Cuprous Oxide Research Articles

Catalysis of cupric and cuprous oxides in copper pipes on the diatrizoate transformation with peroxymonosulfate as a disinfectant

Cupric and cuprous oxides (CuO and Cu2O) are the main corrosion products of copper pipes; peroxymonosulfate (PMS) is a good drinking water disinfectant; micropollutants are ubiquitous in the factory waters. Corrosion products influence the micropollutant transformation under the action of disinfectants. This study compared the conversion of diatrizoate (DTZ) with PMS as a disinfectant under the catalysis of CuO (Cu(II)PS) and Cu2O (Cu(I)PS). The pseudo-first-order constant (kobs) for the DTZ degradation in the Cu(II)PS was 11.8 times that in the Cu(I)PS, with values of 0.092 and 0.0078 min−1, respectively. SO4− and HO played dominant roles in the Cu(II)PS, while O2− and 1O2 were the primary contributors in the Cu(I)PS. The yield ratio of reactive species were 92.8% and 69.6% in the Cu(II)PS and Cu(I)PS, respectively. The DTZ degradation was promoted by the increase of CuO dose, while inhibited by the increase of Cu2O dose (0.1–1.0 g L−1). In both Cu(II)PS and Cu(I)PS, the DTZ degradation was enhanced by the increasing PMS dose (10–100 mg L−1) and neutral pH (7.0), whereas weakened by water matrix (NOM, HCO3− and Cl−). The total organic iodine was mainly converted to IO3− with a ratio of 45.3 and 7.4% in the Cu(II)PS and Cu(I)PS, respectively. In the Cu(II)PS, the DTZ transformation was mainly through the amide hydrolysis followed by amino oxidation and stepwise deiodination followed by hydroxyl addition. However, hydroxyl addition is not thought to occur in the Cu(I)PS since the related intermediates have not been identified. The study helps to comprehensively understand the conversion of iodine-containing micropollutants in copper pipes when PMS is a disinfectant.

Facile, cost-effective, large-scale, reliable, and efficient fabrication of CuO as a potential catalyst for organic dyes removal from water

In recent decades, copper (II) oxide, also called cupric oxide (CuO) catalyst has shown promising results for decomposing organic water contaminants. This work aimed to optimize the different parameters linked with the fabrication of cupric oxide (CuO) to become feasible for industrial and commercial applications, meeting the technology-based treatment standards. The effects of calcination temperatures (CTs) and cooling rates (CRs) on the crystallographic properties were thoroughly studied employing Rietveld refinement and Statistical analysis. The phases are CuO > Cu2O > Cuo, with crystallite sizes <80 nm. The optimum conditions are 450 °C and air quench, yielding 98.5% cupric oxide [CuO] (54 nm) and 1.3% copper (I) oxide, also called cuprous oxide (Cu2O). The particle size distribution was found to follow the normal distribution at CT of 600 °C, indicating the maturity of the crystal system. The textural analysis exhibited Type-II adsorption. The preliminary catalytic activity results revealed high activity and room for enhancing process kinetics at mild conditions.

An Electrochemical Sensor Based on a Porous Biochar/Cuprous Oxide (BC/Cu2O) Composite for the Determination of Hg(II).

Mercuric ion (Hg2+) in aqueous media is extremely toxic to the environment and organisms. Therefore, the ultra-trace electrochemical determination of Hg2+ in the environment is of critical importance. In this work, a new electrochemical Hg2+ sensing platform based on porous activated carbon (BC/Cu2O) modified with cuprous oxide was developed using a simple impregnation pyrolysis method. Differential pulse anodic stripping voltammetry (DPASV) was used to investigate the sensing capability of the BC/Cu2O electrode towards Hg2+. Due to the excellent conductivity and large specific surface area of BC, and the excellent catalytic activity of Cu2O nanoparticles, the prepared BC/Cu2O electrode exhibited excellent electrochemical activity. The high sensitivity of the proposed system resulted in a low detection limit of 0.3 ng·L-1 and a wide linear response in the ranges from 1.0 ng·L-1 to 1.0 mg·L-1. In addition, this sensor was found to have good accuracy, acceptable precision, and reproducibility. All of these results show that the BC/Cu2O composite is a promising material for Hg2+ electrochemical detection.

