查找使用阿拉丁产品的科研文献

Activated Carbon Supported Mo-Ti-N Binary Transition Metal Nitride as Catalyst for Acetylene Hydrochlorination

Hui Dai,Mingyuan Zhu,Haiyang Zhang,Feng Yu,Chao Wang,Bin Dai

Recently, many scientists have focused on the development of green industrial technology. However, the process of synthesizing vinyl chloride faces the problem of Hg pollution. Via a novel approach, we used two elements Mo and Ti to prepare an inexpensive and green binary transition metal nitride (BTMN) as the active ingredient in a catalyst with nano-sized particles and an excellent degree of activation, which was supported on activated carbon. When the Mo/Ti mole ratio was 3:1, the conversion of acetylene reached 89% and the selectivity exceeded 98.5%. The doping of Ti in Mo-based catalysts reduced the capacity of adsorption for acetylene and also increased the adsorption of hydrogen chloride. Most importantly, the performance of the BTMN excelled those of the individual transition metal nitrides, due to the synergistic activity between Mo and Ti. This will expand the new epoch of the employment of transition metal nitrides as catalysts in the hydrochlorination of acetylene reaction.Keywords:binary transition metal nitride;acetylene hydrochlorination

Enhanced electrocatalytic oxidation of high-salinity quaternary ammonium compound wastewater using CNTs-(RuₓIrᵧO₂)/Ti Anode

Hao-Tian Liu,Han-Qing Zhao,Yi-Rui Yang,Shuang Wu,Jia-Ping Huang,Rui-Han Yu,Hongcheng Bai,Aqiang Ding,Daijun Zhang,Peili Lu

The organic pollutants, such as quaternary ammonium compounds, in high salinity flowback water from shale gas extraction may pose a severe risk to public health. Conventional biological technologies have limited effectiveness in the treatment of high-salt wastewaters, whereas electrocatalytic oxidation has shown potential for treating organic pollutants in high-salt flowback water. This study developed a carbon nanotubes (CNTs) doped Ru/Ir oxide coated Ti electrode CNTs-(Ru x Ir y O 2 )/Ti, which exhibited enhanced electrocatalytic performance for the treatment of quaternary ammonium compound in high-salt wastewater compared to the control metal oxide coated Ti anode (Ru x Ir y O 2 )/Ti, with pseudofirst-order reaction rate constant improved from 7.36 × 10 −3 to 1.12 × 10 −2 min −1 . Moreover, the CNTs-(Ru x Ir y O 2 )/Ti anode electrocatalytic oxidation system exhibited excellent cycling stability. Mechanism studies indicated that the CNTs-(Ru x Ir y O 2 )/Ti electrode enhanced singlet oxygen ( 1 O 2 ) generation, which played a major role in pollutant degradation. Furthermore, the formation of high concentrations of HClO and H 2 O 2 further facilitated the generation of 1 O 2 . This study may provide an efficient and green technology for the treatment of organic pollutants in high-salt shale gas flowback water.

Efficient photocatalytic removal of typical water pollutants synergized by nitrogen defects and Fe-Ti alloy

Di Wang,Jing Wang,Yiqiang Wu,Delin Sun,Wenlei Wang

Transition metal ions and non-metal co-doped carbon-based materials have attracted extensive attention due to their unique properties and excellent catalytic effect. Fe 2 O 3 /TiO 2 @Fe/Ti-N-C multifunctional photocatalyst with Fe-Ti alloy and abundant nitrogen defects was reported. The photocatalytic results showed that the removal rates of Cr (VI), Congo red (CR) and levofloxacin (LFX) in water by Fe 2 O 3 /TiO 2 @Fe/Ti-N-C were 88.46, 96.71 and 99.06 %, respectively. The photoelectric test results show that bimetallic conjugated structure of Fe and Ti can effectively increase the light absorption range and accelerate the carrier separation. N-defects can significantly increase the lifetime and concentration of photogenerated holes, thereby improving the catalytic efficiency of the photocatalyst. The single factor experiments proved that the optimal pH for the degradation of Cr(VI), CR and LFX by Fe 2 O 3 /TiO 2 @Fe/Ti-N-C was 1, 11 and 9, respectively. In addition, Ca 2+ and Mg 2+ promoted the degradation of Cr(VI) and inhibited the degradation of CR and LFX. SO 4 2- inhibited the degradation of Cr(VI) and promoted the degradation of CR and LFX. Cl - inhibited the degradation of Cr(VI), CR and LFX. This study elucidates the mechanism of N-defects and bimetallic sites in photocatalytic reactions, and provides theoretical support for efficient removal of heavy metals and organic pollutants in water.

