Ti-10V-2Fe-3Al alloy with fine-grainedβphases was fabricated by friction stir processing with opti-mized processing parameters.The superplastic behavior of the specimens was investigated by tensile deformation at dif...Ti-10V-2Fe-3Al alloy with fine-grainedβphases was fabricated by friction stir processing with opti-mized processing parameters.The superplastic behavior of the specimens was investigated by tensile deformation at different strain rates and temperatures,and an optimal superplastic elongation of 634%was achieved at 700℃ and 3×10^(-4)/s.An annealing treatment at 650℃ for 60 min showed a mi-crostructure withαprecipitates distributed in theβmatrix in the friction stir specimen.Such pre-heat treatment improves the superplasticity of the specimen,achieving an elongation of up to 807%at 750℃ and 3×10^(-4)/s.The influences of tensile temperatures and strain rates on the microstructural evolution,such as grain size variation,grain morphology,and phase transformations,were discussed.The super-plastic deformation behavior of fine-grained Ti-10V-2Fe-3Al alloy is controlled by grain boundary sliding and accompanied by dynamic phase transformation and recrystallization.展开更多
Electrochromic(EC)smart windows utilizing a reversible metal electrodeposition device(RMED)offer a compelling alternative for dynamically regulating transmissions of optical and thermal energy.An EC device(ECD)is cons...Electrochromic(EC)smart windows utilizing a reversible metal electrodeposition device(RMED)offer a compelling alternative for dynamically regulating transmissions of optical and thermal energy.An EC device(ECD)is constructed by reversible metal electrodeposition(RME)of Bi/Cu on WO_(3)·xH_(2)O film electrodeposited onto fluorine-doped tin oxide(FTO)transparent conductive glass.The electrolyte consists of CuCl_(2),BiCl_(3),KCl and HCl aqueous solution,supplying necessary components for both electrochemical and electrodeposition processes.The ECD shows ability to rapidly transition between colorless and black states,which achieves a large optical modulation of 77.0%at 570 nm.In the black state,the ECD exhibits a near-zero transmittance in the wavelength range of 400-1100 nm while maintaining 96.6%of its initial optical modulation after coloration/bleaching cycling of 60000 s,exhibiting good cyclic stability.This RMED has relatively high stability under open-circuit voltage and also possesses excellent heat insulation performance.The results offer a solution to overcome the poor cyclic stability of RMEDs and improve the optical modulation of ECDs.展开更多
以硝酸铝和尿素为原料,通过水热法成功合成富含五配位Al^(3+)的γ-Al_(2)O_(3)载体,采用XRD、SEM、STEM-HAADF、27Al MAS NMR、N_(2)吸附-脱附等手段表征了载体的物理化学性质,并对采用该载体制备的Pd/Al_(2)O_(3)催化剂进行了蒽醌加氢...以硝酸铝和尿素为原料,通过水热法成功合成富含五配位Al^(3+)的γ-Al_(2)O_(3)载体,采用XRD、SEM、STEM-HAADF、27Al MAS NMR、N_(2)吸附-脱附等手段表征了载体的物理化学性质,并对采用该载体制备的Pd/Al_(2)O_(3)催化剂进行了蒽醌加氢制H_(2)O_(2)的初步性能评价。表征结果显示,合成的载体中的五配位Al^(3+)相对含量可达40.88%(w),微观粒子呈棒状,棒的长度1~4μm,直径0.1~0.3μm,BET比表面积可达494 m^(2)/g;所制备的Pd/Al_(2)O_(3)催化剂中Pd纳米粒子分散良好,平均粒径为3.51 nm,且分布较窄。评价结果表明,该催化剂相对于参比剂具有较高的加氢活性。展开更多
Herein,we established a Zn_(3)(OH)_(2)(V_(2)O_(7))(H_(2)O)_(2)/V-Zn(O,S)Z-scheme heterojunction labeled ZnVO/V-Zn(O,S)with a heterovalent V^(4+)/V^(5+)states and oxygen vacancies in both phases via a one-step in-situ ...Herein,we established a Zn_(3)(OH)_(2)(V_(2)O_(7))(H_(2)O)_(2)/V-Zn(O,S)Z-scheme heterojunction labeled ZnVO/V-Zn(O,S)with a heterovalent V^(4+)/V^(5+)states and oxygen vacancies in both phases via a one-step in-situ hydrolysis method.The NaBH_(4) regulated the ZnVO/V-Zn(O,S)-3 with rich Vo and suitable n(V^(4+))/n(V^(5+))ratio achieved an excellent photocatalytic nitrogen fixation activity of 301.7μmol/(g×h)and apparent quantum efficiency of 1.148%at 420 nm without any sacrificial agent,which is 11 times than that of V-Zn(O,S).The Vo acts as the active site to trap and activate N_(2) molecules and to trap and activate H_(2)O to produce the H for N_(2) molecules photocatalytic reduction.The rich Vo defects can also reduce the competitive adsorption of H_(2)O and N_(2) molecules on the surface active site of the catalyst.The heterovalent vanadium states act as the photogenerated electrons,quickly hopping between V^(4+)and V^(5+)to transfer for the photocatalytic N_(2) reduction reaction.Additionally,the Z-scheme heterojunction effectively minimizes photogenerated carrier recombination.These synergistic effects collectively boost the photocatalytic nitrogen fixation activity.This study provides a practical method for designing Z-scheme heterojunctions for efficient photocatalytic N_(2) fixation under mild conditions.展开更多
