在過去許多過渡金屬氧化物(Co、Ni、Fe)已被廣泛應用於催化水氧化反應上，但同為過渡金屬的銅(Cu)卻鮮少被關注，與Co、Ni相比，Cu具有低成本且地球含量豐富以及無毒，直到近年來才有相關報導氧化銅(CuO)為水氧化催化劑，而CuO由於其較差的電荷傳輸性能而仍然不能取代最先進的催化劑，因此急需提升其性能。
奈米結構可以通過縮短離子擴散途徑和增加電化學表面積來增強催化性能。在本研究中，通過一種簡便而快速的電沉積方法以及熱轉化來製備2D CuO。通過控制電鍍液中的陰離子的種類，獲得一系列的CuO奈米結構。將CuO沉積在光電極BiVO4的表面用作光電化學水氧化的助催化劑，探討陰離子對CuO的形貌和催化活性的影響，。
本實驗使用簡便的電沉積法製備出銅金屬之層狀羥基鹽(Cu-LHS)作為氧化銅(CuO)之前驅物，在電沉積的溶液中含有銅源、輔助電解質以及苯醌，分別將銅源及輔助電解質換成帶有NO3-、SO42-、Cl-三種陰離子的組成，經過電沉積程序可得Cu-LHS，然後以400 °C進行熱轉化程序持續一小時得到三種不同的CuO，將這三種CuO添加於BiVO4上進行光電化學水氧化反應。其中，NO3-系統所得之CuO擁有最緻密的奈米片結構、最高的表面積，因此其表現出最低的起始電位0.5 V vs.RHE，以及最高的電流密度0.83 mA/cm2，這證實了氧化銅(CuO)能作為水氧化催化劑且有顯著的效果。本實驗亦進行了電極穩定性及氣體產物的分析，使用定電壓(1.23 V vs. RHE)進行反應100分鐘，BiVO4光電極之法拉第效率僅有60至70%，部分電流來自於光腐蝕現象，並未進行產氧反應，而加上CuO觸媒後由氣體產物分析可得到趨近於100%的法拉第效率，這證明了氧化銅(CuO)能提高與水之間的反應動力學獲得更高的水氧化效率，同時抑制了光腐蝕現象。

Over the past decades, transition metal oxides (Co,Ni,Fe)have been widely studied a catalyst for water oxidation . Cu-based materials has received little attention. In addi-tion to these earth-abundant elements , Cu is an attractive low cost and relatively less harmful to the environment compared to Co or Ni. It is only recently that Cu-based oxides have been reported is electrochemically oxidize. Neverless , CuO is still outper-formed by state-of-art catalyst due to its poor charge transport properties. Therefore there is a high demand for further enhancing their performance.
Given that nanostructures can enhance catalytic performance by shortening ion diffusion pathway and large electrochemical surface area. In this work , 2D CuO has been controllably prepared by a facile and rapid electrodeposition method coupled with thermal conversion. A series of CuO nano structures have been obtained by controlling the species of the presenting anion in the electroplating solution. Effects of anions on the morphologies and catalytic activities of CuO was thoroughly studies. These ob-tained CuOs were usedas a cocatalyst for photoelectrochemical water oxidation by de-positing on the top of a typical light absorber , i.e , BiVO4. Among them, the CuO obtained by NO3- system has the densest nanosheet structure, the highest surface area and high crystallinity It proves that the higher the surface area will be, the better the photoelectrochemical performance will be. And also confirmed that copper oxide (CuO), whether crystalline or amorphous, can be used as a water oxidation catalyst and has a remarkable effect. The stability and gas product analysis were also performed in this study. The reaction was performed at a constant voltage (1.23 V vs. RHE) for 100 minutes. The Faraday efficiency of the BiVO4 photoanode is only 60% to 70%, and part of the current comes from the photocorrosion The analysis of the gas products after adding the CuO catalyst can obtain a Faraday efficiency close to 100%, which proves
iv
that copper oxide (CuO) can improve the reaction kinetics with water to obtain a higher efficiency of water oxidation, while suppressing the phenomenon of photocorrosion.

