Photothermally active nanoparticles as a promising tool for eliminating bacteria and biofilms

• Mykola Borzenkov,
• Piersandro Pallavicini,
• Angelo Taglietti,
• Laura D’Alfonso,
• Maddalena Collini and
• Giuseppe Chirico

Beilstein J. Nanotechnol. 2020, 11, 1134–1146, doi:10.3762/bjnano.11.98

• ][23] and CuO [24][25][26], are also well described in the literature. The antibacterial activity of polymeric nanoparticles, such as the polystyrene sulfate coated with a bilayer of dioctadecyldimethylammonium bromide [27] and poly(lactic-co-glycolic acid) loaded with gentamicin [28], were also

Gram-scale synthesis of splat-shaped Ag–TiO₂ nanocomposites for enhanced antimicrobial properties

• Mohammad Jaber,
• Asim Mushtaq,
• Kebiao Zhang,
• Jindan Wu,
• Dandan Luo,
• Zihan Yi,
• M. Zubair Iqbal and
• Xiangdong Kong

Beilstein J. Nanotechnol. 2020, 11, 1119–1125, doi:10.3762/bjnano.11.96

• , silver (Ag), zinc oxide (ZnO), copper oxide (CuO), iron oxide (Fe3O4) and titanium oxide (TiO2) are well recognized options due to their outstanding antibacterial properties. These nanoparticles have antibacterial activity due to the production of reactive oxygen species (ROS) [9][10][11]; more

Preparation, characterization and photocatalytic performance of heterostructured CuO–ZnO-loaded composite nanofiber membranes

• Wei Fang,
• Liang Yu and
• Lan Xu

Beilstein J. Nanotechnol. 2020, 11, 631–650, doi:10.3762/bjnano.11.50

• environmental monitoring, industry, aviation, and transportation. In this paper, heterostructured CuO–ZnO-loaded CNF membranes (CNFMs) were prepared successfully by a combination of electrospinning, heat treatment, and hydrothermal synthesis. The influence of the synthesis parameters on morphology, structure

• three times, and the degradation rate remained above 90%. Keywords: electrospinning; composite nanofibers; heterostructured CuO–ZnO; hydrothermal synthesis; photocatalysis; semiconductor oxide; Introduction Water remediation is one of the main scientific research subjects regarding environmental

• semiconductor material to the other [7][8][9][10]. ZnO is a semiconductor material with a wide direct bandgap of 3.2 eV, which can absorb a small part of the solar spectrum in the UV region [11][12][13]. CuO is a nontoxic, chemically stable and naturally abundant material. It is a p-type semiconductor with a

Synthesis and enhanced photocatalytic performance of 0D/2D CuO/tourmaline composite photocatalysts

• Changqiang Yu,
• Min Wen,
• Zhen Tong,
• Shuhua Li,
• Yanhong Yin,
• Xianbin Liu,
• Yesheng Li,
• Tongxiang Liang,
• Ziping Wu and
• Dionysios D. Dionysiou

Beilstein J. Nanotechnol. 2020, 11, 407–416, doi:10.3762/bjnano.11.31

• nontoxic products. In this work, a CuO/tourmaline composite with zero-dimensional/two-dimensional (0D/2D) CuO architecture was successfully obtained via a facile hydrothermal process, and its photocatalytic activity was evaluated by the degradation of methylene blue (MB). Surface element valence state and

• molecular vibration characterization revealed that CuO chemically interacted with tourmaline via Si–O–Cu bonds. The specific surface area of the CuO/tourmaline composite (23.60 m2 g−1) was larger than that of the pristine CuO sample (3.41 m2 g−1). The CuO/tourmaline composite exhibited excellent

• photocatalytic activity for the degradation of MB, which was ascribed to the increase in the quantity of the adsorption-photoreactive sites and the efficient utilization of the photoinduced charge carriers. This study provides a facile strategy for the construction of 0D/2D CuO structures and the design of

Targeted therapeutic effect against the breast cancer cell line MCF-7 with a CuFe₂O₄/silica/cisplatin nanocomposite formulation

• B. Rabindran Jermy,
• Vijaya Ravinayagam,
• Widyan A. Alamoudi,
• Dana Almohazey,
• Hatim Dafalla,
• Lina Hussain Allehaibi,
• Abdulhadi Baykal,
• Muhammet S. Toprak and
• Thirunavukkarasu Somanathan

