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High-performance oxygen reduction and evolution carbon catalysis： From mechanistic studies to device integration

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nano Research 2017年第4期10卷 1163-1177页

作者： John W. F. To Jia Wei Desmond Ng Samira Siahrostami Ai Leen Koh Yangjin Lee Zhihua Chen Kara D. Fong Shucheng Chen Jiajun He Won-Gyu Bae Jennifer Wilcox Hu Young Jeong Kwanpyo Kim Felix Studt Jens K. Nфrskov Thomas F. Jaramillo Zhenan Bao Department of Chemical Engineering Stan ford University Stanford CA 94305 USA Institute of Chemical and Engineering Sciences Agency for Science Technology and Research Jurong Island 627833 Singapore stanford nano shared facilities Stanford University Stanford CA 94305 USA Department of Physics Ulsan National Institute of Science and Technology (UNIST) Ulsan 689-798 Republic of Korea Department of Chemical and Biological Engineering Colorado School of Mines Golden CO 80401 USA UNIST Central Research facilities (UCRF) Ulsan National Institute of Science and Technology (UNIST) Ulsan 689-798 Republic of Korea SUNCAT Center for Interface Science and Catalysis SLAC National Accelerator Laboratory 2575 Sand Hill Road Menlo Park CA 94025 USA Institute of Catalysis Research and Technology Karlsruhe Institute of Technology Hermann-von-Helmholtz Platz 1 76344 Eggenstein-Leopoldshafen Germany Institute for Chemical Technology and Polymer Chemistry Karlsruhe Institute of Technology Engesserstr. 18 76131 Karlsruhe Germany

The development of high-performance and low-cost oxygen reduction and evolution catalysts that can be easily integrated into existing devices is crucial for the wide deployment of energy storage systems that utilize O2-H2O chemistries, such as regenerative fuel cells and metal-air batteries. Herein, we report an NHB-activated N-doped hierarchical carbon （NHC） catalyst synthesized via a scalable route, and demonstrate its device integration. The NHC catalyst exhibited good performance for both the oxygen reduction reaction （ORR） and the oxygen evolution reaction （OER）, as demonstrated by means of electrochemical studies and evaluation when integrated into the oxygen electrode of a regenerative fuel cell. The activities observed for both the ORR and the OER were comparable to those achieved by state-of-the-art Pt and Ir catalysts in alkaline environments. We have further identified the critical role of carbon defects as active sites for electrochemical activity through density functional theory calculations and high-resolution TEM visualization. This work highlights the potential of NHC to replace commercial precious metals in regenerative fuel cells and possibly metal-air batteries for cost-effective storage of intermittent renewable energy.

关键词： electrocatalysis porous carbon density functional theory

A dry-electrode enabled ECG-on-Chip with arrhythmia-aware data transmission

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Science China(Information Sciences) 2025年第2期68卷 338-353页

作者： Xinzi XU Yanxing SUO Yang ZHAO Peiyi ZHOU Xiao HAN Qiao CAI Min WANG Jiajun YUAN Liebin ZHAO Yongfu LI Guoxing WANG Yong LIAN Department of Micro-nano Electronics and MoE Key Lab of Artificial Intelligence Shanghai Jiao Tong University Pediatric AI Clinical Application and Research Center Shanghai Engineering Research Center of Intelligence Pediatrics (SERCIP)Child Health Advocacy InstituteShanghai Children's Medical CenterSchool of MedicineShanghai Jiao Tong University Shanghai Engineering Research Center of Intelligence Pediatrics (SERCIP) Xin Hua Hospital Affiliate to Shanghai Jiao Tong University School of Medicine

