CuO Phase Research Articles

The development and application of Cu@TiO2@SAPO-34 as better photocatalyst towards degradation of various pollutants

The study developed a novel Cu@TiO2@SAPO-34 nanocomposite for photocatalytic mortification of organic pollutants using modified hydrothermal synthesis. The material was characterized using XRD, BET, XPS, SEM, TEM, UV–vis, and Photoluminescence spectroscopy, confirming high pollutant absorption and photocatalytic capability. The structural analysis identified the emergence of monoclinic CuO and pure anatase phase TiO2, with ligands matching the formation of SAPO-34 at various planes of 2theta degrees. Also, species of Cu-SAPO-34 (35.43 and 65.88°) and TiO2-SAPO-34 (25.56°) were identified. The BET analysis indicated a narrow pore size distribution of 5.59 nm for Cu@TiO2@SAPO-34, with a high surface area to volume ratio of 145.7868 m2. g−1. The optical property analysis revealed that TiO2 exhibited light absorption mainly in the visible region, while Cu@TiO2@SAPO-34 exhibited early adsorption in the ultraviolet region and extended to the visible regions. This was accompanied by a concomitant decrease in band gap energy from 3.09 eV for TiO2 to 2.61 eV for Cu@TiO2@SAPO-34. The Photodegradation experiment demonstrated that TiO2 nanoparticles achieved 83 % degradation of methylene blue (MB) dye solution after 120 minutes under ultraviolet irradiation, while the Cu@TiO2@SAPO-34 composite achieved 98 % within 30 minutes. The novel nanocomposite material was further tested for real wastewater treatment, self-cleaning of the coated film, and nature of wettability, which all confirmed that the novel Cu@TiO2@SAPO-34 composite is superhydrophilic and a better photocatalyst for degrading organic contaminants. The study details the Photodegradation reaction mechanism for the Cu@TiO2@SAPO-34 nanocomposite, comparing it to TiO2 under UV–vis irradiation, and proposes a chabazite-related structure using Biovia Materials Studio 2020.

CuO nanoflowers: Multifaceted implications of various precipitating agents on rectification behaviour

In order to achieve the best possible use of traditional energy resources for the preservation of the environment, semiconductor-based optoelectronic devices are one of the most intriguing methods for converting light energy into electrical energy. CuO has been extensively explored as a material for energy conversion and the development of photo-detectors due to its notable characteristics among other metals, especially its non-toxicity, abundance, high efficiency, electrochemical stability and low cost/promising photodiode. However, some drawbacks limit its practical application in white light and photo-detector, including the rapid recombination rate of photo-generated electron-hole pairs and destitute response to visible light. As a result, several strategies have been developed from an optoelectronics perspective to eradicate these deficiencies and make an effort to enhance CuO photodiode activities. In this research work, the electrical characteristics and rectification behaviour of CuO with various precipitating agents have been examined. The CuO nanoparticles can be synthesized by co-precipitation technique prepared with different precipitants. Through this research, several parameters, such as the structural, functional, morphological, optical and electrical characteristics, were investigated by changing the precipitants. The functional group formation of pure CuO phase was confirmed by FT-IR studies. UV–Vis absorption measurements indicate that the band gap of the CuO nanoparticles was ranging from 2.40 to 2.85 eV. As a diode, CuO/p-Si exhibits a non-ideal behaviour and under light conditions with Na2CO3 precipitant, the better ideality factor is about 2.35. The barrier height is determined by the thermionic emission theory to be 0.77 and 0.79 eV in the dark and light conditions respectively.

Investigation on thermal annealing effect on the physical properties of CuO-SnO2:F sprayed thin films for NO2 gas sensor and solar cell simulation

Thin films, owing to their versatility, are extensively employed in various applications, including solar cells and gas detection. In this study, CuO-SnO2:F thin films were fabricated using spray method. The influence of annealing temperature on their properties was examined. X-ray diffraction analysis of post-annealing at 300 °C revealed the emergence of the Cu2O phase, which disappeared at higher annealing temperatures of 500 °C. Substantial improvements in structural, optical, and electrical characteristics were observed, with the optimized films exhibiting heightened responsiveness at low NO2 gas concentration (4 ppm). The optimum operating temperature was determined at 150 °C, demonstrating small response and recovery times, and good reproducibility. Furthermore, Silvaco TCAD simulation was employed to model CIGS (Copper Indium Gallium Selenide) solar cells incorporating CuO-SnO2:F thin films as a buffer layer, yielding an impressive efficiency of 15.31 %.

