Doped TiO2 Research Articles

DFT-Guided Design of Dual Dopants in Anatase TiO2 for Boosted Sodium Storage.

Anatase titanium dioxide (TiO2) has drawn great attention as an anode material in sodium ion batteries (SIBs), but it suffers from the sluggish diffusion kinetics of Na+ within TiO2 and inferior electronic conductivity. Herein, under the guidance of density functional theory (DFT), we propose a nitrogen and selenium dual-doped TiO2 system as an advanced SIB anode. Both DFT and experimental investigations reveal the cooperative effect of dopants in boosting the electrochemical performance of TiO2, finding the optimal content ratio (N/Se at 1:3) for overall improved SIB performances. As expected, experimental results exhibit excellent sodium storage behavior of the N,Se-doped TiO2, including high discharge capacity (142 mAh g-1 at 2 A g-1), good rate performance (82 mAh g-1 at 20 A g-1), and ultralong cyclability (97% retention over 5000 cycles at 2 A g-1). Our study underscores the importance of dual-heteroatom doping in the rational design of advanced electrode materials.

Synthesis and characterization of Nd‐TiO2 and Nd‐ZnO nanostructures for photocatalytic degradation of textile wastewater

AbstractThis study was executed on textile wastewater degradation using laboratory‐prepared Nd‐TiO2 and Nd‐ZnO nanostructures by sol–gel and hydrothermal ultrasonication methods, respectively. The synthesized nano‐photocatalysts were fully characterized using XRD, FE‐SEM/EDX, FT‐IR, and UV‐DRS. The XRD analysis shows that TiO2 crystalline size with Nd doping is 6.14 nm with only the anatase phase, whereas ZnO is 29.59 nm. DRS spectra show that the energy band gap of the doped TiO2 nanostructure was 3.16 eV, whereas, in the case of the Nd‐ZnO nanostructure, it was 3.19 eV, which further indicates more photocatalytic activity. Photocatalytic application for textile wastewater degradation was tested regarding biological oxygen demand and chemical oxygen demand. The maximum degradation of textile wastewater at dilution 1:9 was observed to be 96% and 91% for Nd‐TiO2 and 89% and 87% for Nd‐ZnO under UV and solar irradiations, respectively, with the optimized catalyst dose of 0.2 g/L (Nd‐TiO2) and 0.3 g/L (Nd‐ZnO) at a pH of 7.52. The recyclability shows a slight decrease in efficiency throughout five cycles. The photocatalytic activity of Nd‐TiO2 was higher due to the favorable band gap and smaller crystallite size. The findings indicate that solar light may be a long‐term, cost‐effective renewable source for large‐scale wastewater treatment.

Novel Anodic TiO2 Synthesis Method with Embedded Graphene Quantum Dots for Improved Photocatalytic Activity

Photocatalytic degradation of pollutants have a high potential for sustainable and renewable uses. TiO2 is a widely studied photocatalyst due to its high chemical and photochemical stability and wide range of applications. However, the wide band gap and low capacity of photo-induced charge separation provide lower catalytic activity; thus, improvement of these properties must be found. The doping of TiO2 with other elements, such as carbon nanoparticles (CNP) in a quantum dot form, offers a promising pathway to improve the aforementioned properties. In addition, in situ doping methods should be investigated for practical scalability, as they offer the advantage of integrating dopants directly during material synthesis, ensuring a more uniform distribution and better interaction between the dopant and the host material, in turn leading to more consistent photocatalytic properties. Current technologies primarily involve nanoparticle combinations. This work focuses on the development of a novel in situ synthesis methodology by the introduction of three different graphene-based quantum nanodots into anodic TiO2 and the following investigation of structural, morphological, and photocatalytic properties. Results indicate that the introduction of CNP allows for the shift of a set of parameters, such as the optical band gap, increased photo-induced charge carrier density of TiO2/CNP composite, and, most importantly, the change of crystalline phase composition depending on added CNP material. Research indicates that not only a higher concentration of added CNP enhances higher photocatalytic activity as tested by the degradation of methylene blue dye, but also the type of CNP determines final crystalline phase. For the first time brookite and rutile phases were obtained in anodic titania synthesized in inorganic electrolyte by introducing hydrothermally treated exfoliated graphene.