Beilstein J. Nanotechnol. 2019, 10, 2217–2228, doi:10.3762/bjnano.10.214

• between 15–30°. For the metal oxides, the diffraction patterns correlate with the cubic phase of copper ferrite (JCPDS 77-0010) and CuO. The presence of broad CuFe2O4 peaks demonstrates the formation of nanometer-sized particles at the nanopores of HYPS. In order to optimize the saturation magnetization

Materials nanoarchitectonics at two-dimensional liquid interfaces

• Katsuhiko Ariga,
• Michio Matsumoto,
• Taizo Mori and
• Lok Kumar Shrestha

Beilstein J. Nanotechnol. 2019, 10, 1559–1587, doi:10.3762/bjnano.10.153

• -dimensional CuO petal assemblies (by Abe and co-workers [133]), perovskite nanosheets and their layer-by-layer assemblies as high-k dielectric/ferroelectric materials (by Osada and Sasaki [134]), the manipulation of transition-metal dichalcogenides nanosheets for the usage in energy storage/conversion

Synthesis of MnO₂–CuO–Fe₂O₃/CNTs catalysts: low-temperature SCR activity and formation mechanism

• Yanbing Zhang,
• Lihua Liu,
• Yingzan Chen,
• Xianglong Cheng,
• Chengjian Song,
• Mingjie Ding and
• Haipeng Zhao

Beilstein J. Nanotechnol. 2019, 10, 848–855, doi:10.3762/bjnano.10.85

• Coal Salt Resources, Pingdingshan 467000, People′s Republic of China 10.3762/bjnano.10.85 Abstract MnO2–CuO–Fe2O3/CNTs catalysts, as a low-dimensional material, were fabricated by a mild redox strategy and used in denitration reactions. A formation mechanism of the catalysts was proposed. NO

• conversions of 4% MnO2–CuO–Fe2O3/CNTs catalyst of 43.1–87.9% at 80–180 °C were achieved, which was ascribed to the generation of amorphous MnO2, CuO and Fe2O3, and a high surface-oxygen (Os) content. Keywords: amorphous materials; carbon nanotubes; low-dimensional materials; low-temperature catalysis; SCR

• uneconomic and unsafe. Our previous studies, including MnO2–Fe2O3–CeO2–Ce2O3/CNTs [16] and Ce2O3–CeO2–CuO–MnO2/CNTs [17] catalysts, have reported a simple and mild redox method for the preparation of ternary and quaternary catalysts, and the resultant catalysts show outstanding denitration activity at 80–180

An efficient electrode material for high performance solid-state hybrid supercapacitors based on a Cu/CuO/porous carbon nanofiber/TiO₂ hybrid composite

• Mamta Sham Lal,
• Thirugnanam Lavanya and
• Sundara Ramaprabhu

Beilstein J. Nanotechnol. 2019, 10, 781–793, doi:10.3762/bjnano.10.78

• Mamta Sham Lal Thirugnanam Lavanya Sundara Ramaprabhu Alternative Energy and Nanotechnology Laboratory (AENL), Nano Functional Materials Technology Centre (NFMTC), Department of Physics, Indian Institute of Technology Madras, Chennai-600036, India 10.3762/bjnano.10.78 Abstract A Cu/CuO/porous

• carbon nanofiber/TiO2 (Cu/CuO/PCNF/TiO2) composite uniformly covered with TiO2 nanoparticles was synthesized by electrospinning and a simple hydrothermal technique. The synthesized composite exhibits a unique morphology and excellent supercapacitive performance, including both electric double layer and

• pseudo-capacitance behavior. Electrochemical measurements were performed by cyclic voltammetry, galvanostatic charge–discharge and electrochemical impedance spectroscopy. The highest specific capacitance value of 530 F g−1 at a current density of 1.5 A g−1 was obtained for the Cu/CuO/PCNF/TiO2 composite

Nanocomposite–parylene C thin films with high dielectric constant and low losses for future organic electronic devices

• Marwa Mokni,
• Gianluigi Maggioni,
• Abdelkader Kahouli,
• Sara M. Carturan,
• Walter Raniero and
• Alain Sylvestre

