查找使用阿拉丁产品的科研文献

Photocatalytic degradation of tetracycline hydrochloride by ZnO/TiO2 composite photocatalyst

Hu Lifang,Xing Mengting,He Xin,Yang Kun,Zhu Jichao,Wang Jianquan,He Jie,Shi Jianjun

Semiconductor photocatalytic technology is widely used in the degradation of antibiotic pollutants due to its easy operation, low energy consumption, and no secondary pollution. In this study, ZnO/TiO 2 composite photocatalysts with the different sturcture and the different content were constructed using layered double hydroxide as precursor. The structure and physicochemical properties of the photocatalysts were characterized by the different characterization technologyies, such as XRD, SEM, FT-IR, LRS, UV–vis DRS, N 2 adsorption–desorption isotherm, XPS, UPS, EIS, and so on. The photocatalytic degradation performance and mechanism for tetracycline hydrochloride were studied. The results show that the light response performances of the as-prepared samples are improved by a calcination process. The surface active sites are increased and the transport and separation efficiency of photogenerated electrons and holes are improved. Among them, ZnO/TiO 2 -200 has the fastest degradation rate and the best catalytic activity, and its maximum apparent rate constant is 0.9576 × 10 –3 L·mg −1 ·min −1 . The analysis of photocatalytic mechanism and energy band structure shows that the main active substance of the system is ·O 2 − , and the photocatalytic degradation process follows the type II heterojunction photocatalytic reaction mechanism. This study provides ideas for the design and construction of high-efficiency photocatalytic composites, and provides a reference for the photocatalytic degradation of other organic pollutants.

Synergizing W/H Co-Doping and Oxygen Vacancy Incorporation in TiO 2 for CO 2 Photoreduction

Qunhua Zhong,Yimeng Zhou,Tianle Ren,Jianjun Zhu,Di Li,Deli Jiang

Abstract Photocatalytic CO2 reduction to carbonaceous fuels is a promising strategy to mitigate massive carbon emissions, yet the highly selective CO2 conversion remains challenging due to the unsatisfactory charge separation and limited active sites of pristine semiconductor photocatalysts. Herein, we report the in situ fabrication of oxygen vacancy rich W/H co-doped rutile TiO2 (W/H-TiO2) via a two-step wet chemical approach for high-efficiency photocatalytic CO2 reduction to CO. The optimized W/H-TiO2 exhibited high activity and selectivity for the photocatalytic reduction of CO2 to CO (57.96 μmol g–1 h–1 and 96.3%), which were significantly higher than those of other TiO2 counterparts. Experimental characterizations and density functional theory (DFT) calculations reveal that the synergistic effect of H/W co-doping accelerates the migration and separation of photogenerated charge carriers and reduces the formation energy barrier for the key *COOH intermediate, thereby markedly boosting the CO2 photoreduction activity and product selectivity of W/H-TiO2. This work establishes a dual-doping-induced oxygen vacancy strategy for electronic structure engineering, providing a new paradigm for the rational design of high-performance TiO2 based photocatalysts toward efficient CO2 photoreduction.

Dewar-Chatt-Duncanson model-regulated adsorption-catalysis site migration in self-adaptive Cuδ+-SiO₂@TiO₂ aerogels for industrial CO₂ photoreduction

Meidan Que,Ziang Liu,Peihong Ma,Yanbo Sun,Shilei Cao,Xun Sun,Jun Xu,Liangliang Zhu

