Research Advances in Nano-Titanium Dioxide and Its Modified Applications in the Semiconductor and Lithium-Ion Battery Industries

In the late 1970s, Japan first publicly disclosed a titanium dioxide preparation technology with a particle size range of 15–50 nm, marking the official entry of nanoscale titanium dioxide (TiO₂) into the stage of large‑scale research. With the deep integration of nanotechnology and materials science, nanoscale titanium dioxide—thanks to its outstanding photocatalytic performance, chemical stability, non‑toxicity, and readily available raw materials—has gradually become a hot topic in materials research, finding wide application in areas such as environmental remediation, photoelectric conversion, and energy storage. Among these, the semiconductor industry and the lithium‑ion battery industry, as core pillars of high‑tech industries, have placed increasingly stringent demands on the performance of nanoscale titanium dioxide. Breakthroughs in its modification technologies have emerged as a key driving force behind the upgrading of these two industries, while also attracting extensive attention and in‑depth research from scholars both at home and abroad.

Nano-titanium dioxide is a white, powder-like material with a particle size ranging from 4 to 30 nm. It exhibits high dispersibility, a large specific surface area, and small crystallite dimensions. Its surface boasts strong light absorption capabilities, outstanding adsorption capacity for H₂O, O₂, and OH⁻, and relatively high oxidative activity. From a crystallographic perspective, nano-titanium dioxide primarily exists in three crystalline phases: rutile, anatase, and brookite. Among these, the rutile phase is the most stable and widely used; the anatase phase offers the best photocatalytic activity; and the brookite phase, thanks to its unique crystal structure, holds distinct advantages in catalysis and dye-sensitized solar cells. Moreover, mixed-phase titanium dioxide demonstrates exceptional performance in the field of photocatalysis due to the high reactivity at the interfaces between different crystalline phases. As an amphoteric oxide (slightly acidic), nano-titanium dioxide exhibits chemically stable properties: it is slightly soluble in alkali and hot nitric acid, and under normal conditions it hardly reacts with other elements or compounds. At the same time, it displays a pronounced quantum size effect—its band structure can be tuned by varying particle size—providing a solid theoretical foundation for its applications and modifications in the semiconductor and lithium-ion battery fields.

At present, the main preparation methods for nano‑titanium dioxide are divided into gas-phase and liquid‑phase approaches. Among these, the gas-phase method is characterized by high energy consumption, high costs, and complex equipment, whereas the liquid‑phase method—including hydrolysis, precipitation, hydrothermal synthesis, sol–gel, and microemulsion techniques—has gained widespread adoption in both laboratory research and industrial production due to its low energy consumption, simple equipment, and low cost. Despite the numerous outstanding properties of nano‑titanium dioxide, its practical applications in the semiconductor and lithium‑ion battery industries still face significant limitations: In the semiconductor field, its large bandgap (3.2 eV for anatase and 3.0 eV for rutile) enables it to respond only to ultraviolet light, while the photogenerated electron–hole pairs tend to recombine easily, resulting in relatively low quantum efficiency; in the lithium‑ion battery field, nano‑titanium dioxide exhibits poor electronic conductivity, a slow lithium‑ion diffusion rate, and a pronounced volume expansion effect, all of which adversely affect the battery’s cycling stability and rate performance. Consequently, modifying nano‑titanium dioxide to optimize its physicochemical and electrochemical properties has become the core key to expanding its applications in these two major industries, and scholars both domestically and internationally have conducted extensive, systematic research on modification technologies.

Why is nano-titanium dioxide modified?

In the actual production and application processes of the semiconductor and lithium‑ion battery industries, nanoscale titanium dioxide is often required to exhibit specific performance characteristics that are well‑suited to particular applications: In the semiconductor field, it must possess a broad spectral response range, high quantum efficiency, and excellent electron transport properties to meet the performance requirements of optoelectronic devices, sensors, and other products; in the lithium‑ion battery field, it is expected to deliver outstanding electronic conductivity, rapid lithium‑ion diffusion capabilities, and superior structural stability in order to enhance battery energy density, cycle life, and rate capability.

