Oxidation Of Cu Research Articles

Revealing the Facet-Selective Electrochemistry That Drives Metal Nanostructure Growth

Since about 20 years ago, researchers have developed a variety of syntheses to control the morphology of metal nanostructures grown in solution.1 Control over nanostructure morphology has enabled the optimization of their properties for applications including electrocatalysis, solution-coatable transparent conducting films, conductive composites and plasmonic biosensors.1 To explain how anisotropic nanostructures can grow from metals with symmetric cubic crystal structures, researchers have often invoked the capping agent hypothesis, which proposes that the organic additives added to nanostructure syntheses are facet-selective in that they block atomic addition to certain facets but not others. However, direct evidence of such facet-selective blocking by organic additives has been lacking. This talk will discuss efforts to use electrochemical measurements on single crystals to test the capping agent hypothesis. For a copper nanowire synthesis in which ethylenediamine was thought to act as a capping agent for {100} facets, single crystal measurements showed it in fact acted as a facet-selective promoter of Cu nanowire growth by keeping the {111} facets on the ends of a nanowire relatively free of surface oxidation.2 In another synthesis in which hexadecylamine is thought to serve as a capping agent for {100} facets, single crystal measurements showed that in fact hexadecylamine passivates both Cu(111) and Cu(100) equally.3 The presence of chloride ions in the synthesis selectively disrupts the alkylamine monolayer on the {111} facets on the ends of the nanowires, enabling anisotropic growth.Addition of iodide ions to the same copper nanowire synthesis results in the formation of Cu microplates instead of nanowires. Single-crystal electrochemistry confirmed that a 75 micromolar concentration of iodide resulted in passivation of {111} facets on the top and bottom surface of microplates due to the displacement of chloride by iodide. At the same time, iodide activated the {100} facets on the sides of the microplates by disrupting the hexadecylamine monolayer on those facets. Results from density functional theory calculations indicate the stronger binding affinity of iodide causes it to displace both chloride and the hexadecylamine monolayer from copper surfaces. The binding of iodide to copper leads to a lower surface energy for {111} facets than {100} facets, resulting in the preferential atomic addition of Cu to the {100} facets on the sides of microplates.These examples illustrate that organic additives do not always act as facet-selective capping agents, and that halide ions can play a dominant in driving the anisotropic growth of copper nanostructures. 1. Huo, D.; Kim, M.J.; Lyu, Z.; Shi, Y.; Wiley, B.J.; Xia, Y. One-Dimensional Metal Nanostructures: From Colloidal Syntheses to Applications. Chem. Rev., 2019, 119, 8972-9073. 2. Kim, M.J.; Flowers, P.F.; Stewart, I.E.; Ye, S.; Baek, S.; Kim, J.J.; Wiley, B.J. Ethylenediamine Promotes Cu Nanowire Growth by Inhibiting Oxidation of Cu (111). J. Am. Chem. Soc. 2017, 39, 277-284. 3. Kim, M.J.; Alvarez, S.; Chen, Z.; Fichthorn, K.A.; Wiley, B.J. Single-Crystal Electrochemistry Reveals Why Metal Nanowires Grow. J. Am. Chem. Soc., 2018, 140, 14740-14746.

Electrochemical copper dissolution: A benchmark for stable CO2 reduction on copper electrocatalysts

Copper is well known in fundamental electrocatalysis research due to its ability to selectively reduce CO2 to C2 products. Recent, more applied studies have revealed that electrolyzers based on Cu electrocatalysts can reach current densities of up to hundreds of mA cm−2. This opens up the opportunity for industrial application of Cu-based electrocatalysts. However, the stability of copper must first be assessed. In this communication we investigate the electrochemical corrosion behavior of copper in a broad pH window relevant to CO2 reduction applications. Using an electrochemical on-line inductively coupled plasma mass spectrometer (ICP-MS), we quantify Cu dissolution during anodic oxidation and during the reduction of electrochemically formed oxide species. We show that electrochemical oxidation of Cu leads to high dissolution in neutral and highly alkaline environments, while an intermediate pH of around 9–10 leads to minimal dissolution. The obtained results are discussed in relation to the CO2 reduction reaction to set a benchmark for stable Cu-based electrocatalysts.

