In this work,we reported a high-performance-based ultraviolet-visible(UV-VIS)photodetector based on a TiO_(2)@GaO_(x)N_(y)-Ag heterostructure.Ag particles were introduced into TiO_(2)@GaO_(x)N_(y)to enhance the visibl...In this work,we reported a high-performance-based ultraviolet-visible(UV-VIS)photodetector based on a TiO_(2)@GaO_(x)N_(y)-Ag heterostructure.Ag particles were introduced into TiO_(2)@GaO_(x)N_(y)to enhance the visible light detection perfor-mance of the heterojunction device.At 380 nm,the responsivity and detectivity of TiO_(2)@GaO_(x)N_(y)-Ag were 0.94 A/W and 4.79×109 Jones,respectively,and they increased to 2.86 A/W and 7.96×1010 Jones at 580 nm.The rise and fall times of the response were 0.19/0.23 and 0.50/0.57 s,respectively.Uniquely,at 580 nm,the responsivity of fabricated devices is one to four orders of magnitude higher than that of the photodetectors based on TiO_(2),Ga_(2)O_(3),and other heterojunctions.The excellent optoelectronic characteristics of the TiO_(2)@GaO_(x)N_(y)-Ag heterojunction device could be mainly attributed to the synergistic effect of the type-Ⅱband structure of the metal-semiconductor-metal heterojunction and the plasmon resonance effect of Ag,which not only effectively promotes the separation of photogenerated carriers but also reduces the recombination rate.It is fur-ther illuminated by finite difference time domain method(FDTD)simulation and photoelectric measurements.The TiO_(2)@GaO_(x)N_(y)-Ag arrays with high-efficiency detection are suitable candidates for applications in energy-saving communica-tion,imaging,and sensing networks.展开更多
Carbonaceous materials have been regarded as highly promising anode candidates for potassium storage with their cost-effectiveness and environmental benignity.However,low specific capacity and difficulty in large-scal...Carbonaceous materials have been regarded as highly promising anode candidates for potassium storage with their cost-effectiveness and environmental benignity.However,low specific capacity and difficulty in large-scale synthesis largely hinder their further development.Herein,a thermal-induced potassium–carbon alloy phase(K_(x)C_(y))with the expanded interlayer spacing strategy is first put forward.Through in situ high-temperature X-ray diffraction,a K_(2)C_(2) phase is evoked by thermal energy during the in-situ carbonization process of carbon quantum dots intermediate derived from potassium-containing precursors,whereas no lithium or sodium–carbon alloy phase is observed from lithium/sodium-containing precursors.The asobtained ultra-thin carbon nanosheets achieve adjustable layer spacing,preparation in bulk,delivering reversible potassium storage of 403.4 mAh g^(−1) at 100 mA g^(−1) and 161.2 mAh g^(−1) even at 5.0 A g^(−1),which is one of the most impressive K-storage performances reported so far with great potential application.Furthermore,the assembled potassium-ion hybrid capacitor by combining the impressive CFMs-900 anode with the three-dimensional framework-activated carbon delivers a high energy-power density of 251.7 Wh kg^(−1) at 250Wkg^(−1) with long-term stability.This study opens a scalable avenue to realize the expanded interlayer spacing,which can be extended to other multicarboxyl potassium salts and can provide approach for the design of high-performance carbon anode materials for potassium storage.展开更多
Incorporating metal nanodots(NDs)into heterostructures for high charge separation and transfer capacities is one of the most effective strategies for improving their photocatalytic activities.However,controlling the s...Incorporating metal nanodots(NDs)into heterostructures for high charge separation and transfer capacities is one of the most effective strategies for improving their photocatalytic activities.However,controlling the space distribution of metal NDs for optimizing charge transport pathways remains a significant challenge,particularly in two-dimensional(2D)face-to-face heterostructures.Herein,we develop a simple targeted self-reduction strategy for selectively loading Ru NDs onto the Ti_(3−x)C_(2)T_(y)(TC)surface of 2D TC/g-C_(3)N_(4)(CN)heterojunction