本研究將分為兩部分，在第一部分中，以鋯為基底的金屬有機骨架 (Zirconium-based metal–organic frameworks, Zr-MOFs)被用以安裝具氧化還原活性銥位點，這些在MOF骨架中均勻分散的銥活性位點能使電荷在骨架中以氧化還原躍遷的方式進行傳遞並同時展現電催化亞硝酸鹽的活性。藉由調整以過氯酸鹽水溶液為基底之電解液的pH值，此材料對亞硝酸鹽之電催化活性能以被最佳化，與其他以MOF為基底製備的亞硝酸鹽電化學感測器相比，此系統能以定電位測量的手法得到相對較高的感測靈敏度與更低的偵測下限。由於以銥為基底的材料在電催化產氧方面亦是廣為人知的觸媒，本研究將在第二部分中對此進行討論，利用MOF直接生長於邊緣羧酸官能化多層壁奈米碳管(Carboxylic acid-functionalized multi-walled carbon nanotubes, CNT)的合成手法，具塊材導電性的MOF-CNT複合材料得以被成功設計，經銥後修飾之複合材料將可同時藉由氧化還原躍遷及電子傳導更有效地傳遞電荷，此策略解決了以MOF為基底材料的遲緩電荷傳導，終使最佳MOF對CNT比例的複合材料能在高電流密度區間展現更低的電催化產氧反應過電位。

In this study, a zirconium-based MOF, UiO-66, is utilized to install redox-active iridium sites to render redox hopping, and the resulting Ir-decorated UiO-66 is applied for electrochemical sensors toward nitrite. By using a self-limiting solvothermal deposition in MOFs (SIM) technique, iridium sites can be uniformly immobilized in the entire framework of UiO-66. The resulting immobilized iridium sites not only render the redox hopping-based electron transport in aqueous electrolytes, but also exhibit electrocatalytic activity for the oxidation of nitrite, which allows the application of this material for electrochemical nitrite sensor. In final, Ir-decorated UiO-66 could achieve a good sensitivity (168.79 μA/mM-cm2) for detecting nitrite with a low limit of detection (0.41 μM).
In addition to the oxidation of nitrite, the electrochemically active Ir sites installed in UiO-66 can also electrocatalyze oxygen evolution reaction (OER). However, the sluggish interparticle charge transport of the Ir-decorated UiO-66 strongly restricts its use for OER, which usually operated at high current density condition. Therefore, nanocomposites composed of Ir-functionalized UiO-66 nanocrystals interconnected by carbon nanotubes (CNT) were further synthesized. As a result, the Ir-decorated UiO-66-CNT nanocomposite with the optimal MOF-to-CNT ratio achieves a much lower overpotential for OER at 10 mA/cm2 compared to those of the Ir-decorated MOF and In-decorated CNT.

[1] E.E. Benson, C.P. Kubiak, A.J. Sathrum, J.M. Smieja, Electrocatalytic and homogeneous approaches to conversion of CO2 to liquid fuels. Chem. Soc. Rev., 38, 89-99, 2009.
[2] S. Anantharaj, S.R. Ede, K. Sakthikumar, K. Karthick, S. Mishra, S. Kundu, Recent trends and perspectives in electrochemical water splitting with an emphasis on sulfide, selenide, and phosphide catalysts of Fe, Co, and Ni: a review. ACS Catal., 6, 8069-8097, 2016.
[3] M. Shao, Q. Chang, J.-P. Dodelet, R. Chenitz, Recent advances in electrocatalysts for oxygen reduction reaction. Chem. Rev., 116, 3594-3657, 2016.
[4] X. Wang, Q. Wang, Q. Wang, F. Gao, F. Gao, Y. Yang, H. Guo, Highly dispersible and stable copper terephthalate metal–organic framework–graphene oxide nanocomposite for an electrochemical sensing application. ACS Appl. Mater. Interfaces, 6, 11573-11580, 2014.
[5] D.-W. Hwang, S. Lee, M. Seo, T.D. Chung, Recent advances in electrochemical non-enzymatic glucose sensors – a review. Anal. Chim. Acta, 1033, 1-34, 2018.
[6] P. Simon, Y. Gogotsi, Materials for electrochemical capacitors. Nat. Mater., 7, 845-854, 2008.
[7] J.M. Tarascon, M. Armand, Issues and challenges facing rechargeable lithium batteries. Nature, 414, 359-367, 2001.