A chemiresistive ppt level NO2 gas sensor based on CeO2 nanoparticles modified CuO nanosheets operated at 100 °C

Inducing chemisorbed oxygen and constructing heterostructures are important strategies for improving sensors performance. Therefore, we prepared cupric oxide (CuO) composite modified by cerium dioxide (CeO2) via a low-cost hydrothermal method and calcination technology. The material was analyzed using scanning electron microscopy (SEM), transmission electron microscopy (TEM), and X-ray powder diffraction (XRD) techniques, confirming the composition of the sensing material and analyzing the morphology. Afterward, different morphology-sensing materials are characterized using Brunauer‐Emmett‐Teller (BET), and the influence of the specific surface area of different morphologies of the sensing material on the sensing characteristics was explored. During gas sensing tests, the response of the optimal sample to 50 parts per million (ppm) nitrogen dioxide (NO2) gas is 9.59. Meanwhile, the detection limit is 600 parts per trillion (ppt), and the response and recovery times are 15 s and 110 s, respectively. Additionally, we test the selectivity, responses under different relative humidity levels, and long-term stability (30 days) of the optimal sample. Therefore, the sensor has great prospects in applications such as real-time detection and trace monitoring. Eventually, according to the structure, composition, and morphology of the material, we proposed a sensing mechanism for enhancing the sensing characteristics of NO2 gas sensor.

Heat management of LED-based Cu2O deposits on the optimal structure of heat sink

Abstract This report investigates the thermal performance of light-emitting diodes (LEDs) using a heat sink structure based on an optimized design and a sprayed cuprous oxide (Cu2O) coating. An orthogonal array of 18 aluminum plates with various heat-dissipated structures was created. The optimal junction temperature of the LED package is determined by using the signal-to-noise ratio (S/N) of the heat-dissipated structure based on Taguchi’s method as well as the heat dissipation coating. According to the analysis of variance, the most important factors that influence the junction temperature can be obtained as the depth of groove, the layout of holes, the layout of LEDs, and the number of Cu block. These significant factors constituted approximately 91.06% of the variation in the experiment. The results show that by optimizing the structure of the LED heat sink based on the heat-dissipated coating, the efficiency of the junction temperature is increased by 23.88%. Also, a gain of 1.30 dB corresponds to a 9.67% reduction in variance, which indicates the improvement through the optimal setting by 1.162 times of variance, showing good reproducibility. Overall, the coating is based on the optimized design of the structure of the heat sink that has good heat transfer capability, which can provide a good solution to the heat-dissipated problem of LED and further give guidance to the future development of LED.

Understanding the role of oxygen-vacancy defects in Cu2O(111) from first-principle calculations

The presence of defects, such as copper and oxygen vacancies, in cuprous oxide films determines their characteristic carrier conductivity and consequently their application as semiconducting systems. There are still open questions on the induced electronic re-distribution, including the formation of polarons. Indeed, to accurately reproduce the structural and electronic properties at the cuprous oxide surface, very large slab models and theoretical approaches that go beyond the standard generalized gradient corrected density functional theory are needed. In this work we investigate oxygen vacancies formed in proximity of a reconstructed Cu2O(111) surface, where the outermost unsaturated copper atoms are removed, thus forming non-stoichiometric surface layers with copper vacancies. We address simultaneously surface and bulk properties by modelling a thick and symmetric slab, to find that hybrid exchange-correlation functionals are needed to describe the oxygen vacancy in this system. Our simulations show that the formation of oxygen vacancies is favoured in the sub-surface layer. Moreover, the oxygen vacancy leads to a splitting and left-shift of the shallow hole states in the gap, which are associated with the deficiency of copper at the surface. These findings suggest that surface electronic structure and reactivity are sensitive to the presence of oxygen vacancies, also when the latter are formed deeper within the film.

