Small
·
2025
·
IF 12.1
Ruiqi Guo,Shujuan Wang,Minqi Sheng,Xingli Zou,Mingzhi Zhang,Guangcheng Li,Yi Cao,Zhenglong Fan,Jinxin Chen,Wenxiang Zhu,Fan Liao,Tianjiao Ling,Hao Ren,Fan Lv,Zhenhui Kang
Iridium (Ir) is recognized to have extremely high catalytic activity in the hydrogen evolution reaction (HER). However, there are still technical challenges in maximizing the utilization of Ir atoms in the catalytic reaction process through dimensional regulation strategies. Herein, an innovative strategy is utilized to fabricate porous phosphorus-doped iridium (P-Ir) with a 2D structure, specifically the reduction of 1T phase-IrO 2 (1T-IrO 2 ) nanosheets using phosphine gas. The optimized P-Ir achieves an overpotential of 17.2 mV (vs RHE without i R-correction) in 0.5 m H 2 SO 4 during the HER process, outperforming benchmark Pt/C (27.0 mV) and most reported Ir-based electrocatalysts. During the long-term stability tests, P-Ir maintains stable operation for more than 100 h at both −10 and −100 mA cm −2 , respectively. Moreover, the HER activity and transient potential scanning results of Ir-based phosphides prove that doping P atoms in the Ir lattice promotes the reaction kinetic rate and charge transport capacity during hydrogen evolution. Theoretical calculations reveal that P atoms doping weakens the adsorption energy of H intermediates (H*) by regulating the d -band center of the Ir sites. Simultaneously, the desorption process of H* is also facilitated by forming a special bridged-H* bond structure, eventually accelerating the HER kinetics.
研究领域:
材料科学
·
电催化
·
理论计算
✓ 已验证
产品关联
DOI
PubMed
高影响因子
TRANSITION METAL CHEMISTRY
·
2025
·
IF 1.7
Feng Qiying,Zhou Lin,Tian Shuang,Yang Jiawan,Liu Yunjun
Herein, we reported the synthesis and characterization of two new iridium(III) complexes [Ir(ppy) 2 (fpp)](PF 6 ) (Ir1a, ppy = 2-phenylpyridine, fpp = 2-(2,2-difluorobenzo[1,3]dioxol-5-yl-1H-imidazo[4,5-f][1,10]phenanthroline) and [Ir(bzq) 2 (fpp)](PF 6 ) (Ir1b, bzq = benzo[h]quinoline) through high resolution mass spectrometry (HRMS), 1 H NMR and 13 C NMR. The cytotoxicity in vitro of Ir1a and Ir1b on normal NIH3T3 cells and cancer SGC-7901, A549, SK-Hep1 cells was tested using MTT (3-(4,5-dimethylthiazole-2-yl)-diphenyltetrazolium bromide) method. Ir1a exhibits high cytotoxicity on SGC-7901 cells (IC 50 = 2.7 ± 0.7 µM), whereas Ir1b shows moderate cytotoxicity toward the selected cancer cells. The ROS content was investigated using a fluorescence probe of 2′,7′-dichlorodihydrofluorescein diacetate (DCHF-DA), the results show that Ir1a and Ir1b elevate ROS content. The co-localization and the change of mitochondrial membrane potential were explored. Apoptotic studies using Annex V/PI double staining method demonstrate that Ir1a and Ir1b can efficiently cause apoptosis. Ir1a and Ir1b inhibit the cell proliferation at the G2/M period. Additionally, lipid peroxidation and downregulation of ferritin protein suggest that Ir1a and Ir1b can trigger ferroptosis.
研究领域:
药理学
·
肿瘤学
·
生物化学
✓ 已验证
产品关联
DOI
高影响因子
Journal of the American Chemical Society
·
2024
·
IF 14.4
Hao Yu,Yujin Ji,Chenchen Li,Wenxiang Zhu,Yue Wang,Zhiwei Hu,Jing Zhou,Chih-Wen Pao,Wei-Hsiang Huang,Youyong Li,Xiaoqing Huang,Qi Shao
A strain engineering strategy is crucial for designing a high-performance catalyst. However, how to control the strain in metastable phase two-dimensional (2D) materials is technically challenging due to their nanoscale sizes. Here, we report that cerium dioxide (CeO2) is an ideal loading material for tuning the in-plane strain in 2D metastable 1T-phase IrO2 (1T-IrO2) via an in situ growth method. Surprisingly, 5% CeO2 loaded 1T-IrO2 with 8% compressive strain achieves an overpotential of 194 mV at 10 mA cm–2 in a three-electrode system. It also retained a high current density of 900 mA cm–2 at a cell voltage of 1.8 V for a 400 h stability test in the proton-exchange membrane device. More importantly, the Fourier transform infrared measurements and density functional theory calculation reveal that the CeO2 induced strained 1T-IrO2 directly undergo the *O–*O radical coupling mechanism for O2 generation, totally different from the traditional adsorbate evolution mechanism in pure 1T-IrO2. These findings illustrate the important role of strain engineering in paving up an optimal catalytic pathway in order to achieve robust electrochemical performance.
