查找使用阿拉丁产品的科研文献

Mn-doped RuO2 as superior pH-universal electrocatalyst for oxygen evolution reaction

Xiaojing Dong,Yangyang Wang,Jintao Wang,Yiqiang Sun,Bo Xu,Cuncheng Li,Lifeng Hang

In the field of research on renewable energy conversion and storage methods, the development of catalysts with excellent properties and outstanding stability for oxygen evolution reaction (OER) acting at various pH values has become a much-anticipated research focus. RuO 2 as a benchmark OER catalyst, its wide application has always been limited by slow reaction kinetics and limited persistence. In this paper, Mn-doped RuO 2 material was developed and the optimum doping ratio was identified for using as an OER electrocatalyst under general purpose pH media. Mn 0.1 Ru 0.9 O 2 exhibited a lower overpotential value of 224 mV in acidic environment with a Tafel slope value of 51.62 mV dec −1 . Moreover, in alkaline and neutral environments, overpotentials of 231 mV and 376 mV were required to obtain a current density of 10 mA cm −2 , respectively. In addition, through continuous stability testing over 24 h in alkaline, acidic and neutral solutions, it has been further demonstrated that the Mn-doped RuO 2 material exhibits extremely high stability. The advancements in this research offer crucial insight into the rational development of efficient and durable RuO 2 -based catalysts.

Triple-function Mn regulation of NiFe (oxy)hydroxide for oxygen evolution reaction

Hui Wan,Meng-Yuan Xie,Bo Li,Jian-Hang Nie,Tao Huang,Lei Li,Jing-Hui Shi,Ming-Hua Xian,Jia-Rong Huang,Wangyu Hu,Gui-Fang Huang,Fei Gao,Wei-Qing Huang

Transition metal (oxy)hydroxides are potential oxygen evolution reaction (OER) electrocatalysts; however, simultaneously modulating multiple factors to enhance their performance is a grand challenge. Here, we report an incorporating heteroatom strategy via one-step hydrothermal approach to adjust more than one factor of Mn-doped NiFe (oxy)hydroxide (Mn-NiFeOOH/LDH) heterojunction . Mn doping regulates heterojunction morphology (reducing nanoparticles and becoming thinner and denser nanosheets), Ni/Fe ratio and valence states (Ni 2+ , Ni 3+ , and Ni 3+Δ ) of Ni ions. The former could effectively increase surface active sites, and the latter two reduce the content of Fe in the Mn x -NiFeOOH/LDH heterojunction, enabling more Ni 2+ convert to Ni 3+/3+Δ that have higher intrinsic OER activity. As a result, the first-rank Mn-NiFeOOH/LDH with ultra-low overpotential of 185 mV@20 mA cm −2 and 296 mV@500 mA cm −2 , and the improved OER performance are outdo to those of commercial RuO 2 catalyst for OER. Moreover, the Mn-NiFeOOH/LDH affords the earliest initial potential (1.392 V vs. RHE), corresponds to a recorded low overpotential (162 mV). Based on the density functional theory (DFT), Mn dopants can alter intermediate adsorption energy and effectively decrease *OOH’s energy barrier. This research exhibits a feasible strategy to design low cost electrocatalysts and provide new possibilities for future industrialization.