Emulating Synaptic and Nociceptive Behavior via Negative Photoconductivity of a Memristor

In comparison to electrical memristive synapses, photoelectric synapses have the capability for ultrafast computing with less power consumption. In this work, a photoelectric synaptic memristor (PSM) based on Zn <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$_{{\text{2}}}$</tex-math> </inline-formula> SnO <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$_{{\text{4}}}$</tex-math> </inline-formula> (ZSO)/cuprous oxide (Cu <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$_{{\text{2}}}$</tex-math> </inline-formula> O) heterostructure is fabricated. This two-terminal PSM device with a simple structure exhibits primary synaptic functions such as long-term potentiation (LTP)/long-term depression (LTD), and spike-timing-dependent plasticity (STDP) by electrical stimulation. Under the exposure of violet light, the observed negative persistent photoconductivity (NPPC) of our PSM is associated with inhibitory synaptic plasticity, which leads to synaptic performances such as short to long-term memory (STM-LTM) transition, learning experience behavior, and a transition from post-tetanic potentiation (PTP) to post-tetanic depression (PTD). Furthermore, this PSM mimics the five essential features of a nociceptive receptor (nociceptor) like threshold, relaxation, no-adaptation, hyperalgesia, and allodynia in response to violet light pulse-induced NPPC phenomenon. These results provide a new path to propel the development of neuro-inspired perceptual systems.

In situ-activated photothermal nanoplatform for on-demand NO gas delivery and enhanced colorectal cancer treatment

The naturally evolved and intestinal pathogenic Fusobacterium nucleatum (Fn)-induced drug resistance profoundly impaired the efficacy of chemotherapy against colorectal cancer (CRC). Alternative treatment modalities against Fn-associated CRC are desperately needed. Herein, we engineer an in situ-activated anti-tumor and antibacterial nanoplatform (Cu2O/BNN6@MSN-Dex) to allow photoacoustic (PA) imaging-guided photothermal and NO gas combinatorial therapy for enhanced Fn-associated CRC treatment. The nanoplatform is constructed by loading cuprous oxide (Cu2O) and nitric oxide (NO) donor (BNN6) into dextran-decorated mesoporous silica nanoparticles (MSN), which is finally surface-functionalized with dextran via dynamic boronate linkage. Cu2O can be sulfuretted in situ by endogenous hydrogen sulfide overexpressed in CRC to produce copper sulfide with remarkable PA and photothermal properties, enabling the generation of NO from BNN6 under 808nm laser irradiation, which is eventually triggered to release by multiple biological cues in the tumor microenvironment. Cu2O/BNN6@MSN-Dex exhibits superior biocompatibility, as well as H2S-triggered near-infrared-controlled antibacterial and anti-tumor performance in vitro and in vivo via photothermal and NO gas combination therapy. Furthermore, Cu2O/BNN6@MSN-Dex provokes systemic immune responses, thereby promoting anti-tumor efficacy. This study provides a conbinational strategy to effectively inhibit tumors and intratumor pathogens for enhanced CRC treatment.

