Copper-based Oxides Research Articles

Modulating surface chemistry of copper oxides through annealing environment for enhanced selective HMF oxidation: A DFT-electrochemical approach

A comprehensive study was reported to address the effects of both copper (I) and copper (II) oxides on the electrocatalytic 5-hydroxymethylfurfural (HMF) oxidation reaction. Cu2O (1 1 1) demonstrated an outstanding selectivity (80 %) and product yield in the oxidation process towards 2,5-diformylfuran (DFF). The recorded current density of 0.12 mA/cm2 for Cu2O-dominated sample was doubled comparing to its counterpart electrocatalyst, CuO, under mild pH 9.6 condition. Periodic density functional theory calculations show that the higher DFF selectivity for the Cu2O dominant catalyst can be explained by the Cu2O (1 1 1) surface being more oxyphilic while being less carbophilic than the CuO (1 1 1) surface. As a result, all the reaction intermediates that lead to DFF are stabilized significantly more than those that lead to other products. This work deepens the understanding of copper-based oxide material for the HMF electrooxidation and provides a new window for designing electrocatalyst.

Ce-doped copper oxide and copper vanadate Cu3VO4 hybrid for boosting nitrate electroreduction to ammonia

The electrocatalytic nitrate reduction to ammonia reaction (ENO3RR) holds great potential as a cost-effective method for synthesizing ammonia. This work designed a cerium (Ce) doped Cu2+1O/Cu3VO4 catalyst. The coupling of vanadium-based oxides with Cu2+1O effectively adjusts the catalyst’s electronic structure, addressing the inherent issues of limited activity and low conductivity in typical copper-based oxides; moreover, Ce doping generates oxygen vacancies (Ov), providing more active sites and thereby enhancing the ENO3RR performance. The catalyst exhibits superior NH3Faradaic efficiency (93.7 %) with a NH3 yield of 18.905 mg h−1 cm−2at −0.5 V vs. RHE under alkaline conditions. This study provides guidance for the design of highly efficient catalysts for ENO3RR.

Realizing Persistent Zero Area Compressibility over a Wide Pressure Range in Cu2 GeO4 by Microscopic Orthogonal-Braiding Strategy.

Zero area compressibility (ZAC) is an extremely rare mechanical response that exhibits an invariant two-dimensional size under hydrostatic pressure. All known ZAC materials are constructed from units in two dimensions as a whole. Here, we propose another strategy to obtain the ZAC by microscopically orthogonal-braiding one-dimensional zero compressibility strips. Accordingly, ZAC is identified in a copper-based compound with a planar [CuO4 ] unit, Cu2 GeO4 , that possesses an area compressibility as low as 1.58(26) TPa-1 over a wide pressure range from ≈0 GPa to 21.22 GPa. Based on our structural analysis, the subtle counterbalance between the shrinkage of [CuO4 ] and the expansion effect from the increase in the [CuO4 ]-[CuO4 ] dihedral angle attributes to the ZAC response. High-pressure Raman spectroscopy, in combination with first-principles calculations, shows that the electron transfer from in-plane bonding dx 2 -y 2 to out-of-plane nonbonding dz 2 orbitals within copper atoms causes the counterintuitive extension of the [CuO4 ]-[CuO4 ] dihedral angle under pressure. Our study provides an understanding on the pressure-induced structural evolution of copper-based oxides at an electronic level and facilitates a new avenue for the exploration of high-dimensional anomalous mechanical materials.

Aqueous Solution-Gel Deposition of Copper-Based Photo-Electrodes for Multipurpose Photo-Electrochemical Systems