[8] K. Zhao, H. Song, S. Zhuang, L. Dai, P. He, Y. Fang, Determination of nitrite with the electrocatalytic property to the oxidation of nitrite on thionine modified aligned carbon nanotubes. Electrochem. Commun., 9, 65-70, 2007.
[9] Z. Sun, J. Li, H. Zheng, X. Liu, S. Ye, P. Du, Pyrolyzed cobalt porphyrinmodified carbon nanomaterial as an active catalyst for electrocatalytic water oxidation. Int. J. Hydrog. Energy, 40, 6538-6545, 2015.
[10] M. Shi, F.C. Anson, Rapid oxidation of Ru(NH3)63+ by Os(bpy)33+ within Nafion coatings on electrodes. Langmuir, 12, 2068-2075, 1996.
[11] A.P. O'Mullane, J.V. Macpherson, P.R. Unwin, J. Cervera-Montesinos, J.A. Manzanares, F. Frehill, J.G. Vos, Measurement of lateral charge propagation in [Os(bpy)2(PVP)nCl]Cl thin films: a scanning electrochemical microscopy approach. J. Phys. Chem. B, 108, 7219-7227, 2004.
[12] C. Sandford, M.A. Edwards, K.J. Klunder, D.P. Hickey, M. Li, K. Barman, M.S. Sigman, H.S. White, S.D. Minteer, A synthetic chemist's guide to electroanalytical tools for studying reaction mechanisms. Chem. Sci., 10, 6404-6422, 2019.
[13] F. Bedioui, N. Villeneuve, Electrochemical nitric oxide sensors for biological samples – principle, selected examples and applications. Electroanalysis, 15, 5-18, 2003.
[14] Y. Li, H. Wang, X. Liu, L. Guo, X. Ji, L. Wang, D. Tian, X. Yang, Nonenzymatic nitrite sensor based on a titanium dioxide nanoparticles/ionic liquid composite electrode. J. Electroanal. Chem., 719, 35-40, 2014.
[15] K. Wang, C. Wu, F. Wang, C. Liu, C. Yu, G. Jiang, In-situ insertion of carbon nanotubes into metal–organic frameworks-derived α-Fe2O3 polyhedrons for highly sensitive electrochemical detection of nitrite. Electrochim. Acta, 285, 128-138, 2018.
[16] F. Bedioui, N. Villeneuve, Electrochemical nitric oxide sensors for biological samples - principle, selected examples and applications. Electroanalysis, 15, 5-18, 2003.
[17] J.R. Stetter, J. Li, Amperometric gas sensors–a review. Chem. Rev., 108, 352-366, 2008.
[18] B. Sahin, T. Kaya, Electrochemical amperometric biosensor applications of nanostructured metal oxides: a review. Mater. Res. Express, 6, 042003, 2019.
[19] P.K. Rastogi, V. Ganesan, S. Krishnamoorthi, A promising electrochemical sensing platform based on a silver nanoparticles decorated copolymer for sensitive nitrite determination. J. Mater. Chem. A, 2, 933-943, 2014.
[20] H. Wu, S. Fan, X. Jin, H. Zhang, H. Chen, Z. Dai, X. Zou, Construction of a zinc porphyrin–fullerene-derivative based nonenzymatic electrochemical sensor for sensitive sensing of hydrogen peroxide and nitrite. Anal. Chem., 86, 6285-6290, 2014.
[21] T. Dodevska, I. Shterev, Y. Lazarova, An electrochemical sensing platform based on iridium oxide for highly sensitive and selective detection of nitrite and ascorbic acid. Acta Chim. Slov., 65, 970-979, 2018.
[22] C.-Y. Lin, V.S. Vasantha, K.-C. Ho, Detection of nitrite using poly(3,4-ethylenedioxythiophene) modified SPCEs. Sens. Actuators B: Chem., 140, 51-57, 2009.
[23] W. Kanan Matthew, G. Nocera Daniel, In Situ formation of an oxygenevolving catalyst in neutral water containing phosphate and Co2+. Science, 321, 1072-1075, 2008.
[24] Y. Lee, J. Suntivich, K.J. May, E.E. Perry, Y. Shao-Horn, Synthesis and activities of rutile IrO2 and RuO2 nanoparticles for oxygen evolution in acid and alkaline solutions. J. Phys. Chem. Lett., 3, 399-404, 2012.
