An attractive approach to controlling spin effects in semiconductor nanostructures for applications in electronics is the use of light to generate, manipulate, or read out spins. Here, we demonstrate spontaneous photoinduced polarization of manganese(II) spins in doped colloidal cadmium selenide quantum dots. Photoexcitation generates large dopant-carrier exchange fields, enhanced by strong spatial confinement, that lead to giant Zeeman splittings of the semiconductor band structure in the absence of applied magnetic fields. These internal exchange fields allow spontaneous magnetic saturation of the manganese(II) spins to be achieved at zero external magnetic field up to approximately 50 kelvin. Photomagnetic effects are observed all the way up to room temperature.
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http://dx.doi.org/10.1126/science.1174419 | DOI Listing |
J Colloid Interface Sci
December 2024
State Key Laboratory of Reliability and Intelligence of Electrical Equipment, Hebei University of Technology, Tianjin 300401, PR China; Engineering Research Center of Ministry of Education for Intelligent Rehabilitation Device and Detection Technology, Hebei University of Technology, Tianjin 300401, PR China; Hebei Key Laboratory of Smart Sensing and Human-Robot Interaction, Hebei University of Technology, Tianjin 300401, PR China; School of Mechanical Engineering, Hebei University of Technology, 5340 Xiping Road, Beichen District, Tianjin 300401, PR China. Electronic address:
Transition-metal-loaded carbon-based electrocatalysts are promising alternatives to conventional precious metal electrocatalysts for the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) in high-performance zinc-air batteries. However, efficiently doping transition-metal single atoms onto carbon-based frameworks is a significant challenge. Herein, an improved template-sacrificing method combining a two-step carbonization process is proposed to fabricate Cu/Co diatomic sites coanchored on a three-dimensional nitrogen-doped carbon-based framework.
View Article and Find Full Text PDFJ Colloid Interface Sci
December 2024
School of Petrochemical Engineering, Lanzhou University of Technology, Lanzhou 730050, PR China; Key Laboratory of Low Carbon Energy and Chemical Engineering of Gansu Province, Lanzhou 730050, PR China.
Heteroatom-doped carbon materials are widely used to improve the electrocatalytic oxidation of methanol; however, the underlying mechanisms driving this enhancement remain poorly understood. A major challenge lies in developing non-doped carbon supports with tunable intrinsic defect types tailored for metal-based catalysts. In this study, we synthesize a series of ordered mesoporous carbon (OMC) supports with adjustable edge defect densities by varying roasting temperatures and employing a zinc (Zn) evaporation strategy to systematically investigate the impact of edge defects on methanol oxidation reaction (MOR) performance.
View Article and Find Full Text PDFJ Colloid Interface Sci
December 2024
College of Chemistry and Materials Engineering, Bohai University, Jinzhou 121013, China. Electronic address:
The unique structure and strong interaction of multiphase hybrid materials have garnered significant attention as prospective candidates for electrode materials in the realm of energy storage. The present study presents a rational design of a functional NiSe-CoSe/N, B double-doped carbon hybrid composite (NCS/C), resulting in the emergence of various novel cooperative regulatory mechanisms involving: (i) the heterogeneous structure of NiSe and CoSe generates built-in electric fields to increase electron mobility; (ii) the incorporation of polyatomic double-doped carbon (N, and B) expedites electron transfer rate; intriguingly, (iii) ionic liquids not only serve as polyatomic dopants in the reaction system but also influence the microstructure of the composite. Benefiting from these synergistic effects, the NCS/C hybrid exhibits remarkable charge storage capacity and rapid electrochemical kinetics, driven by its multi-fold hollow structure and multicomponent cooperative modulation.
View Article and Find Full Text PDFColloids Surf B Biointerfaces
December 2024
College of Materials Science and Engineering, Qingdao University of Science and Technology, Qingdao, Shandong 266042, China. Electronic address:
Traditional design approaches for nanozymes typically rely on empirical methods and trial-and-error, which hampers systematic optimization of their structure and performance, thus limiting the efficiency of developing innovative nanozymes. This study leverages machine learning techniques supported by high-throughput computations to effectively design nanozymes with multi-enzyme activities and to elucidate their reaction mechanisms. Additionally, it investigates the impact of dopants on the microphysical properties of nanozymes.
View Article and Find Full Text PDFJ Colloid Interface Sci
December 2024
Department of Vascular Surgery, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200011, China. Electronic address:
Abdominal aortic aneurysm (AAA) is a chronic inflammation-driven disease characterized by aortic wall destruction and expansion, leading to high morbidity and mortality. However, previous drug treatments for its common risk factors have not achieved favorable results, and the early prevention and treatment is still the main clinical dilemma. Anti-inflammation therapy is a promising therapeutical method targeting its pathogenesis mechanism, but it has not been explored in depth.
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