O₂ and UV synergistically establish Cu + /Cu 2+ equilibrium for exceptional oxygen tolerance. • The catalyst shows self-adaptive redox behavior and self-recovery capability for long-term stability. • A dual-site synergy via Dewar-Chatt-Duncanson mechanism enhances both CO₂ adsorption and reduction. Photocatalytic CO₂ reduction represents a promising solar-driven technology for converting CO₂ into high-value chemicals. Nonetheless, its practical application is significantly hindered by challenges such as low CO₂ concentration, competitive O₂ reduction, and photocatalyst instability under industrial conditions. To address these issues, a Cu δ+ -functionalized TiO₂@SiO₂ aerogel (TS-3HF-1Cu δ+ ) was synthesized via sol-gel, HF etching, and photoreduction. This catalyst enables durable CO₂ reduction under simulated flue gas and dilute conditions. Experimental results indicate that TS-3HF-1Cu δ+ photocatalyst exhibits CO and CH₄ production rates 2.21 and 1.57 times higher, respectively, than those of TS-3HF. Theoretical calculations based on the Dewar-Chatt-Duncanson model reveal that, Cu 2+ with partially vacant d orbitals, serves as the adsorption site to enhance CO₂ uptake by accepting σ-donation from CO₂ during reduction reaction. In contrast, Cu + , characterized by occupied d orbitals, serves as the active sites to facilitate electron transfer via π-backdonation, activating CO₂ for further reduction. The complementary functionality between the two valence states endows the catalyst with improved cycling stability in oxygen-rich environments and self-recovery capability, thus achieving photocatalytic performance restoration after 96 h of air exposure. These findings highlight the strong potential of Cu δ+ -modified catalysts toward practical industrial photocatalytic CO₂ reduction. Self-adaptive Cu δ+ sites in TiO₂@SiO₂ aerogels drive robust CO₂ photoreduction via reversible Cu + /Cu 2+ valence cycles. Regulated by the Dewar-Chatt-Duncanson model, this dual-site mechanism optimizes σ-donation and π-backdonation, ensuring exceptional stability and “self-recovery” even in oxygen-rich industrial environments. Download: Download high-res image (237KB) Download: Download full-size image

Synergistic effect of novel CS/N-TiO₂/NT coating and low temperature in prolonging the storage life of Stropharia rugosoannulata

Xingjun Lu,Kun Qiao,Xinyan Liu,Xiaozhen Peng,Bangzhu Peng

Postharvest Stropharia rugosoannulata deteriorates from fungal infection and active metabolism. A novel chitosan/nitrogen doped titanium dioxide/natamycin (CS/N TiO₂/NT) composite film was developedinhibiting Fusarium pseudoanthophilum and Talaromyces purpureogenus by 71.30% and 75.04%, with 132.20% higher tensile strength and 69.29% lower oxygen permeability. Preservation efficacy was markedly temperature dependent. At 25 °C, only marginal improvements were observed. At 10 °C, the coating significantly reduced total colony counts and modulated enzymatic activities, notably activating peroxidase, retarding the decline of superoxide dismutase (SOD), and inhibiting polyphenol oxidase. Optimal preservation was achieved at 4 °C, where respiratory intensity and microbial proliferation were suppressed while SOD activity was effectively sustained. Cox proportional hazards analysis further confirmed that coated samples stored at 4 °C exhibited a 33.33%–38.46% extension in storage life relative to uncoated controls. These findings establish a temperature responsive preservation strategy and provide a mechanistic framework for extending the shelf life of perishable mushrooms.

Co-doped black carbon nitride (BCN)@TiO₂ heterojunction: A bifunctional material for simultaneous solar evaporation and photothermal catalytic wastewater purification

Guohui Liang,Bohai Li,Lifen Liu

In response to the dual challenges of water scarcity and organic pollution, this study developed a dual-functional solar evaporator based on cobalt-doped BCN@TiO₂ heterojunctions (Co-BCT). The Co-BCT composite was prepared using a combination of sol-gel method and the hydrothermal method, and is uniformly embedded in a superhydrophilic melamine foam scaffold. Distinct from most reported integrated SDIE (solar desalination integrated with evaporation) -AOP (advanced oxidation process) systems that solely rely on photothermal-photocatalytic coupling, this system further integrates a Z -scheme heterojunction for efficient charge separation, a Co 2+ /Co 3+ redox cycle for boosted peroxymonosulfate (PMS) activation, and a superhydrophilic SA (sodium alginate) -MF (melamine foam) scaffold for self-desalination and rapid water transport—enabling multi-field synergy that addresses the trade-off between evaporation efficiency and pollutant degradation in complex systems. When exposed to simulated sunlight (1 Sun), the device achieves an evaporation rate of 2.51 kg·m −2 ·h −1 in pure water and 2.42 kg·m −2 ·h −1 in simulated seawater (3.5 wt% NaCl solution) with electrical stimulation. The system can efficiently degrade organic pollutants under solar power by activating PMS. Thanks to Co 2+ /Co 3+ -mediated PMS activation and a multi-pathway reactive oxygen species (ROS) generation mechanism (including ·OH, SO₄· − , ·O₂ − and h + ), over 98 % of Rhodamine B (RhB) is degraded within 30 min. Compared with recent Co-based PMS activators that suffer from limited ROS types or Co leaching, the atomically dispersed Co anchored at BCN nitrogen vacancies in Co-BCT not only enhances the generation of multi-type ROS but also improves catalytic stability, with no significant performance decay after 5 cycles. When applied to effluent from the biological treatment of coking wastewater, the system removes nearly all COD (51.36 mg/L to ~0 mg/L), with conductivity decreasing sharply from 2423.9 μS/cm to 21.2 μS/cm. The device also demonstrates excellent salt tolerance (evaporation rate ≥ 1.8 kg·m −2 ·h −1 in 15 wt% NaCl solution) and fouling resistance, as well as being applicable to wastewater treatment. This proves its feasibility and sustainability for use in complex wastewater purification and solar-driven seawater desalination.