[25] N.L.W. Septiani, Y.V. Kaneti, K.B. Fathoni, K. Kani, A.E. Allah, B. Yuliarto, Nugraha, H.K. Dipojono, Z.A. Alothman, D. Golberg, Y. Yamauchi, Self-assembly of two-dimensional bimetallic nickel–cobalt phosphate nanoplates into one-dimensional porous chainlike architecture for efficient oxygen evolution reaction. Chem. Mater., 32, 7005-7018, 2020.
[26] N.L.W. Septiani, Y.V. Kaneti, Y. Guo, B. Yuliarto, X. Jiang, Y. Ide, N. Nugraha, H.K. Dipojono, A. Yu, Y. Sugahara, D. Golberg, Y. Yamauchi, Holey assembly of two-dimensional iron-doped nickel-cobalt layered double hydroxide nanosheets for energy conversion application. ChemSusChem, 13, 1645-1655, 2020.
[27] S. Dutta, A. Indra, Y. Feng, T. Song, U. Paik, Self-supported nickel iron layered double hydroxide-nickel selenide electrocatalyst for superior water splitting activity. ACS Appl. Mater. Interfaces, 9, 33766-33774, 2017.
[28] T.-J. Wang, X. Liu, Y. Li, F. Li, Z. Deng, Y. Chen, Ultrasonicationassisted and gram-scale synthesis of Co-LDH nanosheet aggregates for oxygen evolution reaction. Nano Res., 13, 79-85, 2020.
[29] C.C.L. McCrory, S. Jung, I.M. Ferrer, S.M. Chatman, J.C. Peters, T.F. Jaramillo, Benchmarking hydrogen evolving reaction and oxygen evolving reaction electrocatalysts for solar water splitting devices. J. Am. Chem. Soc., 137, 4347-4357, 2015.
[30] H. Furukawa, E. Cordova Kyle, M. O’Keeffe, M. Yaghi Omar, The chemistry and applications of metal–organic frameworks. Science, 341, 1230444, 2013.
[31] G. Férey, Hybrid porous solids: past, present, future. Chem. Soc. Rev., 37, 191-214, 2008.
[32] S. Kitagawa, R. Kitaura, S.-i. Noro, Functional porous coordination polymers. Angew. Chem. Int. Ed., 43, 2334-2375, 2004.
[33] A.J. Howarth, Y. Liu, P. Li, Z. Li, T.C. Wang, J.T. Hupp, O.K. Farha, Chemical, thermal and mechanical stabilities of metal–organic frameworks. Nat. Rev. Mater., 1, 15018, 2016.
[34] I.M. Hönicke, I. Senkovska, V. Bon, I.A. Baburin, N. Bönisch, S. Raschke, J.D. Evans, S. Kaskel, Balancing mechanical stability and ultrahigh porosity in crystalline framework materials. Angew. Chem. Int. Ed., 57, 13780-13783, 2018.
[35] N.C. Burtch, H. Jasuja, K.S. Walton, Water stability and adsorption in metal–organic frameworks. Chem. Rev., 114, 10575-10612, 2014.
[36] L.J. Murray, M. Dincă, J.R. Long, Hydrogen storage in metal–organic frameworks. Chem. Soc. Rev., 38, 1294-1314, 2009.
[37] Y. He, W. Zhou, G. Qian, B. Chen, Methane storage in metal–organic frameworks. Chem. Soc. Rev., 43, 5657-5678, 2014.
[38] Y.-Z. Chen, R. Zhang, L. Jiao, H.-L. Jiang, Metal–organic framework-derived porous materials for catalysis. Coord. Chem. Rev., 362, 1-23, 2018.
[39] M.B. Majewski, A.W. Peters, M.R. Wasielewski, J.T. Hupp, O.K. Farha, Metal–organic frameworks as platform materials for solar fuels catalysis. ACS Energy Lett., 3, 598-611, 2018.
[40] J. Lee, O.K. Farha, J. Roberts, K.A. Scheidt, S.T. Nguyen, J.T. Hupp, Metal–organic framework materials as catalysts. Chem. Soc. Rev., 38, 1450-1459, 2009.
[41] L. Ma, C. Abney, W. Lin, Enantioselective catalysis with homochiral metal–organic frameworks. Chem. Soc. Rev., 38, 1248-1256, 2009.
[42] L.E. Kreno, K. Leong, O.K. Farha, M. Allendorf, R.P. Van Duyne, J.T. Hupp, Metal–organic framework materials as chemical sensors. Chem. Rev., 112, 1105-1125, 2012.
