Sunlight-Driven Photocatalytic Degradation of Methylene Blue with Facile One-Step Synthesized Cu-Cu2O-Cu3N Nanoparticle Mixtures

Sunlight-driven photocatalytic degradation is an effective and eco-friendly technology for the removal of organic pollutants from contaminated water. Herein, we describe the one-step synthesis of Cu-Cu₂O-Cu₃N nanoparticle mixtures using a novel non-aqueous, sol-gel route and their application in the solar-driven photocatalytic degradation of methylene blue. The crystalline structure and morphology were investigated with XRD, SEM and TEM. The optical properties of the as-prepared photocatalysts were investigated with Raman, FTIR, UV-Vis and photoluminescence spectroscopies. The influence of the phase proportions of Cu, Cu₂O and Cu₃N in the nanoparticle mixtures on the photocatalytic activity was also investigated. Overall, the sample containing the highest quantity of Cu₃N exhibits the highest photocatalytic degradation efficiency (95%). This enhancement is attributed to factors such as absorption range broadening, increased specific surface of the photocatalysts and the downward band bending in the p-type semiconductors, i.e., Cu₃N and Cu₂O. Two different catalytic dosages were studied, i.e., 5 mg and 10 mg. The higher catalytic dosage exhibited lower photocatalytic degradation efficiency owing to the increase in the turbidity of the solution.

Experimental and Theoretical Studies of Green Synthesized Cu2O Nanoparticles Using Datura Metel L

In biomedical applications, Cu₂O nanoparticles are of great interest. The bioengineered route is eco-friendly for the synthesis of nanoparticles. Therefore, in the present study, there is an attempt to synthesis Cu₂O nanoparticles using Datura metel L. The synthesized nanoparticles were characterized by UV-Vis, XRD, and FT-IR. UV-Vis results suggest the presence of hyoscyamine, atropine in Datura metel L, and also, nanoparticles formation has been confirmed by the presence of absorption peak at 790 nm. The average crystallite size (19.56 nm) was obtained by XRD. FT-IR was also used to confirm the different functional groups. Fourier Power Spectrum was also employed to examine the synthesized nanomaterials spectrum data to emphasize the peak of the prominent frequencies. Density functional theory (DFT) was also utilized to assess the energy of the substance over time, which appears to indicate a stable molecule. Furthermore, calculated energies, thermodynamic properties (such as enthalpies, entropies, and Gibbs-free energies), modeled structures of complexes, crystals, and clusters, and predicted yields, rates, and regio- and stereospecificity of reactions were all in good agreement with experimental results. Overall, the results show that the successful production of Cu₂O nanoparticles with Datura metel L. corresponds to theoretical research.

A Review of Recent Advances of Dielectric Barrier Discharge Plasma in Catalysis

Dielectric barrier discharge plasma is one of the most popular methods to generate nanthermal plasma, which is made up of a host of high-energy electrons, free radicals, chemically active ions and excited species, so it has the property of being prone to chemical reactions. Due to these unique advantages, the plasma technology has been widely used in the catalytic fields. Compared with the conventional method, the heterogeneous catalyst prepared by plasma technology has good dispersion and smaller particle size, and its catalytic activity, selectivity and stability are significantly improved. In addition, the interaction between plasma and catalyst can achieve synergistic effects, so the catalytic effect is further improved. The review mainly introduces the characteristics of dielectric barrier discharge plasma, development trend and its recent advances in catalysis; then, we sum up the advantages of using plasma technology to prepare catalysts. At the same time, the synergistic effect of plasma technology combined with catalyst on methanation, CH₄ reforming, NO_x decomposition, H₂O₂ synthesis, Fischer–Tropsch synthesis, volatile organic compounds removal, catalytic sterilization, wastewater treatment and degradation of pesticide residues are discussed. Finally, the properties of plasma in catalytic reaction are summarized, and the application prospect of plasma in the future catalytic field is prospected.

Cu2O/TiO2 nanoparticles as visible light photocatalysts concerning C(sp2)–P bond formation

A novel and efficient method has been developed for the construction of an aromatic-phosphorus (Ar-P) bond under visible light irradiation using Cu₂O/TiO₂ nanoparticles as inexpensive and available photocatalysts.

Photoreduction route for Cu2O/TiO2 nanotubes junction for enhanced photocatalytic activity

Here, we synthesized copper(i) oxide and titanium dioxide nanotubes (TNTs) heterojunctions (HJs) by a photoreduction method using a low-power UV lamp without involving any additional steps, such as chemical reduction, surfactant, or protection agents. Transmission electron microscopy, X-ray diffraction, Raman scattering, X-ray photoelectron spectroscopy, diffuse reflectance spectra, and photoluminescence spectroscopy were carried out to verify the formation of a HJ between the Cu₂O nanoparticles (Cu₂O NPs) and TNTs. The efficiency and the rate of methylene blue photo-degradation over the Cu₂O/TNTs HJ were found to be nearly double and triple compared to the isolated TNTs. The enhanced efficiency is attributed to the narrow band gap and defect states caused by the oxygen vacancies in the vicinity of HJs. Moreover, the type II band alignment of Cu₂O NPs and TNTs naturally separates the photo-generated carriers and constrains the recombination process owing to the internal electric field across the Cu₂O/TNTs interface.

Good photocatalytic performance is demonstrated by Cu₂O NPs directly loaded onto hydrothermally synthesized TiO₂ NTs via photoreduction method conducted with a lower power UV lamp at room temp. This is due to narrowing bandgap and forming an internal electric field.

Surface co-modification of TiO2 with N doping and Ag loading for enhanced visible-light photoactivity

A composite of N-doped TiO₂ with Ag loading (Ag/N-TiO₂) was successfully synthesized by a facile in situ calcination process using titanium nitride (TiN) and silver nitrate (AgNO₃) as the starting materials.

Highly efficient CuxO/TiO2 catalysts: controllable dispersion and isolation of metal active species

Cu_xO/TiO₂ architectures with enhanced dispersion of the active phase are synthesized by a MOF-templated method. Such composites show excellent catalytic activity for CO oxidation.

Photocatalytic reduction of CO2 with H2O to CH4 on Cu(i) supported TiO2 nanosheets with defective {001} facets

A series of Cu–TiO₂-x has been reasonably designed and synthesized as efficient photocatalysts for the reduction of CO₂ with H₂O to CH₄. It is found that the high activity may be contributed by the co-existence of surface oxygen vacancies and Cu(i) species on {001} facets of TiO₂.

Simultaneous glucose sensing and biohydrogen evolution from direct photoelectrocatalytic glucose oxidation on robust Cu2O–TiO2 electrodes

An efficient solar-driven biofuel hydrogen production from direct photoelectrocatalytic oxidation of glucose on a robust Cu₂O–TiO₂ photoelectrode was demonstrated.

Ag/Cu co-doped ZnS–In2S3 solid solutions: facile synthesis, theoretical calculations and enhanced photocatalytic activity

ZnS–In₂S₃ nanospheres were prepared by a simple hydrothermal method without using any organic solvents or templates.