研究领域:
材料科学
·
电化学
·
催化科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
INORGANIC CHEMISTRY
·
2024
·
IF 4.3
Huiyu Sun,Shudi Yu,Jiongting Yin,Jie Li,Jun Yu,Tianpeng Liu,Wanyu Liang,Nannan Zhang,Yangping Zhang,Changqing Ye,Mengyun Hu,Yukou Du
Electrolysis of water to produce hydrogen is an efficient, clean, and environmentally friendly hydrogen production method with unlimited development prospects. However, its overall efficiency is hampered by the slow oxygen evolution reaction (OER) with complex electron transfer processes. Therefore, designing efficient and low-cost OER catalysts is the key to solving this problem. In this paper, Ir-doped Co2P/Fe2P (abbreviated as Ir-CoFeP/NF) was grown on nickel foam through the strategies of low amount noble-metal doping and mild phosphating. Phosphide derived from a floral metal–organic framework (MOF) exhibits regular three-dimensional (3D) morphology and large active area, avoiding the stacking of active sites. The addition of Ir can effectively adjust the electronic structure, change the position of the d-band center, and increase active sites, thus enhancing the catalytic activity. Hence, the optimized catalyst exhibits unexpected electrocatalytic OER activity with an ideal overpotential of 213 mV at 10 mA cm–2, as well as a low Tafel slope of 40.63 mV dec–1. Coupling with Pt/C for overall water splitting (OWS), the entire device only needs an ultralow cell voltage of 1.50 V to achieve a current density of 10 mA cm–2. Besides, the OWS can be maintained for more than 70 h. This study demonstrates the superiority of Ir-doped phosphide in accelerating water oxidation.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF MOLECULAR CATALYSIS A-CHEMICAL
·
2015
·
IF 3.615
Heng Zhang,Yong-Qi Li,Peng Wang,Yong Lu,Xiao-Li Zhao,Ye Liu
The effect of positive charges in the diphosphino-imidazolium salts of L2 was investigated in terms of coordinating character, structures of corresponding Ir-complexes and catalysis for hydroformylation. It was found that the involved positive charges exhibited strong electron-withdrawing effect on the neighbored phosphine fragment, rendering L2 more π -acceptor ability than the corresponding neutral counterpart of L1 . Consequently, the changed coordinating ability of L1 and L2 led to the variety in the structures and components for the Ir-complexes ( Ir-L1a , Ir-L1b , Ir-L2a , and Ir-L2b ). The complexation of L2 with Ir(acac)(CO) 2 led to a novel five-coordinate Ir(II)-complex of Ir-L2a chelated by a PCC (phosphine–carboanion–carbene) pincer in tripodal mode, whereas the complexation of L1 with Ir(acac)(CO) 2 led to a four-coordinate square-planar Ir(I)-complex of Ir-L1a chelated by a PCP (phosphine–carboanion–phosphine) pincer. In addition, the different catalytic performances of these Ir-complexes ligated by L1 and L2 for hydroformylation of olefins were investigated.
