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Surface contamination by microbes is a major public health concern. A damp environment is one of potential sources for microbe proliferation. Smart photocatalytic coatings on building surfaces using semiconductors like titania (TiO2) can effectively curb this growing threat. Metal-doped titania in anatase phase has been proven as a promising candidate for energy and environmental applications. In this present work, the antimicrobial efficacy of copper (Cu)-doped TiO2 (Cu-TiO2) was evaluated against Escherichia coli (Gram-negative) and Staphylococcus aureus (Gram-positive) under visible light irradiation. Doping of a minute fraction of Cu (0.5 mol %) in TiO2 was carried out via sol-gel technique. Cu-TiO2 further calcined at various temperatures (in the range of 500–700 °C) to evaluate the thermal stability of TiO2 anatase phase. The physico-chemical properties of the samples were characterized through X-ray diffraction (XRD), Raman spectroscopy, X-ray photo-electron spectroscopy (XPS) and UV–visible spectroscopy techniques. XRD results revealed that the anatase phase of TiO2 was maintained well, up to 650 °C, by the Cu dopant. UV–vis results suggested that the visible light absorption property of Cu-TiO2 was enhanced and the band gap is reduced to 2.8 eV. Density functional theory (DFT) studies emphasize the introduction of Cu+ and Cu2+ ions by replacing Ti4+ ions in the TiO2 lattice, creating oxygen vacancies. These further promoted the photocatalytic efficiency. A significantly high bacterial inactivation (99.9999%) was attained in 30 min of visible light irradiation by Cu-TiO2.

Photocatalytic oxidation is considered one of the most effective ways to remove formaldehyde from indoor air. However, the use of powder photocatalysts is limited by their low adsorption capacity and strong aggregation tendency. Hence, there is a need for a composite material with good cycling stability and high degradation efficiency. In the present study, a unique wood-based composite is produced by arranging Cu–TiO2 nanoparticles on porous structured wood. The porous structure of wood can adsorb formaldehyde, and the abundant functional groups on the surface can act as a reaction platform for anchoring the Cu–TiO2 nanoparticles. Cu doping facilitates electron interaction between TiO2 and Cu, promotes the transfer of charge carriers, lowers the electron–hole recombination rate, and improves the photocatalytic degradation efficiency of formaldehyde. The photocatalytic efficiency of the wood-based composites was highest (85.59%) when the n(Cu)/n(Ti) ratio was 7%. After nine cycles, the wood composites still had a high degradation rate, indicating good recyclability. Overall, this wood composite is an eco-friendly and promising material for indoor air filtration.

In this work, metal-doped titanium dioxide (TiO2) was synthesised with the aim of improving photocatalytic degradation and antimicrobial activities; TiO2 was doped with copper (Cu) ranging from 0.1 to 1.0 wt%. The physical and chemical properties of the Cu-doped TiO2 nanoparticles were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), the Brunauer–Emmett–Teller method (BET) and diffuse reflection spectroscopy (DRS). The results revealed that the anatase phase of TiO2 was maintained well in all the Cu-doped TiO2 samples. No significant difference in the particle sizes or the specific surface areas was caused by increasing Cu doping. However, the band gap decreased continuously from 3.20 eV for undoped TiO2 to 3.12 eV for 1.0 wt.% Cu-doped TiO2. In addition, the 0.1 wt.% Cu-doped TiO2 displayed a much greater photocatalytic degradation of methylene blue (MB) and excellent antibacterial ability for Escherichia coli (E. coli) compared to undoped TiO2. On the other hand, the high Cu doping levels had negative impacts on the surface charge of nanoparticles and charge transfer for OH• generation, resulting in decreasing MB degradation and E. coli photokilling for 1.0 wt.% Cu-doped TiO2.