Efficiency boost of inverted polymer solar cells using electrodeposited n-type Cu&lt;sub&gt;2&lt;/sub&gt;O electrons selective transport layers (ESTLs)

Polymer solar cells (PSCs) have attracted tremendous interest as suitable candidates for harnessing solar energy in the recent years. The inherent optoelectronic properties of the inorganic transition metal oxide, negative type cuprous oxide (n-Cu2O), makes it an attractive candidate to improve the performance of PSCs when incorporated as the electron selective transport layers (ESTLs) in the device. In this study, inverted PSCs were fabricated on stainless steel (SS) substrates with n-Cu2O as the ESTL. The n-Cu2O films were prepared by electrodeposition method, followed by annealing under ambient conditions. The active layer material was prepared as bulk heterojunction blend using regioregular poly(3-hexylthiophene) (P3HT) and phenyl-C61-butyric acid methyl ester (PCBM). Poly-(4,3-ethylene dioxythiophene):poly(styrenesulphonate) (PEDOT:PSS) was used as the hole transport layer (HTL) and the final device structure was SS/n-Cu2O/P3HT:PCBM/PEDOT:PSS/Au. Annealing of the n-Cu2O ESTL in air was optimized observing the photoactive performance of the device. Optoelectronic performance of the devices was characterized using spectral response and dark and light current-voltage (I-V) measurements. n-Cu2O ESTL- incorporated devices have absorbed more photons in the short wavelength region of 450‒600 nm with the annealing of n-Cu2O ESTL due to the reduction of electron-hole recombination. The performance of the devices was significantly increased after incorporating pre-annealed n-Cu2O ESTL at 175 °C for 30 min in air. The maximum power conversion efficiency (PCE) was 0.35%.

SERS-Active Silver Nanoprisms Deposited on Cuprous Oxide Microspheres for Detection of Nitrofurazone

SERS-Active Silver Nanoprisms Deposited on Cuprous Oxide Microspheres for Detection of Nitrofurazone

Experimental Revelation of Surface and Bulk Lattices in Faceted Cu2 O Crystals.

Semiconductor crystals have generally shown facet-dependent electrical, photocatalytic, and optical properties. These phenomena have been proposed to result from the presence of a surface layer with bond-level deviations. To provide experimental evidence of this structural feature, synchrotron X-ray sources areused to obtain X-ray diffraction (XRD) patterns of polyhedral cuprous oxide crystals. Cu2 O rhombic dodecahedra display two distinct cell constants from peak splitting. Peak disappearance during slow Cu2 O reduction to Cu with ammonia borane differentiates bulk and surface layer lattices. Cubes and octahedra also show two peak components, while diffraction peaks of cuboctahedra are comprised of three components. Temperature-varying lattice changes in the bulk and surface regions also show shape dependence. From transmission electron microscopy (TEM) images, slight plane spacing deviations in surface and inner crystal regions are measured. Image processing provides visualization of the surface layer with depths of about 1.5-4nm giving dashed lattice points instead of dots from atomic position deviations. Close TEM examination reveals considerable variation in lattice spot size and shape for different particle morphologies, explaining why facet-dependent properties are emerged. Raman spectrum reflects the large bulk and surface lattice difference in rhombic dodecahedra. Surface lattice difference can change the particle bandgap.

Synergistic antibacterial study of nano-Cu2O/CuO@Ag-tetracycline composites

The rapid increase in drug resistance has not reduced the antibacterial activity of most antibacterial drugs but also brought great challenges to society. Therefore, there is an urgent need to develop new antibacterial agents. In this study, copper nitrate trihydrate [Cu(NO3)2·3H2O] was used as a raw material and hydrazine hydrate as a reducing agent to prepare cuprous oxide (Cu2O/CuO). Next, silver nitrate (AgNO3) was added and monomeric silver was loaded on the surface of Cu2O by in situ reduction to obtain Cu2O/CuO@Ag composites. Lastly, nano-Cu2O/CuO@Ag-tetracycline composites were obtained by combining them with tetracycline. Systematic characterization of inhibitors was conducted using transmission electron microscopy (TEM), energy dispersive spectrometry (EDS), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Fourier-transform infrared spectroscopy (FT-IR), and ultraviolet–visible spectroscopy (UV–vis). The inhibitory properties and mechanism of Cu2O/CuO@Ag-tetracycline on the Gram-positive bacterium Staphylococcus aureus (S. aureus), Gram-negative bacterium Escherichia coli (E. coli), and drug-resistant bacterium Salmonella (T-Salmonella) were studied. The inhibition performance study showed that the inhibition rate of Cu2O@CuO@Ag-tetracycline was almost 99.99% against the three tested bacteria at 40 min when used at a concentration of 150 μg/mL. Compared with tetracycline and Cu2O/CuO alone, Cu2O/CuO-tetracycline composites have several times higher antibacterial efficiency against E. coli, S. aureus and T-Salmonella. Moreover, the nano-Cu2O/CuO@Ag-tetracycline composites were most sensitive to E. coli. The inhibition mechanism revealed that the nanocomposites could effectively destroy the cell wall of Gram-negative bacteria, enter the cell interior, inhibit cell respiration, and eventually lead to bacterial rupture and death. The nano-Cu2O/CuO@Ag-tetracycline composites exhibited excellent antibacterial properties, indicating their wide application prospects in the fields of medical devices and medical materials.

