CuInS2 Nanoparticles Research Articles

Thermal effect on the photoelectrochemical performance and interface charge transfer of CuInS2/TiO2 NTs photoelectrode

As a photothermal material, CuInS2 can effectively use the infrared spectrum to trigger the thermal effect and provide the required endothermic energy for the reaction. Here, CuInS2/TiO2 NTs composite photoanode was constructed, and the influence of thermal effect on its photoelectrochemical properties was systematically studied. It was found that CuInS2 nanoparticles could effectively convert light energy into heat energy, which led to the local temperature rise of CuInS2/TiO2 NTs under light irradiation. Furthermore, by regulating the ambient temperature from 20 ℃ to 60 ℃, the photocurrent density and photocurrent efficiency of CuInS2/TiO2 NTs increased significantly because the thermal effect could effectively inhibit the bulk recombination of photogenerated carriers and accelerate the charge transfer. The oxygen bubbles on the surface of CuInS2/TiO2 NTs photoanode had smaller diameter and showed faster desorption. Therefore, the thermal effect was conducive to charge transfer in the interfacial charge transfer kinetics of CuInS2/TiO2 NTs. It suggests that the introduction of thermal effect plays an auxiliary role in improving the photoelectrochemical reaction, and can provide a cheap and competitive method to effectively improve the photochemical performance of the photoanode.

An insight of light-enhanced electrochemical kinetic behaviors and interfacial charge transfer of CuInS2/MoS2-based sensing nanoplatform for ultra-sensitive detection of chloramphenicol

Owing to the effective combination between MoS2 sheets with CuInS2 nanoparticles (NPs), a direct Z-scheme heterojunction was successfully constructed and proved as a promising structure to modify the working electrode surface with the aim of enhancing overall sensing performance towards CAP detection. Herein, MoS2 was employed as a high mobility carrier transport channel with a strong photo-response, large specific surface area, and high in-plane electron mobility, while CuInS2 acted as an efficient light absorber. This not only offered a stable nanocomposite structure but also created impressive synergistic effects of high electron conductivity, large surface area, highlight exposure interface, as well as favorable electron transfer process. Moreover, the possible mechanism and hypothesis of the transfer pathway of photo-induced electron-hole pairs on the CuInS2–MoS2/SPE as well as their impacts on the redox reaction of K3/K4 probes and CAP were proposed and investigated in detail via a series of calculated kinetic parameters, demonstrating the high practical applicability of light-assisted electrodes. Indeed, the detection concentration range of the proposed electrode was widened from 0.1 to 50 μM, compared with that of 1–50 μM without irradiation. Also, the LOD and sensitivity values were calculated to be approximately 0.06 μM and 0.4623 μA μM−1, which is better than that of 0.3 μM and 0.095 μA μM−1 without irradiation.

Liposomes as nanoreactors for copper nanoparticles synthesis

Copper nanoparticles 3.8 –10.9 nm in size were synthesized in solid-phase membrane liposomes by a facile method of copper sulfate reduction with hydrazine. A change in the excess of hydrazine leads to the controlled formation of either Cu2O or Cu0 nanoparticles.

Well-dispersed Cu[sbnd]Fe doping nanoparticles with mixed valence in carbon aerogel as effective adsorbent for H2S removal at low temperature

In order to overcome the deficiencies of low adsorption capacity and poor tolerance to high space velocities of commercial adsorbents for H2S removal, core-shell structured Cu-Fe/carbon aerogels (CA) with mixed valence of Cu and Fe were synthesized. The doping of Cu decreased the average size of Fe nanoparticles and enhanced the dispersion of nanoparticles. In addition, parts of oxides were reduced to Cu0 and Fe0 by carbon shell during carbonization process, resulting in the coexistence of mixed valence CuFe doped nanoparticles in CA. The existence of Cu0 and Fe0 nanoparticles is the key contributor for excellent tolerance to high space velocities, where the H2S could be easily adsorbed and dissociated to form reactive intermediate such as HS− and S2−. The well dispersed CuFe doping oxides are the active sites for H2S capture, benefiting for the high H2S adsorption capacity. The adsorbed water can be dissociated to hydroxyl groups over iron oxide, which is more conducive to the removal of H2S. The H2S (200 ppm H2S in CH4) adsorption capacity of optimized adsorbent was 221.1 mg∙g−1 at 100% relative humidity. This study provided a new insight into the synthesis of Cu-based and Fe-based adsorbents for the removal of H2S.