Beilstein J. Nanotechnol. 2019, 10, 428–441, doi:10.3762/bjnano.10.42

• recently proposed for low operating voltages of TFTs [1][2]. By using water-inducement, scandium oxide was succesfully integrated as gate dielectric in both InZnO and CuO TFTs [1]. Using a sol–gel approach, high-k ink hybrid AlOOH nanocomposites demonstrated low leakage currents suitable for low operating

Graphene-enhanced metal oxide gas sensors at room temperature: a review

• Dongjin Sun,
• Yifan Luo,
• Marc Debliquy and
• Chao Zhang

Beilstein J. Nanotechnol. 2018, 9, 2832–2844, doi:10.3762/bjnano.9.264

• achieved at all [19][20]. Metal-oxide semiconductors (MOS), including tin oxide (SnO2), titanium dioxide (TiO2), zinc oxide (ZnO), copper oxide (CuO), tungsten oxide (WO3), indium oxide (In2O3), ferric oxide (Fe2O3) and cobalt oxide (Co3O4) are important materials for gas sensors [21][22][23][24][25][26

• , ammonia adsorbed on the surface of sensor by dissolving into water, leading to the higher response. This is quite different from the usual opinion that sensitivity will decrease at high humidity levels. Zhang et al. [47] synthesized CuO nanoflowers via hydrothermal method, then CuO and rGO were deposited

• on the substrate with Ni/Cu IDEs to fabricate the CuO–rGO sensor. The CuO–rGO sensor showed a three-times higher sensitivity to CO and faster response/recovery time than the rGO sensor, while the pure CuO sensor showed no response to CO at room temperature. The p–p junctions constituted between p

Improved catalytic combustion of methane using CuO nanobelts with predominantly (001) surfaces

• Qingquan Kong,
• Yichun Yin,
• Bing Xue,
• Yonggang Jin,
• Wei Feng,
• Zhi-Gang Chen,
• Shi Su and
• Chenghua Sun

Beilstein J. Nanotechnol. 2018, 9, 2526–2532, doi:10.3762/bjnano.9.235

• Chemistry and Biotechnology, Faculty of Science, Engineering & Technology, Swinburne University of Technology, Hawthorn, VIC 3122, Australia 10.3762/bjnano.9.235 Abstract Through computational calculations, CuO(001) has been identified as an active surface for methane oxidation. Experimental validation

• with CuO nanobelts comprised of predominantly (001) surfaces has been performed and it is confirmed that the performance of such nanobelts is much higher than normal nanoparticles and nanowires. First principle calculations further clarified that two-coordinated oxygen plays a key role for methane

• this strategy, this work explores the catalysis of copper oxide (CuO), a promising catalyst for CH4 oxidation as identified in the literature [8]. Different from these reports, we focus on the performance of the minority surface (001). Results and Discussion Starting with computational calculations

Electrospun one-dimensional nanostructures: a new horizon for gas sensing materials

• Muhammad Imran,
• Nunzio Motta and
• Mahnaz Shafiei

Beilstein J. Nanotechnol. 2018, 9, 2128–2170, doi:10.3762/bjnano.9.202

• deposited directly onto a controlled and selective deposition area using a multifield electrospinning setup as shown in Figure 2. The scanning transmission electron microscopy (STEM) image confirms the uniform distribution of MoO3 NPs inside the electrospun fibers. Similarly, CuO NPs are embedded in

• of electrospun metal oxide (MOx) semiconductors have been used for gas sensing applications. These semiconductors include titanium dioxide (TiO2) [93][94][95], tungsten trioxide (WO3) [27][96][97][98][99][100][101][102][103][104][105][106][107][108][109][110], copper oxide (CuO) [111], NiO [112

• annealing and calcination [83]. A very low detection limit (9.7 ppb NOx) with an optimal response time (20 s) is achieved with nanocrystalline (5–10 nm) SnO2 NTs at room temperature [141]. Similar behaviour is exhibited by p-type NiO and CuO toward CO and NO2 [111][112]. The gas sensing behaviour also

Comparative study of antibacterial properties of polystyrene films with TiO_x and Cu nanoparticles fabricated using cluster beam technique

• Vladimir N. Popok,
• Cesarino M. Jeppesen,
• Peter Fojan,
• Anna Kuzminova,
• Jan Hanuš and
• Ondřej Kylián