The ineluctable introduction of lithium salt to polymer solid-state electrolytes incurs a compromise between strength,ionic conductivity,and thickness.Here,we propose Al_(2)O_(3)-coated polyimide(AO/PI)porous film as ...The ineluctable introduction of lithium salt to polymer solid-state electrolytes incurs a compromise between strength,ionic conductivity,and thickness.Here,we propose Al_(2)O_(3)-coated polyimide(AO/PI)porous film as a high-strength substrate to support fast-ion-conducting polymer-in-salt(PIS)solid-state electrolytes,aiming to suppress lithium dendrite growth and improve full-cell performance.The Al_(2)O_(3)coating layer not only refines the wettability of polyimide porous film to PIS,but also performs as a high modulus protective layer to suppress the growth of lithium dendrites.The resulting PI/AO@PIS exhibits a small thickness of only 35μm with an outstanding tensile strength of 11.3 MPa and Young's modulus of 537.6 MPa.In addition,the PI/AO@PIS delivers a high ionic conductivity of 0.1 m S/cm at 25°C.As a result,the PI/AO@PIS enables symmetric Li cells to achieve exceptional cyclability for over 1000 h at 0.1 m A/cm2without noticeable lithium dendrite formation.Moreover,the PI/AO@PIS-based LiFePO4||Li full cells demonstrate outstanding rate performance(125.7 m Ah/g at 5 C)and impressive cycling stability(96.1%capacity retention at 1 C after 200 cycles).This work highlights the efficacy of enhancing the mechanical properties of polymer matrices and extending cell performance through the incorporation of a dense inorganic interface layer.展开更多
The rapid recombination of photogenerated carriers poses a significant limitation on the use of CdS quantum dots(QDs)in photocatalysis.Herein,the construction of a novel S-scheme heterojunction between cubic-phase CdS...The rapid recombination of photogenerated carriers poses a significant limitation on the use of CdS quantum dots(QDs)in photocatalysis.Herein,the construction of a novel S-scheme heterojunction between cubic-phase CdS QDs and hollow nanotube In_(2)O_(3)is successfully achieved using an electrostatic self-assembly method.Under visible light irradiation,all CdS-In_(2)O_(3)composites exhibit higher hydrogen evolution efficiency compared to pure CdS QDs.Notably,the photocatalytic H_(2)evolution rate of the optimal CdS-7%In_(2)O_(3)composite is determined to be 2258.59μmol g^(−1)h^(−1),approximately 12.3 times higher than that of pure CdS.The cyclic test indicates that the CdS-In_(2)O_(3)composite maintains considerable activity even after 5 cycles,indicating its excellent stability.In situ X-ray photoelectron spectroscopy and density functional theory calculations confirm that carrier migration in CdS-In_(2)O_(3)composites adheres to a typical S-scheme heterojunction mechanism.Additionally,a series of characterizations demonstrate that the formation of S-scheme heterojunctions between In_(2)O_(3)and CdS inhibits charge recombination and accelerates the separation and migration of photogenerated carriers in the CdS QDs,thus achieving enhanced photocatalytic performance.This work elucidates the pivotal role of S-scheme heterojunctions in photocatalytic H_(2)production and offers novel insights into the construction of effective composite photocatalysts.展开更多
基金financially supported by the National Natural Science Foundation of China(No.52105373)the China Scholarship Council(No.202106020094).