Biogenic production of silver, zinc oxide, and cuprous oxide nanoparticles, and their impregnation into textiles with antiviral activity against SARS-CoV-2

Nanotechnology is being used to fight off infections caused by viruses, and one of the most outstanding nanotechnological uses is the design of protective barriers made of textiles functionalized with antimicrobial agents, with the challenge of combating the SARS-CoV-2 virus, the causal agent of COVID-19. This research is framed within two fundamental aspects: the first one is linked to the proposal of new methods of biogenic synthesis of silver, cuprous oxide, and zinc oxide nanoparticles using organic extracts as reducing agents. The second one is the application of nanomaterials in the impregnation (functionalization) of textiles based on methods called "in situ" (within the synthesis), and "post-synthesis" (after the synthesis), with subsequent evaluation of their effectiveness in reducing the viral load of SARS-CoV-2. The results show that stable, monodisperse nanoparticles with defined geometry can be obtained. Likewise, the "in situ" impregnation method emerges as the best way to adhere nanoparticles. The results of viral load reduction show that 'in situ' textiles with Cu2O NP achieved a 99.79% load reduction of the SARS-CoV-2 virus.

Minimization of carrier recombination in La2NiMnO6 double perovskite solar cells by optimizing defects and band offsets

In the present work, an extensive study has been carried out on the parameters that govern the non-radiative recombination losses associated with the absorber double perovskite material. Four different device configurations have been proposed by incorporating different electron transport layers (ETL) namely tungsten disulfide (WS2), tungsten trioxide (WO3), zinc selenide (ZnSe), and strontium titanate (STO) with La2NiMnO6 (LNMO) double perovskite material as an active layer and cuprous oxide (Cu2O) as a hole transport layer (HTL). In this investigation, the role of band offsets in the collection, transportation, and recombination of charge carriers has been examined in detail. Further, the impact of thickness and the defect positions i.e. shallow defects and deep defects on the photovoltaic (PV) parameters of the cells has been thoroughly elucidated. The ideal barrier height between HTL and back contact (C, Ni, Ag, and Au) at various valence band maximum (VBM) levels has also been investigated for the proper collection of charge carriers. Interestingly, the results of the present simulation reveal that the WS2-based device with configuration FTO/WS2/LNMO/Cu2O/Au shows the highest PCE of 24.08% after optimization. The findings and interpretation of this work demonstrate that La2NiMnO6 an eco-friendly and non-toxic material can be used to produce high-efficiency perovskite devices.

