In this work, we present a new versatile strategy to prepare noble metal （Au, Ag and Cu） nanoclusters on TiO2 nanosheets in large scales with exposed （001） facets with controlled size, crystalline interface, and l...In this work, we present a new versatile strategy to prepare noble metal （Au, Ag and Cu） nanoclusters on TiO2 nanosheets in large scales with exposed （001） facets with controlled size, crystalline interface, and loading amount. By precise in situ calcination, the metal （M = Au, Ag, and Cu） nanocrystals with controllable size and better crystalline interface with the TiO2 support have been prepared. The potential application of the as-prepared Au, Ag, and Cu nanoclusters on TiO2 nanosheets as potential heterogeneous catalysts for organic synthesis, such as catalytic reduction of 4-nitrophenol to 4-aminophenol, has been demonstrated. After calcination, Au, Ag, and Cu nanocrystals were found to be proficient cocatalysts for photocatalytic H2 evolution, particularly the Au cocatalyst. Based on precise high-resolution transmission electron microscopy （HRTEM） and inductively coupled plasma optical emission spectrometry （ICP-OES） analyses, the flexible control of their size and loading amount as well as their intimate contact with the TiO2 nanosheet enhanced the photocatalytic H2 evolution activity and the sensitivity of the photocurrent response of the film. Furthermore, this aqueous-directed synthesis of metal nanoclusters on a support will generate further interest in the field of nanocatalysis.展开更多
The combination of CrO4^2-anion and N,N′-dimethylformamide(DMF)-containing solvent helps to stabilize an atom-precise ultrasmall Ag6 kernel into a 52-nuclei silver shell,giving a core-shell Ag6@Ag52 wheel-like struct...The combination of CrO4^2-anion and N,N′-dimethylformamide(DMF)-containing solvent helps to stabilize an atom-precise ultrasmall Ag6 kernel into a 52-nuclei silver shell,giving a core-shell Ag6@Ag52 wheel-like structure(SD/Ag58b).The solution behavior and photocurrent response property were investigated in details.展开更多
Undoped (ND) semi-insulating (SI) liquid encapsulated Czochralski (LEC) GaAscrystals were investigated by photocurrent and temperature-dependent Hall measurements. It isindicated that strong nonuniformities in the dis...Undoped (ND) semi-insulating (SI) liquid encapsulated Czochralski (LEC) GaAscrystals were investigated by photocurrent and temperature-dependent Hall measurements. It isindicated that strong nonuniformities in the distributions of impurities and defects can occur forthe NDSILEC GaAs crystal grown under a condition with strong constitutional supercooling. In suchcase, the deep level that dominates Fermi level is spacial location dependent, and the GaAs crystalbecomes a composite consisting of a large number of elementary domains with differentconductivities. The sub-bandgap photocurrent response and the carrier transport properties for thiskind of composite are quite different from those for homogeneous NDSILEC GaAs.展开更多
Although inorganic anion templates are highly appreciated in the synthesis of nanosized silver clusters,supramolecular clusters used as templates to mold silver nanoclusters remain as-yet-unknown due to their existenc...Although inorganic anion templates are highly appreciated in the synthesis of nanosized silver clusters,supramolecular clusters used as templates to mold silver nanoclusters remain as-yet-unknown due to their existence as volatile forms in solution.Here,we report the synthesis of a novel silver-thiolate nanocluster(SD/Ag58a),comprising an outer tetrahedral cage of 58 silver atoms and a central supramolecular cluster[CH_(3)OH@(SO_(4))_(4)(H_(2)O)6]8−(hereafter abbreviated as CS_(4)H_(6)).Ternary CS_(4)H_(6) cluster was constructed from an(SO_(4))_(4) tetrahedron encaging one CH_(3)OH molecule inside and six water molecules sitting between paired SO_(4)^(2−)ions to form the[SO_(4)…H_(2)O…SO_(4)]hydrogen bonds(H-bonds).Also,the CS4H6 could coordinate to the inner wall of the Ag58 cage by forming Ag-O bonds,exerting templating effect on the formation of SD/Ag58a.Moreover,SD/Ag58a showed a photocurrent response upon visible light irradiation and emitted luminescence in the near-infrared(NIR)region at a cryogenic temperature.This work exemplifies the ternary supramolecule templating effect in the construction of silver nanocluster and facilitates understanding of the structure of complex solvated anion cluster in atomic precision.展开更多
The fabrication of zinc oxide(ZnO) from inexpensive solution-processing techniques,namely,electrochemical deposition and electrospinning were explored on various conducting and mesoporous semiconducting surfaces.Optim...The fabrication of zinc oxide(ZnO) from inexpensive solution-processing techniques,namely,electrochemical deposition and electrospinning were explored on various conducting and mesoporous semiconducting surfaces.Optimised conditions were derived for template- and self-assisted nano/micro structures and composites. ZnO thin films were annealed at a fixed temperature under ambient conditions and characterised using physical and optical techniques.The photocurrent response in the UV region shows a fast rise and double decay behaviour with a fast component followed by a slow oscillatory decay.Photocurrent results were correlated with surface chemical analysis from X-ray photoelectron spectroscopy.Various characterisation details reveal the importance of fabrication parameter optimisation for useful low-cost optoelectronic applications.展开更多