Solar Light Elimination of Bacteria, Yeast and Organic Pollutants by Effective Photocatalysts Based on Ag/Cr-TiO2 and Pd/Cr-TiO2.

This study focused on searching for more effective nanomaterials for environmental remediation and health protection; thus, coliform bacteria, yeast and the organic food dye sunset yellow were selected as target pollutants to be eliminated under solar light by Ag/Cr-TiO2 and Pd/Cr-TiO2. Firstly, Cr3+ was in situ incorporated into the anatase crystalline lattice by the sol-gel method; then, Ag or Pd nanoparticles were deposited on Cr-TiO2 by chemical photoreduction. The scientific challenge addressed by the development of these composites was to analyse the recovery of Cr, to be employed in photocatalyst formulation and the enhancement of the TiO2 photocatalytic activity by addition of other noble metals. By extensive characterization, it was found that after TiO2 doping with chromium, the parameters of the crystal lattice slightly increased, due to the incorporation of Cr ions into the lattice. The TiO2 band gap decreased after Cr addition, but an increase in the optical absorptions towards the visible region after noble metals deposition was also observed, which was dependent of the Ag or Pd loading. Generally, it was observed that the noble metals type is a factor that strongly influenced the effectiveness of the photocatalysts concerning each substrate studied. Thus, by using Ag(0.1%)/Cr-TiO2, the complete elimination of E. coli from samples of water coming from a highly polluted river was achieved. Pd(0.5%)/Cr-TiO2 showed the highest efficiency in the elimination of S. cerevisiae from a lab prepared strain. On the other hand, the Pd(0.1%)/Cr-TiO2 sample shows the highest dye degradation rate, achieving 92% of TOC removal after 180 min.

Modified Titanium Dioxide Nanoparticles for Photocatalytic Splitting of Water and Its Application in Environmental Remediation as a Potential Alternative

Herein we reviewed Titanium dioxide (TiO2) nanoparticles and how they are applied in the photocatalytic splitting of water to generate hydrogen but also to remove both organic and inorganic pollutants. Hydrogen generation through the splitting of water by TiO2 which is a cheap, efficient, and non-toxic photocatalyst has found wide application in clean energy production. The efficiency of the photocatalyst can be improved by using water or sacrificial agents as electron donors, thereby enhancing hydrogen production. In addition, this review explores the fundamental principles, mechanisms, and applications of TiO2-based photocatalysis. It further, highlights the structural properties, bandgap engineering, and surface modifications that influence the catalytic activity of TiO2. Additionally, we discuss the doping of TiO2 with both metals and non-metals to narrow the energy band gap which lowers the recombination effects. Finally, it introduces the potential applications of TiO2-based photocatalysis in the photodegradation of organic and inorganic pollutants.

Flexible TiO2-WO3−x hybrid memristor with enhanced linearity and synaptic plasticity for precise weight tuning in neuromorphic computing

Tungsten oxide (WO3)-based memristors show promising applications in neuromorphic computing. However, single-layer WO3 memristors suffer from issues such as weak memory performance and nonlinear conductance variations. In this work, a functional layer based on the hybrids of WO3−x and TiO2 is proposed for constructing flexible memristors featuring outstanding synaptic characteristics. Applying diverse electrical stimulations to the memristor enables a range of synaptic functions, elucidating its conduction mechanism through the conductive filament model. The incorporation of TiO2 not only enhances the memristor’s memory characteristics but makes its conductance more linear, symmetrical and uniform during the long-term changes. Furthermore, in view of the enhanced device performance by TiO2 doping, the potential of this device for simple behavioral simulation and processing of complex computing problems is explored. The “learning-forgetting-relearning” characteristics and device integrability are visually demonstrated. Applying the device to a convolutional neural network, the recognition accuracy of MNIST handwritten digits reaches 98.7%.