[43] M.G. Campbell, M. Dincă, Metal–organic frameworks as active materials in electronic sensor devices. Sensors, 17, 2017.
[44] J.E. Mondloch, M.J. Katz, N. Planas, D. Semrouni, L. Gagliardi, J.T. Hupp, O.K. Farha, Are Zr6-based MOFs water stable? linker hydrolysis vs. capillary-force-driven channel collapse. Chem. Commun., 50, 8944-8946, 2014.
[45] J.H. Cavka, S. Jakobsen, U. Olsbye, N. Guillou, C. Lamberti, S. Bordiga, K.P. Lillerud, A new zirconium inorganic building brick forming metal–organic frameworks with exceptional stability. J. Am. Chem. Soc., 130, 13850-13851, 2008.
[46] S. Pal, S.-S. Yu, C.-W. Kung, Group 4 metal-based metal–organic frameworks for chemical sensors. Chemosensors, 9, 2021.
[47] S. Yuan, J.-S. Qin, C.T. Lollar, H.-C. Zhou, Stable metal–organic frameworks with group 4 metals: Current status and trends. ACS Cent. Sci., 4, 440-450, 2018.
[48] M. Sk, S. Nandi, R.K. Singh, V. Trivedi, S. Biswas, Selective sensing of peroxynitrite by Hf-based UiO-66-B(OH)2 metal–organic framework: applicability to cell imaging. Inorg. Chem., 57, 10128-10136, 2018.
[49] W.H. Ho, T.-Y. Chen, K.-i. Otake, Y.-C. Chen, Y.-S. Wang, J.-H. Li, H.-Y. Chen, C.-W. Kung, Polyoxometalate adsorbed in a metal–organic framework for electrocatalytic dopamine oxidation. Chem. Commun., 56, 11763-11766, 2020.
[50] J. Yang, L. Yang, H. Ye, F. Zhao, B. Zeng, Highly dispersed AuPd alloy nanoparticles immobilized on UiO-66-NH2 metal–organic framework for the detection of nitrite. Electrochim. Acta, 219, 647-654, 2016.
[51] Q. Xu, Y. Wang, G. Jin, D. Jin, K. Li, A. Mao, X. Hu, Photooxidation assisted sensitive detection of trace Mn2+ in tea by NH2-MIL-125 (Ti) modified carbon paste electrode. Sens. Actuators B: Chem., 201, 274-280, 2014.
[52] Q. Hu, J. Di, B. Wang, M. Ji, Y. Chen, J. Xia, H. Li, Y. Zhao, In-situ preparation of NH2-MIL-125(Ti)/BiOCl composite with accelerating charge carriers for boosting visible light photocatalytic activity. Appl. Surf. Sci., 466, 525-534, 2019.
[53] C.-H. Shen, C.-H. Chuang, Y.-J. Gu, W.H. Ho, Y.-D. Song, Y.-C. Chen, Y.-C. Wang, C.-W. Kung, Cerium-based metal–organic framework nanocrystals interconnected by carbon nanotubes for boosting electrochemical capacitor performance. ACS Appl. Mater. Interfaces, 13, 16418-16426, 2021.
[54] P.M. Usov, C. Fabian, D.M. D'Alessandro, Rapid determination of the optical and redox properties of a metal–organic framework via in situ solid state spectroelectrochemistry. Chem. Commun., 48, 3945-3947, 2012.
[55] J.-H. Li, Y.-S. Wang, Y.-C. Chen, C.-W. Kung, Metal–organic frameworks toward electrocatalytic applications. Appl. Sci., 9, 2019.
[56] C.-W. Kung, T.C. Wang, J.E. Mondloch, D. Fairen-Jimenez, D.M. Gardner, W. Bury, J.M. Klingsporn, J.C. Barnes, R. Van Duyne, J.F. Stoddart, M.R. Wasielewski, O.K. Farha, J.T. Hupp, Metal–organic framework thin films composed of free-standing acicular nanorods exhibiting reversible electrochromism. Chem. Mater., 25, 5012-5017, 2013.
[57] S. Goswami, D. Ray, K.-i. Otake, C.-W. Kung, S.J. Garibay, T. Islamoglu, A. Atilgan, Y. Cui, C.J. Cramer, O.K. Farha, J.T. Hupp, A porous, electrically conductive hexa-zirconium(iv) metal–organic framework. Chem. Sci., 9, 4477-4482, 2018.