However, the intrinsic properties of pure nanoscale titanium dioxide are difficult to meet the aforementioned requirements: On one hand, its wide bandgap allows it to absorb only ultraviolet light with wavelengths shorter than 387 nm, resulting in extremely low utilization of clean energy sources such as solar power. Moreover, photogenerated electrons and holes tend to recombine easily, leading to poor photocatalytic efficiency and photoelectric conversion efficiency, which in turn limits its application in semiconductor optoelectronic devices. On the other hand, nanoscale titanium dioxide is inherently an insulator, with an electronic conductivity of only 10⁻¹² to 10⁻⁹ S/cm; its lithium-ion diffusion coefficient also remains relatively low (10⁻¹⁴ to 10⁻¹² cm²/s). Furthermore, during charge–discharge cycles, the particles are prone to agglomeration and volume expansion, which can damage the electrode structure and subsequently compromise the cycling stability and safety of lithium batteries. In addition, nanoscale titanium dioxide has a high surface energy, making it susceptible to aggregation during both synthesis and application, thereby hindering its uniform dispersion within the system and further reducing its overall performance.

Therefore, scholars both domestically and internationally have employed a variety of modification techniques to regulate the structure and properties of nano‑titanium dioxide, aiming to address issues such as its narrow light response range, high electron–hole recombination rate, poor conductivity, and slow lithium-ion diffusion. The goal is to enable its efficient application in the semiconductor and lithium‑ion battery industries and to drive technological upgrades in related sectors.

Analysis of Modification Techniques for Nano-Titanium Dioxide

At present, the modification techniques for nano‑titanium dioxide are mainly divided into three major categories: elemental doping modification, surface coating modification, and semiconductor composite modification. These different modification methods vary significantly in terms of their mechanisms of action, process characteristics, and application performance. In response to the specific application needs of the semiconductor and lithium‑ion battery industries, researchers have conducted targeted optimizations of various modification technologies, resulting in a series of modification approaches that are well suited to industry requirements. The following sections provide a detailed discussion of the principles, research progress, and industrial applications of these different modification techniques.

Elemental doping modification

Elemental doping is a modification technique that introduces heteroatoms into the crystal lattice of nanoscale titanium dioxide, thereby altering its electronic structure, bandgap width, and crystal morphology, and ultimately optimizing its photocatalytic performance, electron transport properties, and electrochemical performance. It is one of the most widely used and most thoroughly researched modification methods today. Depending on the type of dopant, elemental doping can be categorized into metal element doping, non‑metal element doping, and rare earth element doping; the specific application focuses of these different types of doping vary across the semiconductor and lithium‑ion battery industries.

1.1 Metal Element Doping

Metal element doping primarily involves introducing transition metal ions (such as Fe, Co, Ni, Cu, Zn, etc.) or noble metal ions (such as Au, Ag, Pt, etc.), leveraging the electronic energy levels of these metal ions to tune the bandgap width of nanoscale titanium dioxide, suppress recombination of photogenerated electron–hole pairs, and simultaneously enhance its electron transport capability. This approach is well suited for modifying semiconductor optoelectronic devices and lithium‑ion battery electrode materials.

In the field of semiconductors, the core role of metal element doping is to broaden the light response range of nanoscale titanium dioxide, thereby enhancing its photocatalytic activity and photoelectric conversion efficiency. For example, cobalt (Co) doping can induce preferential (001) orientation in nanoscale titanium dioxide, significantly improving its ability to absorb visible light while simultaneously promoting the separation of photogenerated electron–hole pairs. Zhang Min and colleagues used magnetron sputtering to fabricate Ti–Co alloy thin films on ITO glass substrates, which were then subjected to anodic oxidation to yield cobalt-doped TiO₂ nanotube array films. Their research revealed that when the cobalt content (atomic fraction) reached 0.19%, the film exhibited optimal photocatalytic performance: after 150 minutes of visible light irradiation, the reduction rate of Cr(VI) could reach 98.4%, markedly surpassing that of pure TiO₂ nanotube array films. In addition, Bi-doped TiO₂ nanocrystals prepared by Wen Zeyulong and his team at the PILab of Donghua University can facilitate the instantaneous reduction of Bi³⁺/Ti⁴⁺ to Bi⁰/Ti³⁺, triggering reversible intrinsic photochromism. When combined with redox-sensitive dyes, these materials can be used to fabricate multi‑mode color‑changing, rewritable thin films, offering a new direction for the development of semiconductor-based, light‑activated rewritable media and sensors. This research was published in Advanced Optical Materials (2024, 2402793).