[1] Z. Chen, T.J. Meyer, Copper (II) catalysis of water oxidation, Angewandte Chemie International Edition 52 (2013) 700-703.
[2] Z. Chen, P. Kang, M.-T. Zhang, B.R. Stoner, T.J. Meyer, Cu (ii)/Cu (0) electrocatalyzed CO2 and H2O splitting, Energy & Environmental Science 6 (2013) 813-817.
[3] M.-T. Zhang, Z. Chen, P. Kang, T.J. Meyer, Electrocatalytic water oxidation with a copper (II) polypeptide complex, Journal of the American Chemical Society 135 (2013) 2048-2051.
[4] T. Zhang, C. Wang, S. Liu, J.-L. Wang, W. Lin, A biomimetic copper water oxidation catalyst with low overpotential, Journal of the American Chemical Society 136 (2013) 273-281.
[5] N. Cheng, Y. Xue, Q. Liu, J. Tian, L. Zhang, A.M. Asiri, X. Sun, Cu/(Cu(OH)2-CuO) core/shell nanorods array: in-situ growth and application as an efficient 3D oxygen evolution anode, Electrochimica Acta 163 (2015) 102-106.
[6] C.-C. Hou, C.-J. Wang, Q.-Q. Chen, X.-J. Lv, W.-F. Fu, Y. Chen, Rapid synthesis of ultralong Fe(OH)3: Cu(OH)2 core–shell nanowires self-supported on copper foam as a highly efficient 3D electrode for water oxidation, Chemical Communications 52 (2016) 14470-14473.
[7] C.-C. Hou, Q.-Q. Chen, C.-J. Wang, F. Liang, Z. Lin, W.-F. Fu, Y. Chen, Self-supported cedarlike semimetallic Cu3P nanoarrays as a 3D high-performance Janus electrode for both oxygen and hydrogen evolution under basic conditions, ACS applied materials & interfaces 8 (2016) 23037-23048.
[8] M. Qian, X. Liu, S. Cui, H. Jia, P. Du, Copper oxide nanosheets prepared by molten salt method for efficient electrocatalytic oxygen evolution reaction with low catalyst loading, Electrochimica Acta 263 (2018) 318-327.
[9] S. Cui, X. Liu, Z. Sun, P. Du, Noble metal-free copper hydroxide as an active and robust electrocatalyst for water oxidation at weakly basic pH, ACS Sustainable Chemistry & Engineering 4 (2016) 2593-2600.
[10] X. Liu, S. Cui, Z. Sun, Y. Ren, X. Zhang, P. Du, Self-supported copper oxide electrocatalyst for water oxidation at low overpotential and confirmation of its robustness by Cu K-edge X-ray absorption spectroscopy, The Journal of Physical Chemistry C 120 (2016) 831-840.
[11] X. Liu, S. Cui, Z. Sun, P. Du, Copper oxide nanomaterials synthesized from simple copper salts as active catalysts for electrocatalytic water oxidation, Electrochimica Acta 160 (2015) 202-208.
[12] T.-T. Li, J. Qian, Y.-Q. Zheng, Facile synthesis of porous CuO polyhedron from Cu-based metal organic framework (MOF-199) for electrocatalytic water oxidation, RSC Advances 6 (2016) 77358-77365.
[13] K.S. Joya, H.J. de Groot, Controlled surface-assembly of nanoscale leaf-type Cu-oxide electrocatalyst for high activity water oxidation, ACS Catalysis 6 (2016) 1768-1771.
[14] S.M. Barnett, K.I. Goldberg, J.M. Mayer, A soluble copper–bipyridine water-oxidation electrocatalyst, Nature chemistry 4 (2012) 498.