[58] Z. Li, A.W. Peters, V. Bernales, M.A. Ortuño, N.M. Schweitzer, M.R. DeStefano, L.C. Gallington, A.E. Platero-Prats, K.W. Chapman, C.J. Cramer, L. Gagliardi, J.T. Hupp, O.K. Farha, Metal–organic framework supported cobalt catalysts for the oxidative dehydrogenation of propane at low temperature. ACS Cent. Sci., 3, 31-38, 2017.
[59] J.-H. Li, Y.-C. Chen, Y.-S. Wang, W.H. Ho, Y.-J. Gu, C.-H. Chuang, Y.-D. Song, C.-W. Kung, Electrochemical evolution of pore-confined metallic molybdenum in a metal–organic framework (MOF) for allMOF-based pseudocapacitors. ACS Appl. Energy Mater., 3, 6258-6267, 2020.
[60] D. Yang, S.O. Odoh, T.C. Wang, O.K. Farha, J.T. Hupp, C.J. Cramer, L. Gagliardi, B.C. Gates, Metal–organic framework nodes as nearly ideal supports for molecular catalysts: NU-1000- and UiO-66-supported iridium complexes. J. Am. Chem. Soc., 137, 7391-7396, 2015.
[61] Y.-S. Wang, Y.-C. Chen, J.-H. Li, C.-W. Kung, Toward metal–organic framework-based supercapacitors: room-temperature synthesis of electrically conducting MOF-based nanocomposites decorated with redox-active manganese. Eur. J. Inorg. Chem., 2019, 3036-3044, 2019.
[62] C.-H. Chuang, J.-H. Li, Y.-C. Chen, Y.-S. Wang, C.-W. Kung, Redoxhopping and electrochemical behaviors of metal–organic framework thin films fabricated by various approaches. J. Phys. Chem. C, 124, 20854-20863, 2020.
[63] C.-W. Kung, C.O. Audu, A.W. Peters, H. Noh, O.K. Farha, J.T. Hupp, Copper nanoparticles installed in metal–organic framework thin films are electrocatalytically competent for CO2 reduction. ACS Energy Lett., 2, 2394-2401, 2017.
[64] Y.-S. Wang, J.-L. Liao, Y.-S. Li, Y.-C. Chen, J.-H. Li, W.H. Ho, W.-H. Chiang, C.-W. Kung, Zirconium-based metal–organic framework nanocomposites containing dimensionally distinct nanocarbons for pseudocapacitors. ACS Appl. Nano Mater., 3, 1448-1456, 2020.
[65] S. Lin, Y. Pineda-Galvan, W.A. Maza, C.C. Epley, J. Zhu, M.C. Kessinger, Y. Pushkar, A.J. Morris, Electrochemical water oxidation by a catalyst-modified metal–organic framework thin film. ChemSusChem, 10, 514-522, 2017.
[66] I. Hod, M.D. Sampson, P. Deria, C.P. Kubiak, O.K. Farha, J.T. Hupp, Feporphyrin-based metal–organic framework films as high-surface concentration, heterogeneous catalysts for electrochemical reduction of CO2. ACS Catal., 5, 6302-6309, 2015.
[67] S. Lin, P.M. Usov, A.J. Morris, The role of redox hopping in metal–organic framework electrocatalysis. Chem. Commun., 54, 6965-6974, 2018.
[68] C.-W. Kung, P.-C. Han, C.-H. Chuang, K.C.W. Wu, Electronically conductive metal–organic framework-based materials. APL Mater., 7, 110902, 2019.
[69] D. Micheroni, G. Lan, W. Lin, Efficient electrocatalytic proton reduction with carbon nanotube-supported metal–organic frameworks. J. Am. Chem. Soc., 140, 15591-15595, 2018.
[70] Y. Pu, W. Wu, J. Liu, T. Liu, F. Ding, J. Zhang, Z. Tang, A defective MOF architecture threaded by interlaced carbon nanotubes for high-cycling lithium–sulfur batteries. RSC Adv., 8, 18604-18612, 2018.
[71] H.A. Schulze, B. Hoppe, M. Schäfer, D.P. Warwas, P. Behrens, Electrically conducting nanocomposites of carbon nanotubes and metal–organic frameworks with strong interactions between the two components. ChemNanoMat, 5, 1159-1169, 2019.
[72] C. Li, C. Hu, Y. Zhao, L. Song, J. Zhang, R. Huang, L. Qu, Decoration of graphene network with metal–organic frameworks for enhanced electrochemical capacitive behavior. Carbon, 78, 231-242, 2014.