based on the reductive Ti vacancy defects creatively increased during the preparation of TC/CN by reducing calcination.Notably,the optimized Ru/TC/CN photocatalyst exhibits an outstanding H_(2)evolution rate of 3.21 mmol·g^(−1)·h^(−1)and a high apparent quantum efficiency of 30.9%at 380 nm,which is contributed by the unidirectional transfer of the photogenerated electrons from CN to Ru active sites(CN→TC→Ru)and the suppressed backflow of electrons from Ru sites to CN,as revealed by comprehensive characterizations and density functional theory(DFT)calculations.This work provides a novel strategy for synthesizing the highly efficient photocatalysts with a controllable charge transfer paths,which will boost the development of photocatalysis.展开更多
As a class of metal-free two-dimensional(2D)semiconductor materials,polymeric carbon nitrides have attracted wide attention recently due to its facile regulation of the molecular and electronic structures,availability...As a class of metal-free two-dimensional(2D)semiconductor materials,polymeric carbon nitrides have attracted wide attention recently due to its facile regulation of the molecular and electronic structures,availability in abundance and high stability.According to the different ratios of C and N atoms in the fra mework,a series of C_(x)N_(y)materials have been successfully synthesized by virtue of various precursors,which further triggers extensive investigations of broad applications ranging from sustainable photocatalytic reactions and highly sensitive optoelectronic biosensing.In view of topological structures on their electronic structures and material properties,the as-reported C_(x)N_(y)could be generally classified into two main categories with three-or six-bond-extending frameworks.Owing to the effective n→π*transition in most C_(x)N_(y)materials,the relative energy level of the lone-pair electrons on N atoms is high,which thus endows the mate rials with the capability of visible light absorption.Meanwhile,the different repeating units,bridging groups and defect sites of these two kinds of C_(x)N_(y)allow them to effectively drive a diverse of promising applications that require specific electronic,inte rfacial and geometric properties.This review paper aims to summarize the recent progress in topological structure design and the relevant electronic band structures and striking properties of C_(x)N_(y)materials,In the final part,we also discuss the existing challenges of C_(x)N_(y)and outlook the prospect possibilities.展开更多
基金supported by National Natural Science Foundation of China(Nos.62027818,61874034,and 51861135105)Natural Science Foundation of Shanghai(No.18ZR1405000)Shanghai Science and Technology Innovation Program(No.19520711500).
文摘In this work,we reported a high-performance-based ultraviolet-visible(UV-VIS)photodetector based on a TiO_(2)@GaO_(x)N_(y)-Ag heterostructure.Ag particles were introduced into TiO_(2)@GaO_(x)N_(y)to enhance the visible light detection perfor-mance of the heterojunction device.At 380 nm,the responsivity and detectivity of TiO_(2)@GaO_(x)N_(y)-Ag were 0.94 A/W and 4.79×109 Jones,respectively,and they increased to 2.86 A/W and 7.96×1010 Jones at 580 nm.The rise and fall times of the response were 0.19/0.23 and 0.50/0.57 s,respectively.Uniquely,at 580 nm,the responsivity of fabricated devices is one to four orders of magnitude higher than that of the photodetectors based on TiO_(2),Ga_(2)O_(3),and other heterojunctions.The excellent optoelectronic characteristics of the TiO_(2)@GaO_(x)N_(y)-Ag heterojunction device could be mainly attributed to the synergistic effect of the type-Ⅱband structure of the metal-semiconductor-metal heterojunction and the plasmon resonance effect of Ag,which not only effectively promotes the separation of photogenerated carriers but also reduces the recombination rate.It is fur-ther illuminated by finite difference time domain method(FDTD)simulation and photoelectric measurements.The TiO_(2)@GaO_(x)N_(y)-Ag arrays with high-efficiency detection are suitable candidates for applications in energy-saving communica-tion,imaging,and sensing networks.