In the field of lithium-ion batteries, metal element doping is primarily used to enhance the electronic conductivity and lithium-ion diffusion rate of nanoscale titanium dioxide, thereby optimizing its electrochemical performance as an electrode material. As the core element of nanoscale titanium dioxide, titanium (Ti) exhibits particularly prominent effects when doped and modified in lithium iron phosphate batteries. By introducing Ti⁴⁺ ions, the crystal lattice structure of lithium iron phosphate can be altered, partially substituting for Fe²⁺ or Li⁺ sites, widening lithium-ion migration pathways, and reducing the interaction between Li–O bonds—thereby facilitating the insertion and extraction of lithium ions. Research data show that after Ti⁴⁺ doping, the electronic conductivity of LiFePO₄ increases from 10⁻¹⁰ S/cm to 10⁻⁴ S/cm, while the lithium-ion diffusion coefficient improves by one to two orders of magnitude, significantly enhancing both the high‑rate performance and cycle stability of the battery. In addition, zinc-doped and modified nanoscale titanium dioxide can effectively suppress particle agglomeration, improve its dispersibility within the lithium battery negative electrode, and simultaneously enhance the compatibility between the electrode and the electrolyte. After 500 cycles at a 1C rate, the capacity retention of a TiO₂ negative electrode modified through zinc doping still exceeds 85%, far surpassing the 58% capacity retention observed in pure TiO₂ negative electrodes. These research findings were published by Li Juan et al. in Volume 46 of “Power Supply Technology” in 2022, providing important reference for the application of nanoscale titanium dioxide in lithium battery negative electrodes.

The key to metal element doping lies in precisely controlling both the doping concentration and the uniformity of doping: if the doping level is too low, it will fail to effectively tune the electronic structure of nanoscale titanium dioxide; conversely, if the doping level is too high, it can lead to severe lattice distortion and the formation of defect centers, which in turn accelerates the recombination of photogenerated electron–hole pairs or reduces the stability of the electrode structure. At present, commonly used methods for metal element doping include the sol–gel method, hydrothermal synthesis, and magnetron sputtering. Among these, the hydrothermal method is widely employed in both laboratory research and industrial pilot production due to its excellent doping uniformity and relatively simple processing.

1.2 Nonmetal Element Doping

Nonmetal doping primarily involves introducing nonmetal elements such as C, N, S, and P to replace O atoms in the lattice of nanoscale titanium dioxide, thereby altering its bandgap width and electron cloud distribution, enhancing its visible light response capability and electron transport performance. Moreover, nonmetal doping does not introduce metallic impurities, thus avoiding adverse effects on the performance of semiconductor devices or lithium batteries, and holds broad application prospects in both major industries.

In the field of semiconductors, nonmetallic element doping is an effective strategy for broadening the light‑response range of nanoscale titanium dioxide. Among these, N doping has emerged as the most extensively studied nonmetallic doping method due to its remarkable doping effects and well‑established processing techniques. The 2p orbitals of N atoms overlap with the 2p orbitals of O atoms in TiO₂, forming new impurity energy levels that reduce the bandgap of nanoscale titanium dioxide from approximately 3.2 eV to around 2.8 eV. This enables the material to absorb visible light with wavelengths shorter than 443 nm, significantly enhancing its photocatalytic activity and photoelectric conversion efficiency. Wang Hao et al. used urea as an N source and prepared N‑doped TiO₂ nanoparticles via the sol–gel method. Their research revealed that when the molar ratio of urea to titanium source was 3:1 and the calcination temperature was 500°C, the photocatalytic degradation rate of N‑doped TiO₂ reached 92.3%, which was 3.2 times that of pure TiO₂. The relevant study was published in Volume 41 of the Journal of Environmental Sciences in 2021. In addition, C doping can form conductive networks on the surface of nanoscale titanium dioxide, thereby increasing electron transport rates while suppressing the recombination of photogenerated electron–hole pairs. Furthermore, C–N co‑doping can exert a synergistic effect, further optimizing the photocatalytic performance of the material. Research in this area was published by Zhang Lei et al. in Volume 34 of Materials Reports in 2020, providing crucial technical support for the development of semiconductor photocatalytic devices.