[73] M. Jahan, Q. Bao, K.P. Loh, Electrocatalytically active graphene–porphyrin MOF composite for oxygen reduction reaction. J. Am. Chem. Soc., 134, 6707-6713, 2012.
[74] C. Li, T. Zhang, J. Zhao, H. Liu, B. Zheng, Y. Gu, X. Yan, Y. Li, N. Lu, Z. Zhang, G. Feng, Boosted sensor performance by surface modification of bifunctional rht-type metal–organic framework with nanosized electrochemically reduced graphene oxide. ACS Appl. Mater. Interfaces, 9, 2984-2994, 2017.
[75] M.H. Hassan, R.R. Haikal, T. Hashem, J. Rinck, F. Koeniger, P. Thissen, H. Stefan, C. Wöll, M.H. Alkordi, Electrically conductive, monolithic metal–organic framework–graphene (MOF@G) composite coatings. ACS Appl. Mater. Interfaces, 11, 6442-6447, 2019.
[76] C.-W. Kung, Y.-S. Li, M.-H. Lee, S.-Y. Wang, W.-H. Chiang, K.-C. Ho, In situ growth of porphyrinic metal–organic framework nanocrystals on graphene nanoribbons for the electrocatalytic oxidation of nitrite. J. Mater. Chem. A, 4, 10673-10682, 2016.
[77] Y. Zhang, X. Bo, A. Nsabimana, C. Han, M. Li, L. Guo, Electrocatalytically active cobalt-based metal–organic framework with incorporated macroporous carbon composite for electrochemical applications. J. Mater. Chem. A, 3, 732-738, 2015.
[78] S. Gonen, O. Lori, G. Cohen-Taguri, L. Elbaz, Metal–organic frameworks as a catalyst for oxygen reduction: An unexpected outcome of a highly active Mn-MOF-based catalyst incorporated in activated carbon. Nanoscale, 10, 9634-9641, 2018.
[79] D.K. Yadav, V. Ganesan, P.K. Sonkar, R. Gupta, P.K. Rastogi, Electrochemical investigation of gold nanoparticles incorporated zinc based metal–organic framework for selective recognition of nitrite and nitrobenzene. Electrochim. Acta, 200, 276-282, 2016.
[80] D. Cheng, X. Li, Y. Qiu, Q. Chen, J. Zhou, Y. Yang, Z. Xie, P. Liu, W. Cai, C. Zhang, A simple modified electrode based on MIL-53(Fe) for the highly sensitive detection of hydrogen peroxide and nitrite. Anal. Methods, 9, 2082-2088, 2017.
[81] H. Chen, T. Yang, F. Liu, W. Li, Electrodeposition of gold nanoparticles on Cu-based metal–organic framework for the electrochemical detection of nitrite. Sens. Actuators B: Chem., 286, 401-407, 2019.
[82] C.-W. Kung, T.-H. Chang, L.-Y. Chou, J.T. Hupp, O.K. Farha, K.-C. Ho, Porphyrin-based metal–organic framework thin films for electrochemical nitrite detection. Electrochem. Commun., 58, 51-56, 2015.
[83] Y.-C. Chen, W.-H. Chiang, D. Kurniawan, P.-C. Yeh, K.-i. Otake, C.-W. Kung, Impregnation of graphene quantum dots into a metal–organic framework to render increased electrical conductivity and activity for electrochemical sensing. ACS Appl. Mater. Interfaces, 11, 35319-35326, 2019.
[84] C. Wang, Z. Xie, K.E. deKrafft, W. Lin, Doping metal–organic frameworks for water oxidation, carbon dioxide reduction, and organic photocatalysis. J. Am. Chem. Soc., 133, 13445-13454, 2011.
[85] C. Wang, J.-L. Wang, W. Lin, Elucidating molecular iridium water oxidation catalysts using metal–organic frameworks: a comprehensive structural, catalytic, spectroscopic, and kinetic study. J. Am. Chem. Soc., 134, 19895-19908, 2012.
[86] Y. Zhao, S. Zhang, M. Wang, J. Han, H. Wang, Z. Li, X. Liu, Engineering iridium-based metal–organic frameworks towards electrocatalytic water oxidation. Dalton Trans., 47, 4646-4652, 2018.