A study on the influence of metal Ag, Cu, and Fe doping on the morphological, structural, and photocatalytic activity of TiO2 nanostructures

Metal-doped TiO2 nanoparticles (NPs) were elaborated by a sol–gel method using n-butoxide of titanium (IV) as precursors. The resulting NPs were characterized by scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), Raman spectroscopy, and FTIR analysis. The SEM study shows the formation of a spheres-like structure. The EDX analysis proves the presence of Ag, Fe, and Cu on the doped TiO2 NPs. XRD and Raman spectroscopy analysis show that the doping inhibited the phase transformation and stabilized the anatase phase. The photocatalytic activity of prepared TiO2 NPs was evaluated in methylene blue (MB) photodegradation under UV irradiation. The results reveal that the doped TiO2 NPs were more efficient than undoped TiO2 NPs in the degradation of MB. The Cu-doped TiO2 NPs were found to be more efficient in this reaction with a degradation efficiency of about 92.31 % and a kinetic rate constant of about 10−2 min−1. The studies of the reactive species show that the holes are the main reactive species responsible for the photocatalytic oxidation of MB. Furthermore, the reusability studies showed that the photocatalysts are globally stable for the photodegradation of MB.

Photoluminescence and photocatalytic activity of sol gel synthesized Mg doped TiO2 nanoparticles

The influence of magnesium doping on the optical properties, structural characteristics, and photocatalytic performance of TiO2 nanoparticles was investigated. Pure and Mg-doped TiO2 nanoparticles with varying weight percentages of magnesium were synthesized via the sol–gel method, followed by calcination at 100 °C for 12 h and annealing at 400 °C for 2 h to promote crystallization. X-ray diffraction (XRD) analyses confirmed the formation of crystalline mixed phases of anatase and rutile TiO2 nanoparticles, exhibiting their crystalline nature upon synthesis. Scanning electron microscopy (SEM) images were employed to study the morphological features of the samples, while energy dispersive spectroscopy (EDS) provided insights into their elemental composition. Photoluminescence (PL) emission spectra revealed ultraviolet (UV) to visible region emission for both pure and doped TiO2 samples. The photocatalytic activity was evaluated by monitoring the degradation of methyl orange under natural sunlight irradiation, elucidating the impact of visible light exposure. Furthermore, investigations were conducted to assess the influence of catalyst loading, initial dye concentration, and pH of the dye solution on the methyl orange removal efficiency. The 3 wt% Mg doped TiO2 exhibited 95 % of decolorization of Methyl Orange. X-ray photoelectron spectroscopy measurements was performed to verify the elemental composition and chemical valence states of each element. The scavenger test in photodegradation mechanism revealed that the main reactive species was superoxide species. The electron species resonance (ESR) measurement demonstrate that the synthesized sample shows the low spin state of Mg2+ in TiO2. The correlation between Mg doping on photocatalytic activity and crystal structure were studied. Theoretical calculations were performed to gain insights into the potential mechanism underlying the tuning of luminescent and photocatalytic properties of Mg-doped TiO2 nanoparticles, enabling a comprehensive discussion.

Synergistic Effect of Sn Doping in TiO2 Nanoparticles as an Additive in Anti‐Corrosion Coatings

ABSTRACTCorrosion is a major problem and protective coatings offer an effective solution. However, organic coatings are often associated with microcracks caused by the evaporation of solvents during coating preparation. This study investigates the use of titanium dioxide (TiO2) nanoparticles as a coating additive to protect mild steel surfaces. Additionally, doping TiO2 with tin (Sn) is believed to enhance its properties due to the reduced size of the nanoparticles. These nanoparticles were synthesised using the sol–gel method and subjected to various analyses. The coated mild steel samples were prepared using the dip‐coating method and immersed in 3.5 wt.% sodium chloride (NaCl) solution for 30 days. Electrochemical impedance spectroscopy (EIS) and Tafel polarisation showed that the Sn‐doped TiO2 nanoparticles as an additive improved the corrosion resistance, as evidenced by a positive shift in corrosion potential (Ecorr) and reduced corrosion current density (Icorr).