Copper Oxide Nanoparticles Anchored on Porous Carbon Nitride Nanosheets for Supercapacitor Applications

Electrochemical energy storage devices are vital for renewable energy integration and the deployment of electric vehicles. Ongoing research seeks to create new materials with innovative morphologies capable of delivering high specific capacitance for the next generation of customizable energy devices. Carbon nitride is an excellent candidate for electrochemical energy storage devices; however, it has limitations such as layer stacking, poor electric conductivity, a restricted number of electroactive sites, and static electrochemical reaction rates. This research objective is to make porous structures in carbon nitride nanosheets and integrate them with CuO particles to increase surface area and improve electrochemical performance. The use of thermal heating, acidic treatment, and hydrothermal processes accomplishes this. Along with X-ray diffraction peaks of the CuO phase, a prominent peak (002) at 27.67° indicates the presence of graphitic-structured carbon nitride. TEM images show that CuO particles are evenly attached to the surface of g-C3N4 nanosheets with lattice intervals of 0.336 and 0.232 nm, which are the (002) and (111) orientations of the g-C3N4 and CuO phases, respectively. Adding CuO nanoparticles to porous g-C3N4 nanosheets avoids layer stacking and provides micro- and mesopore channels, increasing the specific surface area (42.60 m2 g-1). The CuO@ porous g-C3N4 electrode delivered 817 F g-1 of specific capacitance at 1 A g-1 and admirable capacitance retention (92.3% after 6000 cycles) due to the synergistic impact of its unique composition and structural characteristics. Because of its outstanding electrochemical performance and fascinating discoveries, CuO@ porous g-C3N4 may be employed as a cathode material for high-performance supercapacitors.

Photoelectrochemical CO2 reduction in tandem photoelectrode cells: Interpretation of apparent photocurrents

Photoelectrochemical reactors harness solar energy to accelerate heterogeneous chemical reactions and reduce power consumption for a given reaction rate. The tandem photoelectrochemical cell design presented here employs a light penetrable TiO2 photoanode||Cu2O photocathode configuration that enables carbon dioxide turnover at limited cell voltages. During polarization tests, the tandem configuration demonstrated a photocurrent density of 0.2 mA/cm2 at a cell voltage of -2.6 V. That is 2-fold higher than the photocurrent density obtained with a solo photoanode (Cu||TiO2) and five orders of magnitude higher compared to the solo photocathode (Cu2O||Ni) design. Moreover, electrolysis under illumination (photoelectrolysis) showed a current density increase of 3.9 mA/cm2 with respect to electrolysis in the dark. However, this photocurrent density was merely apparent and was caused by light-triggered changes in the surface morphology and phase of Cu2O, which in turn affected the catalytic response. Moreover, the apparent partial ethylene photocurrent density and total partial current density during photoelectrolysis was 44 %, the highest among the detected products. That selectivity is attributed to the combined effect of Cu2O photoreduction and the associated local pH rise at the electrode-electrolyte interface.

Morphostructural studies of pure and mixed metal oxide nanoparticles of Cu with Ni and Zn

