查找使用阿拉丁产品的科研文献

Fe/P Dual-Doped NiMoO4 with Hierarchical Structure for Urea Electrolysis-Assisted Hydrogen Production

Wenxiang Sheng,Xiaoxing Zhou,Yuanhang Ma,Irsa Tariq,Dong Xu,Ping Chen,Peng Li

The urea oxidation reaction (UOR) presents a sustainable pathway for energy-saving hydrogen production by replacing the sluggish oxygen evolution reaction (OER) in water electrolysis. However, developing efficient and stable UOR catalysts remains challenging. NiMoO4 has emerged as a highly efficient UOR catalyst due to its synergistic intermetallic interactions and tunable electronic structure. Leveraging heteroatom doping, we engineered an Fe,P-codoped NiMoO4 nanosheet array anchored on nickel foam (Fe,P-NiMnO4/NF) with dandelion-like hierarchical architecture via a facile hydrothermal-phosphorization approach. Systematic characterization demonstrates that Fe doping creates a porous hierarchical structure, facilitating mass transport and exposing abundant active sites, while P doping simultaneously optimizes the electronic configuration and enhancing hydrophilicity, leading to an expanding electrochemical active surface area. The resulting catalyst exhibits exceptional performance, achieving a current density of 100 mA cm–2 at just 1.345 V (vs RHE) for UOR, alongside a low HER overpotential of 270 mV at the same current density. When employed in a two-electrode overall urea splitting (OUS) system, it delivers 100 mA cm–2 at a cell voltage of 1.6 V with outstanding long-term stability of 50 h. This work introduces a design strategy for high-efficiency electrocatalysts in energy-efficient hydrogen production through urea-assisted electrolysis.

Electronically modified hierarchical porous carbon by N, P heteroatoms for zinc ion hybrid capacitor

Shengtao Gao,Feng Wei,Xinyao Zhu,Zihao Tai,Jun Qiao

Due to the low cost and steady physicochemical properties of carbon materials, zinc-ion hybrid capacitors (ZICs) composed of carbon cathode and Zn anode have aroused considerable attracts in recent years. However, the unsatisfactory capacity and electrochemical kinetics of carbonaceous cathode hinder its application in ZICs. Herein, a facile self-template thermal treatment method was proposed to prepare N, P co-doped hierarchical porous carbons (NP-HPCs). The electronically modified NP-HPC 3 has an ultrahigh ratio of active N species and abundant micropores, which is favorable for zinc ions adsorption. In addition, the three-dimensional cross-linked network with abundant mesoporous cavities synchronously boosts electrons/ions transfer kinetics. Ex-situ characterization shows that the introduction of N, P heteroatoms is helpful to improve the adsorption of zinc ions. Thanks to these favorable structural characteristics, the NP-HPC 3 displays an exceptional specific capacitance (275.0 F g −1 at 0.1 A g −1 ) and rate capability (182.0 F g −1 at 20 A g −1 ). More significantly, the NP-HPC 3 -based ZIC delivers a prominent energy density of 107.8 Wh kg −1 at a power density of 90.7 W kg −1 , a long cycle life (96.9 % capacitance retention after 10,000 cycles) together with an outstanding anti-self-discharge performance (0.001145 V h −1 @200 h). This study not only affords a feasible and environmental route to construct advanced heteroatom doped carbonaceous materials, but also explores the interrelation between zinc ions storage behavior and structural characteristics of carbon materials.

Boosting carrier separation over ultrathin g-C3N4 by P doping for enhanced photocatalytic performance