Surface complexation adsorption of Tl(III) by Fe and Mn (hydr)oxides

Wanpeng Chen,Hongxia Liu,Yunzhu Wang,Yu Liu,Die Hu,Yuheng Huang,Xiaoliu Huangfu

Thallium(III) (Tl(III)) is mobile in acidic environments and under ligand complexation, posing a potential threat to the environment and human health. The adsorption of Tl(III) on manganese and iron (hydr)oxides will affect its environmental mobility and engineering removal efficiency. However, the adsorption behavior and interfacial reaction mechanism of Tl(III) remain largely unknown. This study is the first to elucidate the surface complexation mechanism of Tl(III) on Fe/Mn (hydr)oxides and to investigate the adsorption behavior of Tl(III) under the influence of typical environmental ligands. Deprotonation of surface hydroxyl groups contributes to the increase in adsorption capacity for Tl(III) (δ-MnO 2 , 1619.93 mg g −1 ; α-FeOOH, 48.25 mg g −1 ; and α-Fe 2 O 3 , 58.66 mg g −1 from Langmuir thermodynamic fitting). Surface complexation modeling reveals tridentate complexation of Tl(III) on birnessite and monodentate complexation on iron (hydr)oxides. The anionic ligand strongly inhibits the adsorption of Tl(III) (up to 16.0 %–40.0 %) by complexing with Tl(III) and occupying the adsorption sites. In addition, HA also reduces the adsorption of Tl(III) by 8.2 %–23.2 % by exacerbating the aggregation and surface coating of the adsorbent particles. New insights into the binding mechanism of Tl(III) on Fe/Mn oxides can help to guide the development of efficient Tl(III) removal adsorbents.

Polyethylenimine-Coated Pt–Mn Nanostructures for Synergistic Photodynamic/Photothermal/Chemodynamic Tumor Therapy

Bixiao Li,Danyang Xu,Yitong Chen,Wenjing Li,Hanyu Liu,Anees A. Ansari,Ruichan Lv

How to develop antitumor nanodrugs with low toxicity and a good curative effect is an urgent problem in the current biomedicine field. In this work, different proposed composites were simulated by the finite difference time domain (FDTD) and COMSOL, including the material element, refractive index, particle size, and shape. Also, different machine learning algorithms are utilized to predict the absorbance at the near-infrared laser of 980 nm of different materials. Through train, validation, and test, the prediction of the as-synthesized Pt–Mn has high absorbance. Then, inorganic Pt–Mn was coated with PEI in order to improve their biocompatibility. Pt–Mn nanoparticles can generate ROS under the single 980 nm laser irradiation as a photodynamic therapy (PDT) agent and as a photothermal therapy (PTT) agent to heat the cells with a photothermal conversion efficiency of 23.6%. In addition, the electrochemical and in vitro chemodynamic therapy (CDT) experiments prove that Pt–Mn nanozymes could mimic the activity of peroxidase and enhance the Fenton reaction, thereby catalyzing excess H2O2 to produce hydroxyl free radicals and illustrating the potential to induce tumor cell apoptosis as the CDT agent in a weakly acidic tumor environment to complete high-efficiency chemokinetic therapy. Finally, Pt–Mn–PEI nanoparticles were used for PDT/PTT/CDT and the immune checkpoint inhibitor of anti-PD-L1 is injected in order to obtain the assistant immunotherapy, providing a potential choice to anticancer through effective synergistic cancer therapies.

Mn-dox metal-organic nanoparticles for cancer therapy and magnetic resonance imaging

He Ma,Xiaoming Zhang,Long Pang,Bing Yu,Hailin Cong,Youqing Shen

The high toxicity and side effects of drugs as well as the difficulty of tracking their trends and metabolism have always been the core difficulties of anticancer drugs. In this paper, doxorubicin (DOX) was used as therapeutic drug to coordinate with Mn 2+ to obtain the hydrophobic core of nanomedicine . The outer layer was self-assembled and coated with amphiphilic block copolymer-distearyl phosphatidylethanolamine-polyethylene glycol (DSPE-mPEG2000) to form [email protected] micellar nanoparticles (MDDM NPs) with good dispersion and stability. Cell experiments showed that MDDM micellar nanoparticles could be effectively uptaked by cells in a short time, and had good biocompatibility and tumor inhibition. In vivo experiments have shown that nanoparticles not only have excellent therapeutic effects, but also have magnetic resonance imaging contrast as contrast agents due to Mn 2+ coordination, which can assist in tracking drug trends and metabolism in vivo. The above work provides a certain reference significance for the study of combining organic drugs with metals to realize the reduction of drug toxicity and provide multimodal function of metals.