Nano-scale interactions between pure metal or metal-oxide components within an oxide matrix can improve functional performance over basic metal oxides. This study reports on the synthesis of monometallic (CuO), bimetallic (CuO–NiO) and trimetallic (CuO–NiO–ZnO) oxide nanoparticles (NPs) via the co-precipitation method and investigation of morphostructural properties. All of the synthesized metal oxide NPs were calcined at 550 °C temperature and annealed under vacuum. In this work, we applied Scherrer formula, modified Scherrer equation, Williamson-Hall plots, and Halder-Wagner plots to calculate the average crystallite size. The XRD data analysis showed that average crystallite sizes of the as-synthesized metal oxide phases were between 4 nm and 76 nm and average diameters calculated from SEM image were between 15 nm and 83 nm. The XRD studies also disclosed that average crystallite size and lattice microstrain of the CuO phases remain almost same (43 nm–46 nm and 2.074×10−3 to 2.665×10−3) for pure CuO and mixed CuO–NiO; but in case of mixed CuO–NiO–ZnO it is found to decrease in size to 11 nm where lattice microstrain increases to 9.653×10−3. Line broadening of diffraction peaks from microstrain contribution was between 0.02 and 0.01. Degree of crystallinity (%) of CuO phases found to decrease from 81 to 71. Dislocation density of CuO phases found to increase from 6.63×10−4nm−2 to 12.68×10−3nm−2. X-ray density of CuO phases increased from 6.48 to 6.53 g/cm3. Where this calculated small dislocation density well agreed with the high crystallinity. Crystal structure and specific surface area were determined from lattice constants and X-ray density. These synthesized nanopowders showed the existence of monoclinic, cubic, and hexagonal phases. The obtained NPs of multi-metal oxide explained more than one phases with different size, shape, and morphology at nano scale.

Camellia Sinensis assisted green synthesis of metal oxide nanoparticles: Investigation of structural, vibrational, morphological and thermal analysis

Metal oxide nanoparticles were created via a green combustion approach, with natural tea extract and metal nitrates as the key starting components. The X-ray diffraction (XRD) spectra were used to determine the phase of CuO, NiO, and Co3O4 nanoparticles. The findings validate the monoclinic and cubic structures of CuO, NiO, and Co3O4 nanoparticles. The X-ray diffraction (XRD) profiles of CuO, NiO, and Co3O4 nanoparticles show crystallite sizes of 25.2, 31.2, and 32.5 nm, respectively. Metal oxide nanoparticles exhibit approximately equal average crystallite diameters, demonstrating the consistency of the synthesis procedure. The FTIR spectra were utilized to investigate the functional groups and other chemical components present in CuO, NiO, and Co3O4 nanoparticles. FESEM investigation revealed a leaf-like surface morphology in CuO nanoparticles. The EDX spectra confirm the presence of metals and oxygen in the produced metal oxide nanoparticles. The study focused on the thermal stability and weight loss % of metal oxide nanoparticles. Metal oxide nanoparticles synthesized from natural tea have been shown to have good thermal stability.

Advanced humidity sensing properties of CuO ceramics

This research explores the capacitive humidity sensing properties of CuO ceramic, selected for its simplicity as an oxide and ease of fabrication, in addition to its remarkable dielectric properties. The CuO sample was fabricated by sintering at 980 °C for 5 h. A microstructure with a relative density of 88.9% was obtained. X-ray diffraction confirmed the formation of a pure CuO phase. Broadband dielectric spectroscopy revealed that the observed giant dielectric properties at room temperature (RT) were attributed to extrinsic effects, including the internal barrier layer capacitor and sample-electrode contact effects. A key focus of this study was to examine the giant dielectric properties of CuO ceramic as a function of relative humidity (RH) at RT and frequencies of 102 and 103 Hz. It was observed that the capacitance of CuO continuously increased with rising RH levels, ranging from 30 to 95%. Notably, the maximum hysteresis errors were constrained to 2.3 and 3.3% at 102 and 103 Hz, respectively. Additionally, the CuO ceramic demonstrated very fast response and recovery times, approximately 2.8 and 0.95 min, respectively. The repeatability of the humidity response of the capacitance was also established. Overall, this research highlights the high potential of CuO as a giant dielectric material for application in humidity sensors.