Beilstein J. Nanotechnol. 2018, 9, 861–869, doi:10.3762/bjnano.9.80

• organic cells. Because of these toxic properties the films and nanostructures of such metals or metal compounds are widely used as antibacterial and antimicrobial agents. Among them are Ag, Cu, Au, CuO, ZnO, Fe3O4, Al2O3 and TiO2, to name just a few [1][2][3]. They all exhibit bactericidal properties

• antibacterial effect. Furthermore, Cu NPs under ambient conditions can easily lead to the formation of CuO, which also displays a direct toxicity for microorganisms [18]. They already disturb microorganisms when being in contact with the bacterial surface by reacting with proteins forming pores in the membrane

Facile synthesis of a ZnO–BiOI p–n nano-heterojunction with excellent visible-light photocatalytic activity

• Mengyuan Zhang,
• Jiaqian Qin,
• Pengfei Yu,
• Bing Zhang,
• Mingzhen Ma,
• Xinyu Zhang and
• Riping Liu

Beilstein J. Nanotechnol. 2018, 9, 789–800, doi:10.3762/bjnano.9.72

• degradation [3][4][5][6], nitrogen fixation [7][8], to solar fuel production [9]. The metal oxides, such as CdO [10], Al2O3 [11], and CuO [12][13], has attracted a lot of interest in photocatalytic applications. And among all of these metal oxides, it is titanium dioxide and zinc oxide (TiO2 and ZnO) that are

A review of carbon-based and non-carbon-based catalyst supports for the selective catalytic reduction of nitric oxide

• Shahreen Binti Izwan Anthonysamy,
• Syahidah Binti Afandi,
• Mehrnoush Khavarian and
• Abdul Rahman Bin Mohamed

Beilstein J. Nanotechnol. 2018, 9, 740–761, doi:10.3762/bjnano.9.68

• influenced by the function of support materials. In their study, SiO2 was synthesised using the sol–gel method. Zeng et al. [41] implemented the sol–gel technique to prepare CuO–TiO2 catalysts for the selective catalytic oxidation of NO. Based on the results, the CuO–TiO2 catalysts demonstrated higher

• catalytic activity than the Cu0.07/Ti catalyst prepared using the impregnation method. The CuO–TiO2 catalyst possessed more highly dispersed CuO species as well as many oxygen vacancy active sites, which enhanced the NO gas and made it easily attachable during the catalytic reaction. Similar to previous

• -R exhibited high tolerance towards SO2 and H2O. Bai et al. [52] studied CuO supported on CNTs. The catalyst was developed to better understand the catalytic behaviour of CNT-based catalysts especially in reducing the amount of nitric oxide in an SCR reaction. Different amounts of CuO loadings were

BN/Ag hybrid nanomaterials with petal-like surfaces as catalysts and antibacterial agents

• Konstantin L. Firestein,
• Denis V. Leybo,
• Alexander E. Steinman,
• Andrey M. Kovalskii,
• Andrei T. Matveev,
• Anton M. Manakhov,
• Irina V. Sukhorukova,
• Pavel V. Slukin,
• Nadezda K. Fursova,
• Sergey G. Ignatov,
• Dmitri V. Golberg and
• Dmitry V. Shtansky

Beilstein J. Nanotechnol. 2018, 9, 250–261, doi:10.3762/bjnano.9.27

• only improve the colloidal stability of Ag NPs but also improve their antibacterial characteristics. A wide range of materials, such as graphene oxide [30][31], carbon nanotubes [32], SiO2 [33], Fe3O4 [34], ZnO [35], CuO [36], TiO2 [37] and others, have been tested as the supports for Ag NPs. Compared

Fabrication of CeO₂–MO_x (M = Cu, Co, Ni) composite yolk–shell nanospheres with enhanced catalytic properties for CO oxidation

• Ling Liu,
• Jingjing Shi,
• Hongxia Cao,
• Ruiyu Wang and
• Ziwu Liu

Beilstein J. Nanotechnol. 2017, 8, 2425–2437, doi:10.3762/bjnano.8.241

• ]. Taking the CeO2–CuO catalyst as a typical example, the improved catalytic activity is closely related to the synergistic interaction between copper and ceria, which promotes the exchange of charges between Ce4+/Ce3+ and Cu2+/Cu+ and leads to faster oxidation and reduction than that of the corresponding