Xiangmei Wang,Huimin Zhang,Hubing Li,Zhiling Qiu,Xin Xiao

In light of the escalating severity of water pollution, the development of innovative and efficient photocatalytic materials has emerged as an urgent requirement. In this study, P-doped ultrathin g-C3N4 was successfully synthesized using the chemical vapor deposition technique, specifically to enhance the photocatalytic degradation of the antibiotic tetracycline hydrochloride (TC) and the dye rhodamine B (RhB). The purpose of P doping was to modify the electronic structure of g-C3N4 and increase its photocatalytic efficiency. The microstructure, chemical state, and light absorption properties of the material were extensively analyzed using advanced characterization techniques such as high-resolution transmission electron microscopy (HRTEM), X-ray photoelectron spectroscopy (XPS), and ultraviolet-visible diffuse reflectance spectroscopy (UV-vis DRS). The study revealed that P doping not only enhanced the structural stability of the nanosheets but also effectively broadened the material's light-responsive range by creating new band structures. Photocatalytic tests showed that under visible light irradiation, P-doped ultrathin g-C3N4 demonstrated outstanding degradation efficiency against TC and RhB. Specifically, the doped catalyst reduced the concentrations of TC and RhB by more than 90% within 60 minutes, markedly surpassing the performance of undoped graphitic carbon nitride nanosheets. Moreover, the phosphorus-doped materials retained high catalytic activity and stability after repeated usage cycles. From a theoretical perspective, this research applied density functional theory (DFT) based on first principles to deeply investigate the electronic properties of P-doped ultrathin g-C3N4. The calculations disclosed that phosphorus doping led to modifications in the band structure, particularly an increase in localized states at the valence band top, which is vital for facilitating the effective separation of photogenerated electron–hole pairs. Additionally, the doping significantly altered the charge distribution on the material's surface, enhancing the catalyst's capacity to adsorb and activate molecules of TC and RhB. Overall, this research not only provided an efficient photocatalytic material for addressing persistent pollutants in aquatic environments but also explored the fundamental mechanisms by which P doping improves the photocatalytic performance of g-C3N4, thereby offering theoretical and experimental bases for the design of novel photocatalysts.

P(VDF-TrFE-CTFE)/PMMA Films with Enhanced Dielectric and Breakdown Properties for EWOD

Yangjie Zhong,Chengming Tang,Jidong Sun,Yafeng Zhang,Shaoxiong Cai,Jiaxin Yu

A dielectric film with high breakdown strength and dielectric constant are crucial for the reliable operation of electrowetting on dielectric (EWOD). In this study, barium titanate (BaTiO3) nanoparticles modified with a silane coupling agent (KH550) were incorporated into poly(vinyl fluoride-trifluoroethylene-chlorotrifluoroethylene) (P(VDF-TrFE-CTFE)) and poly(methyl methacrylate) (PMMA) to prepare a BaTiO3–KH550/P(VDF-TrFE-CTFE)/PMMA composite film to enhance the breakdown strength and dielectric constant of a dielectric layer. Results revealed that BaTiO3–KH550 is uniformly dispersed within the P(VDF-TrFE-CTFE)/PMMA polymer matrix. When the BaTiO3–KH550 content is 10 wt %, the dielectric constant reached 24.6, and the energy density was 2.65 J cm–3, representing increases of 94% and 73%, respectively, compared to the pure P(VDF-TrFE-CTFE)/PMMA film, where was 12.7 and 1.53 J cm–3. Additionally, the breakdown strength of all films remains above 150 kV mm–1 due to the strong interfacial interaction between PMMA and P(VDF-TrFE-CTFE). Furthermore, the breakdown strength can keep at 194.90 kV mm–1. Electrowetting experiments demonstrated that the composite film exhibited a high initial contact angle of 105.04°, with a contact angle variation range of 35.3° under a low DC voltage ranged from 0 to 50 V. The results indicated that this film is potential for applications in low-cost and high-dielectric-performance EWOD dielectric layer materials.

Synthesizing Nanoparticles of Co-P-Se compounds as Electrocatalysts for the Hydrogen Evolution Reaction

Mingshu Xiao,Yuqing Miao,Yanping Tian,Yuhua Yan

A new catalyst based on Co-P-Se compound that is comprised entirely of cheap and earthabundant elements, was first reported for electrolytic hydrogen production . The hydrothermal method at only 473   K was employed to prepare the nanoparticles (NPs) of Co-P-Se compound. The transmission electron microscope images reveal the nanoparticles of quasis-spherical structure and extremely small size with an average diameter of around 5   nm. The composites of Co-P-Se NPs and multi-walled carbon nanotubes (MWCNT) was loaded onto the electrode surface as an active hydrogen evolution reaction (HER) electrocatalyst , which is observed using a scanning electron microscopy. The electrochemical study shows that MWCNT helps to load more Co-P-Se catalysts and enhance the electron transfer between catalysts and electrode, and Co-P-Se exhibits more catalytic activity than Co-P or Co-Se alone. A small Tafel slope of 46   mV/dec and good acid stability was observed for the hydrogen evolution reaction of Co-P-Se/MWCNT.