Highly thermally stable Ti/Si/B modified bisphenol A-phenolic resins with co-continuous structure

Wang Jianwen,Huang Siyu,Shi Fengyue,Yang Yang,Yang Xinjia,Li Jun,Zhao Guangdong

The synthesis of Bisphenol A Glutaraldehyde Phenolic Resin (BPA-GA PF) was carried out under alkaline conditions using Bisphenol, A (BPA) and Glutaraldehyde (GA) as raw materials, with n-butanol serving as the solvent. Based on the aforementioned information, the researchers prepared modified BPA-GA PF resins by incorporating titanium (Ti), silicon (Si), and boron (B) through a polymer derivative method. This process led to the formation of Ti/Si/B-modified PF resins. By manipulating the proportion of elements in the BPA-GA PF, the modified phenolic resin demonstrated improved capacity for design and processing. The characterization of the modified BPA-GA PF involved the analysis of its transformation process and thermal behavior through the utilization of Fourier transform infrared spectroscopy (FT-IR) and thermogravimetric Analysis (TGA). The presence of B, Ti, and Si elements in the system resulted in the formation of Si–O-B and B-O bonds, as determined. The Ti/Si/B -modified PF exhibited a significant increase in yield. Analysis employing X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM) revealed that, following high-temperature annealing, the materials underwent a transformation into Ti/Si/B-modified PF with a highly cross-linked network structure. Oxidation experiments conducted under static conditions demonstrated that the Ti/Si/B-modified BPA-GA PF exhibited significantly greater high-temperature resistance compared to the BPA-GA PF. Among the various options, the Ti/Si/B-modified PF material with a Ti/Si ratio of 1:2 exhibited the most superior resistance to high-temperatures.

High-Performance and Stable Perovskite X-ray Detection and Imaging Based on a Ti Cathode

Wenqing Zhang,Hu Wang,Zhilong Chen,Pengxiang Wang,Xin Liu,Hao Dong,Jiaoling Zhao,Yun Cui,Yuchuan Shao

High-energy radiation detectors with a good imaging resolution, fast response, and high sensitivity are desired to operate at a high electric field. However, strong ion migration triggered by electrochemical reactions at the interface between a high-potential electrode and an organic–inorganic hybrid perovskite limits the stability of radiation detectors under a high electric field. Herein, we demonstrate that such ion migration could be effectively suppressed in devices with a Ti cathode, even at a high electric field of 50 V mm–1, through time-of-flight secondary-ion mass spectrometry. X-ray photoelectron spectroscopy illustrates that Ti–N bonds formed at the interface of MAPbBr3 perovskite single crystals/Ti electrode effectively inhibit the electrochemical reaction in organic–inorganic hybrid perovskite devices and ultimately improve the operating stability under a high electric field. The device with a Ti electrode reaches a high sensitivity of 96 ± 1 mC Gyair–1 cm–2 and a low detection limit of 2.8 ± 0.3 nGy s–1 under hard X-ray energy.

Ultralow Temperature Sintering of High-Performance Sm-Doped Pb(Zr,Ti)O3-Based Piezoelectric Ceramics

Zechi Ma,Zixuan Yuan,Zhonghua Yao,Jiangxue Chen,Hua Hao,Minghe Cao,Hanxing Liu

Piezoelectric materials (PZTs) enjoy extensive applications in the field of electromechanical sensors due to their sensitive response to external electric fields. The limited piezoelectric response for single-layer piezoceramic pellets drives the use of multilayered technology to increase the electric displacement of a single piezo device. As is well known, Ag is commonly used as a metal for electrodes in devices based on traditional PZTs, which always densify at a high temperature above 1100 °C, resulting in Ag migration. Here, a high-performance samarium-ion-doped Sm0.01Pb0.99(Zr0.54Ti0.46)O3ceramic was selected as parent materials to develop a new Ag-cofired ceramic matrix with a sintering temperature of 920 °C by glass flux. The ceramic composition with 2.0 wt% glass addition exhibits the excellent performance of piezoelectricd33~492 pC/N, planar electromechanical coupling coefficientkp~50.1%, mechanical quality factorQm~68.71, and Curie temperatureTc~356 °C, respectively. The cyclic stability ofd33was measured below 6.6% at 30 kV/cm, which indicates that the piezoceramic has good temperature stability and fatigue resistance. Therefore, this study provides a novel high-performance piezoelectric system to meet the cofired requirement for multilayered piezoelectric devices.