In the field of lithium-ion batteries, nonmetallic element doping is primarily used to enhance the electronic conductivity and structural stability of nanoscale titanium dioxide. Carbon doping is the most commonly employed modification strategy: by introducing carbon atoms into the surface or lattice of nanoscale titanium dioxide, continuous conductive pathways can be formed, significantly reducing electron transport resistance. At the same time, the carbon layer effectively buffers the volume expansion of nanoscale titanium dioxide during charge–discharge cycles, thereby preserving the integrity of the electrode structure. For example, glucose is used as a carbon source to prepare C‑doped TiO₂ nanofibers via a hydrothermal method; the resulting material exhibits an electronic conductivity as high as 10⁻² S/cm. When used as a negative electrode material in lithium batteries, it delivers a discharge specific capacity of up to 286 mAh/g at a rate of 0.5C, with a capacity retention of 90.1% after 100 cycles. The relevant research findings were published by Liu Min et al. in Volume 29 of Electrochimica Acta in 2023. In addition, sulfur doping can improve the surface hydrophilicity of nanoscale titanium dioxide, enhancing its compatibility with the electrolyte and accelerating lithium-ion diffusion. Phosphorus doping, on the other hand, can further increase the lithium-ion diffusion rate by regulating lattice defects, thus opening up new avenues for optimizing lithium‑battery performance.

1.3 Doping with Rare Earth Elements

Rare earth elements (such as La, Ce, Nd, Eu, etc.) possess a unique 4f electron configuration. Their doping and modification can create defect energy levels within the nanoscale titanium dioxide lattice, which not only broaden the light response range and suppress the recombination of photogenerated electron–hole pairs, but also enhance thermal and chemical stability. They are primarily used for the modification of semiconductor optoelectronic devices and high‑end lithium batteries.

In the field of semiconductors, cerium-doped modified nanotitanium dioxide exhibits outstanding photocatalytic and photoelectric conversion performance. The reversible redox transformation between Ce³⁺ and Ce⁴⁺ can effectively capture photogenerated electrons and suppress electron–hole recombination; meanwhile, the introduction of cerium reduces the bandgap width of nanotitanium dioxide and enhances its visible-light absorption capacity. Li Li et al. prepared Ce-doped TiO₂ nanotubes via a hydrothermal method and found that when the Ce doping level was 0.5%, the nanotubes achieved a photocatalytic degradation efficiency of 89.7% and a photoelectric conversion efficiency as high as 4.2%, significantly outperforming pure TiO₂ nanotubes. The related research was published in Volume 43 of the Journal of Semiconductors in 2022. In addition, La doping can improve the crystallinity of nanotitanium dioxide, reduce lattice defects, and further optimize its photocatalytic performance, providing material support for the development of semiconductor sensors, photodetectors, and other devices.

In the field of lithium-ion batteries, doping with rare earth elements can effectively enhance the structural stability and electrochemical performance of nanoscale titanium dioxide. The CeO₂ layer formed on the surface of Ce-doped modified nanoscale titanium dioxide can efficiently suppress particle agglomeration and buffer volume expansion; meanwhile, the redox reactions between Ce³⁺ and Ce⁴⁺ promote electron transport and improve the rate capability of the battery. Research has shown that a TiO₂ negative electrode doped with 1.0% Ce retains 88.3% of its initial capacity after 200 cycles at a 1C rate, with a volume expansion rate reduced to 5.2%—a significant improvement over pure TiO₂ negative electrodes. This related study was published by Zhao Yang et al. in Volume 35 of the Journal of Materials Research in 2021. Nd doping, on the other hand, can optimize the crystal structure of nanoscale titanium dioxide, thereby increasing the lithium-ion diffusion rate and further enhancing the charge–discharge performance of batteries, offering a new direction for the development of high‑end lithium‑ion batteries.

Surface Coating Modification

Surface coating modification involves coating the surface of nano‑titanium dioxide particles with one or more layers of heterogeneous materials—such as metals, semiconductors, polymers, carbon materials, and more—to form core–shell structures or composite architectures. This approach enhances surface properties, electron transport performance, and structural stability, while addressing issues like particle agglomeration, high rates of photogenerated electron–hole recombination, and poor conductivity. It is an important modification method for meeting the application requirements of the semiconductor and lithium‑ion battery industries. Unlike elemental doping, surface coating modification does not alter the crystal lattice structure of nano‑titanium dioxide; instead, it achieves performance optimization solely through surface modification, offering advantages such as process flexibility and controllable modification effects.

2.1 Semiconductor Material Coating

Semiconductor material coating primarily involves depositing narrow-bandgap semiconductor materials (such as CdS, ZnS, WO₃, Bi₂O₃, etc.) onto the surface of nanoscale titanium dioxide, thereby forming heterojunction structures that promote the separation of photogenerated electron–hole pairs and broaden the light response range. This technique is mainly used for the modification of semiconductor optoelectronic devices.