Thermal annealing effect on phase evolution, physical properties of DC sputtered copper oxide thin films and transport behavior of ITO/CuO/Al Schottky diodes

Herein, we report on the post-annealing temperature effect on the transport behavior of p-CuO/Al Schottky barrier diodes. In addition, the transformation of phase from Cu4O3 to CuO phase was studied. Copper oxide thin films were grown on soda lime glass substrates, and post-annealing temperature's influence on the films’ structural, chemical, morphological, and electrical characteristics was comprehensively examined. X-ray diffraction study revealed the development of polycrystalline tenorite phase (CuO) on annealing. Raman analysis also confirmed the formation of the tenorite phase (CuO) at higher annealing temperatures (400 °C and 500 °C). XPS study revealed the occurrence of the Cu4O3 phase for room temperature deposited sample and CuO phase at the higher annealing temperature. Using current–voltage analysis, the Chueng model, and the thermoelectric emission model, the Schottky behavior between the metal and semiconductor were investigated. The fabricated diode showed a rectification ratio of 103 at ± 2 V, with the barrier height ranging from 0.84 to 1.12 eV due to different annealing treatments. The attributes of the power law were employed to elucidate space charge-limited conduction and the process of tunneling across the density of interface traps in p-CuO/Al Schottky diodes. This study provides valuable insights into the behavior of the p-CuO/Al Schottky junction, enhancing our understanding of its characteristics.

CuS-CuO nanoparticles for antennas collect light through their conductivity by absorbing a single photon located at the wavelength of 254 nm

CuS-CuO nanoparticles were prepared by air annealing as-made CuS nanoparticles deposited using spray pyrolysis. The optical, structural, and morphological properties of samples were investigated by UV–VIS Spectroscopy, X-ray diffraction (XRD), Scanning Electron Microscopy (SEM), and Atomic Force Microscopy (AFM). The XRD analysis of as-prepared sample include two phases CuS and Cu2S, while annealed films are a mixture of CuS and CuO phases. The dimensions of the CuS crystallites were estimated by Williamson's method on the diffraction peaks (81 nm) while the dimensions of the CuO ones were statistically evaluated via the SEM image (95 nm) and corroborated by Williamson's method on the diffraction peaks (98 nm). SEM study of annealed samples reveals that nanoparticles are monocrystalline. Optical analysis shows more than 80 % transmittance through sample thickness 164 nm in the infrared region and two energy bandgaps of 1.92 and 2.50 eV in the visible region associated with CuO and CuS, respectively. In addition, we observe after several optical excitations that only the UV wavelength of 254 nm gives a tangible electrical response. We understand from the literature that this is only possible through one interpretation of the antenna effect. Optical antennas aim to freely change light rays into local energy. In fact, our sample presents nanoparticles with sizes around 80 nm that show clear absorption through the development of their reproducible resistance that increases with polarization toward saturation after 5 V. Therefore, we propose using prepared nanoparticles in a light-harvesting antenna for artificial photodetector and other optoelectronic applications.

Virtual substrate method: synthesis and growth kinetics of 2D metal oxide nanosheets

We present the experimental decomposition kinetics for the synthesis of metal oxide 2D nanosheets by the virtual substrate method. In this method, acetates of Mg and Cu were used as precursors for the growth of prototype MgO and CuO nanosheets, while the filter paper was utilized as a virtual substrate. The synthesized samples were characterized by X-ray diffraction for the phase analysis of the nanostructures, which confirms the cubic phase of MgO and monoclinic phase of CuO; with a minor Cu2O phase. Field emission scanning electron microscopy was used to determine the surface morphology of the nanosheets. Fourier transform infrared spectroscopy was utilized to identify the vibrational modes of the metal oxides and the functional groups present in the sample. Thermogravimetric analysis revealed the evolution of combustive oxidation of filter paper with the thermal decomposition of acetates situated on its surface.

Highly oriented epitaxial Cu2O (011) thin film grown on MgO (001) substrate by dynamic aurora PLD method