Advanced electrocatalytic materials based biosensors for cancer cell detection – A review

AbstractHerein, we have highlighted the latest developments on biosensors for cancer cell detection. Electrochemical (EC) biosensors offer several advantages such as high sensitivity, selectivity, rapid analysis, portability, low‐cost, etc. Generally, biosensors could be classified into other basic categories such as immunosensors, aptasensors, cytosensors, electrochemiluminescence (ECL), and photo‐electrochemical (PEC) sensors. The significance of the EC biosensors is that they could detect several biomolecules in human body including cholesterol, glucose, lactate, uric acid, DNA, blood ketones, hemoglobin, and others. Recently, various EC biosensors have been developed by using electrocatalytic materials such as silver sulfide (Ag2S), black phosphene (BPene), hexagonal carbon nitrogen tube (HCNT), carbon dots (CDs)/cobalt oxy‐hydroxide (CoOOH), cuprous oxide (Cu2O), polymer dots (PDs), manganese oxide (MnO2), graphene derivatives, and gold nanoparticles (Au‐NPs). In some cases, these newly developed biosensors could be able to detect cancer cells with a limit of detection (LOD) of 1 cell/mL. In addition, many remaining challenges have to be addressed and validated by testing more real samples and confirm that these EC biosensors are more accurate and reliable to measure cancer cells in the blood and salivary samples.

Comparative analysis of the substitutional and interstitial Li-, Na-doped, and Li∖Na-Codoped Cu2O via density functional calculations

A comprehensive comparative study utilizing HSE06 and GGA density functional calculations was conducted to investigate the impact of Li and Na doping, as well as their co-doping, on the physical properties of cuprous oxide (Cu2O). This study examined three possible structures, including substitution of Li, Na, and Li/Na for Cu, and interstitial Li, Na, and Li/Na in both tetrahedral and octahedral sites. The results of the study revealed that the introduction of alkaline atoms leads to structural changes in Cu2O, and the degree of lattice parameter extension or compression varies across different doping sites. Additionally, the study provided an estimation of the enthalpies of formation for pure and doped-Cu2O, which is useful in understanding the stability of the systems. Notably, the study found that Li, Na, and Li/Na-doped-Cu2O were more readily formed in substitutional sites rather than in interstitial sites. The findings also indicate that substitutional doping and co-doping exhibit a large band gap while maintaining the properties of a p-type semiconductor, while interstitial doping and co-doping of Cu2O led to significant absorption enhancement and n-type conductivity characteristics. These results provide new insights into the structural and electronic properties of Cu2O, with the findings suggesting that interstitial doping of Li and Na could be a promising approach for improving the absorption of visible light in Cu2O-based solar cells, thus contributing to the development of more efficient and cost-effective photovoltaic devices.

Cuprous oxide core-shell heterostructure facilely encapsulated by cadmium metal organic frameworks for enhanced photocatalytic hydrogen generation

Light absorption and separation of photo-generated electrons and holes are important to photocatalytic hydrogen evolution of a photocatalyst. Herein, a special metal organic framework (MOFs) was fabricated by encapsulating of 2-methylimidazole and cadmium nitrate on the silica coated cuprous oxide (Cu2O/SiO2/CdIF). The structure, morphology, composition, and valence state of the obtained materials were analyzed. It was demonstrated that the core-shell Cu2O/SiO2/CdIF heterostructure was achieved. Also, the photocatalytic activity and stability of H2 generation over the Cu2O/SiO2/CdIF nanocomposite were investigated. Interestingly, the Cu2O/SiO2/CdIF nanocomposite exhibited high activity which was hardly changed after five recycles. By means of Raman spectra, solid diffuse reflection UV–vis spectra, photoelectric response, and interfacial resistance, it was shown that higher light absorption, efficient charge separation and strong synergistic effect among the components in the heterostructure were responsible to the enhanced performance in the Cu2O/SiO2/CdIF nanocomposite.