Efficient valorization of solar energy is expected to contribute significantly to a sustainable supply of energy and fuel sources, as well as the reduction of atmospheric pollution. To this end, photo-electrochemical systems show encouraging potential by converting light into chemical energy. These devices rely on semiconducting photoanodes and/or -cathodes that absorb light efficiently and generate electron-hole pairs with sufficient energy for initiating redox reactions. Several copper-based oxides exhibit appropriate band edges for both photo-electrochemical water splitting and CO2 reduction [1]. This, in combination with their bandgap values, low toxicity, and earth-abundance, has recently increased the attention for copper-based photo-electrodes for multipurpose photo-electrochemical systems. Substantial photocorrosion of CuO and Cu2O is the main issue restricting their application as functional photo-electrodes. In contrast, copper-based ternary oxides are found to be significantly less susceptible to photocorrosion. The citrate-based aqueous solution-gel method has proven to be a versatile approach for the formulation of stable aqueous metal ion precursor solutions, and the subsequent synthesis of (doped) multi-metal oxides by this method has been demonstrated numerously. [2,3] Still, due to the flexible redox chemistry of copper, the solution-gel synthesis of phase-pure copper-based ternary oxides remains challenging. This work describes the synthesis of copper-based photo-electrode materials by focusing on copper ferrite (CFO), copper tungstate (CWO), copper niobate (CNO), and copper bismuth oxide (CBO). The formulation of the respective precursor solutions is described, and their thermal decomposition is investigated. Thin-film photo-electrodes are deposited on transparent conductive substrates by spin coating. The phase purity of the resulting copper-based oxides is determined by X-ray diffraction and Raman spectroscopy. Using UV-Vis spectroscopy, the optical bandgap of the oxide semiconductors is calculated. Furthermore, the photo-electrodes are subjected to linear sweep voltammetry in dark and under illumination to evaluate their photo-electrochemical performance. [1] Wang et al. “Insights into the development of Cu-based photocathodes for carbon dioxide conversion” Green Chem. (2021) 23, 3207[2] Van den Rul et al. “Aqueous Solution-Based Synthesis of Nanostructured Metal Oxides” in “Handbook of Nanoceramics and Their Based Nanodevices” (2009) Ed. T-Y Tseng and H. S. Nalwa[3] Marchal et al. “Precursor Design Strategies for the Low-Temperature Synthesis of Functional Oxides: It’s All in the Chemistry” Chem. Eur. J. (2020) 26, 9070 This work has received funding from the Belgian federal government through the ETF project T-REX and from the VLAIO network “Flanders Innovation & Entrepreneurship” through the Catalisti Moonshot project SYN-CAT. Part of this work was financially supported by TNO in the framework of the “Energy Conversion and Storage” Early Research Program.

Heterogeneous-Driven Glutathione Oxidation: Defining the Catalytic Role of Chalcopyrite Nanoparticles.

Transition-metal nanocatalysis represents a novel alternative currently experiencing flourishing progress to tackle the tumor microenvironment (TME) in cancer therapy. These nanomaterials aim at attacking tumor cells using the intrinsic selectivity of inorganic catalysts. In addition, special attention to tune and control the release of these transition metals is also required. Understanding the chemical reactions behind the catalytic action of the transition-metal nanocatalysts and preventing potential undesired side reactions caused by acute cytotoxicity of the released ionic species represent another important field of research. Specifically, copper-based oxides may suffer from acute leaching that potentially may induce toxicity not only to target cancer cells but also to nearby cells and tissues. In this work, we propose the synthesis of chalcopyrite (CuFeS2) nanostructures capable of triggering two key reactions for an effective chemodynamic therapy (CDT) in the heterogeneous phase: (i) glutathione (GSH) oxidation and (ii) oxidation of organic substrates using H2O2, with negligible leaching of metals under TME-like conditions. This represents an appealing alternative toward the development of safer copper-iron-based nanocatalytic materials with an active catalytic response without incurring leaching side phenomena.

Insight into the low-temperature DeNOx performance of copper-based oxides: Perspective from the valence state distribution

Understanding the effect of CuOx valence state specifically is significant for constructing high-performance Cu based oxide catalyst for low-temperature selective catalytic reduction of NO with NH3 (NH3-SCR). In this work, CuOx with different valence state including Cu2O, Cu2O-CuO and CuO particles are synthetized as model catalysts, which present same variation laws in catalytic performance at 180 ℃, 210 ℃ and 240 ℃. NH3-SCR catalytic performance of Cu2O-CuO heterojunction is the best, CuO exhibits good catalytic activity, while Cu2O possesses excellent N2 selectivity. Experimental results combined with density functional theory (DFT) calculations reveal that Cu2+ favor to form monodentate nitrate and possess strong ability of activation and dehydrogenation of NH3. The energy barrier for the form of NH2* is 79.5 kJ/mol, which is much lower than that for Cu+. While Cu+ is beneficial to NH3 and NOx adsorption and the form of bidentate nitrate, which have a positive impact on improving the selectivity of N2. Moreover, the collaboration of Cu2+ and Cu+ facilitates the redox capability and the form of surface adsorbed oxygen species, thus the reaction progress is further promoted. The SCR reaction catalyzed by three samples are dominated mainly by Langmuir-Hinshelwood (L-H) mechanism at 180 ℃. While at 240 ℃, the reaction over Cu2O follows Eley-Rideal (E-R) mechanism, during which the rate-limiting step is the internal hydrogen transfer procedure (NH2NO*→NHNOH*). Over CuO, the reaction follows L-H mechanism, the process of atomic isomerism (NHNOH*+ *→N2*+H2O*) is the rate-determining step. The energy barriers are 136 and 146 kJ/mol, respectively. This work may supply important theoretical support for the preparation of high-performance Cu-based oxide catalysts.