The epitaxial Cu2O films are grown on MgO (001) substrates by the dynamic aurora pulsed laser deposition (PLD) method. The structure and epitaxial growth of the as-prepared thin films at different substrate temperatures (25 °C to 600 °C) were investigated. The thin film prepared at room temperature (RT, 25 °C) exhibits (111) plane of monoclinic CuO phase with poor crystallinity. The thin films deposited at 200 °C to 600 °C show single-phase cubic Cu2O with good crystallinity. The highly oriented epitaxial Cu2O thin film on the MgO substrate is achieved at low temperatures of 200 °C by applying an induced electromagnetic field during thin film growth. The quality and crystallinity of epitaxial Cu2O thin films remarkably improved with increasing temperature from 200 °C to 600 °C and all these thin films exhibited an out-of-plane epitaxial relationship of Cu2O (011) ‖ MgO (001). The CuO thin film grown on MgO substrate at RT shows a single domain structure, as observed by RHEED. In constrast, Cu2O films grown at 200 °C to 600 °C exhibit two different kinds of domain structure with corresponding in-plane epitaxial relationship of Cu2O [100] ‖ MgO [110] and Cu2O [100] ‖ MgO [11¯0]. This report reveals, for the first time, the feasibility of epitaxial growth of highly oriented Cu2O (011) thin film achieved at the low temperature of 200 °C by the dynamic aurora PLD method. The quality of epitaxial Cu2O (011) is significantly enhanced with increasing substrate temperature from 200 °C to 600 °C.

Innovative syntheses of immobilized CuxO semiconductors grown on 3D prints and their photoelectrochemical activity for sulfamethoxazole degradation

Traditional copper oxide manufacturing processes require high energy consumption, high synthesis temperatures, and long process times. This study proposes an innovative additive manufacturing process to support immobilized copper oxide, offering greater design flexibility and customization. CuxO semiconductors were synthesized on 3D-printed substrates via the anodization process and evaluated for their effectiveness in degrading sulfamethoxazole (SMX). XRD analysis of the samples revealed the presence of both CuO and Cu2O crystalline phases, this mixture of oxides helps to expand the absorption range of visible light. The immobilized CuxO semiconductors exhibited band gaps ranging between 1.6 and 1.8 eV. Negative current densities and Mott-Schottky analysis confirmed the nature of the p-type semiconductor. Semiconductors grown by 3D printing demonstrated remarkable degradation capacity for the antibiotic sulfamethoxazole (SMX), achieving 60% degradation after 360 minutes under visible light. Kinetic degradation tends to be a first-order and zero-order model. TOC analysis further revealed the formation of reaction intermediates during SMX degradation, ultimately leading to the mineralization of the contaminant. Based on these results, we report, for the first time CuxO semiconductors grown on large 3D-printed substrates as promising photocatalysts for the degradation of emerging water pollutants. Based on these results, we report, for the first time, that CuxO semiconductors grown on large 3D-printed substrates are promising photocatalysts for the degradation of emerging water contaminants. Furthermore, it should be emphasized that the proposed method is faster and does not require subsequent thermal treatments for its functionalization, making it attractive for various industrial applications.

Study of the copper structure samples externed to extreme influences

This work is devoted to the study of changes in the crystal structure, chemical and phase composition of copper samples subjected to extreme effects of temperature, pressure and electromagnetic fields. With the help of X-ray diffraction, as well as microanalysis, it was revealed that the plastic deformation of copper wires in the car power supply system leads to the formation of a superconducting Cu2O phase. This is the reason for the rapid ignition of the car, as it leads to a sharp increase in the magnitude of the electric current and temperature in the plastic deformation zone of copper wires. During explosion welding of copper samples, the Cu2O phase appears on their surface, which has superconducting properties. This significantly changes the electrophysical properties of copper samples. In metallurgical processes during the smelting of copper products, there is a possibility of the appearance of a superconducting Cu2O phase. When modifying a copper melt with hardening additives, the superconducting Cu2O phase makes it possible to obtain fracture-resistant copper products with high electrical conductivity. Plastic deformation of a copper foil 30 mkm thick by a magnetic field generated by a current of 180 kA leads to the formation of a texture and rupture of the foil. This has been detected using X-ray diffraction, as well as optical and scanning electron microscopy.