Thermodynamic and Experimental Study on Efficient Extraction of Valuable Metals from Polymetallic Nodules

Polymetallic nodules are promising resources for the extraction of valuable metals such as copper, nickel, and cobalt, as well as manganese alloys. To achieve efficient extraction of useful metals from the emerging resource, high-temperature carbothermic reduction of nodules was investigated by optimizing the reductant addition, slag and alloy systems. Thermochemical software FactSage was used to predict the liquidus temperature of the slag system, which is not sensitive to FeO, CaO and Al2O3, but decreases significantly with decreasing MnO/SiO2 mass ratio. The experiments were designed to reduce the oxides of Cu, Co and Ni completely, and reduce FeOx partially depending on the amount of graphite addition while leaving the residual slag for further processing into ferromanganese and/or silicomanganese alloys. Co, Cu and Ni concentrations in the alloy decreased with increasing graphite addition. The optimal reduction condition was reached by adding 4 wt% graphite at the MnO/SiO2 mass ratio of 1.6 in slag. The most effective metal-slag separation was achieved at 1350 °C, which enables the smelting reduction to be carried out in various furnaces.

Copper Corrosion Behavior in Simulated Concrete-Pore Solutions

The copper corrosion was studied for 30 days in two alkaline electrolytes: saturated Ca(OH)2 and cement extract, employed to simulate concrete-pore environments. Electrochemical Impedance Spectroscopy (EIS) and Cyclic Voltammetry were carried out at the open circuit potential (OCP), and potentiodynamic polarization (PDP) curves were performed for comparative purposes. Electrochemical current fluctuations, considered as electrochemical noise (EN), were employed as non-destructive methods. The tests revealed that sat. Ca(OH)2 is the less aggressive to the Cu surface, mainly because of the lower in one order pH. In consequence, the OCP values of Cu were more positive, the polarization resistance values were higher by one order of magnitude, and the anodic currents of Cu were lower than those in the cement extract. The analyzed EN indicated that the initial corrosion attacks on the Cu surface are quasi-uniform, resulting from the stationary persistent corrosion process occurring in both model solutions. XPS analysis and X-ray diffraction (XRD) patterns revealed that in sat. Ca(OH)2, a Cu2O/CuO corrosion layer was formed, which effectively protects the metallic Cu-surface. We present evidence for the sequential oxidation of Cu to the (+1) and (+2) species, its impact on the corrosion layer, and also its protective properties.

Pulsed Electrodeposition for Copper Nanowires

Copper nanowires (Cu NWs) are a promising alternative to indium tin oxide (ITO), for use as transparent conductors that exhibit comparable performance at a lower cost. Furthermore, Cu NWs are flexible, a property not possessed by ITO. However, the Cu NW-based transparent electrode has a reddish color and tends to deteriorate in ambient conditions due to the oxidation of Cu. In this paper, we propose a pulsed-current (PC) plating method to deposit nickel onto the Cu NWs in order to reduce oxidation over a 30-day period, and to minimize the sheet resistance. Additionally, the effects of the pulse current, duty cycle, and pulse frequency on the performance of the Cu–Ni (copper–nickel) NW films have also been investigated. As a result, the reddish color of the electrode was eliminated, as oxidation was completely suppressed, and the sheet resistance was reduced from 35 Ω/sq to 27 Ω/sq. However, the transmittance decreased slightly from 86% to 76% at a wavelength of 550 nm. The Cu–Ni NW electrodes also exhibited excellent long-term cycling stability after 6000 bending cycles. Our fabricated Cu–Ni electrodes were successfully applied in flexible polymer-dispersed liquid crystal smart windows.

Fabrication of a leaf-like superhydrophobic CuO coating on 6061Al with good self-cleaning, mechanical and chemical stability

Copper oxide is widely used to obtain superhydrophobic surfaces due to its special micro/nano-structures and properties. However, there are few studies on a leaf-like CuO superhydrophobic coating by direct thermal oxidation of Cu on 6061Al substrate. In this work, there is a simple and low-cost method including chemical replacement, thermal oxidation and low-energy-modification with stearic acid. The resultant coating is superhydrophobic and oleophilic with water contact and sliding angles of 157.3∘±0.5∘ and 3.6∘±1∘, respectively. Additionally, it has low adhesion and excellent self-cleaning performances, whose corresponding mechanical analyses are conducted to theoretically discuss that stable micro/nano-structures and trapped air pockets could effectively influence the interfacial adhesion. Importantly, after tape-peeling, sandpaper-abrasion, and chemical stability tests, the coating still keeps superhydrophobic. Especially, in 3.5 wt% NaCl aqueous solution, compared with the corrosion current density of bare 6061Al substrate (7.18×10−7A/cm2), that of the SHP CuO coating (0.77×10−7A/cm2) decreases obviously. In sum, the method is especially suitable for large-scale industrial production of a stable superhydrophobic coating on Al alloys.