Dual roles of TiO₂ nanoparticles under cadmium stress: Alleviating oxidative damage while exacerbating growth inhibition in rice (Oryza sativa L.)

Nan Zhao,Wendong Zhou,Xinran Yang,Lanxin Shi,Chang Liu,Chenyang Ji,Zezheng Li,Xichao Sun,Liwen Qiang

Cadmium (Cd) pollution poses a serious threat to agricultural ecosystems and food security. Titanium dioxide nanoparticles (TiO₂ NPs) have been proposed as a strategy to alleviate heavy metal stress, yet their effects under Cd exposure remain controversial. In this study, rice seedlings were exposed to Cd (0 or 30 mg/kg) with or without TiO₂ NPs (anatase or rutile; 0, 20, 50, or 100 mg/kg) for 40 days. Compared with the blank, Cd exposure alone did not significantly affect root length, root dry weight, shoot length, shoot dry weight, or chlorophyll content (ANOVA, p  > 0.05). In contrast, under Cd stress, TiO₂ NP treatment induced significant growth inhibition relative to the blank, with shoot length, root dry weight, and chlorophyll content reduced by 22–29 %, 27–47 %, and 29–41 %, respectively ( p  < 0.05). With respect to oxidative stress indicators, Cd exposure reduced antioxidant enzyme activities (e.g., peroxidase) and increased malondialdehyde levels, while co-treatment with TiO₂ NPs substantially reversed these alterations, restoring values close to those of the blank. Multi-omics analyses revealed that under Cd stress, anatase TiO₂ NPs alleviated oxidative stress by modulating flavonoid metabolism but impaired growth through energy disruption, whereas rutile exerted its effects via thiamine metabolism, amino acid metabolism, and the TCA cycle. These findings suggest that under Cd stress, crystal structure was not the primary determinant of TiO₂-mediated effects, as both anatase and rutile activated distinct molecular pathways yet converged on comparable physiological and growth outcomes. Overall, our results support a defense-growth trade-off model, in which TiO₂ NPs alleviate Cd-induced oxidative stress while concurrently exacerbating growth inhibition. The paradoxical role of TiO₂ NPs highlights the need for comprehensive safety assessments prior to their use in nano-enabled agriculture on heavy metal-contaminated soils.

Single-atom Pt-engineered TiO₂ photoanode enabling low-charge voltage and high-efficiency neutral Zn-air batteries via photoelectrochemical enhancement

Wenliang Wang,JiangYuan Qiu,Tao Yu,Shuming Zhang,Xingwang Niu,Rui Guo,Jinsheng Li,Xuanwen Liu