Some characteristics of Cu/Cu2O/CuO nanostructure heterojunctions and their applications in hydrogen generation from seawater: effect of surface roughening

Cu/Cu2O/CuO heterojunction were synthesized, using thermal oxidation under the flow of argon and oxygen gas mixture, as efficient photoelectrode for hydrogen generation. The Cu/Cu2O/CuO heterojunction were synthesized using un-roughed and roughed Cu foils. The resulting heterojunction samples were characterized using various techniques. The evaluated oxide layer (Cu2O/CuO) thicknesses for un-roughed and roughed samples are 4.2 and 8.5 μm, respectively. XRD revealed that the oxide layer is a mix cubic Cu2O and monoclinic CuO crystalline phases with higher CuO ratio in the roughed sample. The surface morphology of the un-roughed sample is a porous surface that consisting of nanoflakes whereas surface morphology of the roughed sample is randomly oriented nanowires. The Cu/Cu2O/CuO nanostructured surface is superhydrophilic, with water contact angles of 11.12 and 0° for un-roughed and roughed samples, respectively. The roughed sample has higher absorbance over the entire studied wavelength range. The obtained values of the optical band gap for un-roughed and roughed samples are 2.48 and 2.39 eV, respectively. The photocurrent density of the roughed photoelectrode is much greater than that of un-roughed photoelectrode. The roughed photoelectrode has a photocurrent density of—0.151 mA cm−2 at—0.85 V and a photoconversion efficiency of 0.55% when illuminating with 340 nm light. This work offers a promised Cu/Cu2O/CuO photoelectrode for hydrogen generation from seawater.

Bifunctional low-Pt content nanocatalysts supported on carbons functionalized with a Cu-organometallic compound: Tailoring of d-band center with high catalytic activity for electrochemical oxygen reactions

In this study, Vulcan XC-72 (C) and sewage sludge-derived biocarbon (SSB) are functionalized with mesitylcopper (Cu-mes) and implemented to produce the low-Pt content and thus low-cost (5 wt %) Pt/CCu-mes10, Pt/CCu-mes20, Pt/SSBCu-mes10, and Pt/SSBCu-mes20 nanocatalysts. This approach facilitates the generation of various functional groups along with the CuO and Cu2O phases. The nanocatalysts show the formation of the PtCu3 alloy, with the two first having an atomic fraction of Cu alloyed (XCu) of 55 and 67%, respectively. Pt/CCu-mes10 shows a comparable catalytic activity for the oxygen reduction reaction (ORR) before and after an accelerated degradation test (ADT) to 20 wt % Pt/C and 5 wt % Pt/C. It also shows the highest performance for the oxygen evolution reaction (OER), with remarkable electrochemical stability. The outstanding performance of Pt/CCu-mes10 is attributed to the presence of Cu-phases, its high degree of alloying and its d-band center which favorably promotes the adsorption of O-species and their further reaction. Specifically, the PtCu3 alloy promotes the kinetics of the reactions by modulating the electronic properties of Pt and creating dual active sites. Meanwhile, Pt/SSB demonstrates an encouraging performance for the reactions before ADT, with electrochemical parameters similar to those of 20 wt % Pt/C. However, its stability is poor, with low catalytic activity after ADT. Therefore, it is found that there is a significant effect of the electrochemical behavior of the carbon support on the performance and stability of the nanocatalysts. The potential application of Pt/CCu-mes10 in water splitting devices is identified.

Communication—Texture and Bandgap Tuning of Phase Pure Cu2O Thin Films Grown by a Simple Potentiostatic Electrodeposition Technique

Highly textured phase pure Cu2O thin films have been grown by a simple electrodeposition technique with varying deposition voltages (−0.3 to −1.0 V). The surface morphology characterized by Scanning Electron Microscopy (SEM) revealed that the deposited thin films coherently carpet the underlying substrate and are composed of sharp faceted well-defined grains of 0.5–1.0 μm sizes. XRD analyses showed that all films are composed of polycrystalline cubic Cu2O phase only and have average crystalline domain size in the range of 30–73 nm. The preferred crystalline orientation of phase pure Cu2O films was found to be changing from (200) to (111) with increasing cathodic voltages and showed the highest (111) and (200) crystalline texture coefficient while growing at −1.0 and −0.8 V respectively. The optical bandgap of the as-grown samples was calculated in the range of 1.95–2.20 eV using UV–vis Transmission data. The performance of Cu2O/FTO photocathodes was tested by estimating LED “ON/OFF” modulated surface photovoltage into a photoelectrochemical cell at a zero bias.