Map of 20 reactions that take place during vapor–solid phase photocatalytic dehydrogenation of ethanol on metal‐loaded TiO2

AbstractWe report the map of 20 reactions that take place during vapor‐phase photochemical dehydrogenation of ethanol on four metal‐doped TiO2 (Mn/TiO2, Mn = nanoparticles of Pd, Pt, Au, and Cu) under solar simulated light. The reactions are sensitively affected by the moisture amount and the nature of the carrier gas. To construct the above map, we also used CH3CHO, CH3CO2H, (C2H5O)2CHCH3, and CH3CO2C2H5, respectively, as an independent starting reagent. Amazingly, Mn/TiO2 not only serves as photocatalysts but also as thermocatalysts for various reactions that appear in the above map. The reaction is proposed to proceed by a radical mechanism in which photoinduced electron transfer from the valence band to the conduction band of TiO2 is the initial step and the subsequent electron injection from organic reactants to the hole in the TiO2 valence band. This report also features highly valuable unprecedented reactions, which bear great potential to be commercialized.

Improved utilization of Cu0 for efficient adsorption of iodine in gas and solution by mesoporous Cu0-SBA-15 via solvothermal reduction method

Cu-based materials have been considered as good adsorbents for iodine adsorption. However, the development of Cu-based adsorbent with high Cu utilization remains a significant challenge. Herein, we report a new Cu0-SBA-15 adsorbent with high Cu utilization for high capacity adsorption of iodine in gas and solution. An improved solvothermal reduction strategy was proposed to fabricate Cu0-SBA-15 composite with high Cu utilization. The benefit of the strategy was that the Cu0 nanoparticles were confined on the surface or pore wall of mesoporous SBA-15, which improved the utilization of adsorption sites for iodine. The results demonstrated that the obtained Cu0-SBA-15 composite showed high adsorption capacities of 954 mg/g and 842 mg/g for iodine in gas and solution, respectively, and reached a record high Cu utilization of 96.93%. The obtained Cu0-SBA-15 composite showed high thermal stability. Furthermore, the iodine adsorption mechanism was that Cu0 reacted with I2 to form stable CuI. Owing to the excellent adsorption performance, the obtained Cu0-SBA-15 might be potential promising iodine adsorbent.

Cu-loaded MOF-303 for iodine adsorption: The roles of Cu species and pyrazole ligands

The capture of toxic radioiodine is an increasingly important priority for the safe development of nuclear energy. Copper is a promising alternative for expensive silver to capture iodine. To develop novel copper-based adsorbents and determine the effect of copper species on iodine adsorption, the metal–organic framework with dual-pyrazole ligands (MOF-303) is employed as the scaffold to bind Cu2+ species. Cu0 nanoparticles were formed after the reduction by NaBH4. The obtained Cu2+-MOF-303 and Cu0-MOF-303 show high iodine uptake capacities at 353 K, 747 mg·g−1 and 837 mg·g−1, respectively. They also show high iodine uptake capacities of more than 300 mg·g−1 at a high temperature (423 K), which are better than other Cu-based adsorbents. Besides, the loading of Cu can enhance the iodine selectivity under humid vapor, and iodine adsorption rate in iodine-cyclohexane solutions. The Cu0 on Cu0-MOF-303 can react with iodine directly via the redox mechanism. For Cu2+-MOF-303, the adjacent pyrazole ligands can chelate with Cu2+ ions strongly and transfer charges to trapped iodine to form polyiodide anions, and thus stable CuI species could also be generated. The strategy of anchoring Cu species using MOF-303 provides large channels for iodine diffusion, and highly-dispersed Cu and N sites for iodine capture.