Dynamic Atom Clusters on AuCu Nanoparticle Surface during CO Oxidation

Supported alloy nanoparticles are prevailing alternative low-cost catalysts for both heterogeneous and electrochemical catalytic processes. Gas molecules selectively interacting with one metal element induces a dynamic structural change of alloy nanoparticles under reaction conditions and largely controls their catalytic properties. However, such a multicomponent dynamic-interaction-controlled evolution, both structural and chemical, remains far from clear. Herein, by using state-of-the-art environmental TEM, we directly visualize, in situ at the atomic scale, the evolution of a AuCu alloy nanoparticle supported on CeO2 during CO oxidation. We find that gas molecules can "free" metal atoms on the (010) surface and form highly mobile atom clusters. Remarkably, we discover that CO exposure induces Au segregation and activation on the nanoparticle surface, while O2 exposure leads to the segregation and oxidation of Cu on the particle surface. The as-formed Cu2O/AuCu interface may facilitate CO-O interaction corroborated by DFT calculations. These findings provide insights into the atomistic mechanisms on alloy nanoparticles during catalytic CO oxidation reaction and to a broad scope of rational design of alloy nanoparticle catalysts.

Strong Negative Thermal Expansion in a Low-Cost and Facile Oxide of Cu2P2O7.

Negative thermal expansion (NTE) behaviors have been observed in various types of compounds. The achievement in the merits of promising low-cost and facile NTE oxides remains challenging. In the present work, a simple and low-cost Cu2P2O7 has been found to exhibit the strongest NTE among the oxides (αV ∼ -27.69 × 10-6 K-1, 5-375 K). The complex NTE mechanism has been investigated by the combined methods of high-resolution synchrotron X-ray diffraction, neutron powder diffraction, X-ray pair distribution function, extended X-ray absorption fine structure spectroscopy, and density functional theory calculations. Interesting, the direct experimental evidence reveals that the coupling twist and rotation of PO4 and CuO5 polyhedra are the inherent factors for the NTE nature of Cu2P2O7, which is triggered by the transverse vibrations of oxygen atoms. The present new NTE material of Cu2P2O7 also has been verified for the practical application.

Study of self-oscillations during CO oxidation over Cu foil

The oscillatory behavior during CO oxidation over Cu foil has been observed in the temperature range of 350–750 °C. The oscillatory behavior occurred in CO excess similar to the well-known oscillations during CO oxidation over Ni and Co, but in contrast to the oscillations over Pt, Pd, Ir, and Ru. The periodic variation in oxygen imbalance together with variation in color changes during the oscillations and ex situ XRD measurements indicate that the oscillations were closely connected with the reversible oxidation of Cu to Cu2O. The oscillations were accompanied by propagation of oxidation and reduction wavefronts.

Low‐Temperature Synthesis of Honeycomb CuP2@C in Molten ZnCl2 Salt for High‐Performance Lithium Ion Batteries

AbstractPhosphorus‐rich metal phosphides have very high lithium storage capacities, but they are difficult to prepare. A low‐temperature phosphorization method based on Mg reducing PCl3 in ZnCl2 molten salt at 300 °C is developed to synthesize phosphorus‐rich CuP2@C from a Cu‐MOF derived Cu@C composite. Abnormal oxidation of Cu by Zn2+ in the molten salt is observed, which leads to the porous honeycomb nanostructure and homogeneously distributed ultrafine CuP2 nanocrystals. The honeycomb CuP2@C exhibits excellent lithium storage performance with high reversible capacity (1146 mAh g−1 at 0.2 A g−1) and superior cycling stability (720 mAh g−1 after 600 cycles at 1.0 A g−1), showing the promising application of P‐rich metal phosphides in lithium ion batteries.

Low-Temperature Synthesis of Honeycomb CuP2 @C in Molten ZnCl2 Salt for High-Performance Lithium Ion Batteries.

Phosphorus-rich metal phosphides have very high lithium storage capacities, but they are difficult to prepare. A low-temperature phosphorization method based on Mg reducing PCl3 in ZnCl2 molten salt at 300 °C is developed to synthesize phosphorus-rich CuP2 @C from a Cu-MOF derived Cu@C composite. Abnormal oxidation of Cu by Zn2+ in the molten salt is observed, which leads to the porous honeycomb nanostructure and homogeneously distributed ultrafine CuP2 nanocrystals. The honeycomb CuP2 @C exhibits excellent lithium storage performance with high reversible capacity (1146 mAh g-1 at 0.2 A g-1 ) and superior cycling stability (720 mAh g-1 after 600 cycles at 1.0 A g-1 ), showing the promising application of P-rich metal phosphides in lithium ion batteries.