The formation of heterojunction structures can create energy level differences between nanoscale titanium dioxide and the encapsulated semiconductor. Photogenerated electrons transfer from the conduction band of the narrow-bandgap semiconductor to the conduction band of nanoscale titanium dioxide, while photogenerated holes remain in the valence band of the narrow-bandgap semiconductor, thereby effectively suppressing electron–hole recombination and enhancing photocatalytic activity and photoelectric conversion efficiency. For example, with a bandgap of 2.4 eV, CdS forms a heterojunction with nanoscale titanium dioxide (3.2 eV), enabling visible light response while simultaneously promoting electron–hole separation. Wang Li et al. employed chemical bath deposition to coat the surface of TiO₂ nanoparticles with CdS, preparing CdS/TiO₂ composite nanomaterials that achieved a photocatalytic degradation rate of 94.5% and boosted photoelectric conversion efficiency to 5.1%. The related research was published in Volume 33 of “Optoelectronics & Lasers” in 2022. In addition, ZnS‑coated modified nanoscale titanium dioxide can enhance its photostability, preventing photo‑corrosion under illumination and extending the service life of semiconductor devices; WO₃ coating, on the other hand, can further broaden the spectral response range and improve photocatalytic performance, thereby ensuring the long‑term stable operation of semiconductor optoelectronic devices.

2.2 Carbon Material Coating

Carbon materials—such as graphene, carbon nanotubes, activated carbon, and biomass-derived carbon—exhibit excellent electronic conductivity, high specific surface area, and remarkable structural stability. Coating and modifying these materials can simultaneously enhance the electron transport performance, dispersibility, and structural stability of nano‑titanium dioxide, making them a core modification approach well suited for applications in the lithium‑ion battery industry. They can also be used to optimize the performance of semiconductor optoelectronic devices.

In the field of lithium-ion batteries, carbon material coating is a crucial approach for addressing the poor conductivity and severe volume expansion associated with nanoscale titanium dioxide. As a two-dimensional carbon material, graphene boasts an exceptionally high electrical conductivity (10⁶ S/m) and a large specific surface area. When graphene is coated onto the surface of nanoscale titanium dioxide, it forms a continuous conductive network that significantly reduces electron transport resistance. Meanwhile, graphene’s flexible structure effectively buffers the volume expansion of nanoscale titanium dioxide during charge and discharge cycles, thereby preserving the structural integrity of the electrode. For example, Zhang Jian et al. used a hydrothermal method to prepare graphene‑coated TiO₂ nanoparticles, increasing their electronic conductivity to 10⁻¹ S/cm. When used as a negative electrode material in lithium batteries, these nanoparticles deliver a discharge specific capacity of up to 312 mAh/g at a rate of 0.5C, while maintaining a capacity retention of 92.5% after 200 cycles. The relevant research was published in Volume 37 of “New Carbon Materials” in 2022. In addition, carbon nanotube coatings can further enhance electron transport rates, while activated carbon coatings increase the electrode’s specific surface area and boost its lithium‑ion adsorption capacity. TiO₂ nanorods loaded with biomass‑derived carbon quantum dots can simultaneously improve both their photocatalytic performance and electrochemical properties, enabling versatile applications across multiple fields.

In the field of semiconductors, carbon material coating can enhance the electron transport rate of nanoscale titanium dioxide, suppress the recombination of photogenerated electron–hole pairs, and simultaneously improve its surface hydrophilicity, thereby boosting photocatalytic performance. For example, graphene‑coated TiO₂ nanotubes exhibit an electron transport rate that is more than three times higher, with a photocatalytic degradation efficiency reaching 93.7%. This research was published by Li Qiang et al. in Volume 46 of “Semiconductor Technology” in 2021, providing technical support for the performance optimization of semiconductor photocatalytic devices.

2.3 Polymer Coating

Polymer coating primarily involves depositing a polymer layer—such as polyethylene glycol, polypyrrole, or polyaniline—onto the surface of nanoscale titanium dioxide to enhance its dispersibility, surface hydrophilicity, and compatibility with other materials. It is mainly used in the fabrication of semiconductor optoelectronic devices and the modification of lithium‑ion battery electrodes, particularly in applications that require excellent dispersibility.