[15] X. Liu, H. Jia, Z. Sun, H. Chen, P. Xu, P. Du, Nanostructured copper oxide electrodeposited from copper (II) complexes as an active catalyst for electrocatalytic oxygen evolution reaction, Electrochemistry Communications 46 (2014) 1-4.
[16] J. Wang, L. Zhu, L. Ji, Z. Chen, Preparation of nanostructured Cu(OH)2 and CuO electrocatalysts for water oxidation by electrophoresis deposition, Journal of Materials Research 33 (2018) 581-589.
[17] A. Radha, P.V. Kamath, G. Subbanna, Disorder in layered hydroxides: synthesis and DIFFaX simulation studies of Mg (OH)2, Materials research bulletin 38 (2003) 731-740.
[18] T. Ramesh, M. Rajamathi, P.V. Kamath, Ammonia induced precipitation of cobalt hydroxide: observation of turbostratic disorder, Solid State Sciences 5 (2003) 751-756.
[19] R. Lieth, Preparation and crystal growth of materials with layered structures, Springer Science & Business Media1977.
[20] G.G.C. Arizaga, K.G. Satyanarayana, F. Wypych, Layered hydroxide salts: synthesis, properties and potential applications, Solid State Ionics 178 (2007) 1143-1162.
[21] J. Sun, Y. Jia, Y. Jing, Y. Yao, J. Ma, F. Gao, C. Xia, Formation process of Cu2(OH)2CO3 and CuO hierarchical nanostructures by assembly of hydrated nanoparticles, Journal of nanoscience and nanotechnology 9 (2009) 5903-5909.
[22] F. Bakhtiari, E. Darezereshki, One-step synthesis of tenorite (CuO) nano-particles from Cu4(SO4)(OH)6 by direct thermal-decomposition method, Materials letters 65 (2011) 171-174.
[23] W. Jia, E. Reitz, H. Sun, H. Zhang, Y. Lei, Synthesis and characterization of novel nanostructured fishbone-like Cu (OH)2 and CuO from Cu4SO4(OH)6, Materials letters 63 (2009) 519-522.
[24] H. Jiu, Y. Sun, Z. Li, Y. Wang, Y. Fu, Z. Zhang, J. Zhang, X. Fan, L. Zhang, Fabrication of Cu2(OH)2CO3 and CuO particles: from spindle to nanorod, nanoribbon and hollow structure, Micro & Nano Letters 6 (2011) 639-642.
[25] H. Siddiqui, M. Qureshi, F.Z. Haque, Effect of copper precursor salts: facile and sustainable synthesis of controlled shaped copper oxide nanoparticles, Optik 127 (2016) 4726-4730.
[26] A.C. Cardiel, K.J. McDonald, K.-S. Choi, Electrochemical growth of copper hydroxy double salt films and their conversion to nanostructured p-type CuO photocathodes, Langmuir 33 (2017) 9262-9270.
[27] Q. Mei, W. Lv, M. Du, Q. Zheng, Morphological control of poly (vinylidene fluoride)@ layered double hydroxide composite fibers using metal salt anions and their enhanced performance for dye removal, RSC Advances 7 (2017) 46576-46588.
[28] A. Fujishima, K. Honda, Electrochemical Photolysis of Water at a Semiconductor Electrode, Nature 238 (1972) 37-38.
[29] J.-Q. Li, Z.-Y. Guo, D.-F. Wang, H. Lui, J. Du, Z.-F. Zhu, Effects of pH value on the surface morphology of BiVO4 microspheres and removal of methylene blue under visible light, Journal of Experimental Nanoscience 9 (2012) 616-624.
[30] J. Hou, C. Yang, H. Cheng, S. Jiao, O. Takeda, H. Zhu, High-performance p-Cu2O/n-TaON heterojunction nanorod photoanodes passivated with an ultrathin carbon sheath for photoelectrochemical water splitting, Energy & Environmental Science 7 (2014) 3758-3768.