Ultrasmall Co3O4 Nanoparticles Confined in P, N-Doped Carbon Matrices for High-Performance Supercapacitors

Jingdong Yang,Xueyan Xu,Xufeng Zhou,Shunqiong Jiang,Wen Chen,Siqi Shi,Da Wang,Zhaoping Liu

Co3O4 nanoparticles with smaller particle size can expose more active sites to react with electrolytes, thereby exhibiting better supercapacitive performance. However, the size of Co3O4 nanoparticles is difficult to be effectively controlled in traditional carbon matrices. Herein, P, N-codoped carbon matrices with ultrahigh surface area and abundant nanocavities are used as a novel host to confine the growth of Co3O4 nanoparticles. The Co3O4/carbon composites with high redox activities of Co3O4 are successfully obtained, in which Co3O4 nanoparticles are strongly anchored in the carbon matrices, resulting in the enhancement of the composites’ capacitive performance (1310 F g–1 at 0.5 A g–1). Meanwhile, the strong anchoring effect of the carbon host on Co3O4 nanoparticles because of the rich doping elements and the confinement effect of the nanocavities ensure long-term stability (92% capacitance retention after 5000 cycles). Furthermore, the assembled asymmetric supercapacitor using this composite as the cathode material and activated carbon as the anode material delivers a high energy density of 47.18 W h kg–1 at 375 W kg–1.

Poly (γ-Glutamic Acid) Promotes Enhanced Dechlorination of p-Chlorophenol by Fe-Pd Nanoparticles

Zhang Shiyu,Zhang Chao,Liu Mingyue,Huang Renliang,Su Rongxin,Qi Wei,He Zhimin

Nanoscale zero-valent iron (nZVI) has shown considerable promise in the treatment of chlorinated organic compounds, but rapid aggregation and inactivation hinder its application. In this study, palladium-doped zero-valent iron nanoparticles involving poly (γ-glutamic acid) (Fe-Pd@PGA NPs) were synthesized. The nanoparticles were small (~100 nm), uniformly distributed, and highly stable. The dechlorination performance of Fe-Pd@PGA NPs was evaluated using p -CP as a model. The results demonstrated that Fe-Pd@PGA NPs show high activity even in weakly alkaline conditions. The maximum rate constant reached 0.331 min − 1 at pH 9.0 with a Fe to p -CP ratio of 100. Additionally, the dechlorination activity of Fe-Pd@PGA NPs is more than ten times higher than that of the bare Fe-Pd NPs, demonstrating the crucial role of PGA in this system. Furthermore, we investigated the dechlorination performance in the presence of different anions. The results indicated that Fe-Pd@PGA NPs can maintain high activity in the presence of Cl − , H 2 PO 4 − , and humic acid, while HPO 4 2− and HCO 3 − ions slightly reduce the dechlorination activity. We believed that PGA is a promising stabilizer and promoter for Fe-Pd NPs and the Fe-Pd@PGA NPs have the potential for practical applications.

Sol–Gel Processed p-Type CuAlO2 Semiconductor Thin Films and the Integration in Transistors

Chunfeng Wang,Haotian Zhu,You Meng,Shengbin Nie,Yuna Zhao,Byoungchul Shin,Elvira Fortunato,Rodrigo Martins,Fukai Shan,Guoxia Liu

Sensitizers designed toward efficient intramolecular charge separation for p-type dye-sensitized solar cells

Fengsheng Ge,Fang Xu,Kun Gong,Dongzhi Liu,Wei Li,Lichang Wang,Xueqin Zhou

Effective charge separation is demonstrated as one of the rational design strategies for organic sensitizers of both n-type and p-type dye-sensitized solar cells. Herein, we report the design and synthesis of novel D-A dye cTPAPh-NO 2 and D-A 1 -A 2 dye cTPABT-PyCN2 using triphenylamine as the donor, di-carboxylic acid group as anchoring group. Photophysical and electrochemical properties of both dyes were investigated to discuss the effect of anchoring group and molecular structure on the photophysical processes and charge separation feature of the sensitizers. For D-A dyes, the attachment of carboxyl groups reduces both the light harvesting and intramolecular charge separation ability of cTPAPh-NO 2 . In comparison, cTPABT-PyCN2 exhibits weak fluorescence and efficient intramolecular charge separation characteristics. Exceeding 80% of cTPABT-PyCN2 singlets decays via intramolecular electron transfer from the first acceptor to the dicyanovinyl pyrimidine. Finally, these synthesis dyes were used as sensitizers in p-type DSSCs and cTPABT-PyCN2 showed the overall power conversion efficiency of 0.103%, which is comparable to that of reported dyes. The results demonstrate that D-A 1 -A 2 structure can be a promising strategy to design p-type sensitizers with effective charge separation characteristics.