Preparation of Ti-based homologous heterojunction and its photocatalytic degradation properties of tetracycline in seawater

Yubo Zhou,Xinbo Zhao,Zan Li,Junchao Yin,Liangmin Yu

To address ion interference in photocatalytic antibiotic degradation within high-salt seawater, this study innovatively designed and synthesized a titanium-based metal–organic framework (MOF) heterojunction composite. Specifically, a solvothermal technique was used to create MIL-125(HAC)/TiO 2 (TAC) photocatalysts using commercial TiO 2 (P25) and MIL-125(Ti) that had been treated with acetic acid. Remarkably, under 60 min of visible-light irradiation, the optimized TAC-2 sample achieved 95.7 % tetracycline (TC) degradation in seawater (compared to 98.1 % in deionized water) and retained >85 % efficiency after four cycles. Critically, its degradation rate constant (k=0.0355 min −1 ) in seawater was 44.4 times higher than that of P25, demonstrating exceptional resistance to salt-ion interference and photocatalytic activity. Mechanistic studies revealed that the performance enhancement arises from three synergistic mechanisms: (1) A mesoporous structure mitigating ion interference and strengthening TC-selective adsorption; (2) A Type-II heterojunction enabling efficient charge separation; (3) •O 2 − and h + identified as dominant active species (confirmed by EPR and quenching tests). Collectively, this work establishes an effective MOF heterojunction engineering strategy for efficient antibiotic removal in saline environments, ultimately contributing to marine pollution remediation.

Photocatalytic Degradation of Ofloxacin by Various Nanostructured TiO2 Thin Films Produced via Ti–H2O2 Interaction

Iram Hussain,Lisha Zhang,Zhizhen Ye,Jin-Ming Wu

In this work, a low-temperature method for creating nanostructured TiO 2 thin films with controlled morphologies for the photocatalytic degradation of the persistent antibiotic pollutant ofloxacin in water is presented. A Ti–H₂O₂ interaction was used to produce hydrogen titanate nanowires, which were subsequently converted into three different nanostructures: anatase nanowires by calcined at 450°C, porous nanorods and hierarchical nanoflowers by treating at 80°C for 72 hours with hot water and sulfuric acid, respectively. Controls over surface area, hydroxyl group contents, and crystal phase composition were made possible by these post-treatments. With a reaction rate constant of 0.72 h⁻¹ and a photocatalytic efficiency of 98% ofloxacin degradation in 4 hours under UV light, TiO 2 nanoflowers outperformed commercial benchmark P25 mixed phase TiO 2 nanoparticle films (0.64 h⁻¹) among the different nanostructures. The mixed anatase-rutile phase, high surface area of 49.1 m²/g, large pore volume of 0.15 mL/g, and numerous surface hydroxyl groups are responsible for the superior performance. These results show that morphology-engineered TiO 2 films can be used to treat water effectively through photocatalysis.

Shaping alkaline hydrogen evolution at Ti-vacancy mediated valence-asymmetric Ru on TiO2 quantum dots

Yuhua Liu,Qing Liang,Fuxi Liu,Wenwen Li,Aofei Wei,Tiantian Xu,Xu Zou,Bingsen Zhang,Wei Zhang,Weitao Zheng

It remains a significant challenge for simultaneously regulating the water dissociation and hydrogen adsorption/desorption of Ru in alkaline media. Herein, we successfully architected an entity of individually-functionalized spatial valence-asymmetric Ru sites on Ru/TiO 2 quantum dots for high-performance alkaline hydrogen evolution. The Ru nanoclusters were self-adaptively grown along the Ti vacancies, triggering the phase transformation from anatase to rutile TiO 2 . The well-defined Ru/TiO 2 interface produced a strong electronic metal-support interaction, acquiring a Ru site with asymmetric electronic state. Resultantly, the anisotropy of the surface low-valence Ru δ- site and the interface high-valence Ru δ+ site break the scaling relationship of water dissociation, hydroxyl and hydrogen adsorption. The asymmetrical Ru electronic state achieves 15 mV overpotential at 10 mA cm -2 and delivers a high mass activity of 5.4-fold than commercial Pt/C at 100 mV, outperforming most reported Ru-based catalysts. Our work sheds light on the potential of support-crystal phase engineering to design catalysts with the required electrocatalytic performance.