Visual/Photoelectrochemical Off-On Sensor Based on Cu/Mn Double-Doped CeO2 and Branched Sheet Embedded Cu2O/CuO Nanocubes

An integrated dual-signal bioassay was devised to fulfil thrombin (TB) ultrasensitive detection by integrating visualization with the photoelectrochemical technique based on G-quadruplex/hemin. During the process, branched sheet embedded copper-based oxides prepared with illumination and alkaline condition play a vital role in obtaining the desirable photocurrent. The switchover of photoelectrochemical signal was realized by the adjustable distance between electron acceptor G-quadruplex/hemin and interface materials due to dissociation of the Cu/Mn double-doped cerium dioxide (CuMn@CeO2)/DNA caused by the addition of TB. Then, CuMn@CeO2 transferred onto visual zones triggered catalytic reactions under the existence of 3,3',5,5'-tetramethylbenzidine and hydrogen peroxide, making a variation in color recognized by the naked eye and providing visual prediction. Under optimized conditions, this bioassay protocol demonstrated wide linear ranges (0.0001-50 nM), high selectivity, stability, and reproducibility. More importantly, the proposed visual/photoelectrochemical transduction mechanism platform exhibits a lower background signal and more reliable detection results, which also offers an effective way for detecting other proteins and nucleic acids.

Hierarchical hollow CuO/Cu2O and Cu2O/Cu/C derived from metal–organic framework for non-enzymatic oxidation toward glucose

Constructing copper-based oxide composite with ingenious architecture is attracting enormous attention due to the synergistic effect of components and enhanced performance resulted from structure. Herein, hierarchical hollow CuO/Cu2O and Cu2O/Cu/C are prepared via calcining hierarchical tubular metal–organic framework (MOF) in air atmosphere and Ar atmosphere, respectively. With calcining in air atmosphere, the obtained hierarchical hollow CuO/Cu2O is constructed by nanosheets which is composed of particles in diameter of 20–30 nm. In Ar atmosphere, the synthesized hierarchical hollow Cu2O/Cu/C is constructed by larger particles in diameter of about 65 nm. And these differences in component and building unit are ascribed to different dominant reaction involved in calcination of MOF at different atmospheres. Notably, the hollow structure of parent MOF is perfectly remained, which contributes to the enhancement of copper-based oxide composites in electrocatalytic oxidation toward glucose. The hierarchical hollow CuO/Cu2O and Cu2O/Cu/C can be applied as an excellent glucose sensor with higher sensitivity, wider detection range and lower limitation of detection. Selecting suitable MOF as sacrificed template being calcined in effective atmosphere, provides a facile strategy for constructing derivant with functional structures and increased properties.

In-situ growth flower-like binder-free 3D CuO/Cu2O-CTAB with tunable interlayer spacing for high performance lithium storage

Copper-based oxides are attractive anode materials for lithium-ion batteries (LIBs) due to their abundant resources, low cost, non-toxic and high capacity. However, copper-based oxides will produce a huge volume change during lithiation/delithiation, and the structural strain caused by periodic volume changes may cause the exfoliation of active materials. Herein, a flower-like binder-free three-dimensional (3D) CuO/Cu2O-CTAB was prepared by introducing CTAB, which homogeneously grew in situ on a copper mesh framework. The binder-free 3D sample guarantees direct contact between the active material and the copper mesh, maintaining the structure stability. The flower-like CuO/Cu2O-CTAB with a small size reveals larger active interfaces and provides more active sites. The introduction of CTAB enlarges the interlayer spacing of CuO/Cu2O, increases the active sites for lithium storage, and adapts to the volume change of the material during lithiation/delithiation. In addition, the expanded interlayer structure helps decrease the ion diffusion energy barrier for accelerating electrochemical reaction kinetics. Therefore, CuO/Cu2O-CTAB exhibits better lithium storage performance (2.9 mAh cm−2 at 0.5 mA cm−2) than bare CuO/Cu2O (1.8 mAh cm−2 at 0.5 mA cm−2).