• , thus, the facilitation of synergistic interaction between two components are necessary to optimize the catalytic performances. The unique structure and texture of CeO2-based catalysts is also associated with high activity and stability in the catalytic reaction. For instance, rod-like CeO2–CuO

• catalysts with highly dispersed copper oxide clusters as active species had been reported to exhibit superior activity toward CO oxidation in contrast with commonly used CeO2/CuO composite catalysts [13]. Consequently, the construction of ceria-based composite oxides with pore features, hollow structure or

Low-temperature CO oxidation over Cu/Pt co-doped ZrO₂ nanoparticles synthesized by solution combustion

• Amit Singhania and
• Shipra Mital Gupta

Beilstein J. Nanotechnol. 2017, 8, 1546–1552, doi:10.3762/bjnano.8.156

• milling, precipitation, combustion, and reverse microemulsion [30][31][32][33]. Vahidshad et al. [34] synthesized sol–gel-derived Cu–ZrO2 nanoparticles. Similarly, Saha et al. [35] prepared CuO-doped ZrO2 nanoparticles via ball milling. Among the described methods, solution combustion is used frequently

• ), (200), (220), (311) and (222) planes, respectively (JCPDS card no. 27-0997). Peaks were found neither at 2θ = 39.8° for Pt (or 2θ = 33.9° and 27.9° for PtO and PtO2) nor at 2θ = 43.6° for Cu (or 2θ = 38.7° and 36.5° for CuO and Cu2O). This indicates that Cu2+ and Pt2+ ions have entered the ZrO2 lattice

Enhanced catalytic activity without the use of an external light source using microwave-synthesized CuO nanopetals

• Govinda Lakhotiya,
• Sonal Bajaj,
• Arpan Kumar Nayak,
• Debabrata Pradhan,
• Pradip Tekade and
• Abhimanyu Rana

Beilstein J. Nanotechnol. 2017, 8, 1167–1173, doi:10.3762/bjnano.8.118

• , University of Twente, 7500 AE, Enschede, Netherlands 10.3762/bjnano.8.118 Abstract We report enhanced catalytic activity of CuO nanopetals synthesized by microwave-assisted wet chemical synthesis. The catalytic reaction of CuO nanopetals and H2O2 was studied with the application of external light source and

• also under dark conditions for the degradation of the hazardous dye methylene blue. The CuO nanopetals showed significant catalytic activity for the fast degradation of methylene blue and rhodamine B (RhB) under dark conditions, without the application of an external light source. This increased

• conditions is also illustrated. Keywords: CuO nanopetals; dark catalytic activity; fast degradation of dyes; microwave synthesis; Introduction Controlling air quality and water pollutants is a big challenge for environmental research [1]. Particularly, efforts have been taken to control these pollutants

Growth, structure and stability of sputter-deposited MoS₂ thin films

• Reinhard Kaindl,
• Bernhard C. Bayer,
• Roland Resel,
• Thomas Müller,
• Viera Skakalova,
• Gerlinde Habler,
• Rainer Abart,
• Alexey S. Cherevan,
• Dominik Eder,
• Maxime Blatter,
• Fabian Fischer,
• Jannik C. Meyer,
• Dmitry K. Polyushkin and
• Wolfgang Waldhauser

Beilstein J. Nanotechnol. 2017, 8, 1115–1126, doi:10.3762/bjnano.8.113

• was previously reported [29][49]. Given that the films presented in this study have been sputtered from a MoS2 target with a purity of 99.5 wt %, which contains 0.03 wt % SiO2, 0.02 wt % MoO3, 0.01 wt % copper oxide (CuO), 0.019 wt % iron (Fe) and up to 0.20 wt % not specified compounds, in a metallic

• Scituate, MA, USA) and a 6 mm thick MoS2 target with 76.2 mm (3-inch) diameter (Sindlhauser Materials GmbH, Germany). Purity of the target is 99.5 wt % MoS2, according to the materials test certificate further compounds are SiO2 (0.03), MoO3 (0.02), CuO (0.01), Fe (0.019) and not specified elements (<0.20

Treatment of fly ash from power plants using thermal plasma

• Sulaiman Al-Mayman,
• Ibrahim AlShunaifi,
• Abdullah Albeladi,
• Imed Ghiloufi and
• Saud Binjuwair