Neutral aqueous Zn-air batteries have emerged as a compelling alternative to conventional alkaline systems, retaining inherent corrosion resistance and long-term stability while preserving high theoretical energy density. However, their practical application is hindered by sluggish oxygen evolution/reduction reaction (OER/ORR) kinetics and low ionic conductivity in neutral electrolytes, which result in a substantial charge-discharge voltage gap exceeding 600 mV. To address these challenges, this study employs a facile acetonitrile-mediated photocatalytic radical strategy to synthesize TiO₂-supported platinum single-atom (Pt₁/TiO₂) photoanodes under ambient conditions. Compared to pristine TiO₂, the Pt₁/TiO₂ photoanode demonstrates a 73 % enhancement in photocurrent density (reaching 2.11 mA cm⁻²) in neutral electrolytes and retains 92 % of its initial activity after 10 h of continuous illumination. Density functional theory calculations reveal that Pt single atoms not only serve as active sites but also modulate the electronic structure of adjacent Ti atoms. This strengthened Ti 3d z ²−O 2p z ² orbital hybridization optimizes *O intermediate adsorption, thereby reducing the energy barrier (η) of the OER rate-determining step to 1.81 eV. By integrating the Pt₁/TiO₂ photoanode with a CuO photocathode, we construct a dual-electrode photo-assisted neutral Zn-air battery (DEPZAB) that achieves a low charging voltage of 0.81 V at 0.1 mA cm⁻² and a record-breaking round-trip efficiency of approximately 145 %, outperforming traditional alkaline systems in cycling stability. These findings underscore the transformative potential of single-atom engineering in advancing sustainable energy storage technologies.

Asymmetric electrode reactivity for controllable bleaching in a textile-based viologen electrochromic device with an Ag/TiO₂ inert counter electrode

Jingli Tang,Yichao Wang,Jiayu Ma,Yuanyuan Zhang,Liqian Huang,Xueli Wang,Jianyong Yu

Asymmetric electrode reactivity confines viologen redox to ITO interface. • Ag/TiO₂ conduction band edge prevents electron transfer to viologen. • Voltage polarity reversal achieves electrochemically controlled bleaching. • Textile-based planar device design suits wearable electrochromic applications. This study addresses the key challenge of slow bleaching kinetics in conventional viologen-based electrochromic devices (ECDs) employing solid/gel electrolytes by proposing a novel electrode engineering strategy based on differentiated electrode reactivity. The Ag/TiO₂ fabric electrode, due to the semiconducting properties of its TiO₂ coating, exhibits insufficient reducing power to drive the reduction and coloration of dissolved viologen cations. Leveraging this principle, an asymmetric planar ECD with reaction "directionality" was constructed, consisting of an ITO electrode paired with an Ag/TiO₂ fabric electrode in a side-by-side configuration. In this design, the viologen coloration/bleaching reactions are effectively "confined" to the ITO electrode interface. Simply switching the polarity of the applied voltage (±1.0 V) enables controllable coloration (7.4 s) and active bleaching (16.5 s), which is over 98% faster than the natural diffusion-driven bleaching observed under open-circuit conditions (>900 s). Unlike conventional approaches that require complementary electroactive layers or immobilized redox species, this strategy circumvents the slow spontaneous back-reaction solely through electrode-level thermodynamic control. Furthermore, by patterning the ITO electrode, its potential for applications in flexible displays was demonstrated. This work provides a novel and effective electrode engineering strategy for developing high-performance, rapidly switchable, and designable wearable electrochromic devices. Download: Download high-res image (182KB) Download: Download full-size image

High performance and colossal permittivity of (Nb+La) co-doped rutile TiO2 ceramics induced by composition regulation

Yang Yu,Wei-Li Li,Wei-Dong Fei

Enhanced energy storage performance in NBT-based MLCCs via cooperative optimization of polarization and grain alignment

Li Yang,Fan Ningbo,Wu Jie,Xu Bin,Li Xuexin,Liu Xuechen,Xiao Yizhou,Hou Dingwei,Feng Xinya,Zhang Jinjing,Zhang Shujun,Li Jinglei,Li Fei