Ligand-Induced Donor State Destabilisation - A New Route to Panchromatically Absorbing Cu(I) Complexes.

The intense absorption of light to covering a large part of the visible spectrum is highly desirable for solar energy conversion schemes. To this end, we have developed novel anionic bis(4H‐imidazolato)Cu(I) complexes (cuprates), which feature intense, panchromatic light absorption properties throughout the visible spectrum and into the NIR region with extinction coefficients up to 28,000 M−1 cm−1. Steady‐state absorption, (spectro)electrochemical and theoretical investigations reveal low energy (Vis to NIR) metal‐to‐ligand charge‐transfer absorption bands, which are a consequence of destabilized copper‐based donor states. These high‐lying copper‐based states are induced by the σ‐donation of the chelating anionic ligands, which also feature low energy acceptor states. The optical properties are reflected in very low, copper‐based oxidation potentials and three ligand‐based reduction events. These electronic features reveal a new route to panchromatically absorbing Cu(I) complexes.

Electronic structure of higher-order Ruddlesden-Popper nickelates

We analyze the electronic structure of the recently synthesized higher-order nickelate Ruddlesden-Popper phases ${\mathrm{La}}_{n+1}{\mathrm{Ni}}_{n}{\mathrm{O}}_{3n+1}$ $(n=4--6)$ using first-principles calculations. For all materials, our results show large holelike Fermi surfaces with ${d}_{{x}^{2}\ensuremath{-}{y}^{2}}$ character that closely resemble those of optimally hole-doped cuprates. For higher values of $n$, extra non-cuprate-like bands of ${d}_{{z}^{2}}$ orbital character appear. These aspects highlight that this Ruddlesden-Popper series can provide a means to modify the electronic ground states of nickelates by tuning their dimensionality. With their similarities and differences to the cuprates, this new family of materials can potentially shed light on the physics of copper-based oxides.

Investigation of the effect of oxygen partial pressure on the phase composition of copper oxide nanoparticles by vacuum arc synthesis

Copper oxide nanoparticles were obtained in the plasma of a low-pressure arc discharge. The effect of the partial pressure of oxygen (10-40%) on the physical properties of the deposited nanoparticles has been studied. X-ray diffraction analysis shows that the cubic structure of Cu2O changes to monoclinic CuO with increasing O2 pressure. The results of Raman spectroscopy further confirmed the phase variations of copper-based oxide nanoparticles. X-ray photoelectron spectroscopy confirmed the change in the binding energy in the oxidation state of nanoparticles. The optical band gap of the deposited Cu2O is 2.12 eV, while that of CuO is 1.79-1.82 eV. Keywords: vacuum arc, oxides, nanoparticles, plasma-chemical reactions.

Photoinduced phase-transition on CuO electrospun nanofibers over the TiO2 photosensitizer for enhancing non-enzymatic glucose-sensing performance

Constructing metal-oxide-based composites with the multiple valence-states and redox-couples has been proved as an effective strategy to enhance the performance of non-enzymatic glucose sensing. Herein, we report a mild and efficient method to prepare multiple-valent copper-based oxide composite nanofibers (CuxO CNFs) through introducing the TiO2 photosensitizer into the CuO NFs for actuating the localized phase transition from tenorite CuO (Cu2+) to cuprite Cu2O (Cu+) upon UV–visible light irradiation. The sensitivity of the obtained TiO2/Cu2O/CuO CNFs for glucose sensing (0–2 mM) could be enhanced by 1.12–1.31 times as compared to that of the TiO2/CuO CNFs. The enhanced sensitivity is dependent on the TiO2-content in the primal TiO2/CuO CNFs. When introducing 5.0 at.% of TiO2 into the CuO nanofibers, the photoinduced phase-transition process could result in the formation of optimal TiO2/Cu2O/CuO CNFs with the component ratio of Cu2O to CuO at 0.46:1. This TiO2/Cu2O/CuO CNFs (2074.7 µA·mM−1·cm−2; 0.25 µM) exhibited nearly 1.32-fold improvement on the sensitivity and 3.0-fold enhancement on the detection limit as compared to the corresponding values of the pure CuO electrospun nanofibers (1581 µA·mM−1·cm−2; 0.75 µM). After the continuous measurements for 14 days, the sensitivity of the optimal sample could maintain 89.4% of its initial value. Notably, its sensitivity could be further recovered to 97.4% of the initial value after UV–visible light irradiation for 1 h.