[31] K. Iwashina, A. Kudo, Rh-doped SrTiO3 photocatalyst electrode showing cathodic photocurrent for water splitting under visible-light irradiation, Journal of the American Chemical Society 133 (2011) 13272-13275.
[32] T.W. Kim, K.S. Choi, Nanoporous BiVO4 photoanodes with dual-layer oxygen evolution catalysts for solar water splitting, Science 343 (2014) 990-994.
[33] M.M. Momeni, Y. Ghayeb, Visible light-driven photoelectrochemical water splitting on ZnO–TiO2 heterogeneous nanotube photoanodes, Journal of Applied Electrochemistry 45 (2015) 557-566.
[34] K. Sivula, F.L. Formal, M. Grätzel, WO3−Fe2O3 Photoanodes for Water Splitting: A Host Scaffold, Guest Absorber Approach, Chemistry of Materials 21 (2009) 2862-2867.
[35] A. Kudo, K. Ueda, H. Kato, I. Mikami, <Photocatalytic O2 evolution under visible light irradiation on BiVO4 in aqueous AgNO3 solution.pdf>, Catalysis Letters 53 (1998) 229-230.
[36] Y. Liang, T. Tsubota, L.P.A. Mooij, R. van de Krol, Highly Improved Quantum Efficiencies for Thin Film BiVO4 Photoanodes, The Journal of Physical Chemistry C 115 (2011) 17594-17598.
[37] S.J.A. Moniz, J. Zhu, J. Tang, 1D Co-Pi Modified BiVO4/ZnO Junction Cascade for Efficient Photoelectrochemical Water Cleavage, Advanced Energy Materials 4 (2014).
[38] C. Martinez Suarez, S. Hernández, N. Russo, BiVO4 as photocatalyst for solar fuels production through water splitting: A short review, Applied Catalysis A: General 504 (2015) 158-170.
[39] Z. Zhao, Z. Li, Z. Zou, Electronic structure and optical properties of monoclinic clinobisvanite BiVO4, Physical Chemistry Chemical Physics 13 (2011) 4746-4753.
[40] K. Sayama, A. Nomura, Z. Zou, R. Abe, Y. Abe, H. Arakawa, Photoelectrochemical decomposition of water on nanocrystalline BiVO4 film electrodes under visible light, Chemical Communications (2003) 2908-2909.
[41] D. Ressnig, R. Kontic, G.R. Patzke, Morphology control of BiVO4 photocatalysts: pH optimization vs. self-organization, Materials Chemistry and Physics 135 (2012) 457-466.
[42] D. Li, Y. Liu, W. Shi, C. Shao, S. Wang, C. Ding, T. Liu, F. Fan, J. Shi, C. Li, Crystallographic-Orientation-Dependent Charge Separation of BiVO4 for Solar Water Oxidation, ACS Energy Letters 4 (2019) 825-831.
[43] K.J. McDonald, K.-S. Choi, A new electrochemical synthesis route for a BiOI electrode and its conversion to a highly efficient porous BiVO4 photoanode for solar water oxidation, Energy & Environmental Science 5 (2012) 8553-8557.
[44] S.J. Hong, S. Lee, J.S. Jang, J.S. Lee, Heterojunction BiVO4/WO3 electrodes for enhanced photoactivity of water oxidation, Energy & Environmental Science 4 (2011).
[45] J. Su, L. Guo, N. Bao, C.A. Grimes, Nanostructured WO3/BiVO4 heterojunction films for efficient photoelectrochemical water splitting, Nano Letters 11 (2011) 1928-1933.
[46] S. Bai, H. Chu, X. Xiang, R. Luo, J. He, A. Chen, Fabricating of Fe2O3/BiVO4 heterojunction based photoanode modified with NiFe-LDH nanosheets for efficient solar water splitting, Chemical Engineering Journal 350 (2018) 148-156.