Oxygen Vacancies-Induced Dendritic SrTiO3/CdS p–n Heterostructures Photocatalyst for Ultrahigh Hydrogen Evolution

Lianqing Yu,Xiang Li,Lijie Duan,Yaping Zhang,Haifeng Zhu

Owing to great efficient routes for charge carrier separation and transfer, heterostructure photocatalysts play significant roles in many photocatalytic reactions. Based on the bionic structure, an interesting composite photocatalyst of cadmium sulfide dewdrops on ultrathin strontium titanate branches with oxygen vacancies is successfully constructed by a simple chemical bath deposition method. The oxygen vacancies act as electron traps in the dendritic perovskite SrTiO 3 nanostructure. Meanwhile, the CdS can provide abundant active sites for the hydrogen evolution reaction. The results demonstrate that SrTiO 3 /CdS-5% nanocomposite with oxygen vacancies achieves the highest hydrogen production rate of 4537.9 μmol g −1 h −1 under visible light, which is over 50 times more than that of the single SrTiO 3 with oxygen vacancies (79.36 μmol g −1 h −1 ), pure CdS (81.79 μmol g −1 h −1 ), and more than 750 times that of pure SrTiO 3 (6.132 μmol g −1 h −1 ). Density generalized function theory calculations show that the bandgap values of SrTiO 3 /CdS nanocomposite with oxygen vacancies are narrower than that of the original SrTiO 3 and CdS, in which the electrons flow from CdS to SrTiO 3 , and form an internal electric field at the interface, prolonging the carrier lifetime. Importantly, this work provides a reasonable reference for the preparation of efficient structure-based biomimetic composite photocatalysts.

Self-supported TiO2@P nanotube arrays as high-performance anodes for sodium-ion batteries

Bingxue Sun,Jiangfeng Ni

Sodium-ion batteries (SIBs) have received widespread attention because of their scalability, low cost, and environmental advantages. Whereas, the low capacity and disappointing cycle capability of anode materials are unavoidable challenges, and high-capacity electrodes are accompanied by large volume expansion and cycle decay. Herein, self-supported TiO 2 nanotube array nanocomposites are rationally designed by combining the stability of TiO 2 and the high capacity of P . The unique nanotube structure can effectively limit the expansion of phosphorus so that this anode has excellent reversibility and cycling. It affords a reversible capacity of 0.214 mAh cm − 2 at 0.08 mA cm − 2 , a rate capability of 0.146 mAh cm − 2 at 1.6 mA cm − 2 , and a stable cycling up to 5000 cycles.

Grafting p-Aminobenzonitrile for Enhanced High-Temperature Energy Storage Performance of Poly(ether imide)

Mengjia Feng,Jia Shi,Yancheng Liu,Zhiguo Jia,Jianzeng Guo,Hongbo Liu,Yunqi Xing

The combination of high power density, fast charge–discharge rates, excellent breakdown strength (Eb), and intrinsic self-healing properties makes polymer dielectrics attractive for use as electrostatic capacitors. Nevertheless, operation under high temperatures and high electric fields induces a marked increase in conduction loss. This increased loss, in turn, causes the deterioration of both Eb and energy storage density (Ue), consequently restricting the practical application of these materials. This research proposed a molecular-level modification strategy in which p-aminobenzonitrile (pABN) was successfully grafted onto the side chains of poly(ether imide) (PEI). This approach constructs an effective energy barrier on the molecular scale, thereby hindering charge carrier transport and enhancing energy storage performance. At 150 °C, with a pABN grafting mass percentage of 0.25%, the electric field strength required to maintain 90% charge–discharge efficiency (η) increases to 420 MV/m, and the Ue reaches 2.83 J/cm3. Furthermore, the composite dielectric demonstrates outstanding charge–discharge characteristics and maintains stable energy storage efficiency over 50,000 cycles. This work establishes a molecular-level grafting strategy for developing energy storage devices suitable for high-temperature environments.