Early detection and treatment of cardiovascular diseases(CVDs) can be significantly enhanced through the use of flexible wearable electrocardiogram(ECG) sensors, potentially reducing CVD-related mortality. This paper introduces an ECG-on-Chip(EoC) solution tailored for flexible ECG sensors, incorporating novel features to address common challenges in wearable ECG technology. The EoC integrates a chopper-stabilized capacitively-coupled instrumentation amplifier(CS-CCIA),ensuring a high common-mode rejection ratio(CMRR) and low noise performance. Performance is further boosted via a positive feedback loop(PFL) and a programmable gain amplifier(PGA) with shared on-chip calibration logic, which enhances input impedance and minimizes gain variability to ensure consistent algorithm performance. Additionally, a secondary chopping technique is employed to further reduce noise, achieving an input-referred noise level of 454 nVrms. The embedded algorithm within the EoC is designed to extract clinically meaningful features, facilitating robust real-time arrhythmia analysis. Fabricated using a 0.18 μm CMOS process, the EoC consumes 14.9 μW with a supply voltage of 1.2 V. The algorithm's efficacy has been validated over 0.4 million heartbeats, demonstrating a sensitivity of over 99.7% for R-peak detection and 98.3% for arrhythmia analysis. To demonstrate practical application, the EoC has been integrated with a commercial Bluetooth low energy(BLE)transceiver, forming a wireless arrhythmia monitoring sensor equipped with dry electrodes. This system consumes 292.04 μW in arrhythmia-aware transmission mode, supporting 13 days of operation with a 30 mAh thin-film battery.

关键词： ECG flexible dry electrodes analog front-end abnormality detection ASIC wireless transmission

Structured 3D linear space–time light bullets by nonlocal nanophotonics

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Light(Science & Applications) 2021年第9期10卷 1687-1701页

作者： Cheng Guo Meng Xiao Meir Orenstein Shanhui Fan Department of Applied Physics Stanford UniversityStanfordCA94305USA Key Laboratory of Artificial Micro-and nano-structures of Ministry of Education and School of Physics and Technology Wuhan UniversityWuhan430072China Andrew&Erna Viterbi Department of Electrical Engineering Technion–Israel Institute of TechnologyHaifa32000Israel Ginzton Laboratory and Department of Electrical Engineering Stanford UniversityStanfordCA94305USA

We propose the generation of 3D linear light bullets propagating in free space using a single passive nonlocal optical *** nonlocal nanophotonics can generate space–time coupling without any need for bulky pulse-shaping and spatial modulation *** approach provides simultaneous control of various properties of the light bullets,including the external properties such as the group velocity and the propagation distance,and internal degrees of freedom such as the spin angular momentum and the orbital angular momentum.

关键词： surface angular nonlocal

On-demand production of hydrogen by reacting porous silicon nanowires with water

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nano Research 2020年第5期13卷 1459-1464页

作者： Rui Ning Yue Jiang Yitian Zeng Huaxin Gong Jiheng Zhao Jeffrey Weisse Xinjian Shi Thomas M.Gill Xiaolin Zheng Department of Materials Science and Engineering Stanford UniversityStanfordCA 94305USA Department of Mechanical Engineering Stanford UniversityStanfordCA 94305USA Department of Chemical Engineering Stanford UniversityStanfordCA 94305USA

On-demand hydrogen generation is desired for fuel cells,energy storage,and clean energy *** nanowires(SiNWs)and nanoparticles(SiNPs)have been reported to generate hydrogen by reacting with water,but these processes usually require external assistance,such as light,electricity or ***,we demonstrate that a porous SiNWs array,which is fabricated via the metal-assisted anodic etching(MAAE)method,reacts with water under ambient and dark conditions without any energy *** reaction between the SiNWs and water generates hydrogen at a rate that is about ten times faster than the reported rates of other Si *** possible sources of enhancement are discussed:SiNWs maintain their high specific surface area as they don’t agglomerate,and the intrinsic strain of the nanowires promotes the ***,the porous SiNWs array is portable,reusable,and environmentally friendly,yielding a promising route to produce hydrogen in a distributed manner.