[47] S.K. Pilli, T.G. Deutsch, T.E. Furtak, L.D. Brown, J.A. Turner, A.M. Herring, BiVO4/CuWO4 heterojunction photoanodes for efficient solar driven water oxidation, Physical Chemistry Chemical Physics 15 (2013) 3273-3278.
[48] S. Xu, D. Fu, K. Song, L. Wang, Z. Yang, W. Yang, H. Hou, One-dimensional WO3/BiVO4 heterojunction photoanodes for efficient photoelectrochemical water splitting, Chemical Engineering Journal 349 (2018) 368-375.
[49] J.-R. Ding, K.-S. Kim, 1-D WO3@BiVO4 heterojunctions with highly enhanced photoelectrochemical performance, Chemical Engineering Journal 334 (2018) 1650-1656.
[50] P.M. Rao, L. Cai, C. Liu, I.S. Cho, C.H. Lee, J.M. Weisse, P. Yang, X. Zheng, Simultaneously efficient light absorption and charge separation in WO3/BiVO4 core/shell nanowire photoanode for photoelectrochemical water oxidation, Nano Letters 14 (2014) 1099-1105.
[51] X. Chang, T. Wang, P. Zhang, J. Zhang, A. Li, J. Gong, Enhanced Surface Reaction Kinetics and Charge Separation of p-n Heterojunction Co3O4/BiVO4 Photoanodes, Journal of the American Chemical Society 137 (2015) 8356-8359.
[52] X. Chen, G. Wu, J. Chen, X. Chen, Z. Xie, X. Wang, Synthesis of “clean” and well-dispersive Pd nanoparticles with excellent electrocatalytic property on graphene oxide, Journal of the American Chemical Society 133 (2011) 3693-3695.
[53] H. Kato, K. Asakura, A. Kudo, Highly efficient water splitting into H2 and O2 over lanthanum-doped NaTaO3 photocatalysts with high crystallinity and surface nanostructure, Journal of the American Chemical Society 125 (2003) 3082-3089.
[54] J. Ran, J. Zhang, J. Yu, M. Jaroniec, S.Z. Qiao, Earth-abundant cocatalysts for semiconductor-based photocatalytic water splitting, Chemical Society Reviews 43 (2014) 7787-7812.
[55] J. Yu, J. Ran, Facile preparation and enhanced photocatalytic H2-production activity of Cu(OH)2 cluster modified TiO2, Energy & Environmental Science 4 (2011) 1364-1371.
[56] D.K. Zhong, S. Choi, D.R. Gamelin, Near-complete suppression of surface recombination in solar photoelectrolysis by “Co-Pi” catalyst-modified W: BiVO4, Journal of the American Chemical Society 133 (2011) 18370-18377.
[57] F.F. Abdi, N. Firet, R. van de Krol, Efficient BiVO4 thin film photoanodes modified with Cobalt Phosphate catalyst and W‐doping, ChemCatChem 5 (2013) 490-496.
[58] S.P. Berglund, A.J. Rettie, S. Hoang, C.B. Mullins, Incorporation of Mo and W into nanostructured BiVO4 films for efficient photoelectrochemical water oxidation, Physical Chemistry Chemical Physics 14 (2012) 7065-7075.
[59] W. Luo, Z. Li, T. Yu, Z. Zou, Effects of surface electrochemical pretreatment on the photoelectrochemical performance of Mo-doped BiVO4, The Journal of Physical Chemistry C 116 (2012) 5076-5081.
[60] L. Chen, F.M. Toma, J.K. Cooper, A. Lyon, Y. Lin, I.D. Sharp, J.W. Ager, Mo‐Doped BiVO4 Photoanodes Synthesized by Reactive Sputtering, ChemSusChem 8 (2015) 1066-1071.
