Template-free hydrothermal synthesis and gas-sensitivity of hollow-structured Cu_0.3Co_2.7O₄ microspheres

Abstract

Hollow-structured Cu_0.3Co_2.7O₄ microspheres have been synthesized by a simple one-pot template-free hydrothermal method with copper sulfate, cobalt acetate and ammonia as raw materials. The products were characterized by powder X-ray diffraction, energy dispersive X-ray analysis, selected area electron diffraction, high-resolution transmission electron microscopy, scanning electron microscopy and BET measurements. The research results show that the hollow Cu_0.3Co_2.7O₄ microspheres consist of single-crystalline nanocubes with the diameter of about 20 nm. The formation mechanism of hollow Cu_0.3Co_2.7O₄ microspheres is suggested as Ostwald ripening in a solid-solution-solid process, and Cu_0.3Co_2.7O₄ microspheres are mesoporous containing two pore sizes of 3.3 and 5.9 nm. The as-prepared Cu_0.3Co_2.7O₄ sensors have optimal gas responses to 50×10⁻⁶ mg/m³ C₂H₅OH at 190 °C.

Keywords

Cu_0.3Co_2.7O₄ oxides / microsphere / inorganic compounds / nanostructures / template-free hydrothermal method

References

[1] ZhangG-Q, LouX-W. General synthesis of multi-shelled mixed metal oxide hollow spheres with superior lithium storage properties [J]. Angewandte Chemie International Edition, 2014, 126(34): 9087-9190

[2] TianL, YangX-F, LuP, IanD, WangC, WuM-M. Hollow single-crystal spinel nanocubes: The case of zinc cobalt oxide grown by a unique Kirkendall effect [J]. Inorganic Chemistry, 2008, 47(13): 5522-5524

[3] WangZ-Y, ZhouL, LouW-X. Metal oxide hollow nano-structures for lithiumion batteries [J]. Advanced Materials, 2012, 24(14): 1903-1911

[4] PendashtehA, PalmaJ, AndersonM. Nanostructured porous wires of iron cobaltite: Novel positive electrode for high performance hybrid energy storage devices [J]. Journal of Materials Chemistry A, 2015, 3: 16849-16859

[5] ShiY-Q, YuB, ZhouK-Q, RichardK, GuiZ, HuY, JiangS-H. Novel CuCo₂O₄/graphitic carbon nitride nano-hybrids: Highly effective catalysts for reducing CO generation and fire hazards of thermoplastic poly-urethane nanocomposites [J]. Journal of Hazardous Materials, 2015, 293: 87-96

[6] LimT, ParkS, KimJ, KimD. Ordered mesoporous MCo₂O₄ (M=Cu, Zn and Ni) spinel catalysts with high catalytic performance for methane combustion [J]. Journal of Molecular Catalysis A: Chemical, 2017, 426: 68-74

[7] ZhuD, SunX, YuJ, LiuQ, LiuJ-Y, ChenR-R, ZhangH-S, LiR-M, YuJ, WangJ. Rationally designed CuCo₂O₄@Ni(OH)₂ with 3D hierarchical core-shell structure for flexible energy storage [J]. Journal of Colloid and Interface Science, 2019, 557: 76-83

[8] DuX-Q, ZhangX-S, XuZ-F, GongY-Q. CuCo₂O₄ microflowers catalyst with oxygen evolution activity comparable to that of noble metal [J]. International Journal of Hydrogen Energy, 2018, 43(10): 5012-5018

[9] PaknahadP, AskariM. Characterization of nanocrystalline CuCo₂O₄ spinel prepared by sol-gel technique applicable to the SOFC interconnect coating [J]. Ghorbanzadeh, Applied Physics A, 2015, 119: 727-734

[10] TianL, ZhaoR-N, WangJ-J, SunQ-L, ChenL, XiaoQ-G, LiuS-L. Faclie synthesis and luminescence of hollow Eu³⁺-doped LaVO₄ nanospheres [J]. Materials Letters, 2015, 156: 101-104

[11] ChenH-Y, ChenJ. Preparation of p-type CuCo₂O₄ thin films by sol-gel processing [J]. Materials Letters, 2017, 188: 63-65

[12] LiG-F, LiuS-Q, PanY, ZhouT-Y, DingJ-D, SunY-M, WangY-Q. Self-templated formation of CuCo₂O₄ triple-shelled hollow microspheres for all-solid-state asymmetric supercapacitors [J]. Journal of Alloys and Compounds, 2019, 787: 694-699

[13] ZengC-H. Ostwald ripening: A synthetic approach for hollow nanomaterials [J]. Current Nanoscience, 2007, 3(2): 177-181

[14] ChengJ-B, YanH-L, LuY, QiuK-W, HouX-Y, XuJ-Y, LiuX-M, KimJ, LuoY-S. Mesoporous CuCo₂O₄ nanograsses as multifunctional electrodes for supercapacitors and electro-catalysts [J]. Journal of Materials Chemistry A, 2015, 3(18): 9769-9776

[15] WangP-X, ShaoL, ZhangN-Q, SunK. Mesoporous CuCo₂O₄ nanoparticles as an efficient cathode catalyst for Li-O₂ batteries [J]. Journal of Power Sources, 2016, 325: 506-512

[16] YangJ, YeH-L, ZhangZ-Q, ZhaoF, ZengB-Z. Metalorganic framework derived hollow polyhedron CuCo₂O₄ functionalized porous graphene for sensitive glucose sensing [J]. Sensors and Actuators B, 2017, 242: 728-735

[17] ZhaoS-D, LiQ-M, LiF, LiangZ-H. Synthesis of spinel CuCo₂O₄ nanoparticles and its application in pnitrophenol reduction [J]. Journal of Sol-Gel Science and Technology, 2017, 524: 544-555

[18] KuangM, LiuY-X, DongF, ZhangY-X. Tunable design of layered CuCo₂O₄ nanosheets@MnO₂ nanoflakes coreshell arrays on Ni foam for high-performance super-capacitors [J]. Journal of Materials Chemistry A, 2015, 3(43): 21528-21536

[19] NiuX-S, DuW-P, DuW-M. Preparation and gas sensing properties of ZnM₂O₄ (M=Fe, Co, Cr) [J]. Sensors and Actuators B: Chemical, 2004, 99(2): 405-409