Preparation of nano-TiO2 spherical catalyst doped with nonmetallic elements for potential use in CO2 reduction

Abstract P (St-HEA) microsphere was synthesized as template to prepare TiO2. Nano TiO2 spheres, nitrogen doped TiO2 (N-TiO2) spheres and sulfur doped TiO2 (S-TiO2) spheres were prepared by sol-gel method with the above template. The samples were characterized by XRD, SEM, and XPS. The results showed that TiO2 from sulfur and nitrogen atoms in thiourea and urea in situ doped in the crystal lattice. The TiO2 spherical catalyst doped with nonmetallic elements showed typical anatase phase at lower temperature, and spheres structure with pores and different particle size about 200 nm to 1μm. The obtained TiO2 spherical catalyst doped with nonmetallic elements may potentially use in the photo-catalysis of CO2 reduction.

Unveiling the power of TiO2 doped ZnO nanomaterial as an effective antimicrobial solution in the leather industry

The surface protection of leather supplies is a major concern worldwide due to its susceptibility to microbial growth. Different methods are employed to protect leather, their results ends up with the environmental pollution and human safety issues. Nanoparticles with excellent antimicrobial potential can provide sustainable protection to leather accessories. The present work represented a comprehensive investigation into the preparation and characterization of titanium dioxide-doped zinc oxide (ZnO/TiO2 NPs) nanoparticles and their exploring as a potential antimicrobial agent in the leather industry. ZnO nanoparticles were synthesized through Sol-gel method by the reduction of zinc acetate dihydrate via black cardamom seed's extract and subsequently doped with TiO2. The optical, structural, and morphological features of nanoparticles were thoroughly scrutinized through UV–visible spectroscopy, XRD, FT-IR, and SEM-EDAX. The UV–visible spectrum showed enhanced performance between 300 and 350 nm and various peaks of the FT-IR spectrum, i.e. 3315.53, 1566.20, 1402.25, 1340.53, 1014.56, 921.97, 690.52, and 677.01 cm−1, revealed chemical bonds that prove the correct doping of TiO2 in ZnO nanoparticles. The characteristic peaks obtained from XRD at 2Ө of 32°, 35.5°, 37.2°, 47.9°, 55.6° 63.51°, and 70° intimated to the crystal planes of (100), (002), (101), (102), (110), (103), and (112), respectively. SEM-EDAX images revealed the roughly spherical but agglomerated structure of nanoparticles with size 45.44 nm. Furthermore, minimum inhibitory concentration (MIC), antimicrobial potential, and anti-biofilm potential analyses of nanoparticles, against all selected microorganisms (Aspergillus niger, Staphylococcus aureus, and Escherichia coli) provided valuable insights into physical and biological properties of the nanoparticles. The clear zones of inhibition (29–30 mm) against these pathogenic strains showed exceptional antimicrobial action of the ZnO/TiO2 NPs. Overall, these results provide an approachable method to synthesize ZnO/TiO2 nanoparticles and their antimicrobial ability will prove to be beneficial for the protection of leather materials from various microbial contaminations.

Influence of TiO2 doping on the grain growth and electrical properties of ZnO–Cr2O3-based varistor ceramics

The influence of TiO2 doping in the range 0–1 mol% on the microstructure and electrical characteristics of ZnO–Cr2O3-based varistor ceramics was studied. Exaggerated grain growth is observed owing to the presence of TiO2, which triggers the formation of inversion boundaries (IBs) in only a limited number of grains. TiO2 acts as the controller of ZnO grain growth, adjusting the grain size of the ZnO from 5.6 to 9.3 μm, and thus controlling the breakdown voltage. Meanwhile, the TiO2 doping decreased the height of the Schottky barrier, resulting in a lower nonlinear coefficient and a higher leakage current. The results are important for the control of the ZnO grain size with ZnO–Cr2O3-based varistors (having different nominal breakdown voltages) to obtain a suitable thickness for applications.