基金National Natural Science Foundation of China,Grant/Award Numbers:52004338,51904342,52074359Guangdong Provincial Department of Natural Resources,Grant/Award Number:2020-011Hunan Provincial Natural Science Foundation,Grant/Award Number:2020JJ5696。
文摘Carbonaceous materials have been regarded as highly promising anode candidates for potassium storage with their cost-effectiveness and environmental benignity.However,low specific capacity and difficulty in large-scale synthesis largely hinder their further development.Herein,a thermal-induced potassium–carbon alloy phase(K_(x)C_(y))with the expanded interlayer spacing strategy is first put forward.Through in situ high-temperature X-ray diffraction,a K_(2)C_(2) phase is evoked by thermal energy during the in-situ carbonization process of carbon quantum dots intermediate derived from potassium-containing precursors,whereas no lithium or sodium–carbon alloy phase is observed from lithium/sodium-containing precursors.The asobtained ultra-thin carbon nanosheets achieve adjustable layer spacing,preparation in bulk,delivering reversible potassium storage of 403.4 mAh g^(−1) at 100 mA g^(−1) and 161.2 mAh g^(−1) even at 5.0 A g^(−1),which is one of the most impressive K-storage performances reported so far with great potential application.Furthermore,the assembled potassium-ion hybrid capacitor by combining the impressive CFMs-900 anode with the three-dimensional framework-activated carbon delivers a high energy-power density of 251.7 Wh kg^(−1) at 250Wkg^(−1) with long-term stability.This study opens a scalable avenue to realize the expanded interlayer spacing,which can be extended to other multicarboxyl potassium salts and can provide approach for the design of high-performance carbon anode materials for potassium storage.
基金the National Natural Science Foundation of China(No.22002142)China Postdoctoral Science Foundation(No.2020T130605)+2 种基金Natural Science Foundation of Henan Province(No.202300410436)Support Plan for College Science and Technology Innovation Team of Henan Province(No.16IRTSTHN001)the Science&Technology Innovation Talent Plan of Henan Province(No.174200510018).
文摘Incorporating metal nanodots(NDs)into heterostructures for high charge separation and transfer capacities is one of the most effective strategies for improving their photocatalytic activities.However,controlling the space distribution of metal NDs for optimizing charge transport pathways remains a significant challenge,particularly in two-dimensional(2D)face-to-face heterostructures.Herein,we develop a simple targeted self-reduction strategy for selectively loading Ru NDs onto the Ti_(3−x)C_(2)T_(y)(TC)surface of 2D TC/g-C_(3)N_(4)(CN)heterojunction based on the reductive Ti vacancy defects creatively increased during the preparation of TC/CN by reducing calcination.Notably,the optimized Ru/TC/CN photocatalyst exhibits an outstanding H_(2)evolution rate of 3.21 mmol·g^(−1)·h^(−1)and a high apparent quantum efficiency of 30.9%at 380 nm,which is contributed by the unidirectional transfer of the photogenerated electrons from CN to Ru active sites(CN→TC→Ru)and the suppressed backflow of electrons from Ru sites to CN,as revealed by comprehensive characterizations and density functional theory(DFT)calculations.This work provides a novel strategy for synthesizing the highly efficient photocatalysts with a controllable charge transfer paths,which will boost the development of photocatalysis.
基金the National Natural Science Foundation of China(Nos.21775018,21675022)the Natural Science Foundation of Jiangsu Province(No.BK20170084)+1 种基金the Open Funds of the State Key Laboratory of Electroanalytical Chemistry(No.SKLEAC201909)the Fundamental Research Funds for the Central Universities。
文摘As a class of metal-free two-dimensional(2D)semiconductor materials,polymeric carbon nitrides have attracted wide attention recently due to its facile regulation of the molecular and electronic structures,availability in abundance and high stability.According to the different ratios of C and N atoms in the fra mework,a series of C_(x)N_(y)materials have been successfully synthesized by virtue of various precursors,which further triggers extensive investigations of broad applications ranging from sustainable photocatalytic reactions and highly sensitive optoelectronic biosensing.In view of topological structures on their electronic structures and material properties,the as-reported C_(x)N_(y)could be generally classified into two main categories with three-or six-bond-extending frameworks.Owing to the effective n→π*transition in most C_(x)N_(y)materials,the relative energy level of the lone-pair electrons on N atoms is high,which thus endows the mate rials with the capability of visible light absorption.Meanwhile,the different repeating units,bridging groups and defect sites of these two kinds of C_(x)N_(y)allow them to effectively drive a diverse of promising applications that require specific electronic,inte rfacial and geometric properties.This review paper aims to summarize the recent progress in topological structure design and the relevant electronic band structures and striking properties of C_(x)N_(y)materials,In the final part,we also discuss the existing challenges of C_(x)N_(y)and outlook the prospect possibilities.