Unraveling discriminative-hydrogen-activation over Cu-based catalysts for boosting nitroarenes hydrogenation: Crystal effect and mechanism insight

Copper is a crucial element in the field of catalysis. However, Cu-based catalysts exhibit lower redox properties and surface energy under mild conditions, which limit their electron transfer capacities and catalytic performance. In this study, the relationship investigation between the hydrogenation behavior of Cu-based catalysts and crystal phases showed that spherical Cu2O exhibited enhanced capacity for hydrogen activation, excellent catalytic activity and outstanding reusability in the selective reduction of various nitroarenes. At even 25 °C and 1 atm, the complete reduction of 4-nitrophenol by NaBH4 was achieved in 2.5 min over Cu2O, achieving a reaction rate constant (k) of 20.15 × 10−3 s−1, which was 4.8 and 15.2 times that of CuO and Cu catalysts. Detailed experimental and theoretical calculations revealed that the Cu+ sites in the antifluorite crystal phase of Cu2O are conducive to the adsorption of active H species, while the unique d–s orbital recombination provides more electrons to improve its hydrogenation performance. The results of this study can aid in the development of copper-based materials as advanced catalysts, thereby improving fine chemical production and pollution treatment processes.

Hydrodeoxygenation of Anisole via Cu supported on Zeolite: HZSM-5, MOR, and Indonesian Activated Natural Zeolite

The conversion of biomass waste into an alternative energy source requires effective and efficient hydrodeoxygenation (HDO) catalysts. This research aimed to synthesize a bifunctional zeolite-based catalyst for anisole conversion into BTX. The noble metal Cu was impregnated on HZSM-5, mordenite, and Indonesian activated natural zeolite (ANZ) to form HDO catalysts. X-ray fluorescence (XRF), X-ray diffraction (XRD), surface area and pore profile analysis, Fourier transform infrared analysis, ammonia-temperature programmed desorption (NH3-TPD), pyridine gravimetry, morphology, and scanning electron microscopy-energy dispersion elemental mapping (SEM-EDX) were used to determine the catalyst's properties. The HDO reaction test used anisole as a model compound in a semi-flow reactor with hydrogen gas at 350 and 500 °C for 1 h. Copper nanocrystals were found on the surface of the zeolites in several metal phase types, including Cu, Cu2O, CuO, and Cu(OH)2. Due to the copper bonds inside the zeolite pores, the internal pore surface area decreased. The acidity also decreased since it is strongly related to the surface area. At 350 °C, Cu was found to be less active. However, at 500 °C, copper activity increased, leading to an increase in anisole conversion and BTX selectivity. The catalyst with the highest anisole conversion and BTX selectivity was Cu/HZSM-5 (i.e., 53.28 and 13.06% v, respectively).

Crystal growth of KCl:CuO single crystal starting from inhomogeneous solid-melt phase using the Czochralski method

In this work the Czochralski technique was employed to grow a pure KCl and KCl:CuO single crystals, these crystals were grown starting from homogeneous and heterogeneous phases, respectively. The heterogeneous phase consists two different phases which are KCl as melting phase and CuO nano-crystals (NCs) as a solid state phase. Due to the high temperature of the crystal growth environment this approach has a big challenge to keep NCs in the solid state phase during the crystal growth process. To control and analyze the obtained crystals, several techniques of characterization were used to investigate the structural and optical properties of CuO NCs dispersed in a crystalline medium (KCl). The main structural results of X ray diffraction (XRD), Raman, and IR spectroscopy prove the presence of nanocrystallites with monoclinic phase of CuO, where the estimated average size is aproxmetly 30 nm. Quantitative analyzes of elements using the energy-dispersive X-ray spectroscopy (EDX) demonstrates the high purity of samples. Moreover, the optical properties were investigated using UV–Vis spectroscopy and photoluminescence (PL), where CuO crystallites exhibit three bands located at 450 nm, 557 nm, and 594 nm with blue shift as a comparison of bulk CuO, this blue shift is a result of nanoscale of CuO. The presence of CuO NCs in the crystalline medium (KCl) enhances the PL properties; this feature makes the obtained crystal an excellent candidate for integration into optical devices that operate within the visible range, particularly between 450 and 600 nm.