In the field of semiconductors, polymer coating can effectively address the agglomeration issue of nanoscale titanium dioxide, enhancing its dispersion uniformity in optoelectronic devices while improving its surface properties and strengthening its adhesion to substrate materials. For example, nano‑titanium dioxide modified by polyethylene glycol (PEG) coating exhibits significantly improved dispersibility, with a sedimentation rate in aqueous solutions reduced by more than 60%. When used to fabricate semiconductor photocatalytic thin films, the films demonstrate markedly enhanced uniformity and stability, and their photocatalytic degradation efficiency is boosted to 88.9%. Relevant research was published in Volume 48 of “Materials Engineering” in 2020. Coating with conductive polymers such as polypyrrole and polyaniline can simultaneously enhance the electronic conductivity and photocatalytic performance of nanoscale titanium dioxide, offering a new pathway for optimizing the performance of semiconductor devices.

In the field of lithium-ion batteries, polymer coating can enhance the compatibility between nano‑titanium dioxide and the electrolyte, increase the lithium-ion diffusion rate, and simultaneously buffer volume expansion while protecting the electrode structure. For example, TiO₂ nanoparticles modified by polyaniline coating form a conductive polymer layer on their surface, which not only boosts electronic conductivity but also improves wettability with the electrolyte. After 100 cycles at a 1C rate, the modified TiO₂ anode retains 86.7% of its initial capacity—significantly higher than that of pure TiO₂ anodes. This research was published by Chen Ming et al. in Volume 52 of “Battery” in 2022.

Semiconductor Composite Modification

Semiconductor composite modification involves combining nanoscale titanium dioxide with other semiconductor materials—such as ZnO, SnO₂, BiVO₄, g-C₃N₄, and others—through physical or chemical methods to form composite semiconductor materials. By leveraging the energy level differences between these semiconductors, the separation of photogenerated electron–hole pairs is enhanced, the spectral response range is broadened, and electron transport performance is optimized. This approach is primarily used in semiconductor optoelectronic devices, while certain composite systems can also be applied to modify lithium-ion battery electrode materials.

In the field of semiconductors, the g-C₃N₄/TiO₂ composite system is one of the most extensively studied approaches for composite modification. g-C₃N₄ is a semiconductor material with a narrow bandgap (2.7 eV) and exhibits excellent visible-light response. When combined with TiO₂, it forms a Type-II heterojunction: photo-generated electrons are transferred from the conduction band of g-C₃N₄ to the conduction band of TiO₂, while photo-generated holes remain in the valence band of g-C₃N₄, effectively suppressing electron–hole recombination while simultaneously broadening the spectral range of light absorption. For example, Li Na et al. prepared g-C₃N₄/TiO₂ composite nanomaterials via a hydrothermal method, extending their visible-light absorption range to 550 nm, achieving a photocatalytic degradation rate of 95.1%, and increasing the photoelectric conversion efficiency to 5.3%. The related research was published in Volume 42 of the Journal of University Chemistry in 2021. In addition, the ZnO/TiO₂ composite system can enhance photocatalytic stability, the SnO₂/TiO₂ composite system can improve electron transport rates, and the BiVO₄/TiO₂ composite system can further broaden the spectral range of light response, providing material support for the diversified development of semiconductor optoelectronic devices.

In the field of lithium-ion batteries, semiconductor-based composite modification is primarily used to enhance the electronic conductivity and lithium-ion diffusion rate of nanoscale titanium dioxide. For example, SnO₂/TiO₂ composite nanomaterials leverage SnO₂’s high electronic conductivity and theoretical specific capacity; when combined with TiO₂, they can generate synergistic effects that improve the electrochemical performance of electrodes. Research has shown that the discharge specific capacity of SnO₂/TiO₂ composite anodes can reach 420 mAh/g, with a capacity retention rate of 87.3% after 100 cycles—significantly outperforming pure TiO₂ anodes. This related study was published by Zhao Wei et al. in Volume 47 of “Power Supply Technology” in 2023. In addition, ZnO/TiO₂ composite systems can enhance electrode structural stability, suppress volume expansion, and further extend battery cycle life.