Tweaking the structural, micro–structural, optical and dielectric properties of anatase titanium dioxide via doping of nitrogen ions

The pure nanostructured anatase titanium dioxide (TiO2) and subsequent nitrogen–doped derivatives (TiO2–xNx; where, x = 0.005, 0.01, 0.05) were synthesized by sol–gel auto–combustion technique. XRD analysis confirms the formation of pure anatase phase of TiO2 up to doping of 1 mol% (x = 0.01) of nitrogen having tetragonal structure with space group of I41/amd whereas an additional monoclinic phase of TiO2–B was observed at 5 mol% of nitrogen doping in TiO2. This sample has smallest crystallite size of ∼4.7 ± 0.2 nm corresponding to TiO2–B phase and ∼12.0 ± 0.1 nm corresponding to anatase phase. XRD also reveals that the crystallite size of all other samples having pure anatase phase ranges between ∼8.7 ± 0.1 nm & 13.9 ± 0.1 nm. The crystalline phase revealed from XRD of all samples was further supported by the Raman analysis. The direct optical band gap of pure TiO2 (∼3.4 eV) was reduced non–monotonically after nitrogen doping in the ranges from ∼2.8 eV (TiO1.95N0.05) to ∼2.0 eV (TiO1.99N0.01). FTIR spectra confirm the metal oxide bond formation, surface adsorption of water molecules and presence of residual hydroxyl group in all crystalline samples. HRTEM analysis validates the coexistence of secondary phase of TiO2–B along with anatase phase of TiO2 in studied highest doped sample (TiO1.95N0.05) including its broader particle size distribution as compared to pure TiO2. The electrical studies reveal that the highest values of dielectric constant and ac conductivity can be realized for pure TiO2 and at 1 mol% (x = 0.01) of nitrogen doping, among all the studied nitrogen doped samples.

Heterogeneous Photocatalytic Degradation of Selected Pharmaceuticals and Personal Care Products (PPCPs) Using Tungsten Doped TiO2: Effect of the Tungsten Precursors and Solvents.

Pharmaceuticals and personal care products (PPCPs) which include antibiotics such as tetracycline (TC) and ciprofloxacin (CIP), etc., have attracted increasing attention worldwide due to their potential threat to the aquatic environment and human health. In this work, a facile sol-gel method was developed to prepare tungsten-doped TiO2 with tunable W5+/W6+ ratio for the removal of PPCPs. The influence of solvents in the synthesis of the three different tungsten precursors doped TiO2 is also taken into account. WCl6, ammonium metatungstate (AMT), and Na2WO4●2H2O not only acted as the tungsten precursors but also controlled the tungsten ratio. The photocatalyst prepared by WCl6 as the tungsten precursor and ethanol as the solvent showed the highest photodegradation performance for ciprofloxacin (CIP) and tetracycline (TC), and the photodegradation performance for tetracycline (TC) was 2.3, 2.8, and 7.8 times that of AMT, Na2WO4●2H2O as the tungsten precursors and pristine TiO2, respectively. These results were attributed to the influence of the tungsten precursors and solvents on the W5+/W6+ ratio, sample crystallinity and surface properties. This study provides an effective method for the design of tungsten-doped TiO2 with tunable W5+/W6+ ratio, which has a profound impact on future studies in the field of photocatalytic degradation of PPCPs using an environmentally friendly approach.