Enhanced Oxidation of Xylene Using Plasma Activation of an Mn/Al2O3 Catalyst

Zuliang Wu,Weili Zhou,Zhoubin Zhu,Xiaodong Hao,Xuming Zhang

High Catalytic Performance of Mn-Doped Ce-Zr Catalysts for Chlorobenzene Elimination

Lei Zhu,Xi Li,Zhiying Liu,Lin Yao,Peng Yu,Ping Wei,Yanhua Xu,Xingmao Jiang

Mn-Ce-Zr-O catalysts doped with varying Mn content were prepared and assessed for the catalytic combustion of chlorobenzene (CB). Nanosized MCZ-0.67 catalyst with amorphous phase exhibited a high and stable catalytic activity among the studied catalysts, achieving 90% CB conversion at 226 °C and withstanding stability tests, including time-based stability and the successive influence of various operating conditions. Meanwhile, the MCZ-0.67 catalyst used showed good recyclability by calcination in air. Characterization results suggested that Mn doping played a dominant role in improving the catalytic performance, resulting in larger surface area, better redox properties and greater amounts of surface active oxygen. In addition, the introduction of Zr was also indispensable for maintaining the good catalytic performance of catalysts. Finally, trace amounts of polychlorinated by-products during CB oxidation were monitored and the oxidation process was discussed.Keywords:MnOx-CeO2-ZrO2;catalytic combustion;chlorobenzene;active oxygen;product analysis

Mn-doped perovskite quantum dots with thermal stability synthesized at room temperature

Wenzhi Wang,Liwei Wang,Shuo Song,Xinxin Guo,Hongyu Liu,Guangqiang Liu

All inorganic perovskite quantum dots (PQDs) have been studied extensively because of their excellent photoelectric properties. However, its poor stability and lead toxicity limit its practical application. At the same time, the complex synthesis conditions of the hot injection method also limited the preparation of large quantities. Here, we have successfully synthesized Mn-doped CsPb(Cl/Br) 3 PQDs with excellent thermal stability at room temperature by a simple supersaturation crystallization method. The synthesized Mn-doped CsPb(Cl/Br) 3 PQDs has good homogeneity and crystallinity. Meanwhile, Mn-doped CsPb(Cl/Br) 3 PQDs maintains the same crystal structure as CsPb(Cl/Br) 3 PQDs. Importantly, it was found that the activation energy of CsPb(Cl/Br) 3 PQDs after manganese doping increased from 65.1 meV to 222.8 meV through the high and low temperature PL test of 80 K–500 K. The crystal structure of CsPb(Cl/Br) 3 PQDs is more stable due to the introduction of manganese ion, and the thermal stability is significantly improved. In this study, manganese doped CsPb(Cl/Br) 3 PQDs with good crystallinity and thermal stability was rapidly synthesized by a simple supersaturation crystallization method at room temperature, which opened up a new way to improve the stability of PQDs and explore other non-toxic metal elements to replace Pb 2+ .

Demonstration of electrocatalytic oxygen evolution activity of V4AlC3 (Mn+1AXnPhase) bulk powders

Haiyun Tong,Shuai Lin,Hanlu Zhang,Xin Wang,Yanan Huang,Bangchuan Zhao,Xuebin Zhu,Yuping Sun

The present work reports oxygen evolution reaction (OER) activity in metallic V 4 AlC 3 bulk powders prepared by solid-state reactions for the first time. An ultralow overpotential of 253 mV at the current density of 10 mA cm −2 and an excellent stability are observed, demonstrating that V 4 AlC 3 bulk powder can be used as an excellent new type of OER catalyst with low-cost for mass production.