Cu–TiO2 nanoparticles of a broad range of compositions with 0, 0.002, 0.005, 0.02, 0.05, 0.2, 0.5, 1.0, 2.0, 3.0, 5.0, 7.0 and 10.0 mol% Cu were synthesized via the sol–gel method using copper (II) acetate and titanium tetraisopropoxide (TTIP) precursors at a low hydrolysis ratio of H = 1.25, which favours homogeneous TiO2 nucleation and Cu dispersion in the host matrix at nanoscale. The precipitated materials were dried at 80 °C and calcined at 450, 500, and 550 °C to form crystalline nanopowders, whose photocatalytic activity was evaluated on the decomposition of a representative pollutant, methylene blue (MB), in aqueous solutions under UVA and sunlight illuminations. The compositions with small Cu content of ~0.05 mol% showed the highest activity. A gain of activity over pure titania of 4 times after calcination at 450 °C, 2.5 times at 500 °C and 20% at 550 °C was measured under UVA illumination. Even higher gain of activity observed under sunlight illumination might be due to an extension of action spectrum to the visible range due to intra-gap defect states produced by Cu2+ insertion. The time-resolved microwave conductivity (TRMC) measurements of the photoinduced charges relaxation suggest that both excessive calcination temperature and Cu content decrease the activity due to Cu-defects clustering. Modelling relates the activity to the photoinduced electron-hole pair separation; the optimal Cu content is explained by accessibility of the recombination centre by a conduction band (CB) electron. Accordingly, an increase in calcination temperature resulted in a longer pathlength of CB electron.

This work focuses on 3D, self‐supported, nanofibrous TiO2 structures (nanogrids) prepared using blend electrospinning. The presence of anatase and brookite phases in Cu‐doped TiO2 nanogrids significantly enhances the photocatalytic properties of the titania system. The absorption edge in Cu‐doped TiO2 shifts to the visible due to the narrowed bandgap and efficient separation of photogenerated charge carriers facilitated by Cu doping. The presence of the brookite phase further contributes to the enhanced performance, by reducing electron–hole recombination. A wide range of characterization techniques, including cyclic voltammetry and chronoamperometry studies which show that the Cu doped TiO₂ sample generates a significant photocurrent under visible light, are employed to elucidate the role of Cu doping in enhancing the visible light photocatalytic efficiency of TiO2 nanogrids, offering valuable insights for developing advanced photochemical catalysts for environmental and energy applications. The nanogrids studied here are far superior to P25 Degussa and are activated by natural sunlight and do not require a filtration system to remove nanoparticles from the water. These self‐supported nanofibrous photochemical catalysts offer all the benefits of nanomaterials while suffering from none of their drawbacks. This study presents 3D, self‐supported TiO2 nanogrids with enhanced visible‐light photocatalytic efficiency due to Cu doping and the presence of anatase and brookite phases. These nanogrids outperform P25 Degussa, operate under natural sunlight, and eliminate nanoparticle filtration, making them highly effective for environmental and energy applications.

Dye-sensitized solar cells (DSSCs) are a promising alternative to traditional silicon-based technologies due to their low production costs, ease of fabrication, and wide range of applications. Among the semiconductors used in DSSCs, TiO2 stands out for its simple, inexpensive synthesis and lower environmental impact. However, TiO2 has limitations due to its wide bandgap and high charge-carrier recombination. In this study, the incorporation of rGO and its effect on the degree of GO reduction on Cu-doped TiO2 particles were evaluated to enhance light interaction, improve electronic mobility, and suppress recombination. Electrophoretic deposition was employed as an alternative method to obtain Cu-doped, rGO-decorated mesoporous TiO2 films, which were evaluated for power conversion efficiency (PCE) in DSSCs. The materials were characterized using SEM, ICP-OES, UV-Vis, XRD, BET, DLS, and TEM, while the photoanodes were analyzed using FTIR, chronoamperometry, and photovoltaic efficiency tests. The results showed clusters between 1.4 and 2.6 µm, confirming doping, a decrease in the energy gap to 2.99 eV, a stable anatase crystalline phase, and an increase in the specific surface area to 234.82 m2/g. The fabricated cells exhibited a PCE of 2.26% with a TiO2:Cu-rGO photoanode after 20 min of GO reduction, compared to 0.96% for DSSCs with a conventional configuration.