关键词： silicon nanowire porous silicon hydrogen generation metal-assisted anodic etching metal-assisted chemical etching water splitting

Effect of grain size on iron-boride nanoglasses

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Journal of Materials Science & Technology 2023年第10期141卷 116-123页

作者： Melody M.Wang Mehrdad T.Kiani Abhinav Parakh Yue Jiang X.Wendy Gu Department of Materials Science and Engineering Stanford UniversityStanfordCA 94305USA Department of Mechanical Engineering Stanford UniversityStanfordCA 94305USA

Metallic nanoglasses are made of amorphous grains that are separated by lower-density amorphous boundaries,which have been proposed to enhance plasticity through the deflection of cracks and shear bands at *** has been difficult to experimentally control grain size and interfacial structure to understand their roles in plastic ***,we fabricate bulk nanoglasses via compaction and sintering of colloidally synthesized amorphous iron-boride *** nanoglasses have amor-phous grains with diameters from 116 nm to 576 nm and were tested using nanoindentation and mi-cropillar *** nanoglass with a grain size of 576 nm shows the highest elastic modulus and hardness of 101 GPa and 7.4 GPa,*** electron microscopy reveals that nanocrys-tals form within the nanoglasses during *** nanocrystal density correlates with higher nanoparticle crystallization enthalpy,an increase in plasticity,and a decrease in yield *** strain of 5.0%,yield strength of 3.8 GPa,and ultimate compressive strength of 2.7-3.8 GPa were *** show that the compaction of colloidal metallic glass nanoparticles results in robust bulk samples,with mechanical properties similar to that of other iron-based bulk metallic glasses.

关键词： Colloidal nanoparticles Interface nanoindentation Micropillar Plasticity

A mini-review on rare-earth down-conversion nanoparticles for NIR-II imaging of biological systems

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nano Research 2020年第5期13卷 1281-1294页

作者： Yeteng Zhong Hongjie Dai Department of Chemistry Stanford UniversityStanfordCalifornia 94305USA

Rare-earth(RE)based luminescent probes exhibit rich optical properties including upconversion and down-conversion luminescence spanning a broad spectral range from 300 to 3,000 nm,and have generated great scientific and practical interest from telecommunication to biological *** upconversion nanoparticles have been investigated for decades,down-conversion luminescence of RE-based probes in the second near-infrared(NIR-II,1,000-1,700 nm)window for in vivo biological imaging with sub-centimeter tissue penetration and micrometer image resolution has come into light only *** this review,we present recent progress on RE-based NIR-II probes for in vivo vasculature and molecular imaging with a focus on Er3+-based nanoparticles due to the down-conversion luminescence at the long-wavelength end of the NIR-II window(NIR-IIb,1,500-1,700 nm).Imaging in NIR-IIb is superior to imaging with organic probes such as ICG and IRDye800 in the^800 nm NIR range and the 1,000-1,300 nm short end of NIR-II range,owing to minimized light scattering and autofluorescence *** by cerium and other ions and phase engineering of Er^3+-based nanoparticles,combined with surface hydrophilic coating optimization can afford ultrabright,biocompatible NIR-IIb probe towards clinical translation for human *** Nd^3+-based probes with NIR-II emission at 1,050 and 1,330 nm are also discussed,including Nd^3+doped nanocrystals and Nd^3+-organic ligand *** review also points out future directions for further development of multi-functional RE NIR-II probes for biological imaging.

关键词： rare earth down-conversion near-infrared biological imaging

Engineering the surface of LiCoO2 electrodes using atomic layer deposition for stable high-voltage lithium ion batteries

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nano Research 2017年第11期10卷 3754-3764页

作者： Jin Xie Jie Zhao Yayuan Liu Haotian Wang Chong Liu Tong Wu Po-Chun Hsu Dingchang Lin Yang Jin Yi Cui Department of Materials Science and Engineering Stanford University Stanford CA 94305 USA Department of Applied Physics Stanford University Stanford CA 94305 USA Department of Materials Science and Engineering Stanford University Stanford CA 94305 USA stanford Institute for Materials and Energy Sciences SLAC National Accelerator Laboratory Menlo Park CA 94025 USA

Developing advanced technologies to stabilize positive electrodes of lithium ion batteries under high-voltage operation is becoming increasingly important,owing to the potential to achieve substantially enhanced energy density for applications such as portable electronics and electrical ***,we deposited chemically inert and ionically conductive LiAlO2 interfacial layers on LiCoO2 electrodes using the atomic layer deposition *** prolonged cycling at high-voltage,the LiAlO2 coating not only prevented interfacial reactions between the LiCoO2 electrode and electrolyte,as confirmed by electrochemical impedance spectroscopy and Raman characterizations,but also allowed lithium ions to freely diffuse into LiCoO2 without sacrificing the power *** a result,a capacity value close to 200 mA＆#183;h＆#183;g-1 was achieved for the LiCoO2 electrodes with commercial level loading densities,cycled at the cut-off potential of 4.6 V ***＋/Li for 50 stable cycles;this represents a 40% capacity gain,compared with the values obtained for commercial samples cycled at the cut-off potential of 4.2 V ***＋/Li.