Reproducible mechanical-to-optical energy conversion in Mn (II) doped sphalerite ZnS

Ronghua Ma,Xiaoyan Wei,Chunfeng Wang,Shaohui Mao,Bing Chen,Yonghong Shao,Yu Fu,Keyu Yan,Dengfeng Peng

Mechanoluminescenece (ML) is a dynamic luminescence phenomenon of materials under various mechanical stimulation. Impurity doped ZnS shows high ML repeatability without any needs for extra excitation sources, thus making it very promising in applications like stress sensing and battery-free new light source . Lots of progress has been made in the last decades, however, the reproducible ML (RML) mechanism is still unclear to explain some basic phenomena like how the electron is excited to conduction band when undergoing mechanical actions or how the excitation energy is transferred to the dopants so efficiently. Based on comparative study of photoluminescence (PL) and ML in Mn 2+ doped ZnS prepared via melt-salt method, the RML energy routes in sphalerite ZnS: Mn 2+ is proposed herein, and further, a general mechanism is supposed which could apply to other RML systems. The excitation of RML is possibly generated by electron transfer during bond rebuilding in plastic deformation while the highly efficient energy transfer is realized through hole and electron capture by the dopant. According to this mechanism, we provide some prospects for further optimization of RML performance as well as discovery of new RML materials.

Investigating the luminescence mechanism of Mn-doped CsPb(Br/Cl)3 nanocrystals

Jinjin Ma,Qianting Yao,John A. McLeod,Lo-Yueh Chang,Chih-Wen Pao,Jiatang Chen,Tsun-Kong Sham,Lijia Liu

Inorganic lead halide perovskite CsPbX3 (X = Cl, Br, or I) nanocrystals are promising candidate materials for light-emitting devices and optoelectronics. Mn-Doped CsPbX3 is of particular interest, as the Mn-doping introduces an additional emission band, making this material a promising white-light emitter. In this study, Mn-doped CsPb(Br/Cl)3 nanocrystals are prepared at room-temperature and ambient pressure. The chemical environment of Mn, and the luminescence of these nanocrystals are analyzed in detail using X-ray diffraction (XRD), extended X-ray absorption fine structure (EXAFS), X-ray absorption near-edge structure (XANES) and X-ray excited optical luminescence (XEOL). Although the introduction of Mn does not alter the long-range order of the CsPbX3 crystal, it leads to a local lattice contraction with the bond length of Mn–X much shorter than Pb–X. We also find excitation energy-dependence in both the intensity and wavelength of the perovskite excitonic emission band, while only in intensity of the Mn emission band. Detailed fitting of the XEOL reveals that the perovskite emission band is dual-channel, and it is the excitation energy-dependent intensity variation of these two channels that drives the observed red-shift of the combined emission band. Our findings also confirm that the Mn emission band is driven by exciton-Mn energy transfer and clarify the Mn chemical environment and the luminescence mechanism in Mn-doped CsPb(Br/Cl)3 nanocrystals.

Anion-intercalated supercapacitor electrode based on perovskite-type SrB0.875Nb0.125O3 (B = Mn, Co)

Na Lei,Pianpian Ma,Bo Yu,Shuhong Li,Jianming Dai,Guohua Jiang

The perovskite-type SrMn 0.875 Nb 0.125 O 3 (SMN) and SrCo 0.875 Nb 0.125 O 3 (SCN) materials are prepared through the solid-state reaction method as novel oxygen-intercalated electrode materials for supercapacitor . The crystal structure, powder morphology, and electrochemical performance have been characterized in detail. SMN exhibits a six-layer hexagonal (6 H ) structure with space group P 6 3 / mmc , while SCN shows the tetragonal structure of space group P 4/ mmm . Under the three-electrode system with 1 M Na 2 SO 4 neutral electrolyte solution, the specific capacitance ( C s ) of SCN can reach 894 mF cm −2 at 1 mA cm −2 , which is 4.7 times the value of SMN at the same condition. For SCN, the superiority of electrochemical performance is attributed to its porous surface morphology , perovskite structure with shorter B O bond length and large B-O-B bond angle, and a higher oxygen vacancy content. When combined with activated carbon (AC) electrode, the SCN//AC asymmetric supercapacitor with a working voltage of 2.0 V presents a specific energy density of 82.33 μWh cm −2 , while maintaining prominent cycling stability with a capacity retention of 88.88% after 10,000 cycles.