Modification of Structural, Optical, and Electrical Properties of PVA/PVP Blend Filled by Nanostructured Titanium Dioxide for Optoelectronic Applications

The PVA/PVP/TiO2 films were prepared using different TiO2 concentrations by solvent casting technique. An analysis was conducted to investigate the influence of TiO2 on the characteristics of PVA/PVP blends. The FTIR, UV/visible spectroscopy, and electrical bridge circuits were used to characterize the prepared nanocomposite films. The structural changes of the nanocomposite relative to pure PVA/PVP are indicated by FTIR spectra. The optical studies demonstrate that by increasing the TiO2 concentration inside PVA/PVP blends, the band gaps reduce from 5.40 eV for PVA/PVP to 4.20 eV for PVA/PVP/TiO2 (10 wt%), also the refractive indices the nanocomposites increase from 1.2020 for PVA/PVP blend into 2.5380 for PVA/PVP/TiO2 (10 wt%). Also, the transmittance decreased from 97.6% for PVA/PVP blend to approximately 55.4% at the largest concentration of TiO2. Additionally, studies were conducted on the parameters, as well, ac conductivity (σ ac). The outcomes of dielectric parameters of the prepared films are enhanced by the doping of TiO2 with different concentrations and dielectric relaxation is observed. The hopping mechanism of PVA/PVP/TiO2 films is supported by the ac conductivity. It is found that adding 10 wt% TiO2 inside PVA/PVP matrix at 5 MHz increases the conductivity of the pure PVA/PVP blend by 4.46 times.

Thermodynamic Study of Mehtylene Blue Adsorption and Photocatalytic Degradation on The N‐Doped TiO2 Thin Films: A DFT and Experimental Study

AbstractN‐Doped TiO2 coatings (N‐TiO2) were synthesized and characterized. The effect of the doping process on the physical‐chemical properties and photocatalytic efficiency of Methylene Blue (MB) under visible light irradiation were studied. The bare TiO2 showed only anatase crystalline structure. Furthermore, after the doping process, a slight transition from anatase to rutile was verified. The HRXPS confirmed that the doping process was effective. The N2 sorption using the BET assay showed a slight increase in surface area after the doping process. MB adsorption kinetic showed also a slight increase for doped TiO2 films, showing as best fitting the Langmuir model. Furthermore, a modification on the electronic structure was observed, showed by the modification of the optical absorption profile in the doped material. The results showed that the MB adsorption on N‐TiO2 thin films was endothermic (▵H=11 kJ mol−1) and a spontaneous process (▵G=−6.45 kJ mol−1). We performed DFT calculations to three simulated doped‐structures. The Gap value, the global reactivity indexes and, the Fukui function isosurfaces are presented. Finally, the scavenger tests suggested that and OH⋅ could be the main ROS driving the photocatalytic process.

Dielectric properties of (N, B) and (N, Cl) co-doped rutile TiO2 ceramics

Extensive studies on TiO2-based colossal permittivity (CP, dielectric constant ε’ >103) materials have focused on the cation doping of metal elements; however, little attention has been paid to nonmetallic dopants. Compared to metallic elements, nonmetallic atoms with small radii and high activities, such as H, C, B, and N, can be used as anion-doping elements. Their incorporation into the TiO2 lattice includes interstitial and substitutional doping, which can influence the bandgap of TiO2 and its electron transport performance differently, thereby exhibiting considerable potential in TiO2-based applications. In this study, different N-containing compounds (BN and NH4Cl) were doped into rutile TiO2, while homogeneous ceramics of single-phase rutile TiO2 were prepared via solid-state sintering. The effects of co-doping N, Cl, and N, B on the dielectric properties of rutile TiO2 ceramics were investigated. While N and Cl doping showed no considerable effect on the dielectric properties of rutile TiO2 ceramics, the co-doping of N and B doping in rutile TiO2 considerably increased the dielectric constant to >104 with suppressed tan δ in a wide frequency range from 1 kHz to 10 MHz. These ceramics exhibited excellent frequency stability (up to 100 MHz) and temperature stability (153–513 K), which outperforms most reported transition metal co-doped TiO2 ceramics, thereby highlighting the untapped potential of the non-metallic dopants in enhancing dielectric materials.