Synergistic effect of cocatalyst and S-scheme heterojunction over 2D/2D g-C3N4/MoS2 heterostructure coupled Cu nanoparticles for selective photocatalytic CO2 reduction to CO under visible light irradiation

Step-scheme (S-scheme) configuration and cocatalyst are potential strategies for improving the photocatalytic activity of a nanoheterostructure. Herein, Cu nanoparticles (Cu-NPs) coupled 2D/2D van der Waals heterojunction (g-C3N4/MoS2) has been developed for CO2 reduction under visible light irradiation. Several analytical techniques were conducted to confirm the composition, morphology, and band configuration of the g-C3N4/MoS2/Cu heterostructure. XPS and EPR analyses confirm that the charge transfer during photocatalysis follows the S-scheme mechanism. 2D/2D morphology enables a large interfacial intimate contract, and Cu-NPs act as a cocatalyst, boosting catalytic activity, facilitating electron extraction, and tuning the product selectivity. As a result, the g-C3N4/MoS2/Cu heterostructure achieved efficient photocatalytic CO2 to CO reduction with a yield of 146.7 μmol g−1 h−1 and nearly 100 % selectivity. This paper presents a systematic structural development strategy for controlling the different types of heterointerfaces, as well as facilitating a deep understanding of the mechanism of multi-junction photocatalysts.

Pretreated Screen-Printed Carbon Electrode and Cu Nanoparticles for Creatinine Detection in Artificial Saliva

Creatinine is the final metabolic product of creatine in muscles and a widely accepted biomarker for chronic kidney disease. In this work, we present a non-enzymatic sensor based on an electrochemical pretreated screen-printed carbon electrode (PTSPCE) with electrodeposited Cu nanoparticles (CuNPs). To function in a PoC format, the prepared PTSPCE/CuNPs non-enzymatic sensors were used as disposable elements in a portable potentiostat. The pretreatment using mild anodic and cathodic potentials in PBS resulted in an increased electroactive surface area and improved conductivity, confirmed by cyclic voltammetry and electrochemical impedance. Moreover, the detection through the CuNPs–creatinine interaction showed an enhanced performance in the PTSPCE surface compared to the bare electrode. The optimized PTSPCE/CuNPs sensor showed a linear working range from 10 to 160 μM (R2 = 0.995), a sensitivity of 0.2582 μA·μM−1 and an LOD of 0.1 μM. The sensor analytical parameters covered the requirements of creatinine detection in biofluids such as blood and saliva, with a low interference of common biomarkers such as urea, glucose, and uric acid. When evaluated in Fusayama/Meyer artificial saliva, the PTSPCE/CuNPs showed an average recovery rate of 116%. According to the observed results, the non-enzymatic PTSPCE/CuNPs sensor can potentially operate as a creatinine early screening system in PoC format.

Alkaline Electro-Sorption of Hydrogen Onto Nanoparticles of Pt, Pd, Pt80Pd20 and Cu(OH)2 Obtained by Pulsed Laser Ablation.

Recently, hydrogen evolution reaction (HER) in alkaline media has received a renewed interest both in the fundamental research as well as in practical applications. Pulsed Laser Ablation in Liquid (PLAL) has been demonstrated as a very useful technique for the unconventional preparation of nanomaterials with amazing electro-catalyst properties toward HER, compared to those of nanomaterials prepared by conventional methods. In this paper, we compared the electro-sorption properties of hydrogen in alkaline media by Pt, Pd, Pt80Pd20, and Cu(OH)2 nanoparticles (NPs) prepared by PLAL. The NPs were placed onto graphene paper (GP). Noble metal particles have an almost spherical shape, whereas Cu(OH)2 presents a flower-bud-like shape, formed by very thin nanowalls. XPS analyses of Cu(OH)2 are compatible with a high co-ordination of Cu(II) centers by OH and H2O. A thin layer of perfluorosulfone ionomer placed onto the surface of nanoparticles (NPs) enhances their distribution on the surface of graphene paper (GP), thereby improving their electro-catalytic properties. The proposed mechanisms for hydrogen evolution reaction (HER) on noble metals and Cu(OH)2 are in line with the adsorption energies of H, OH, and H2O on the surfaces of Pt, Pd, and oxidized copper. A significant spillover mechanism was observed for the noble metals when supported by graphene paper. Cu(OH)2 prepared by PLAL shows a competitive efficiency toward HER that is attributed to its high hydrophilicity which, in turn, is due to the high co-ordination of Cu(II) centers in very thin Cu(OH)2 layers by OH- and H2O. We propose the formation of an intermediate complex with water which can reduce the barrier energy of water adsorption and dissociation.