研究领域:
化学
·
催化化学
✓ 已验证
产品关联
DOI
高影响因子
MICROCHIMICA ACTA
·
2017
·Vol. 185
·期 1
·1-9
·
IF 4.58
Cui Malin,Wang Chan,Yang Dapeng,Song Qijun
Fluorescent iridium nanoclusters (IrNCs) consisting of up to 7 Ir atoms were prepared by heating IrCl 3 in N,N-dimethylformamide. No other reagents are required. High resolution transmission electron microscopy (HRTEM) shows the IrNCs to be monodispersed with an average size of 0.9 ± 0.2 nm. They are well soluble in polar solvents and stable in these solvents for at least 6 months. Under photoexcitation with 365 nm light, they emit strong bluish green fluorescence with peaks that depend on the excitation wavelength and range from 530 to 650 nm. The fluorescence lifetime typically is 2.2 ns and the quantum yield is 8.3%. Fluorescence is quenched by Cr(VI) ion (chromate), and the emission peak is gradually red-shifted. According to the absorbance spectra of IrNCs in the presence and absence of Cr(VI) and Stern-Volmer quenching behavior study, static quenching is involved. Based on these findings, a selective assay was developed for the determination of Cr(VI). It has a linear response in the 0.1 to 100 μM chromate concentration range and a 25 nM detection limit. Fluorescent iridium nanoclusters (IrNCs), consisting of up to 7 Ir atoms, were prepared in N,N-dimethylformamide (DMF) solution without using any other reagents. Their fluorescence is statically quenched by Cr(VI).
研究领域:
分析化学
·
环境科学
✓ 已验证
DOI
PubMed
高影响因子
Coatings
·
2024
·Vol. 14
·期 11
·1388
·
IF 2.9
Chenxi Ding,Zhongyu Liu,Zhen Fang,Haoxu Wang,Biao Lv,Zhenfeng Hu
A molten salt system was prepared using an optimized method. We studied the complex structure of Ir3+ions in the molten salt system and the influence their concentration had on the quality of the coatings prepared via electrodeposition. Using TG-DSC and in situ XRD experiments, we studied the high-temperature characteristics and properties of IrCl3alongside its thermal stability. Using in situ XRD and Raman spectroscopy, we analyzed the Ir ions’ complex structure and the variation in the molten salt system at high temperatures. Finally, the changes in the Ir ion concentration in the molten salt system and the influence of the microstructure of the coatings’ surfaces were investigated under different anode conditions. IrCl3easily decomposes above 400 °C, and temperature increases accelerate the rate of this decomposition. When the NaCl-KCl-CsCl system is in a high-temperature, molten state, IrCl3forms stable complex structures (IrCl6)3−and (IrCl6)2−, and the valence state of Ir will be transformed with the increase in temperature. Generating these complex structures is conducive to improving the Ir coating quality. During the electrodeposition process, too few Ir ions in the molten salt can lead to concentration polarization, affecting the quality of the coating. Application of the molten NaCl-KCl-CsCl system is conducive to the electrodeposition of Ir coatings in a suitable temperature range. At the same time, using Ir as the anode can enhance the quality of the coatings.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2024
·
IF 8.3
Weiwei Han,Xinuo Cai,Jiahong Liao,Yi He,Chunlin Yu,Xingwang Zhang
The development of proton exchange membrane water electrolysis is a promising technology for hydrogen production, which has always been restricted by the slow kinetics of the oxygen evolution reaction (OER). Although IrOx is one of the benchmark acidic OER electrocatalysts, there are still challenges in designing highly active and stable Ir-based electrocatalysts for commercial application. Herein, a Ru-doped IrOx electrocatalyst with abundant twin boundaries (TB-Ru0.3Ir0.7Ox@ITO) is reported, employing indium tin oxide with high conductivity as the support material. Combing the TB-Ru0.3Ir0.7Ox nanoparticles with ITO support could expose more active sites and accelerate the electron transfer. The TB-Ru0.3Ir0.7Ox@ITO exhibits a low overpotential of 203 mV to achieve 10 mA cm–2 and a high mass activity of 854.45 A g–1noble metal at 1.53 V vs RHE toward acidic OER, which exceeds most reported Ir-based OER catalysts. Moreover, improved long-term stability could be obtained, maintaining the reaction for over 110 h at 10 mA cm–2 with negligible deactivation. DFT calculations further reveal the activity enhancement mechanism, demonstrating the synergistic effects of Ru doping and strains on the optimization of the d-band center (εd) position and the adsorption free energy of oxygen intermediates. This work provides ideas to realize the trade-off between high catalytic activity and good stability for acidic OER electrocatalysts.