A new iodoplumbate/organic hybrid,[（Et_2DABCO）_2（Pb_3I_（11））（H3 O）]n（1,Et_2DABCO = N,N？-diethyl-1,4-diazabicyclo[2.2.2] octane） has been synthesized using solution method.According to X-ray diffraction stru...A new iodoplumbate/organic hybrid,[（Et_2DABCO）_2（Pb_3I_（11））（H3 O）]n（1,Et_2DABCO = N,N？-diethyl-1,4-diazabicyclo[2.2.2] octane） has been synthesized using solution method.According to X-ray diffraction structural analysis,the unique（Pb_3I_（11））_n^（5n-） chain in 1 is constructed from face-and edge-sharing PbI_6 octahedra,which is templated by（Et_2DABCO）^（2＋） dication possessing both rigidity and flexibility.C-H...I hydrogen bonds contribute to the structure extending from 1D chains to a 3D network.Its energy band gap of 2.64 eV indicates its broad-gap semiconductor nature.It exhibits both photocurrent response property and photocatalytic activity for the degradation of rhodamine B.展开更多
Two new ethoxycarbonylmethyl viologen induced metal halide-based hybrids,(Ae V)(BiI)(DMF)(1)and(Ae V)(CoCl)(2)(AeV=N,N?-bis(ethoxycarbonylmethyl)-4,4?-bipyridinium)have been synthesized and structurally determined by ...Two new ethoxycarbonylmethyl viologen induced metal halide-based hybrids,(Ae V)(BiI)(DMF)(1)and(Ae V)(CoCl)(2)(AeV=N,N?-bis(ethoxycarbonylmethyl)-4,4?-bipyridinium)have been synthesized and structurally determined by X-ray diffraction method.Under the direction of a new template AeV,the(BiI)tetramer constructed from four edge-sharing BiIoctahedra(for 1)and(CoCl)mono-nuclear(for 2)were obtained.Furthermore,C–H···O and C–H···X(X=I,Cl)hydrogen bonds contribute to the extension of structures from 0-D to 1-D chains.Their energy band gaps of 2.18 and 2.41 eV indicate their semiconductor properties,and the photoluminescence was detected on 1.Interestingly,2 exhibits good photocurrent response behavior.Electronic structure analysis was executed to correlate the structure/property.展开更多
The response speed of the reported Cs_(2)AgBiBr_(6)-based photodetectors exhibits a wide variation ranging from microseconds to nanoseconds,while the reason is still unclear.Apart from the conventional approaches such...The response speed of the reported Cs_(2)AgBiBr_(6)-based photodetectors exhibits a wide variation ranging from microseconds to nanoseconds,while the reason is still unclear.Apart from the conventional approaches such as reducing effective area,new regulating approaches for response speed improvement have rarely been reported.On the other hand,it is generally believed that ultraviolet(UV)light has negative impact on perovskite devices resulting in performance degradation.In this work,we demonstrated that the response speed of the photodetector with FTO/Cs_(2)AgBiBr_(6)/Au structure can be effectively regulated by utilizing UV light-soaking effect without reducing the device area.Particularly,the decay time is efficiently modulated from 30.1μs to 340 ns.In addition,the−3 dB bandwidth of the device is extended from 5 to 20 kHz.It is worth mentioning that the light current is remarkably boosted by 15 times instead of any attenuation.Furthermore,we prove the universality of UV soaking treatment on Cs_(2)AgBiBr_(6)-based photodetectors with other all-inorganic structures,i.e.,FTO/TiO_(2)/Cs_(2)AgBiBr_(6)/Au,FTO/Cs_(2)AgBiBr_(6)/TiO_(2)/Au and FTO/TiO_(2)/Cs_(2)AgBiBr_(6)/CuSCN/Au.Our results demonstrate a new method to improve the response speed and light current of Cs_(2)AgBiBr_(6)-based perovskite all-inorganic photodetectors.展开更多
文摘In this work, we present a new versatile strategy to prepare noble metal （Au, Ag and Cu） nanoclusters on TiO2 nanosheets in large scales with exposed （001） facets with controlled size, crystalline interface, and loading amount. By precise in situ calcination, the metal （M = Au, Ag, and Cu） nanocrystals with controllable size and better crystalline interface with the TiO2 support have been prepared. The potential application of the as-prepared Au, Ag, and Cu nanoclusters on TiO2 nanosheets as potential heterogeneous catalysts for organic synthesis, such as catalytic reduction of 4-nitrophenol to 4-aminophenol, has been demonstrated. After calcination, Au, Ag, and Cu nanocrystals were found to be proficient cocatalysts for photocatalytic H2 evolution, particularly the Au cocatalyst. Based on precise high-resolution transmission electron microscopy （HRTEM） and inductively coupled plasma optical emission spectrometry （ICP-OES） analyses, the flexible control of their size and loading amount as well as their intimate contact with the TiO2 nanosheet enhanced the photocatalytic H2 evolution activity and the sensitivity of the photocurrent response of the film. Furthermore, this aqueous-directed synthesis of metal nanoclusters on a support will generate further interest in the field of nanocatalysis.