Correlating electronegativity in bimetallic oxygen carriers for chemical looping combustion

Metallic tailoring of oxygen carrier plays a crucial role within chemical looping combustion (CLC) applications, which can be correlated to the redox reaction enhancement and sustainability. Such attributes arise from the electric valence of the material constituents, which can bring about superior oxygen vacancy and structural stability. In the concurrent study, the role of electronegativity of the bimetallic carriers upon CLC performance was scrutinized based on various bimetallic metal oxides composition. Two metallic systems were examined in the current study: Iron based oxides and copper-based oxides, where the secondary metallic element within each of the examined oxide carrier is composed of one of the 5 metallic elements, predefined for the purpose of electronegativity variation. The secondary metallic element include: Calcium, Lanthanum, Magnesium, Manganese, and Chromium. Several gas byproducts were monitored during the course of the CLC reaction, via mass spectrometer, in order to quantify the variations incurred as a result of different metallic composition inclusion. Additionally, electron microscopic techniques, such as the SEM, were utilized in the study, so as to visualize the structural alteration of sintered materials. The experimental results indicate a higher reactivity with the fuel at a higher electronegativity difference within the bimetallic structure, in the case of iron-based oxide system. Also, copper-based oxide system was associated with higher carbon dioxide production with higher selectivity, relative to iron-based oxide systems.

The Synergetic Effect Induced High Electrochemical Performance of CuO/Cu2O/Cu Nanocomposites as Lithium-Ion Battery Anodes.

Due to the high theoretical capability, copper-based oxides were widely investigated. A facile water bath method was used to synthesis CuO nanowires and CuO/Cu2O/Cu nanocomposites. Owing to the synergetic effect, the CuO/Cu2O/Cu nanocomposites exhibit superior electrochemical performance compared to the CuO nanowires. The initial discharge and charge capacities are 2,660.4 mAh/g and 2,107.8 mAh/g, and the reversible capacity is 1,265.7 mAh/g after 200 cycles at 200 mA/g. Moreover, the reversible capacity is 1,180 mAh/g at 800 mA/g and 1,750 mAh/g when back to 100 mA/g, indicating the excellent rate capability. The CuO/Cu2O/Cu nanocomposites also exhibit relatively high electric conductivity and lithium-ion diffusion coefficient, especially after cycling. For the energy storage mechanism, the capacitive controlled mechanism is predominance at the high scan rates, which is consistent with the excellent rate capability. The outstanding electrochemical performance of the CuO/Cu2O/Cu nanocomposites indicates the potential application of copper-based oxides nanomaterials in future lithium-ion batteries.

A General Route of Using Lignite Depolymerized Derivatives for Catalyst Construction: Insights into the Effects of the Derivative Structures and Solvents.

Depolymerization is an emerging and promising route for the value-added utilization of low-rank coal (LRC) resources, and how to use the complex depolymerized mixtures efficiently is of great importance for this route. In this work, we designed the rational route of using depolymerized mixtures from lignite via ruthenium ion-catalyzed oxidation (RICO) depolymerization directly without complex separation to construct a Zr-based hydrogenation catalyst. The prepared catalyst was applied into the catalytic transfer hydrogenation of biomass-derived carbonyl compounds. Meanwhile, a copper-based oxidation catalyst was also constructed via a similar route to investigate the universality of the proposed route. Special insights were given into how the depolymerized components with different structures influenced the performances of the catalysts. The effects of the solvents used during the catalyst preparation (H2O and DMF) were also studied. The results showed that the proposed route using the depolymerized mixtures from lignite via RICO to construct catalysts was feasible for both Zr-based and Cu-based catalysts. The two catalysts prepared gave high efficiency for their corresponding reaction, i.e., the Zr-based catalyst for catalytic transfer hydrogenation of biomass-derived carbonyl compounds and the Cu-based catalyst for selective oxidation of alcohols into aldehydes. Different depolymerized components contributed differently to the activity of the catalyst, and the solvents during the preparation process could also influence the activity of the catalyst. The depolymerized components and the solvents influenced the activities of the Zr-based catalyst mainly via changing the Zr contents, the microenvironment of Zr4+, and the specific areas of the catalyst.