Quantitatively Unraveling the Redox Shuttle of Spontaneous Oxidation/Electroreduction of CuO x on Silver Nanowires Using in Situ X-ray Absorption Spectroscopy.

Oxide-derived copper catalysts have been shown to enhance CO2 reduction reaction (CO2RR) activity with high selectivity toward hydrocarbon products. However, the chemical state of oxide-derived copper during the CO2RR has remained elusive and is lacking in situ observations. Herein, a two-step process was developed to synthesize Ag nanowires coated with various thicknesses of a CuOx layer for the CO2RR. By employing in situ X-ray absorption spectroscopy, a strong correlation between the chemical state under reaction conditions and the CO2RR product profile can be revealed to validate another competing reaction (i.e., the spontaneous oxidation of Cu(0) in aqueous electrolyte) that significantly governs the chemical state of active centers of Cu. In situ Raman spectroscopy reveals the existence of reoxidation behavior under cathodic potential, and the quantification analysis of reoxidized behavior is revealed to indicate that the reoxidation rate is independent of surface morphology and strongly proportional to the electrochemically surface area. The steady oxidation state of Cu in an in situ condition is the paramount key and dominates the products’ profile of the CO2RR rather than other factors (e.g., crystal facets, atomic arrangements, morphology, elements) that have been investigated in numerous reports.

Activation of bimetallic AgCu foam electrocatalysts for ethanol formation from CO2 by selective Cu oxidation/reduction

Bimetallic AgCu metal foams (15 at% Ag, 85 at% Cu) have been synthesized by means of an additive-assisted electrodeposition process using the dynamic hydrogen bubble template approach. Ag and Cu remain fully phase-segregated in the as deposited bimetallic foam exhibiting a high degree of dispersion of pure nm-sized Ag domains embedded in the Cu matrix. An activation of this bimetallic material towards ethanol formation is achieved by thermal annealing of the as deposited foam under mild conditions (200 °C for 12 h). Such annealing quantitatively transforms the Cu in the bimetallic system into a mixture of crystalline Cu2O and amorphous CuO whereas the Ag remains in its metallic state due to the thermal instability of Ag2O above temperatures of 180 °C. The selective oxidation of Cu in the bimetallic Ag15Cu85 catalyst goes along with an enrichment of Cu oxides on the surface of the formed mixed AgCuxO foam.Both operando X-ray diffraction and operando Raman spectroscopy demonstrate, however, that the oxide reduction is completed before the electrochemical CO2 reduction sets in. The thus formed oxide-derived (OD) bimetallic Ag15Cu85 foam catalyst shows high selectivity towards alcohol formation with Faradaic efficiencies of FEEtOH = 33.7% and FEn-PrOH = 6.9% at −1.0 V and −0.9 V vs RHE, respectively. Extended electrolysis experiments (100 h) indicate a superior degradation resistance of the oxide-derived bimetallic catalyst which is ascribed to the effective suppression of the C1 hydrocarbon reaction pathway thus avoiding irreversible carbon contaminations appearing in particular during methane production.

High-efficiency and sustainable photoelectric conversion of CO2 to methanol over CuxO/TNTs catalyst by pulse potential method

Herein, we report a special pulse potential method to increase methanol production and keep the CuxO/TiO2 nanotube array (TNT) catalyst active during photoelectrocatalysis reduction of CO2. The CuO/TNT catalyst was prepared via electrodeposition of copper on anodized titanium oxide followed by heat treatment. The variation of valence of copper in the photoelectrocatalytic reduction process was studied intensively by high-resolution transmission electron microscopy, XPS, and AES characterizations. Results show that the photocatalytically active CuO is apt to be reduced to elementary Cu during photoelectrocatalysis process, leading to rapid decay of photocatalytic activity. While for the case of pulse potential regime, another photocatalytically active oxide, Cu2O, will be produced on the surface during anodic pulse, which can effectively maintain the photocatalytic activity of catalyst. CV study indicates that the oxidation of Cu is prior to the oxidation of methanol, so the methanol oxidation hardly ever happens during anodic pulse stage. The catalyst applied in pulse potential regime provided a much larger photocurrent than that in constant potential regime over an extended period of time. As a result, the yield of methanol produced in optimized pulse potential condition is greatly increased, nearly twice that in constant potential regime.