基金supported by the National Natural Science Foundation of China(21822107,21571115,21827801,21671172)the Natural Science Foundation of Shandong Province(JQ201803,ZR2017MB061)+2 种基金the Taishan Scholar Project of Shandong Province of Chinathe Qilu Youth Scholar Funding of Shandong Universitythe Fundamental Research Funds of Shandong University(104.205.2.5)
文摘The combination of CrO4^2-anion and N,N′-dimethylformamide(DMF)-containing solvent helps to stabilize an atom-precise ultrasmall Ag6 kernel into a 52-nuclei silver shell,giving a core-shell Ag6@Ag52 wheel-like structure(SD/Ag58b).The solution behavior and photocurrent response property were investigated in details.
基金This work was financially supported by the Natural Science Foundation of Tianjin (No. 02380411)the Natural Science Foundation of Hebei Province (No. 601048)
文摘Undoped (ND) semi-insulating (SI) liquid encapsulated Czochralski (LEC) GaAscrystals were investigated by photocurrent and temperature-dependent Hall measurements. It isindicated that strong nonuniformities in the distributions of impurities and defects can occur forthe NDSILEC GaAs crystal grown under a condition with strong constitutional supercooling. In suchcase, the deep level that dominates Fermi level is spacial location dependent, and the GaAs crystalbecomes a composite consisting of a large number of elementary domains with differentconductivities. The sub-bandgap photocurrent response and the carrier transport properties for thiskind of composite are quite different from those for homogeneous NDSILEC GaAs.
基金supported financially by the National Natural Science Foundation of China(grant nos.91961105,21822107,21571115,and 21827801)the Fok Ying Tong Education Foundation(grant no.171009)+3 种基金the Natural Science Foundation of Shandong Province(grant nos.ZR2020ZD35,ZR2019ZD45,JQ201803,and ZR2017MB061)the Taishan Scholar Project of Shandong Province of China(grant nos.tsqn201812003 and ts20190908)the Qilu Youth Scholar Funding of Shandong UniversityProject for Scientific Research Innovation Team of Young Scholar in Colleges and Universities of Shandong Province(grant no.2019KJC028).
文摘Although inorganic anion templates are highly appreciated in the synthesis of nanosized silver clusters,supramolecular clusters used as templates to mold silver nanoclusters remain as-yet-unknown due to their existence as volatile forms in solution.Here,we report the synthesis of a novel silver-thiolate nanocluster(SD/Ag58a),comprising an outer tetrahedral cage of 58 silver atoms and a central supramolecular cluster[CH_(3)OH@(SO_(4))_(4)(H_(2)O)6]8−(hereafter abbreviated as CS_(4)H_(6)).Ternary CS_(4)H_(6) cluster was constructed from an(SO_(4))_(4) tetrahedron encaging one CH_(3)OH molecule inside and six water molecules sitting between paired SO_(4)^(2−)ions to form the[SO_(4)…H_(2)O…SO_(4)]hydrogen bonds(H-bonds).Also,the CS4H6 could coordinate to the inner wall of the Ag58 cage by forming Ag-O bonds,exerting templating effect on the formation of SD/Ag58a.Moreover,SD/Ag58a showed a photocurrent response upon visible light irradiation and emitted luminescence in the near-infrared(NIR)region at a cryogenic temperature.This work exemplifies the ternary supramolecule templating effect in the construction of silver nanocluster and facilitates understanding of the structure of complex solvated anion cluster in atomic precision.