Efficient and Stable Cu‐Cu2O@NC Catalysts for Selective Catalytic Conversion of Glycerol to Lactic Acid

AbstractDeveloping efficient Cu‐based catalysts for catalytic conversion of glycerol to lactic acid has attracted much attention because of the low cost and high activity. However, construction of efficient Cu‐based catalysts with high stability for aqueous reactions at high temperatures still remains a challenge. Herein, highly dispersed Cu0 and Cu2O nanoparticles encapsulated by N‐doped C (Cu‐Cu2O@NC) were constructed by calcination of Cu‐based MOF for the catalytic dehydrogenation of glycerol to lactic acid under N2 atmosphere. The Cu‐Cu2O@NC‐400 catalyst exhibited 100 % conversion of glycerol with 84.8 % selectivity to lactic acid at 220 °C for 90 min. The Cu‐Cu2O@NC‐400 catalyst could be reused for eight times with almost no loss in the catalytic activity. The Cu‐Cu2O@NC‐400 catalyst is stable in the harsh reaction conditions, for the aggregation of Cu nanoparticles is avoided due to the confinement effect. The Cu‐Cu2O@NC‐400 catalyst demonstrated high catalytic activity and superior reusability benefitting from the N‐doping and highly dispersed Cu nanoparticles embedded in N‐doped C. This work will pave the way for designing efficient catalysts with high stability for catalytic dehydrogenation of alcohols.

Biomass-derived photothermal carbon aerogel for efficient solar-driven seawater desalination

Solar-driven interface evaporation is an effective method to produce fresh water to alleviate the shortage of water resources. However, there are still challenges in preparing photothermal conversion materials with high evaporation rate, high photothermal conversion efficiency and low cost. Herein, a 3D carbon aerogel with excellent photothermal conversion performance was prepared by using environmental-friendly biomass materials as the matrix. The hydrophilic 3D photothermal carbon aerogel with low thermal conductivity was prepared by depositing polydopamine and loading Cu nanoparticles (CuNPs) on the surface of bacterial cellulose nanofibers. The deposition of PDA improved the mechanical properties and hydrophilicity of carbon aerogel, and the introduction of CuNPs further enhanced the photothermal conversion performance of carbon aerogel. Interestingly, the side temperature of 3D carbon aerogel was lower than the ambient temperature in the evaporation process, which could absorb energy from the environment and significantly improve the photothermal conversion efficiency, giving rise to the impressive water evaporation rate (2.07 kg·m−2·h−1) and photothermal conversion efficiency (115.36%) of 3D carbon aerogel under 1 sun. Moreover, the prepared 3D carbon aerogel had excellent purification effect on seawater, strong acid/alkali and dye solution, demonstrating its broad application prospect in the field of solar-driven seawater desalination.

Preparation of CuZn-Doped MgAl-Layered Double Hydroxide Catalysts through the Memory Effect of Hydrotalcite for Effective Hydrogenation of CO2 to Methanol