研究领域:
材料科学
·
电化学
·
催化科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Materials Advances
·
2024
·
IF 5.2
Xuan Chen,Lin Zhou,Zhanghong Guo,Qijun Song
In this work, malic acid (MA) stabilized iridium nanoparticles (MA-IrNPs) were prepared by one-pot synthesis using MA and IrCl3 as the precursors and NaBH4 as the reducing agent. The as prepared MA-IrNPs have exhibited multi-enzyme activities, especially an excellent laccase-like activity and improved environment adaptability. For the substrate 2,4-dichlorophenol (2,4-DP), a low Km value of 0.117 mM and a high Vmax value of 0.002 mM s−1 were obtained. Under the catalysis of MA-IrNPs, the colourless norepinephrine (NE) can be selectively oxidized by dissolved oxygen to form an orange-brown product and the reaction can be substantially accelerated in the presence of H2O2 due to the synchronic effect of catalase-like and laccase-like activity of MA-IrNPs. Based on this chromogenic reaction, a sensitive colourimetric method was developed for the determination of NE in urine samples. A limit of detection as low as 0.05 μM and a wide linear range of 0.1–120 μM were achieved, showing a promising application potential of MA-IrNPs in disease diagnosis.
研究领域:
生物化学
·
医学诊断
·
纳米材料
✓ 已验证
产品关联
DOI
高影响因子
Crystals
·
2020
·Vol. 10
·期 7
·575
·
IF 2.404
Rui Zhou,Zhaoyang Zhao,Juanxia Wu,Liming Xie
Two-dimensional (2D) IrTe2has a profound charge ordering and superconducting state, which is related to its thickness and doping. Here, we report the chemical vapor deposition (CVD) of IrTe2films using different Ir precursors on different substrates. The Ir(acac)3precursor and hexagonal boron nitride (h-BN) substrate is found to yield a higher quality of polycrystalline IrTe2films. Temperature-dependent Raman spectroscopic characterization has shown the q1/8phase to HT phase at ~250 K in the as-grown IrTe2films on h-BN. Electrical measurement has shown the HT phase to q1/5phase at around 220 K.Keywords:chemical vapor deposition (CVD);two-dimensional material;IrTe2;iridium acetylacetonate;phase transition
研究领域:
材料科学
·
凝聚态物理
✓ 已验证
产品关联
DOI
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2020
·
IF 3.573
Benyong Yang,Wentao Mu,Benedict Tsz Woon Lo,Sijie Liu,Zhihang Chen,Liam John France,Xuehui Li
NOx and CO formation is, at present, a consequence arising from fuel production, but their emission need not be. In this study, a series of novel Ir-containing TiO2-nanobelt catalysts were designed and prepared for the simultaneous removal of NOx and CO. Activity data demonstrates that the TiO2(B) support promotes NO reduction compared to anatase. Furthermore, reaction efficiency (RE), a measure of NOx consumption vis-à-vis that of CO, reveals that catalysts containing anatase promote CO oxidation more so than their TiO2(B) counterparts. Increasing Ir concentration over the latter promotes low-temperature catalytic performance, an effect believed to be linked to the formation of Ir0–IrO2 composites. In situ DRIFTS experiments reveal the relevance of nitrite/nitrate formation and consumption at 250 °C, a mechanism insinuated by the RE value. However, at 300 °C, both TOF and RE increase, signifying the participation of a faster and more-selective reaction, which appears consistent with the isocyanate-mediated pathway.
研究领域:
环境科学
·
催化化学
✓ 已验证
产品关联
DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2021
·
IF 6.707
Yingnan Yang,Pang Yang,Linsen Zhou,Ruilin He,Yawei Hao,Jingchuan Wang,Ruizhi Qiu,Xiaochong Zhao,Lijun Yang
Platinum-group metals are the most promising catalysts choice for hydrogen evolution reaction (HER) due to their good catalytic stability and optimum Gibbs free energy for hydrogen adsorption and desorption. However, high cost restricts their industrial application. To lower price, the most commonly used method is to reduce noble metals’ dosage. Herein, iridium (Ir) and its diphosphide (IrP 2 ) based on one-dimensional carbon nanofibers (CNFs) are easily fabricated by electrospinning and following calcination, and then are applied as efficient catalysts for HER. Both Ir-CNFs and IrP 2 -CNFs show excellent HER performances with overpotentials of 22 mV and 19 mV under the current density of 10 mA cm −2 in alkaline medium, respectively. The experimental results are further proved by density function theory (DFT) calculations, in which IrP 2 (2 0 0) shows better HER kinetics than Ir (1 1 1) with lower water adsorption and hydrogen evolution energies. This work presents a simple method to prepare Ir-CNFs and IrP 2 -CNFs and provides a new feasibility for design and synthesis of efficient and stable HER catalysts.
研究领域:
材料科学
·
催化化学
·
能源科学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）