[87] M.R. DeStefano, T. Islamoglu, S.J. Garibay, J.T. Hupp, O.K. Farha, Room-temperature synthesis of UiO-66 and thermal modulation of densities of defect sites. Chem. Mater., 29, 1357-1361, 2017.
[88] S. Kim, M. Cho, Y. Lee, Iridium oxide dendrite as a highly efficient dual electro-catalyst for water splitting and sensing of H2O2. J. Electrochem. Soc., 164, B3029-B3035, 2016.
[89] T. Reier, M. Oezaslan, P. Strasser, Electrocatalytic oxygen evolution reaction (OER) on Ru, Ir, and Pt catalysts: a comparative study of nanoparticles and bulk materials. ACS Catal., 2, 1765-1772, 2012.
[90] B. Keita, A. Belhouari, L. Nadjo, R. Contant, Electrocatalysis by polyoxometalate/vbpolymer systems: reduction of nitrite and nitric oxide. J. Electroanal. Chem., 381, 243-250, 1995.
[91] A. Minguzzi, F.-R.F. Fan, A. Vertova, S. Rondinini, A.J. Bard, Dynamic potential–pH diagrams application to electrocatalysts for water oxidation. Chem. Sci., 3, 217-229, 2012.
[92] T. Nishimoto, T. Shinagawa, T. Naito, K. Takanabe, Microkinetic assessment of electrocatalytic oxygen evolution reaction over iridium oxide in unbuffered conditions. J. Catal., 391, 435-445, 2020.
[93] M. Cai, Q. Loague, A.J. Morris, Design rules for efficient charge transfer in metal–organic framework films: The pore size effect. J. Phys. Chem. Lett., 11, 702-709, 2020.
[94] I. Gualandi, E. Scavetta, S. Zappoli, D. Tonelli, Electrocatalytic oxidation of salicylic acid by a cobalt hydrotalcite-like compound modified Pt electrode. Biosens. Bioelectron., 26, 3200-3206, 2011.
[95] R. Guidelli, F. Pergola, G. Raspi, Voltammetric behavior of nitrite ion on platinum in neutral and weakly acidic media. Anal. Chem., 44, 745-755, 1972.
[96] Y. Wang, E. Laborda, R.G. Compton, Electrochemical oxidation of nitrite: kinetic, mechanistic and analytical study by square wave voltammetry. J. Electroanal. Chem., 670, 56-61, 2012.
[97] S. Radhakrishnan, K. Krishnamoorthy, C. Sekar, J. Wilson, S.J. Kim, A highly sensitive electrochemical sensor for nitrite detection based on Fe2O3 nanoparticles decorated reduced graphene oxide nanosheets. Appl. Catal. B: Environ., 148-149, 22-28, 2014.
[98] D. Manoj, R. Saravanan, J. Santhanalakshmi, S. Agarwal, V.K. Gupta, R. Boukherroub, Towards green synthesis of monodisperse Cu nanoparticles: an efficient and high sensitive electrochemical nitrite sensor. Sens. Actuators B: Chem., 266, 873-882, 2018.
[99] Q. Sheng, D. Liu, J. Zheng, A nonenzymatic electrochemical nitrite sensor based on Pt nanoparticles loaded Ni(OH)2/multi-walled carbon nanotubes nanocomposites. J. Electroanal. Chem., 796, 9-16, 2017.
[100] L. Zhang, D. Yang, Poly(2-mercaptobenzothiazole) modified electrode for the simultaneous determinations of dopamine, uric acid and nitrite. Electrochim. Acta, 119, 106-113, 2014.
[101] Y. Zhang, R. Yuan, Y. Chai, W. Li, X. Zhong, H. Zhong, Simultaneous voltammetric determination for DA, AA and NO2- based on graphene/poly-cyclodextrin/MWCNTs nanocomposite platform. Biosens. Bioelectron., 26, 3977-3980, 2011.
[102] Y. Han, R. Zhang, C. Dong, F. Cheng, Y. Guo, Sensitive electrochemical sensor for nitrite ions based on rose-like AuNPs/MoS2/graphene composite. Biosens. Bioelectron., 142, 111529, 2019.
[103] C.-H. Su, C.-W. Kung, T.-H. Chang, H.-C. Lu, K.-C. Ho, Y.-C. Liao, Inkjet-printed porphyrinic metal–organic framework thin films for electrocatalysis. J. Mater. Chem. A, 4, 11094-11102, 2016.