关键词： Lithium ion batteries lithium cobalt oxide atomic layer deposition

MXene‑Graphene Composites:A Perspective on Biomedical Potentials

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nano-Micro Letters 2022年第8期14卷 112-123页

作者： Ebrahim Mostafavi Siavash Iravani stanford Cardiovascular Institute Stanford University School of MedicineStanfordCA 94305USA Department of Medicine Stanford University School of MedicineStanfordCA 94305USA Faculty of Pharmacy and Pharmaceutical Sciences Isfahan University of Medical SciencesIsfahanIran

MXenes,transition metal carbides and nitrides with graphene-like structures,have received considerable attention since their first *** the other hand,Graphene has been extensively used in biomedical and medicinal *** and graphene,both as promising candidates of two-dimensional materials,have shown to possess high potential in future biomedical applications due to their unique physicochemical properties such as superior electrical conductivity,high biocompatibility,large surface area,optical and magnetic features,and extraordinary thermal and mechanical *** special structural,functional,and biological characteristics suggest that the hybrid/composite structure of MXene and graphene would be able to meet many unmet needs in different fields;particularly in medicine and biomedical engineering,where high-performance mechanical,electrical,thermal,magnetic,and optical requirements are ***,the hybridization and surface functionalization should be further explored to obtain biocompatible composites/platforms with unique physicochemical properties,high stability,and *** addition,toxicological and long-term biosafety assessments and clinical translation evaluations should be given high priority in *** very limited studies have revealed the excellent potentials of MXene/graphene in biomedicine,the next steps should be toward the extensive research and detailed analysis in optimizing the properties and improving their functionality with a clinical and industrial ***,different synthesis/fabrication methods and performances of MXene/graphene composites are discussed for potential biomedical *** potential toxicological effects of these composites on human cells and tissues are also covered,and future perspectives toward more successful translational applications are *** current state-of-the-art biotechnological advances in the use of MXene-Graphene composites,as wel

关键词： Graphene MXene Composites Hybrid structures Biocompatibility Cancer theranostics Biomedical engineering

Enabling silicon photoanodes for efficient solar water splitting by electroless-deposited nickel

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nano Research 2018年第6期11卷 3499-3508页

作者： Jiheng Zhao Thomas Mark Gill Xiaolin Zheng Department of Mechanical Engineering Stanford University Stanford 9430S USA

Enabling Si photoanodes for efficient solar water oxidation would facilitate the development of solar fuel conversion, but it is challenging owing to Si surface passivation via photo-induced corrosion in aqueous electrolytes. To overcome this challenge, most approaches have focused on improving the stability of Si by coating dense and thin protective layers using high vacuum-based techniques such as atomic layer deposition. However, these procedures are costly, making scalability for practical applications difficult. Herein, we report a modified electroless deposition （ELD） method to uniformly deposit protective and catalytic Ni films on Si wafers, resulting in efficient and stable Si photoanodes for solar water oxidation. The optimized Ni/n-Si photoanode achieves an onset potential of -1.09 V vs. a reversible hydrogen electrode and a saturation current density of -27.5 mA/cm^2 under AM 1.5 G illumination at pH 14. The ELD method is additionally capable of Ni deposition on a 4-inch n-Si wafer, demonstrating the first 4-inch Si photoanode. The solar water oxidation of the ELD-Ni/n-Si photoanode can be further improved by surface texturing, built-in n-p junctions, or coupling with more efficient catalysts.

关键词： Ni deposition electroless plating Si photoanode oxygen evolution reaction (OER) photoelectrochemical water splitting