Biocidal activity of multifunctional cuprite-doped anion exchanger – Influence of bacteria type and medium composition

The study presents unconventional, bifunctional, heterogeneous antimicrobial agents – Cu2O-loaded anion exchangers. The synergetic effect of a cuprous oxide deposit and polymeric support with trimethyl ammonium groups was studied against the reference strains of Enterococcus faecalis ATCC 29212 and Pseudomonas aeruginosa ATCC 27853. Biological testing (minimum bactericidal concentration, MBC), time- and dose-dependent bactericidal effect (under different conditions – medium composition and static/dynamic culture) demonstrated promising antimicrobial activity and confirmed its multimode character. The standard values of MBC, for all studied hybrid polymers and bacteria, were similar (64–128 mg/mL). However, depending on the medium conditions, due to the copper release into the bulk solution, bacteria were actively killed even at much lower doses of the hybrid polymer (25 mg/mL) and low Cu(II) concentrations in solution (0.01 mg/L). Simultaneously, confocal microscopic studies confirmed the effective inhibition of bacterial adhesion and biofilm formation on their surface. The studies conducted under different conditions showed also the influence of the structure and physical properties of studied materials on the biocidal efficacy and an antimicrobial action mechanism was proposed that could be significantly affected by electrostatic interactions and copper release to the solution. Although the antibacterial activity was also dependent on various strategies of bacterial cell resistance to heavy metals present in the aqueous medium, the studied hybrid polymers are versatile and efficient biocidal agents against bacteria of both types, Gram-positive and Gram-negative. Therefore, they can be a convenient alternative for point-of-use water disinfection systems providing water quality in medical devices such as dental units, spa equipment, and aesthetic devices used in the cosmetic sector.

Enhancing Biocidal Capability in Cuprite Coatings.

The SARS-CoV-2 global pandemic has reinvigorated interest in the creation and widespread deployment of durable, cost-effective, and environmentally benign antipathogenic coatings for high-touch public surfaces. While the contact-kill capability and mechanism of metallic copper and its alloys are well established, the biocidal activity of the refractory oxide forms remains poorly understood. In this study, commercial cuprous oxide (Cu2O, cuprite) powder was rapidly nanostructured using high-energy cryomechanical processing. Coatings made from these processed powders demonstrated a passive "contact-kill" response to Escherichia coli (E. coli) bacteria that was 4× (400%) faster than coatings made from unprocessed powder. No viable bacteria (>99.999% (5-log10) reduction) were detected in bioassays performed after two hours of exposure of E. coli to coatings of processed cuprous oxide, while a greater than 99% bacterial reduction was achieved within 30 min of exposure. Further, these coatings were hydrophobic and no external energy input was required to activate their contact-kill capability. The upregulated antibacterial response of the processed powders is positively correlated with extensive induced crystallographic disorder and microstrain in the Cu2O lattice accompanied by color changes that are consistent with an increased semiconducting bandgap energy. It is deduced that cryomilling creates well-crystallized nanoscale regions enmeshed within the highly lattice-defective particle matrix. Increasing the relative proportion of lattice-defective cuprous oxide exposed to the environment at the coating surface is anticipated to further enhance the antipathogenic capability of this abundant, inexpensive, robust, and easily handled material for wider application in contact-kill surfaces.

Controllable morphology engineering of Cu2O nanoparticles for non-enzymatic glucose sensing

The controllable morphology engineering of active electrode materials is an effective strategy to obtain high performance non-enzymatic glucose sensing. Herein, different morphologic cuprous oxide (Cu2O nanospheres, nanocubes and microcubes) were controllably prepared by wet-chemistry precipitation technique through adjusting the OH– concentration. The growth and evolution mechanism of Cu2O at different OH– concentrations were extensively studied. Electrochemical testing revealed that Cu2O nanospheres had the highest sensitivity of 1438 μA mM−1 cm−2 and the lowest detection limit of 0.17 μM (S/N = 3), making them the best choice for glucose sensing. Additionally, the glucose detection range spanned two orders of concentration magnitude (0.5 μM ∼ 1.332 mM and 1.332 mM ∼ 3.832 mM), and the sensor displayed excellent anti-interference ability, reproducibility, and long-term stability. The electrode material also performed well in detecting glucose in real serum samples, indicating its practical applicability as a non-enzymatic sensor.