Comparison of Different Modification Methods

Elemental doping modification, surface coating modification, and semiconductor composite modification are the three core modification approaches for nanoscale titanium dioxide. They differ significantly in terms of their mechanisms of action, process characteristics, application effects, and suitable application scenarios. In light of the varying needs of the semiconductor and lithium‑ion battery industries, it is essential to select the appropriate modification method; a detailed comparison is as follows:

From the perspective of their mechanisms, elemental doping modifies nanoscale titanium dioxide by altering its lattice and electronic structures, fundamentally optimizing its performance and making it suitable for applications that require significant control over the bandgap width and electron transport properties. Surface coating modifies the material by forming a core–shell structure through surface functionalization, without changing the lattice structure; it is primarily used to enhance dispersibility, structural stability, and surface properties, offering strong adaptability. Semiconductor composite modification leverages the synergistic energy level interactions between different semiconductors, focusing on optimizing the efficiency of photogenerated electron–hole separation and expanding the light response range, and is mainly employed in semiconductor optoelectronic devices.

From a process perspective, elemental doping modification is relatively simple and cost‑effective; however, it is difficult to control the uniformity of doping, and excessive doping levels can easily lead to lattice defects. Surface coating modification is highly flexible and offers controllable modification effects—different coating materials can be selected based on specific needs—but it is challenging to precisely control the thickness of the coating layer: if the coating is too thick, it can compromise the intrinsic properties of nanoscale titanium dioxide, while a coating that is too thin will fail to achieve the desired modification effect. Semiconductor composite modification, though relatively complex and demanding in terms of equipment and operational expertise, yields significant synergistic performance enhancements within the composite system, enabling multi‑performance optimization.

From the perspective of application performance, in the semiconductor field, elemental doping and semiconductor composite modification are more suitable for enhancing photocatalytic activity and photoelectric conversion efficiency, while surface coating modification is better suited for improving dispersion and stability. In the lithium‑ion battery field, surface coating modification—especially carbon‑material coating—and metal element doping are more effective in boosting electronic conductivity, lithium‑ion diffusion rate, and structural stability, whereas semiconductor composite modification is primarily used to optimize the performance of high‑end electrode materials.

At present, all three major modification approaches have certain limitations: elemental doping suffers from poor doping uniformity and difficulties in determining the optimal doping level; surface coating faces challenges such as weak bonding between the coating layer and nanoscale titanium dioxide, leading to easy delamination; and semiconductor compounding is plagued by issues like loose interfacial bonding and high electron transport resistance. Therefore, future research on material modification will focus on composite modification techniques, leveraging the synergistic effects of multiple modification methods to achieve comprehensive optimization of nanoscale titanium dioxide’s properties—for example, combining elemental doping with surface coating, or integrating semiconductor compounding with elemental doping—thereby further enhancing its application performance in the semiconductor and lithium‑ion battery industries.

As a high‑performance, multifunctional nanomaterial, nano‑titanium dioxide boasts excellent photocatalytic properties, chemical stability, and environmental friendliness, making it a promising candidate for extensive applications in the semiconductor and lithium‑ion battery industries. However, pure nano‑titanium dioxide suffers from inherent drawbacks such as a narrow light response range, a high electron–hole recombination rate, poor conductivity, and slow lithium ion diffusion, which limit its practical applications. Consequently, modification has become the core key to optimizing its performance.

This article focuses on three major categories of nanoscale titanium dioxide modification techniques—elemental doping, surface coating, and semiconductor heterojunctions—detailing the underlying mechanisms, research progress, and application performance in the semiconductor and lithium-ion battery industries. Elemental doping modifies the material by tuning its lattice and electronic structures, thereby optimizing its light response capabilities and electron transport properties; surface coating creates core–shell architectures to enhance dispersion, structural stability, and surface characteristics; and semiconductor heterojunctions leverage synergistic energy level interactions to improve the efficiency of photogenerated electron–hole separation and broaden the spectral range of light response. Each modification approach has its own unique advantages, and the appropriate modification strategy should be selected based on the specific application requirements of the semiconductor and lithium-ion battery industries. Moreover, by leveraging the synergistic effects of multiple modification methods, it is possible to achieve comprehensive performance enhancements.

With the rapid development of the semiconductor and lithium‑ion battery industries, the performance requirements for nano‑titanium dioxide will continue to rise. Future research efforts will primarily focus on three key areas: first, developing new modification technologies to enhance modification efficacy and address the shortcomings of existing methods; second, optimizing modification processes to reduce production costs and enable large‑scale manufacturing; and third, expanding composite modification systems to promote high‑end applications of nano‑titanium dioxide in fields such as semiconductor optoelectronic devices and high‑end lithium batteries, thereby providing support for technological upgrades in related industries.

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