[104] Y.-C. Wang, Y.-C. Chen, W.-S. Chuang, J.-H. Li, Y.-S. Wang, C.-H. Chuang, C.-Y. Chen, C.-W. Kung, Pore-confined silver nanoparticles in a porphyrinic metal–organic framework for electrochemical nitrite detection. ACS Appl. Nano Mater., 3, 9440-9448, 2020.
[105] S.A. Ntim, O. Sae-Khow, F.A. Witzmann, S. Mitra, Effects of polymer wrapping and covalent functionalization on the stability of MWCNT in aqueous dispersions. J. Colloid Interface Sci., 355, 383-388, 2011.
[106] T.-E. Chang, C.-H. Chuang, C.-W. Kung, An iridium-decorated metal–organic framework for electrocatalytic oxidation of nitrite. Electrochem. Commun., 122, 106899, 2021.
[107] L.D. Gelb, K.E. Gubbins, R. Radhakrishnan, M. Sliwinska-Bartkowiak, Phase separation in confined systems. Rep. Prog. Phys., 62, 1573-1659, 1999.
[108] M. Thommes, G.H. Findenegg, Pore condensation and critical-point shift of a fluid in controlled-pore glass. Langmuir, 10, 4270-4277, 1994.
[109] M. Thommes, R. Köhn, M. Fröba, Sorption and pore condensation behavior of nitrogen, argon, and krypton in mesoporous MCM-48 silica materials. J. Phys. Chem. B, 104, 7932-7943, 2000.
[110] P.I. Ravikovitch, A.V. Neimark, Characterization of micro- and mesoporosity in SBA-15 materials from adsorption data by the NLDFT method. J. Phys. Chem. B, 105, 6817-6823, 2001.
[111] G.C. Shearer, S. Chavan, S. Bordiga, S. Svelle, U. Olsbye, K.P. Lillerud, Defect engineering: Tuning the porosity and composition of the metal–organic framework UiO-66 via modulated synthesis. Chem. Mater., 28, 3749-3761, 2016.
[112] L. Liu, Z. Chen, J. Wang, D. Zhang, Y. Zhu, S. Ling, K.W. Huang, Y. Belmabkhout, K. Adil, Y. Zhang, B. Slater, M. Eddaoudi, Y. Han, Imaging defects and their evolution in a metal–organic framework at sub-unit-cell resolution. Nat Chem, 11, 622-628, 2019.
[113] P. Leuaa, D. Priyadarshani, A.K. Tripathi, M. Neergat, Internal and external transport of redox species across the porous thin-film electrode/electrolyte interface. J. Phys. Chem. C, 123, 21440-21447, 2019.
[114] S.J. Freakley, J. Ruiz-Esquius, D.J. Morgan, The X-ray photoelectron spectra of Ir, IrO2 and IrCl3 revisited. Surf. Interface Anal., 49, 794-799, 2017.
[115] G.K. Wertheim, H.J. Guggenheim, Conduction-electron screening in metallic oxides: IrO2. Phys. Rev. B, 22, 4680-4683, 1980.
[116] R.-S. Chen, A. Korotcov, Y.-S. Huang, D.-S. Tsai, One-dimensional conductive IrO2 nanocrystals. Nanotechnology, 17, R67-R87, 2006.
[117] V. Pfeifer, T.E. Jones, J.J. Velasco Vélez, C. Massué, M.T. Greiner, R. Arrigo, D. Teschner, F. Girgsdies, M. Scherzer, J. Allan, M. Hashagen, G. Weinberg, S. Piccinin, M. Hävecker, A. Knop-Gericke, R. Schlögl, The electronic structure of iridium oxide electrodes active in water splitting. Phys. Chem. Chem. Phys., 18, 2292-2296, 2016.
[118] D. Escalera-López, S. Czioska, J. Geppert, A. Boubnov, P. Röse, E. Saraçi, U. Krewer, J.-D. Grunwaldt, S. Cherevko, Phase- and surface composition-dependent electrochemical stability of Ir-Ru nanoparticles during oxygen evolution reaction. ACS Catal., 11, 9300-9316, 2021.
[119] D. Weber, L.M. Schoop, D. Wurmbrand, J. Nuss, E.M. Seibel, F.F. Tafti, H. Ji, R.J. Cava, R.E. Dinnebier, B.V. Lotsch, Trivalent iridium oxides: layered triangular lattice iridate K0.75Na0.25IrO2 and oxyhydroxide IrOOH. Chem. Mater., 29, 8338-8345, 2017.