Dielectric ceramics possess a unique competitive advantage in electronic systems due to their high-power density and excellent reliability. Na 1/2 Bi 1/2 TiO 3 -based ceramics, one type of extensively studied energy storage dielectric, however, often experience A-site element volatilization and Ti 4+ reduction during high-temperature sintering. These issues may result in increased energy loss, reduced polarization and low dielectric breakdown electric field, ultimately making it challenging to achieve both high energy storage density and efficiency. To address these issues, we introduce a synergistic optimization strategy that combine polarization engineering and grain alignment engineering. First principles calculations and experimental analyses show that the doping of Mn 2+ can suppress the reduction of Ti 4+ in Na 1/2 Bi 1/2 TiO 3 -based ceramics and enhance ion off-centering displacements, thereby reducing energy loss and improving polarization. In addition, we prepared multilayer ceramic capacitors with grains oriented along the <111> direction using the template grain growth method. This approach effectively reduces electric-field-induced strain by 37% and markedly enhances breakdown electric field by 42% when compared with nontextured counterpart. As a result of this comprehensive strategy, <111 >-textured Na 1/2 Bi 1/2 TiO 3 -based multilayer ceramic capacitors achieve an ultra-high energy density of 15.7 J·cm −3 and an excellent efficiency beyond 95% at 850 kV·cm −1 , exhibiting a superior overall energy storage performance.

Hydrogen-enhanced carbothermal reduction for the synthesis of TiC from TiO2

Tingting Lv,Tu Hu,Fang Tian

The conventional carbothermal reduction method for preparing titanium carbide (TiC) from titanium dioxide (TiO 2 ) suffers from high reaction temperature and long processing time, necessitating development of novel reduction processes to reduce energy consumption and improve efficiency. This study utilizing a composite reducing agent of C+H 2 for reducing TiO 2 enables the efficient synthesis of titanium carbide, combining the advantages of both carbon and hydrogen. Herein, we systematically compare titanium carbide synthesis in TiO 2 -C and TiO 2 -C-H₂ systems to elucidate the mechanism of hydrogen enhancement. Thermodynamic calculations compare the preparation processes of titanium carbide in two different systems and reveal the dual role of hydrogen: participation in the reduction reaction and lowering of the oxygen potential. Experimental results demonstrate that the introduction of hydrogen not only significantly increases the carburizing rate from 36.09% to 92.46%, promoting the formation of TiC x O 1-x as the dominant phase, but also doubles the CO content in the exhaust gas compared to the hydrogen-free system. Integrated theoretical-experimental analysis reveals the triple role of hydrogen in accelerating the TiO 2 →TiC x O 1-x transformation through: (1) synergistic reduction with both C and CO, (2) effective lowering oxygen potential of the system, which enhances the thermodynamic driving force to accelerate both the TiO 2 →Ti 2 O 3 reduction and subsequent carbide formation, and (3) increased pore volume generation within the titanium oxide matrix due to the superior diffusivity and reducing capability of hydrogen, thereby facilitating enhanced gas diffusion pathways. This study provides fundamental mechanistic insights into the hydrogen-enhanced carbothermal reduction process for efficient TiC synthesis from TiO₂.

Dual-function Ti⁴⁺/TiO₂ nanoparticles on beta zeolite for enhanced C–O bond cleavage of bio-oil methoxyphenol to produce polyphenol

Xiaopeng Shi,Jing Su,Qi Ouyang,Bingyan Sun,Linjia Yin,Xin Liu,Dingran Wang,Jianmeng Cen,Kaige Wang

Lignin-derived bio-oils contain abundant methoxyphenols exhibiting limited antioxidant activity, which requires their conversion to high-value polyphenols. This study develops titanium-loaded Hβ zeolite catalysts (xTi/Hβ) for the selective O-demethylation of methoxyphenols to catechols under subcritical aqueous conditions. Comprehensive characterization (XRD, XPS, STEM, NH₃-TPD, Py-FTIR) reveals that Ti exists as both framework-incorporated tetrahedral Ti⁴⁺ species (via Al³⁺ substitution) and surface-anchored anatase TiO 2 nanoparticles (NPs). The optimal 5Ti/Hβ catalyst maximizes synergistic effects: framework Ti sites enhance Brønsted acidity, while Ti NPs facilitate H 2 O enrichment near active sites. This achieves 99.46% conversion of 4-propylguaiacol to 4-propylcatechol. Applied to distilled bio-oil, 5Ti/Hβ reduces methoxyphenol content from 48.50 Area.% to 20.25 Area.% and increases total polyphenols from 25.39 Area.% to 43.64 Area.%. Catalyst stability challenges under prolonged hydrothermal conditions are identified for future optimization.