Copper-based glass-ceramic as an efficient catalyst in the synthesis of pyrazolo[1,5-a] pyrimidineunder solvent-free condition with docking validation as Covid-19 main protease (Mpro) inhibitor

Copper-based oxide glass-ceramic was successfully synthesized through the single-step melt annealing technique. Synthesized glass-ceramics was characterized using X-ray diffraction (XRD) and scanning electron microscopy (SEM) supported with energy dispersive X-ray (EDX) and mapping. Pyrazolo[1,5-a]pyrimidines 5a-f were synthesized via the reaction of 5-amino-1H-pyrazole-4-carboxamide (1) with enaminones 2a-f in the presence of synthesized oxide glass-ceramic catalyst powder under solvent-free condition. The molecular docking study demonstrated that the COVID-19 main protease (MPro) inhibitor.
 
 KEY WORDS: Pyrazolopyrimidine, Enaminones, Copper-based catalysis, Solvent-free, COVID-19
 
 Bull. Chem. Soc. Ethiop. 2021, 35(1), 185-196.
 DOI: https://dx.doi.org/10.4314/bcse.v35i1.16

Structural and morphological tuning of Cu-based metal oxide nanoparticles by a facile chemical method and highly electrochemical sensing of sulphite

A facile one-step chemical method is introduced for the successful synthesis of Cu2O, CuO and CuNa2(OH)4 crystal structures and their electrochemical properties were also investigated. X-ray diffraction studies revealed that these copper-based oxide nanoparticles display different crystal structures such as cubic (Cu2O), monoclinic (CuO) and orthorhombic [CuNa2(OH)4]. The microstructural information of nanoparticles was investigated by transmission electron microscopy. It shows attractive morphologies of different orientation such as rod like structure, nanobeads and well-aligned uniform nanorod for Cu2O, CuO and CuNa2(OH)4, respectively. Electrochemical sensing of sulphite (SO32−) on these three copper-based oxide modified electrodes was investigated. Among the three different crystal structures, CuO shows promising electrocatalytic activity towards oxidation of sulphite. A linear variation in peak current was obtained for SO32− oxidation from 0.2 to 15 mM under the optimum experimental condition. The sensitivity and detection limit were in the order of 48.5 µA cm−2 mM−1 and 1.8 µM, respectively. Finally, practical utility of CuO modified electrode was demonstrated for the estimation of sulphite in commercial wine samples.

Исследование влияния парциального давления кислорода на фазовый состав наночастиц оксида меди вакуумно-дугового синтеза

Copper oxide nanoparticles were obtained in the plasma of a low-pressure arc discharge. The effect of the partial pressure of oxygen (10-40%) on the physical properties of the deposited nanoparticles has been studied. X-ray diffraction analysis shows that the cubic structure of Cu2O changes to monoclinic CuO with increasing O2 pressure. The results of Raman spectroscopy further confirmed the phase variations of copper-based oxide nanoparticles. X-ray photoelectron spectroscopy confirmed the change in the binding energy in the oxidation state of nanoparticles. The optical band gap of the deposited Cu2O is 2.12 eV, while that of CuO is 1.79-1.82 eV.

CuGeO3 Nanoparticles: An Efficient Photothermal Theragnosis Agent for CT Imaging-Guided Photothermal Therapy of Cancers.

The photothermal agents have been widely developed due to the minimally invasive treatment for targeted tumor photothermal therapy, which is considered to have great potential for antitumor bioapplications. The development of multifunctional photothermal agents is extremely challenging. This work presents a novel photothermal theragnosis agent, i.e., CuGeO3 nanoparticles (CGO NPs), showing intense absorption in the near-infrared (NIR) window and excellent ability of CT imaging. Due to the strong NIR absorption, CGO NPs exhibit excellent photothermal effect with a photothermal conversion efficiency of 59.4%. Moreover, because of the high X-ray attenuation coefficient of germanium, the CGO NPs have a great potential of CT imaging diagnosis in clinical application. Additionally, the CGO NPs show negligible cytotoxicity in vitro and in vivo, indicating that it can be served as an outstanding contrast and anticancer agent in a biosafe way. Our work opens the way for the development of bimetallic copper-based oxides used in photothermal diagnostic agents for cancer treatment.