T. C., et al. Comparative study of room-temperature ferromagnetism in Cu-doped ZnO nanowires enhanced by structural inhomogeneity. Adv. Mater.2008, 20, 3521–3527.CrossRefGoogle Scholar
1.International Research Centre for Renewable Energy, State Key Laboratory of Multiphase Flow in Power EngineeringXi’an Jiaotong UniversityShaanxiChina
2.School of Physics and Technology, Center for Ion Beam ApplicationWuhan UniversityWuhanChina