In this study, using pure and copper-doped titanium dioxide (Cu-TiO2) nanostructures as the base matrix, enzyme-less label free myoglobin detection to identify acute myocardial infarction was performed and presented. The Cu-TiO2 nanomaterials were prepared using facile sol–gel method. In order to comprehend the morphologies, compositions, structural, optical, and electrochemical characteristics, the pure and Cu-TiO2 nanomaterials were investigated by several techniques which clearly revealed good crystallinity and high purity. To fabricate the enzyme-less label free biosensor, thick films of synthesized nanomaterials were applied to the surface of a pre-fabricated gold screen-printed electrode (Au-SPE), which serves as a working electrode to construct the myoglobin (Mb) biosensors. The interference study of the fabricated biosensor was also carried out with human serum albumin (HSA) and cytochrome c (cyt-c). Interestingly, the Cu-doped TiO2 nanomaterial-based Mb biosensor displayed a higher sensitivity of 61.51 µAcm−2/nM and a lower detection limit of 14 pM with a response time of less than 10 ms.

The present work aims to study the degradation of mefenamic acid (MFA) in synthetic wastewater experimentally and numerically. The experiments were carried out using utilizing homemade Cu doped TiO 2 in a solar irradiated falling film reactor. Two operating variables are investigated; pH of the wastewater in the range of (3-10) and synthesis wastewater flow rate (1-3 L/min). The numerical study involves the optimization of the variables. The multifactorial design method, Design of Experiments (DOE), and Response Surface Methodology (RSM) were used to evaluate the interaction effect of the two variables on the degradation of mefenamic acid. The significance of 0the results was evaluated by statistical analysis of variance (ANOVA). The results show that the removal efficiency increasing with increasing pH and decreases with wastewater flow rate. The results have shown that the interaction effects between mentioned factors were highly significant in influencing MFA degradation by analyzing statistics and ANOVA.

One of the primary risk factors for implant failure is thought to be implant-related infections during the early healing phase. Developing coatings with cell stimulatory behaviour and bacterial adhesion control is still difficult for bone implants. This study proposes an approach for one-step deposition of biocompatible and antimicrobial Cu-doped TiO2 coatings via glow-discharge sputtering of a mosaic target. During the deposition, the bias of the Ti6Al4V substrates was changed. Structure examination, phase analysis, and surface morphology were carried out using X-ray diffraction (XRD) analysis, scanning electron microscopy (SEM), atomic force microscopy (AFM), and X-ray photoelectron spectroscopy (XPS). The hardness values and hydrophilic and corrosion performance were also evaluated together with cytocompatible and antibacterial examinations against E. coli and S. aureus. The results show great chemical and phase control of the bias identifying rutile, anatase, CuO, or ternary oxide phases. It was found that by increasing the substrate bias from 0 to −50 V the Cu content increased from 15.3 up to 20.7 at% while at a high bias of −100 V, the copper content reduced to 3 at%. Simultaneously, apart from the Cu2+ state, Cu1+ is also found in the biased samples. Compared with the bare alloy, the hardness, the water contact angle and corrosion resistance of the biased coatings increased. According to an assessment of in vitro cytocompatibility, all coatings were found to be nontoxic to MG-63 osteoblast cells over the time studied. Copper release and cell-surface interactions generated an antibacterial effect against E. coli and S. aureus strains. The −50 V biased coating combined the most successful results in inhibiting bacterial growth and eliciting the proper responses from osteoblastic cells because of its phase composition, electrochemical stability, hydrophilicity, improved substrate adhesion, and surface roughness. Using this novel surface modification approach, we achieved multifunctionality through controlled copper content and oxide phase composition in the sputtered films.

Studying the interaction of inorganic systems with organic ones is a highly important avenue for finding new drugs and treatment methods. Tumor cells show an increased demand for amino acids due to their rapid proliferation; thus, targeting their metabolism is becoming a potential oncological therapeutic strategy. One of the inorganic materials that show antitumor properties is titanium dioxide, while its doping was found to enhance interactions with biological systems. Thus, in this study, we investigated the energy landscape of glutamine (L), an amino acid, on pristine and doped TiO2 surfaces. We first locally optimized 2D-slab structures of pristine and Au/Ag/Cu-doped anatase (001 and 101 surfaces) and similarly optimized a single molecule of glutamine in vacuum. Next, we placed the pre-optimized glutamine molecule in various orientations and on a variety of locations onto the relaxed substrate surfaces (in vacuum) and performed ab initio relaxations of the molecule on the substrate slabs. We employed the DFT method with a GGA-PBE functional implemented in the Quantum Espresso code. Comparisons of the optimized conformations and electronic structures of the amino acid in vacuum and on the surfaces yield useful insights into various biological processes.