In this work, a synthesis procedure was developed to introduce transition metal ions into a MgAl-layered double hydroxide (MgAl-LDH, or hydrotalcite) by utilizing the unique “memory effect” property of calcined LDH. This technique allows our MgAl-LDH to retain its pristine flowerlike morphology, which prevents stacking of nanosheets and is fully accessible for reactants. Briefly, calcined MgAl-LDH (or MgAl-layered double oxide, MgAl-LDO) was submerged in dilute monometal or mixed transition metal nitrate solutions, allowing ion exchange of M2+ cations and the rehydration of MgAl-LDO back into LDH through the memory effect. The product was centrifuged and dried, allowing pre-selected transition metals (e.g., Cu, Zn, Ni, and Co) to occupy some of the octahedral sites of the LDH phase in which Mg2+ ions were previously located. A CuZn-doped MgAl-LDH was then carefully reduced under a hydrogen atmosphere, precipitating tiny Cu nanoparticles out of the reformed LDH nanosheets, and was subsequently used in a series of CO2 hydrogenation experiments. The bifunctional material, which comprises a CO2-sorbent LDH support with active metal cocatalysts, has achieved high specific activity per copper loading and high methanol selectivity, while maintaining a stable performance with over 70% methanol selectivity over 40 h at 280 °C. The excellent performance of this catalyst is attributed to the easily accessible active sites (Cu0 nanoparticles) located on the surface of nanostructured petals for the gaseous reactants. The performance was found to be remarkably better than that of a well-established commercial Cu-based catalyst for methanol synthesis. Future potential development could entail the functionalization of other transition metals for the utilization of CO2.

Influences of radiative heat transfer on hydromagnetic hybrid nanofluid flow through two rotating surfaces

This study explores the growth of heat transfer rate for hybrid nanofluid-flow through two rotary plates fixed parallel. For improvement of thermal conductivity nanoparticles of Cu and graphene oxide have dispersed in water. The fluid-flow has been influenced by thermal radiation. Magnetic effects with strength, B0, has employed in the normal direction the plates. The set of equations that controlled the fluid-flow system have been shifted to dimension-free form employing suitable variables. The resultant set of equations has been solved by HAM. It has revealed in this work that with upsurge in the values of magnetic and rotational factors the linear velocity retarded while micro-rotational velocity upsurge. Intensification in volumetric fractions of nanoparticles results in retardation of fluid motion in all directions and growth in thermal flow profiles. Thermal flow profiles are also sup?ported by the augmenting values of radiation factor. It has further revealed that hybrid nanofluid has a better flow performance in contrast of traditional nanofluid.

Copper hydroxide/basic copper salt derived Cu0 with a clear grain boundary for selective electrocatalytic CO2 reduction to produce multicarbon products

Cu(OH)2/basic copper salt compounds are in situ reduced to Cu0 nanoparticles with clear grain boundaries during the electrocatalytic CO2 reduction process, which endows the derived Cu electrocatalyst with high selectivity towards C2+ products.

A Nitrogen‐Doped Porous Carbon Supported Copper Catalyst from a Scalable One‐Step Method for Efficient Carbon Dioxide Electroreduction

AbstractIn this work, a scalable one‐step glucose blowing method has been used to prepare a porous N‐doped carbon supported Cu nanoparticles (Cu‐NC) composite catalyst for CO2 electroreduction. This Cu‐NC catalyst demonstrates efficient catalytic activity for CO2‐to‐C1 product (CO and formate) conversion, with a high efficiency of 69 % at an overpotential of 590 mV. The excellent catalytic activity is correlated to the structure of this composite and the N‐species (pyridinic and graphitic nitrogen) in the carbonaceous matrix that may promote the CO2 adsorption and subsequent formation of reduction reaction intermediates and products.

Enzyme-free and wide-range portable colorimetric sensing system for uric acid and hydrogen peroxide based on copper nanoparticles

Uric acid (UA) is the final product of purine metabolism. A high concentration of UA in body fluid may lead to kidney stones, gout, and some cardiovascular diseases. Therefore, the non-invasive daily monitoring of UA is of great significance for both hyperuricemia patients and fit people. However, most of the current detection methods for UA are enzyme-dependent which limits the application scenarios and lacks portable instruments for on-site detection, including optics and electrochemistry. In this work, an enzyme-free and wide-range colorimetric sensor for UA and H2O2 detection was developed based on a mercaptosuccinic acid (MSA)-modified Cu nanoparticles (CuNPs). Under the action of UA or H2O2, with the cleavage of MSAs on the CuNPs surface, small Cu particles are further aggregated into larger particles with a lightning violet color. With the employment of the multi-channel handheld automatic photometer (MHAP), the concentration of UA and H2O2 can be determined on-site according to the absorbance measurement by the photodiodes. The linear range of UA was 5 μM-4.5 mM with the limit of detection (LOD) of 3.7 μM, while the linear range of H2O2 was 5 mM–500 mM and 5 μM-5 mM with the LOD of 4.3 μM. This approach has been applied to the detection of UA in human urine, providing more possibilities for non-invasive home health monitoring, community medical diagnosis, and broader prospects of on-site disease detection.