Effect of graphene, SiC and graphite addition on hardness, microstructure and electrical conductivity of microwave sintered copper MMCs fabricated by powder metallurgy route

Copper MMCs reinforced with graphene, SiC and graphite flakes with varying mass fractions of 2.5, 5, and 7.5 wt% SiC, 2.5, 5, 7.5, and 10 wt% graphite and 0.2, 0.4, 0.6 and 0.8wt% graphene particles were fabricated through powder metallurgy route. The powder mixtures were blended and then compacted under a uniaxial pressure of 400MPa for both Cu-SiC and Cu-Gr composites and 600Mpa for Cu-Gn composites. Green compacts were sintered by microwave (MW) sintering process. MW sintering was performed at 950°C in open atmosphere with a heating rate of 25°C/min for all composites. Densification parameter (DP) was determined for all MMCs and a reduction in DP values were observed with an increase in weight percentage of reinforcement particles as a result of increase in porosity. Higher mass fractions of reinforcement particles in the Cu matrix tend to offer a diffusion barrier to copper atoms. Micro-structural analysis was performed using Optical and scanning electron microscope which revealed a homogeneous microstructure of all composites at low mass fractions of Sic, graphite and graphene. In order to detect the presence of any oxides of Cu and other elements, EDS analysis was carried out. Hardness data showed an increasing trend for Cu-SiC and Cu-Gn composites and a declining trend for Cu-Gr composites. Porosity has a significant effect on the electrical conductivity values of the composites.

Massively Parallel Nanoparticle Synthesis in Anisotropic Nanoreactors.

This work reports a massively parallel approach for synthesizing inorganic nanoparticles (Au, Ag, Se, and mixed oxides of Cu, Co, Ni, Ge, and Ta) based upon lithographically generated arrays of square pyramidal nanoholes, which serve as nanoreactors. Particle precursor-containing polymers are spin-coated onto the nanoreactors, which upon dewetting generate a morphology of isolated polymer droplets in each nanoreactor. This dewetting process yields a well-defined and precisely controlled volume of polymer and therefore particle precursor in each nanoreactor. Subsequent stepwise annealing (first at 150 °C and then at 500 °C) yields arrays of monodisperse, site-isolated particles with sub-5 nm position control. By varying the precursor loading of the polymer, particle size can be systematically controlled in the 7-30 nm range. This work not only introduces the concept of merging block copolymer inks with nanohole arrays in the synthesis of nanoparticles but also underscores the value of the nanoreactor shape in controlling resulting particle position.

Copper Oxidation on Pt(111)—More than a Surface Oxide?

The growth of copper oxide thin films on a Pt(111) support has been analyzed with a combination of scanning tunneling microscopy, electron-diffraction, and X-ray photoelectron spectroscopy. At low preparation temperature, only a monolayer oxide is formed, whereas most of the precipitated copper accumulates as Cu(111) at the Pt interface. The respective films thus resemble the well-known “29” and “44” surface oxides that are composed of distorted Cu–O six-membered rings and develop in a similar manner upon low-pressure oxidation of Cu(111). With increasing temperature, unreacted Cu mixes with the Pt top layers, resulting in a well-ordered Cu3Pt surface alloy. Following these structural and chemical modifications in the support, the surface oxide undergoes an order–disorder transition, in which the Cu–O honeycomb layer forms an increasing number of 5–7 defects and later disrupts into isolated oxide islands. The most prominent island types, especially at high temperature, are Cu3O shamrock units bound to Pt surface atoms that self-assemble into highly crystalline 2√3 domains on the surface. The preparation of thicker Cu2O films, on the other hand, appears challenging on Pt(111), partly because of difficulties to oxidize copper in a vacuum experiment and partly because of an unfavorable lattice match.