Beilstein J. Nanotechnol. 2017, 8, 1043–1048, doi:10.3762/bjnano.8.105

• contributions of K2O, TiO2, ZnO, Cr2O3, CuO, and RuO2 were detected. The concentrations of product elements measured by ICP-AES are summarized in Table 1. The product has the same major and minor constituents of the feed (Table 1) and also contains toxic elements. As indicated before, fly ash has a high level

Synthesis of graphene–transition metal oxide hybrid nanoparticles and their application in various fields

• Arpita Jana,
• Elke Scheer and
• Sebastian Polarz

Beilstein J. Nanotechnol. 2017, 8, 688–714, doi:10.3762/bjnano.8.74

• by Kumar et al. for supercapacitor applications [206]. This hybrid can also be used as an electrochemical pseudocapacitor material for potential energy storage applications [207][208]. Copper oxide (Cu2O, CuO, CuO2, Cu2O3)–graphene hybrids Cu nanowire (NW) films and indium tin oxide (ITO) films have

• –graphene hybrids, was used as a high-performance NO2 gas sensor (Figure 8). Copper oxide (CuO) is also a p-type semiconductor. CuO–graphene composites have also been used as anode material for LIBs [211][215]. Mathesh et al. prepared GO hybrid materials consisting of Cu ions complexed with GO, where Cu2

• electrical characteristics of CuO–graphene bilayer structure has been modified largely due to the electronic interaction at the hybrid interface. The O2 intake capacity of the multilayer graphene results in reversible bipolar resistive switching properties [217]. Zhou et al. prepared graphene-wrapped CuO

Study of the surface properties of ZnO nanocolumns used for thin-film solar cells

• Neda Neykova,
• Jiri Stuchlik,
• Karel Hruska,
• Ales Poruba,
• Zdenek Remes and
• Ognen Pop-Georgievski

Beilstein J. Nanotechnol. 2017, 8, 446–451, doi:10.3762/bjnano.8.48

• preferred treatment for the preparation of thin-film solar cells based on ZnO NCs. The reported ZnO nanocolumns layer with a proper spacing could be used as a 3-D scaffold not only for amorphous silicon solar cells, but also for other absorbers with a short lifetime such as CuO, CuO2, FeS2, quantum dots or

Role of oxygen in wetting of copper nanoparticles on silicon surfaces at elevated temperature

• Tapas Ghosh and
• Biswarup Satpati

Beilstein J. Nanotechnol. 2017, 8, 425–433, doi:10.3762/bjnano.8.45

• spectroscopy (EDX) and X-ray diffraction (XRD) analysis shows that the thermal oxidation of the copper nanoparticles and formation of cupric oxide (CuO) on silicon surfaces leads to wetting rather than agglomeration. In contrast, agglomeration has been observed when copper nanoparticles were annealed in a

• nitrogen environment. The lattice transformation from cubic Cu to monoclinic CuO, and hence the change in surface energy of the particles, assists the wetting process. The occurrence of wetting during the oxidation step implies a strong interaction between the oxidized film and the silicon surface

• . Keywords: copper; cupric oxide; electron diffraction; galvanic displacement reaction; oxidation; surface wetting; transmission electron microscopy; Introduction The transition metal oxide cupric oxide (CuO) is a stable oxide of copper, and due to its diverse applications, immense research on CuO

Phosphorus-doped silicon nanorod anodes for high power lithium-ion batteries

• Chao Yan,
• Qianru Liu,
• Jianzhi Gao,
• Zhibo Yang and
• Deyan He

Beilstein J. Nanotechnol. 2017, 8, 222–228, doi:10.3762/bjnano.8.24

• were fabricated on CuO nanorods for application in high power lithium-ion batteries. Since the conductivity of lithiated CuO is significantly better than that of CuO, after the first discharge, the voltage cut-off window was then set to the range covering only the discharge–charge range of Si. Thus

• , the CuO core was in situ lithiated and acts merely as the electronic conductor in the following cycles. The Si anode presented herein exhibited a capacity of 990 mAh/g at the rate of 9 A/g after 100 cycles. The anode also presented a stable rate performance even at a current density as high as 20 A/g

• performance for Si-based anodes. In this work, we prepared heavy-phosphorus-doped silicon anodes on CuO nanorods for high power LIBs. In our experiments, once the voltage cut-off window was set in the range that only covers the discharge–charge range of Si, the conductivity of CuO nanorods was highly