Remediation of Diesel-contaminated soil using zero-valent nano-nickel and zero-valent nano copper particles-stabilized Tween 80 surfactant foam

This paper uniquely reports the remediation of diesel-contaminated desert soil by aqueous Tween 80 (TW80) surfactant foams stabilized by zero–valent nickel (Ni0) and zero–valent copper (Cu0) nanoparticles (NPs). The sizes of synthesized nanoparticles, ∼21 nm (Cu0), ∼20 nm (Ni0), are determined by XRD and FE-SEM. The impact of these NPs (1 mg, 2 mg concentrations) on foaming characteristics, remediation of diesel-contaminated soils is explored at 2 vol% TW80 surfactant concentration. With 2 mg concentration of Ni0, Cu0 NPs and 2 vol% TW80 surfactant, it is found that 98.73 and 99.38 % diesel contaminants are removed.

Numerical Investigation on Thermal Performance of Duplex Nanocoolant Jets in Drilling of Ti-6Al-4V Alloy

In the current industry, coolants are widely used in numerous operations for the purpose of cooling and heat transfer. These operations include all kinds of heat sinks for electronic devices and manufacturing processes such as milling, drilling, turning, and CNC machining. The thermophysical properties of coolants play a vital role in determining the effectiveness of heat transfer and help prevent the components from wear and tear caused by extremely high temperatures. The computational domain consists of a drill bit and rectangular workpiece, and hybrid nanocoolants are sprayed from duplex nozzles. The nanocoolant heat transfer and flow characteristics of the drill bit–workpiece interface were analysed using the large eddy simulation (LES) turbulence model. The workpiece is made of Ti-6Al-4V alloy maintained at a temperature of 1073.15 K. The coolant used is a mineral oil into which different nanoparticles of Al2O3, TiO2, Cu, MWCNT, and SWCNT are dispersed by varying the volume concentration. The variations in temperature, Nusselt number, and wall heat transfer coefficient, with respect to the volume fraction of nanoparticles and the Reynolds number, were investigated. It was concluded that Cu–Al2O3 nanoparticles dispersed in mineral oil depicted the most favourable heat transfer.

Green and facile synthesis of heterojunction nanocatalyst: Insights and mechanism of antibiotics removal

Detecting of antibiotics in the aquatic environment is a serious health concern due to the development of antibiotic-resistant genes in humans and marine life. The current investigation aims to synthesize highly efficient heterojunction bimetallic nanocatalyst (Cu0 + Ag0)@Bentonite in a facile and ‘greener’ route. In situ, the phytochemicals of P. guajava leaves synthesize the Cu0 and Ag0 nanoparticles onto the bentonite support media. The advanced analytical methods characterize the nanomaterials extensively. The potential antibiotics (amoxicillin and sulfamethazine) are treated in photo-Fenton-like processes utilizing the UV-A and LED (Visible) light sources. The bimetallic (Cu0 + Ag0)@Bentonite exhibited a synergized in the photo-induced degradation of amoxicillin and sulfamethazine. The effect of pH, initial pollutant concentrations, and the presence of interfering ions optimize the removal efficiency and demonstrate insights into the reaction mechanism. The photo-Fenton-like degradation of AMX and SMZ was found to be 84 % and 74 %, respectively, under the UV-A illumination employing (Cu0 + Ag0)@Bentonite nanocatalyst. Similarly, the process mineralizes a significant amount of these pollutants, i.e., 66 % and 62 % of SMX and SMZ, respectively, using UV-A irradiation., enhancing the applicability of the catalyst. The nanocatalyst showed greater stability in the reactor operations, and Cu(II) leaches very minimally extent in the reaction pathways. The real water implications inferred the potential of novel nanocatalysts in scaling up the process for the decontamination of water contaminated with amoxicillin and sulfamethazine.