[61] S.M. Thalluri, S. Hernández, S. Bensaid, G. Saracco, N. Russo, Green-synthesized W-and Mo-doped BiVO4 oriented along the {0 4 0} facet with enhanced activity for the sun-driven water oxidation, Applied Catalysis B: Environmental 180 (2016) 630-636.
[62] A. Iwase, S. Ikeda, A. Kudo, Efficient Solar Water Oxidation to Oxygen over Mo-doped BiVO4 Thin Film Photoanode Prepared by a Facile Aqueous Solution Route, Chemistry Letters 46 (2017) 651-654.
[63] Y. Jia, Z. Wang, Y. Ma, J. Liu, W. Shi, Y. Lin, X. Hu, K. Zhang, Boosting interfacial charge migration of TiO2/BiVO4 photoanode by W doping for photoelectrochemical water splitting, Electrochimica Acta 300 (2019) 138-144.
[64] R.P. Antony, P.S. Bassi, F.F. Abdi, S.Y. Chiam, Y. Ren, J. Barber, J.S.C. Loo, L.H. Wong, Electrospun Mo-BiVO4 for efficient photoelectrochemical water oxidation: direct evidence of improved hole diffusion length and charge separation, Electrochimica Acta 211 (2016) 173-182.
[65] L. Yang, Y. Xiong, W. Guo, J. Guo, D. Gao, Y. Zhang, P. Xiao, Mo6+ doped BiVO4 with improved charge separation and oxidation kinetics for photoelectrochemical water splitting, Electrochimica Acta 256 (2017) 268-277.
[66] Q. Pan, K. Yang, G. Wang, D. Li, J. Sun, B. Yang, Z. Zou, W. Hu, K. Wen, H. Yang, BiVO4 nanocrystals with controllable oxygen vacancies induced by Zn-doping coupled with graphene quantum dots for enhanced photoelectrochemical water splitting, Chemical Engineering Journal 372 (2019) 399-407.
[67] Y. Bu, J. Tian, Z. Chen, Q. Zhang, W. Li, F. Tian, J.P. Ao, Optimization of the Photo‐Electrochemical Performance of Mo‐Doped BiVO4 Photoanode by Controlling the Metal–Oxygen Bond State on (020) Facet, Advanced Materials Interfaces 4 (2017) 1601235.
[68] X. Chang, T. Wang, P. Zhang, J. Zhang, A. Li, J. Gong, Enhanced surface reaction kinetics and charge separation of p–n heterojunction Co3O4/BiVO4 photoanodes, Journal of the American Chemical Society 137 (2015) 8356-8359.
[69] J. Yang, D. Wang, H. Han, C. Li, Roles of cocatalysts in photocatalysis and photoelectrocatalysis, Accounts of chemical research 46 (2013) 1900-1909.
[70] Y. Ma, A. Kafizas, S.R. Pendlebury, F. Le Formal, J.R. Durrant, Photoinduced absorption spectroscopy of CoPi on BiVO4: the function of CoPi during water oxidation, Advanced Functional Materials 26 (2016) 4951-4960.
[71] F. Lei, Y. Sun, K. Liu, S. Gao, L. Liang, B. Pan, Y. Xie, Oxygen vacancies confined in ultrathin indium oxide porous sheets for promoted visible-light water splitting, Journal of the American Chemical Society 136 (2014) 6826-6829.
[72] M.W. Louie, A.T. Bell, An investigation of thin-film Ni–Fe oxide catalysts for the electrochemical evolution of oxygen, Journal of the American Chemical Society 135 (2013) 12329-12337.
[73] F.F. Abdi, R. van de Krol, Nature and light dependence of bulk recombination in Co-Pi-catalyzed BiVO4 photoanodes, The Journal of Physical Chemistry C 116 (2012) 9398-9404.
[74] S.J. Moniz, J. Zhu, J. Tang, 1D Co‐Pi modified BiVO4/ZnO junction cascade for efficient photoelectrochemical water cleavage, Advanced Energy Materials 4 (2014) 1301590.