文摘Ti-10V-2Fe-3Al alloy with fine-grainedβphases was fabricated by friction stir processing with opti-mized processing parameters.The superplastic behavior of the specimens was investigated by tensile deformation at different strain rates and temperatures,and an optimal superplastic elongation of 634%was achieved at 700℃ and 3×10^(-4)/s.An annealing treatment at 650℃ for 60 min showed a mi-crostructure withαprecipitates distributed in theβmatrix in the friction stir specimen.Such pre-heat treatment improves the superplasticity of the specimen,achieving an elongation of up to 807%at 750℃ and 3×10^(-4)/s.The influences of tensile temperatures and strain rates on the microstructural evolution,such as grain size variation,grain morphology,and phase transformations,were discussed.The super-plastic deformation behavior of fine-grained Ti-10V-2Fe-3Al alloy is controlled by grain boundary sliding and accompanied by dynamic phase transformation and recrystallization.
文摘Electrochromic(EC)smart windows utilizing a reversible metal electrodeposition device(RMED)offer a compelling alternative for dynamically regulating transmissions of optical and thermal energy.An EC device(ECD)is constructed by reversible metal electrodeposition(RME)of Bi/Cu on WO_(3)·xH_(2)O film electrodeposited onto fluorine-doped tin oxide(FTO)transparent conductive glass.The electrolyte consists of CuCl_(2),BiCl_(3),KCl and HCl aqueous solution,supplying necessary components for both electrochemical and electrodeposition processes.The ECD shows ability to rapidly transition between colorless and black states,which achieves a large optical modulation of 77.0%at 570 nm.In the black state,the ECD exhibits a near-zero transmittance in the wavelength range of 400-1100 nm while maintaining 96.6%of its initial optical modulation after coloration/bleaching cycling of 60000 s,exhibiting good cyclic stability.This RMED has relatively high stability under open-circuit voltage and also possesses excellent heat insulation performance.The results offer a solution to overcome the poor cyclic stability of RMEDs and improve the optical modulation of ECDs.
文摘以硝酸铝和尿素为原料,通过水热法成功合成富含五配位Al^(3+)的γ-Al_(2)O_(3)载体,采用XRD、SEM、STEM-HAADF、27Al MAS NMR、N_(2)吸附-脱附等手段表征了载体的物理化学性质,并对采用该载体制备的Pd/Al_(2)O_(3)催化剂进行了蒽醌加氢制H_(2)O_(2)的初步性能评价。表征结果显示,合成的载体中的五配位Al^(3+)相对含量可达40.88%(w),微观粒子呈棒状,棒的长度1~4μm,直径0.1~0.3μm,BET比表面积可达494 m^(2)/g;所制备的Pd/Al_(2)O_(3)催化剂中Pd纳米粒子分散良好,平均粒径为3.51 nm,且分布较窄。评价结果表明,该催化剂相对于参比剂具有较高的加氢活性。
文摘Herein,we established a Zn_(3)(OH)_(2)(V_(2)O_(7))(H_(2)O)_(2)/V-Zn(O,S)Z-scheme heterojunction labeled ZnVO/V-Zn(O,S)with a heterovalent V^(4+)/V^(5+)states and oxygen vacancies in both phases via a one-step in-situ hydrolysis method.The NaBH_(4) regulated the ZnVO/V-Zn(O,S)-3 with rich Vo and suitable n(V^(4+))/n(V^(5+))ratio achieved an excellent photocatalytic nitrogen fixation activity of 301.7μmol/(g×h)and apparent quantum efficiency of 1.148%at 420 nm without any sacrificial agent,which is 11 times than that of V-Zn(O,S).The Vo acts as the active site to trap and activate N_(2) molecules and to trap and activate H_(2)O to produce the H for N_(2) molecules photocatalytic reduction.The rich Vo defects can also reduce the competitive adsorption of H_(2)O and N_(2) molecules on the surface active site of the catalyst.The heterovalent vanadium states act as the photogenerated electrons,quickly hopping between V^(4+)and V^(5+)to transfer for the photocatalytic N_(2) reduction reaction.Additionally,the Z-scheme heterojunction effectively minimizes photogenerated carrier recombination.These synergistic effects collectively boost the photocatalytic nitrogen fixation activity.This study provides a practical method for designing Z-scheme heterojunctions for efficient photocatalytic N_(2) fixation under mild conditions.