Simultaneous effect of microwave sintering and TiO2 addition on sinterability, mechanical properties, and scratch resistance of zirconia toughened alumina ceramics

This paper delves into the transformative impact of varying titanium dioxide (TiO2) content on the sinterability, physical, and mechanical properties, as well as scratch behavior, of zirconia-toughened alumina (ZTA) ceramic composites. By adjusting TiO2 content from 0 wt% to 5 wt% and employing advanced microwave sintering at 1150 °C, the study aims to lower the sintering temperature of ZTA. Microwave sintering, known for its efficiency and rapid processing, enables significant enhancements in material properties at reduced temperatures. Notably, incorporating TiO2 into ZTA yields remarkable improvements in physical and mechanical attributes, with the optimal TiO2 content determined to be 3 wt%. At this concentration, the composite achieves exceptional properties: a relative density of ∼99 %, microhardness of ∼2002 HV, and an indentation fracture toughness of ∼6.13 MPa m0.5. These enhancements represent increases of over 120 % in hardness and 61 % in toughness compared to TiO2-free ZTA. Additionally, the highest scratch resistance is observed at 3 wt% TiO2, evidenced by a minimal scratch depth of ∼7.53 μm. However, exceeding the 3 wt% solubility limit results in the formation of secondary phases, such as tialite (Al2TiO5) and zirconium titanate (ZrTiO4), which degrade the composite's properties. This research underscores the potential of TiO2 doping and microwave sintering to elevate the performance of ZTA ceramics, offering a pathway to superior materials for advanced applications.

Nanoscale Graded Nitrogen-Doping of TiO2 via Pulsed Laser Deposition for Enhancing Charge Transfer in Perovskite Solar Cells.

An electron transport layer (ETL) for highly efficient perovskite solar cells (PSCs) should exhibit superior electrical transport properties and have its band levels aligned with interfacing layers to ensure efficient extraction of photo-generated carriers. Nitrogen-doped TiO2 (TiO2:N) is considered a promising ETL because it offers higher electrical conductivity compared to conventional ETLs made from spray-pyrolyzed TiO2. However, the application of highly doped TiO2:N in PSCs is often limited by the misalignment of energy band levels with adjacent layers and reduced optical transparency. In this study, a novel approach is introduced to enhance the charge transport characteristics and accurately align the electronic band alignment of TiO2:N layer through nanoscale doping level grading, achieved through the pulsed laser deposition (PLD) technique. The TiO2:N ETL with a graded doping profile can combine characteristics of both highly doped and lightly doped phases on each side. Furthermore, a nanoscale doping gradation, employing an ultrathin sub-layer structure with graded doping levels, creates a smoothly cascading band-level alignment that bridges the adjacent layers, enhancing the transport of photo-generated carriers. Consequently, this method leads to a substantial increase in the power conversion efficiency (PCE), exceeding 22%, which represents a relative improvement of 11% compared to traditional spray-pyrolyzed TiO2-based PSCs.

Enhanced photocatalytic activity of titanium-doped copper ferrite for methyl green dye degradation under commercial visible LED light

This study examines the effect of TiO₂ doping on the catalytic performance of copper ferrite (CuFe₂O₄) nanoparticles in degrading methyl green dye under visible light. Copper ferrite nanoparticles were synthesized and doped with varying TiO₂ concentrations. The catalysts were characterized using XRD, SEM, EDX, and BET surface area analysis. The TiO₂-doped copper ferrite catalysts showed significantly enhanced catalytic activity compared to undoped copper ferrite. The optimal doping concentration of 10 wt% TiO₂ achieved a degradation efficiency of 92 % for methyl green dye after 60 min of irradiation. The BET surface area increased with TiO₂ doping, contributing to the improved catalytic performance. Reusability tests over five cycles indicated a slight decrease in efficiency, attributed to the loss of active sites. These results indicate that TiO₂ doping effectively enhances the catalytic properties of copper ferrite, making it a viable option for environmental remediation.