While alloying transition metal chalcogenides(TMCs)with other chalcogen elements can effectively improve their conductivity and electrochemical properties,the optimal alloying content is still uncertain.In this study,...While alloying transition metal chalcogenides(TMCs)with other chalcogen elements can effectively improve their conductivity and electrochemical properties,the optimal alloying content is still uncertain.In this study,we study the influence of dopant concentration on the chemical bonds in TMC and reveal the associated stepwise conversion reaction mechanism for potassium ion storage.According to density function theory calculations,appropriate S-doping in Co0.85Se(Co_(0.85)Se_(1-x)S_(x))can reduce the average length of Co-Co bonds because of the electronegativity variation,which is thermodynamically favourable to the phase transition reactions.The optimal Se/S ratio(x=0.12)for the conductivity has been obtained from experimental results.When assembled as an anode in potassium-ion batteries(PIBs),the sample with optimized Se/S ratio exhibits extraordinary electrochemical performance.The rate performance(229.2 mA h g^(-1)at 10 A g^(-1))is superior to the state-of-the-art results.When assembled with Prussian blue(PB)as a cathode,the pouch cell exhibits excellent performance,demonstrating its great potential for applications.Moreover,the stepwise K+storage mechanism caused by the coexistence of S and Se is revealed by in-situ X-ray diffraction and ex-situ transmission electron microscopy techniques.Hence,this work not only provides an effective strategy to enhance the electrochemical performance of transition metal chalcogenides but also reveals the underlying mechanism for the construction of advanced electrode materials.展开更多
Accurate and clear bioimaging is crucial in the field of medical diagnosis.High-quality bioimaging requires to avoid the effects of ambient light as well as the absorption of biological tissues.Nearinfrared(NIR)narrow...Accurate and clear bioimaging is crucial in the field of medical diagnosis.High-quality bioimaging requires to avoid the effects of ambient light as well as the absorption of biological tissues.Nearinfrared(NIR)narrowband detectors located at wavelength from 650 to 900 nm can meet these requirements;thus,they are the potential solution.In this work,we construct a filter-free and self-power NIR narrowband photodetector based on the structure of n-CdSe/p-Sb_(2)(S_(1-x),Se_(x))_(3)heterojunction,and achieve a narrow spectral response at 735 nm with a full width at half-maximum of 35.3 nm in the detector.Further,the imaging characteristics of the NIR narrowband detector are explored,verifying the ability to narrowband detection and imaging.This filter-free and self-power NIR narrowband detector shows considerable promise in real-life applications.展开更多
基金financially supported by the Natural Science Foundation of Jiangsu Province of China(BK20211172)the Jiangsu Provincial Department of Science and Technology Innovation Support Program(BK20222004,BZ2022036)+1 种基金the National Natural Science Foundation of China(52002366,22075263)the Fundamental Research Funds for the Central Universities(WK2060000039)。
文摘While alloying transition metal chalcogenides(TMCs)with other chalcogen elements can effectively improve their conductivity and electrochemical properties,the optimal alloying content is still uncertain.In this study,we study the influence of dopant concentration on the chemical bonds in TMC and reveal the associated stepwise conversion reaction mechanism for potassium ion storage.According to density function theory calculations,appropriate S-doping in Co0.85Se(Co_(0.85)Se_(1-x)S_(x))can reduce the average length of Co-Co bonds because of the electronegativity variation,which is thermodynamically favourable to the phase transition reactions.The optimal Se/S ratio(x=0.12)for the conductivity has been obtained from experimental results.When assembled as an anode in potassium-ion batteries(PIBs),the sample with optimized Se/S ratio exhibits extraordinary electrochemical performance.The rate performance(229.2 mA h g^(-1)at 10 A g^(-1))is superior to the state-of-the-art results.When assembled with Prussian blue(PB)as a cathode,the pouch cell exhibits excellent performance,demonstrating its great potential for applications.Moreover,the stepwise K+storage mechanism caused by the coexistence of S and Se is revealed by in-situ X-ray diffraction and ex-situ transmission electron microscopy techniques.Hence,this work not only provides an effective strategy to enhance the electrochemical performance of transition metal chalcogenides but also reveals the underlying mechanism for the construction of advanced electrode materials.
基金China Postdoctoral Science Foundation Project,Grant/Award Numbers:2020M680101,2021T140233Fundamental Research Funds for the Central Universities,Grant/Award Number:2021XXJS028+2 种基金National Natural Science Foundation of China,Grant/Award Numbers:61725401,61904058,62050039the Graduates'Innovation Fund of Huazhong University of Science and Technology,Grant/Award Number:2021yjsCXCY051the National Key R&D Program of China,Grant/Award Number:2016YFA0204000。
文摘Accurate and clear bioimaging is crucial in the field of medical diagnosis.High-quality bioimaging requires to avoid the effects of ambient light as well as the absorption of biological tissues.Nearinfrared(NIR)narrowband detectors located at wavelength from 650 to 900 nm can meet these requirements;thus,they are the potential solution.In this work,we construct a filter-free and self-power NIR narrowband photodetector based on the structure of n-CdSe/p-Sb_(2)(S_(1-x),Se_(x))_(3)heterojunction,and achieve a narrow spectral response at 735 nm with a full width at half-maximum of 35.3 nm in the detector.Further,the imaging characteristics of the NIR narrowband detector are explored,verifying the ability to narrowband detection and imaging.This filter-free and self-power NIR narrowband detector shows considerable promise in real-life applications.