基金the financial support from the 261Project of MIIT and Natural Science Foundation of Jiangsu Province(No.BK20240179)。
文摘The ineluctable introduction of lithium salt to polymer solid-state electrolytes incurs a compromise between strength,ionic conductivity,and thickness.Here,we propose Al_(2)O_(3)-coated polyimide(AO/PI)porous film as a high-strength substrate to support fast-ion-conducting polymer-in-salt(PIS)solid-state electrolytes,aiming to suppress lithium dendrite growth and improve full-cell performance.The Al_(2)O_(3)coating layer not only refines the wettability of polyimide porous film to PIS,but also performs as a high modulus protective layer to suppress the growth of lithium dendrites.The resulting PI/AO@PIS exhibits a small thickness of only 35μm with an outstanding tensile strength of 11.3 MPa and Young's modulus of 537.6 MPa.In addition,the PI/AO@PIS delivers a high ionic conductivity of 0.1 m S/cm at 25°C.As a result,the PI/AO@PIS enables symmetric Li cells to achieve exceptional cyclability for over 1000 h at 0.1 m A/cm2without noticeable lithium dendrite formation.Moreover,the PI/AO@PIS-based LiFePO4||Li full cells demonstrate outstanding rate performance(125.7 m Ah/g at 5 C)and impressive cycling stability(96.1%capacity retention at 1 C after 200 cycles).This work highlights the efficacy of enhancing the mechanical properties of polymer matrices and extending cell performance through the incorporation of a dense inorganic interface layer.
文摘The rapid recombination of photogenerated carriers poses a significant limitation on the use of CdS quantum dots(QDs)in photocatalysis.Herein,the construction of a novel S-scheme heterojunction between cubic-phase CdS QDs and hollow nanotube In_(2)O_(3)is successfully achieved using an electrostatic self-assembly method.Under visible light irradiation,all CdS-In_(2)O_(3)composites exhibit higher hydrogen evolution efficiency compared to pure CdS QDs.Notably,the photocatalytic H_(2)evolution rate of the optimal CdS-7%In_(2)O_(3)composite is determined to be 2258.59μmol g^(−1)h^(−1),approximately 12.3 times higher than that of pure CdS.The cyclic test indicates that the CdS-In_(2)O_(3)composite maintains considerable activity even after 5 cycles,indicating its excellent stability.In situ X-ray photoelectron spectroscopy and density functional theory calculations confirm that carrier migration in CdS-In_(2)O_(3)composites adheres to a typical S-scheme heterojunction mechanism.Additionally,a series of characterizations demonstrate that the formation of S-scheme heterojunctions between In_(2)O_(3)and CdS inhibits charge recombination and accelerates the separation and migration of photogenerated carriers in the CdS QDs,thus achieving enhanced photocatalytic performance.This work elucidates the pivotal role of S-scheme heterojunctions in photocatalytic H_(2)production and offers novel insights into the construction of effective composite photocatalysts.