Simultaneous degradation of the anticancer drugs 5-fluorouracil and cyclophosphamide using a heterogeneous photo-Fenton process based on copper-containing magnetites (Fe3-xCuxO4)

The effect of substitution of iron by copper in the magnetite lattice was investigated in terms of the catalytic activity in the heterogeneous photo-Fenton process. The physicochemical properties of the Fe3-xCuxO4 nanoparticles were characterized by X-ray diffraction (XRD), X-ray fluorescence (WD-XRF), specific surface area measurements, field emission scanning electron microscopy (FEG-SEM), and X-ray photoelectron spectroscopy (XPS). Copper-modified magnetite showed higher catalytic activity for H2O2 conversion to HO• (estimated using 7-hydroxycoumarin), compared to pristine magnetite (Fe3O4). Consequently, improved degradation of the anticancer drugs 5-fluorouracil (5-FU) and cyclophosphamide (CP) was observed, with high efficiencies achieved using Fe2.75Cu0.25O4 (0.125 g L−1) and 15 mmol L−1 H2O2, at pH 6.5, which resulted in complete degradation of 7.7 μmol L−1 5-FU and CP after 150 min. Low leaching of Cu and Fe demonstrated the stability of the catalyst in the Fenton process, with high catalytic activity (>90%) maintained after use in 4 cycles. The addition of radical scavengers such as methanol, tert-butanol and iodide ions indicated that surface-bonded hydroxyl radicals played a major role in the degradation of 5-FU and CP in the Fe3-xCuxO4/H2O2 system. The substitution of octahedral Fe(II) sites of the magnetite lattice by Cu(II) and the partial oxidation of Cu(I) to Cu(II) and Fe(II) to Fe(III) on the catalyst surface after the Fenton reaction were confirmed by analysis of the XPS spectra.

BASF, Lutianhua sign MoU for eco-friendly production process for DME

The effects of three different mixing methods of CuO/ZnO/Al2O3 (CZA) and HZSM-5 bifunctional catalyst on the stability for dimethyl ether (DME) synthesis from carbon dioxide (CO2) hydrogenation were investigated. When the bifunctional catalyst was prepared by method A (mixing powder without pelletization), there was no significant change in DME production and catalyst stability when the HZSM-5 loading was varied between 0.1 g and 0.5 g with a fixed CZA loading of 0.5 g,. When the bifunctional catalysts were prepared by method B (pressed into pellets of CZA and pellets of HZSM-5 and then mixed) and method C (mixed CZA and HZSM-5 powders, then pressed into pellets), the mixing methods did not initially impact CO2 conversion and had a minor effect on DME yield. However, long-term tests (100 h) indicated that the mixing method had a significant influence on the catalyst stability. Method B showed the best stability and the extent of catalyst deactivation followed the sequence of method B < method A < method C. Characterizations of spent catalysts indicated that method B could reduce the extent of copper (Cu) oxidation, which due to the relatively low surface contact between Cu active sites and HZSM-5. Large amounts of water generated in CO2 hydrogenation to synthesize DME and intimate contact between CZA and HZSM-5 catalyst could induce severe oxidation of Cu and metal ions migration from hydrogenation catalyst to HZSM-5, which can result in the number reduction of acidic sites.

Understanding the synergetic effect from foreign metals in bimetallic oxides for PMS activation: A common strategy to increase the stoichiometric efficiency of oxidants

Synergistic effect was commonly observed in bimetallic oxide catalysts in sulfate radical-based advanced oxidation processes by forming spinel structures. In this paper, we found the incorporation of Cu demonstrated the most remarkable promotional effect to Co oxides comparing with Fe and Mn in PMS activation, and no spinel structure of mixed metals was found. Moreover, the synergism between oxides of Cu and Co was observed on various supports including MgAl layered double hydroxides, mesoporous MnO2 and ZnO. Under conditions of 0.2 g L−1 catalysts, 2 mM PMS, and 40 ppm 4-chlorophenol (4-CP), CuCo@ZnO/PMS system demonstrated excellent performance that 96.0% 4-CP could be removed, while the removal efficiency of 4-CP in Cu@ZnO/PMS and Co@ZnO/PMS systems was only 12.1% and 45.4%, respectively. The simultaneous incorporation of Co and Cu bimetallic oxides in CuCo@ZnO led to a higher surface hydroxyl density, and this surface hydroxyl density showed a linear relationship to their first order kinetic constant in 4-CP degradation. Moreover, the results of peroxymonosulfate (PMS) decomposition, quantification of sulfate radical (SO4−), EPR, XPS, H2-TPR, and CV indicated that the synergism of Cu/Co also arose from the electron transfer between Cu(I) and Co(III), which altered the redox circle of Co(II)/Co(III) and increased the steady concentration of oxidative radicals. Due to this synergism, the degradation percentage of organic contaminants, stability of heterogeneous catalysts and the stoichiometric efficiency of PMS were all improved. These findings were highly suggestive to the further development of bimetallic heterogeneous catalysts in persulfate based advanced oxidation processes.