基金supported by the UK-India Education and Research Initiative(UKIER1) and the High-Impact Research Scheme ofⅡT Delhithe University Grants Commission(UGC),New Delhi,India,for financial assistance
文摘The fabrication of zinc oxide(ZnO) from inexpensive solution-processing techniques,namely,electrochemical deposition and electrospinning were explored on various conducting and mesoporous semiconducting surfaces.Optimised conditions were derived for template- and self-assisted nano/micro structures and composites. ZnO thin films were annealed at a fixed temperature under ambient conditions and characterised using physical and optical techniques.The photocurrent response in the UV region shows a fast rise and double decay behaviour with a fast component followed by a slow oscillatory decay.Photocurrent results were correlated with surface chemical analysis from X-ray photoelectron spectroscopy.Various characterisation details reveal the importance of fabrication parameter optimisation for useful low-cost optoelectronic applications.
基金supported by the National Natural Science Foundation of China(No.51778374)the Shenzhen Science and Technology Funding Project(JCYJ20150630114140635)
文摘A new iodoplumbate/organic hybrid,[（Et_2DABCO）_2（Pb_3I_（11））（H3 O）]n（1,Et_2DABCO = N,N？-diethyl-1,4-diazabicyclo[2.2.2] octane） has been synthesized using solution method.According to X-ray diffraction structural analysis,the unique（Pb_3I_（11））_n^（5n-） chain in 1 is constructed from face-and edge-sharing PbI_6 octahedra,which is templated by（Et_2DABCO）^（2＋） dication possessing both rigidity and flexibility.C-H...I hydrogen bonds contribute to the structure extending from 1D chains to a 3D network.Its energy band gap of 2.64 eV indicates its broad-gap semiconductor nature.It exhibits both photocurrent response property and photocatalytic activity for the degradation of rhodamine B.
基金supported by the Science and Technology Funding Project of Fujian Provincial Department of Transportation(No.201337)
文摘Two new ethoxycarbonylmethyl viologen induced metal halide-based hybrids,(Ae V)(BiI)(DMF)(1)and(Ae V)(CoCl)(2)(AeV=N,N?-bis(ethoxycarbonylmethyl)-4,4?-bipyridinium)have been synthesized and structurally determined by X-ray diffraction method.Under the direction of a new template AeV,the(BiI)tetramer constructed from four edge-sharing BiIoctahedra(for 1)and(CoCl)mono-nuclear(for 2)were obtained.Furthermore,C–H···O and C–H···X(X=I,Cl)hydrogen bonds contribute to the extension of structures from 0-D to 1-D chains.Their energy band gaps of 2.18 and 2.41 eV indicate their semiconductor properties,and the photoluminescence was detected on 1.Interestingly,2 exhibits good photocurrent response behavior.Electronic structure analysis was executed to correlate the structure/property.
基金supported by the National Natural Science Foundation of China(51772135 and 52002148)the Ministry of Education of China(6141A02022516)+2 种基金the Fundamental Research Funds for the Central Universities(11619103)Guangdong Basic and Applied Basic Research Foundation(2020A1515011377)the support from China and Germany Postdoctoral Exchange Programthe financial support from Agency for Science,Technology,and Research(A*STAR),Singapore by the AME Individual Research Grants(A1883c0004)。
文摘The response speed of the reported Cs_(2)AgBiBr_(6)-based photodetectors exhibits a wide variation ranging from microseconds to nanoseconds,while the reason is still unclear.Apart from the conventional approaches such as reducing effective area,new regulating approaches for response speed improvement have rarely been reported.On the other hand,it is generally believed that ultraviolet(UV)light has negative impact on perovskite devices resulting in performance degradation.In this work,we demonstrated that the response speed of the photodetector with FTO/Cs_(2)AgBiBr_(6)/Au structure can be effectively regulated by utilizing UV light-soaking effect without reducing the device area.Particularly,the decay time is efficiently modulated from 30.1μs to 340 ns.In addition,the−3 dB bandwidth of the device is extended from 5 to 20 kHz.It is worth mentioning that the light current is remarkably boosted by 15 times instead of any attenuation.Furthermore,we prove the universality of UV soaking treatment on Cs_(2)AgBiBr_(6)-based photodetectors with other all-inorganic structures,i.e.,FTO/TiO_(2)/Cs_(2)AgBiBr_(6)/Au,FTO/Cs_(2)AgBiBr_(6)/TiO_(2)/Au and FTO/TiO_(2)/Cs_(2)AgBiBr_(6)/CuSCN/Au.Our results demonstrate a new method to improve the response speed and light current of Cs_(2)AgBiBr_(6)-based perovskite all-inorganic photodetectors.