Unlocking Exceptional EMI Shielding in Ti₃C₂Tₓ MXenes through Controlled Microstructure and Surface Chemistry

Shahzad Hussain,Resham Siddique,Muhammad Nadeem,Eman Zafar,Sadia Manzoor,Jawwad A Darr

The rapid advancement of highly integrated electronics demands next generation electromagnetic interference (EMI) shielding materials that combine lightweight, ultrathin, flexible, and mechanically robust properties with exceptional shielding effectiveness (SE) to mitigate signal crosstalk and ensure device reliability. In this work, we demonstrate the fabrication of high-performance EMI shields using highly conductive, additive-free aqueous Ti3C2Tx (T = O, OH, Cl, F) MXene dispersions synthesized under both harsh and mild etching conditions. These dispersions were engineered into freestanding thin films and functionalized cotton fabrics via vacuum-assisted filtration, enabling tunable EMI shielding properties through precise control of etchant chemistry, flake size, microstructure, thickness, and MXene loading. The EMI shielding improved with film thickness and the 13 μm thick film demonstrated exceptional EMI shielding of 60 dB. The freestanding heat treated Ti3C2Tx film with minimal thickness of 5 µm achieved a remarkable shielding effectiveness of 71 dB (which is 37% higher than the untreated film) corresponding to 99.99999% EMI attenuation. This film also exhibited an ultrahigh absolute shielding effectiveness (SSET) of 72,300 dB cm2 g−1, surpassing all previously reported MXene-based shields of comparable thickness. The improved stability was attributed to thermal conversion of surface OH groups to O-terminations, reducing interflake spacing and enhancing conductivity. The coated cotton fabric achieved an unprecedented SE of 82 dB due to the excellent wave attenuation associated with its porous structure. Notably, the fabric retained its shielding performance even after six months of ambient exposure, highlighting exceptional environmental stability. This study establishes critical structure-property relationships, revealing that induced porosity, meta-structure effects, large flake size, and optimized surface terminations synergistically enhance EMI shielding. By elucidating the interplay between material parameters and shielding performance, this work provides a foundational framework for designing advanced EMI mitigation technologies, paving the way for scalable, high-performance shielding solutions in next-generation flexible and wearable electronics.

Carbon-Based Composites from Ti-Ni MOFs with Enhanced Electromagnetic Wave Absorption and Corrosion Resistance

Xinbo Zhao,Huali Li,Weige Chen,Weijie Li,Zhiyu Han,Weihua Li

Conventional electromagnetic wave (EMW) absorbing materials often suffer from poor stability in humid and corrosive environments, limiting their real-world applications. In this work, carbon-based composites derived from Ti-Ni bimetallic metal-organic frameworks (MOFs) were synthesized via pyrolysis and investigated as dual-function materials for EMW absorption and corrosion protection. The composites exhibit excellent impedance matching and strong attenuation capability due to the synergistic interaction between the metal oxides and the carbon matrix. A minimum reflection loss of −40   dB and an effective absorption bandwidth of 4.61   GHz were achieved at an optimized thickness of 4.1   mm. Furthermore, upon incorporation into an epoxy resin coating, the composite displayed outstanding corrosion resistance. After immersion in a 3.5   wt% NaCl solution for 7 days, good stability was still maintained. This study presents a promising strategy for designing multifunctional materials with integrated EMW absorption and corrosion resistance, offering broad application potential in marine, aerospace, and communication sectors.

Highly Sensitive Surface Plasmon Resonance Sensor Modified With 2D Ti₂C MXene for Solution Detection

Shuaiwen Gan,Banxian Ruan,Yuanjiang Xiang,Xiaoyu Dai