[75] M.R. Nellist, J. Qiu, F.A. Laskowski, F.M. Toma, S.W. Boettcher, Potential-sensing electrochemical AFM shows CoPi as a hole collector and oxygen evolution catalyst on BiVO4 water-splitting photoanodes, ACS Energy Letters 3 (2018) 2286-2291.
[76] K. Nie, S. Kashtanov, Y. Wei, Y.-S. Liu, H. Zhang, M. Kapilashrami, Y. Ye, P.-A. Glans, J. Zhong, L. Vayssieres, Atomic-scale understanding of the electronic structure-crystal facets synergy of nanopyramidal CoPi/BiVO4 hybrid photocatalyst for efficient solar water oxidation, Nano Energy 53 (2018) 483-491.
[77] S.K. Pilli, T.G. Deutsch, T.E. Furtak, J.A. Turner, L.D. Brown, A.M. Herring, Light induced water oxidation on cobalt-phosphate (Co–Pi) catalyst modified semi-transparent, porous SiO2–BiVO4 electrodes, Physical Chemistry Chemical Physics 14 (2012) 7032-7039.
[78] B. Zhang, L. Wang, Y. Zhang, Y. Ding, Y. Bi, Ultrathin FeOOH nanolayers with abundant oxygen vacancies on BiVO4 photoanodes for efficient water oxidation, Angewandte Chemie International Edition 57 (2018) 2248-2252.
[79] L. Elton, D.F. Jackson, X-ray diffraction and the Bragg law, American Journal of Physics 34 (1966) 1036-1038.
[80] Z.-A. Hu, Y.-L. Xie, Y.-X. Wang, L.-J. Xie, G.-R. Fu, X.-Q. Jin, Z.-Y. Zhang, Y.-Y. Yang, H.-Y. Wu, Synthesis of α-cobalt hydroxides with different intercalated anions and effects of intercalated anions on their morphology, basal plane spacing, and capacitive property, The Journal of Physical Chemistry C 113 (2009) 12502-12508.
[81] Y. Marcus, Ionic radii in aqueous solutions, Chemical Reviews 88 (1988) 1475-1498.
[82] Y. Deng, A.D. Handoko, Y. Du, S. Xi, B.S. Yeo, In situ Raman spectroscopy of copper and copper oxide surfaces during electrochemical oxygen evolution reaction: identification of CuIII oxides as catalytically active species, ACS Catalysis 6 (2016) 2473-2481.
[83] Y. Sun, Z. Sun, S. Gao, H. Cheng, Q. Liu, J. Piao, T. Yao, C. Wu, S. Hu, S. Wei, Fabrication of flexible and freestanding zinc chalcogenide single layers, Nature communications 3 (2012) 1057.
[84] Y. Liu, H. Cheng, M. Lyu, S. Fan, Q. Liu, W. Zhang, Y. Zhi, C. Wang, C. Xiao, S. Wei, Low overpotential in vacancy-rich ultrathin CoSe2 nanosheets for water oxidation, Journal of the American Chemical Society 136 (2014) 15670-15675.
[85] G.M. Carroll, D.R. Gamelin, Kinetic analysis of photoelectrochemical water oxidation by mesostructured Co-Pi/α-Fe2O3 photoanodes, Journal of Materials Chemistry A 4 (2016) 2986-2994.
[86] B. Klahr, S. Gimenez, F. Fabregat-Santiago, J. Bisquert, T.W. Hamann, Photoelectrochemical and impedance spectroscopic investigation of water oxidation with “Co–Pi”-coated hematite electrodes, Journal of the American Chemical Society 134 (2012) 16693-16700.
[87] T.-G. Vo, J.-M. Chiu, Y. Tai, C.-Y. Chiang, Turnip-inspired BiVO4/CuSCN nanostructure with close to 100% suppression of surface recombination for solar water splitting, Solar Energy Materials and Solar Cells 185 (2018) 415-424.