Bi/Bi_(2)Fe_(4)O_(9)nanocomposites consisting of Bi_(2)Fe_(4)O_(9)nanosheets decorated with Bi nanodots were synthesized by a hydrothermal method.The formation of Bi nanodots on the Bi_(2)Fe_(4)O_(9)nanosheet surfaces...Bi/Bi_(2)Fe_(4)O_(9)nanocomposites consisting of Bi_(2)Fe_(4)O_(9)nanosheets decorated with Bi nanodots were synthesized by a hydrothermal method.The formation of Bi nanodots on the Bi_(2)Fe_(4)O_(9)nanosheet surfaces was attributed to the reducibility of 2-methoxyethanol in the precursor solution.Comparative photocatalytic evaluation reveals that the Bi/Bi_(2)Fe_(4)O_(9)nanocomposites significantly enhance the degradation efficiency(99.0%)of bisphenol A compared with Bi_(2)Fe_(4)O_(9)nanosheets(64.2%)under 120 min simulated solar irradiation.This remarkable enhancement can be attributed to the established Bi/Bi_(2)Fe_(4)O_(9)heterojunction structure,which effectively facilitates the separation of photogenerated electron-hole pairs and accelerates interfacial charge transfer between the metallic Bi nanodots and semiconductor Bi_(2)Fe_(4)O_(9)nanosheets.The synergistic effects arising from this unique architecture ultimately lead to superior photocatalytic performance.展开更多
High-temperature piezoelectric ceramics are critical for aerospace and other advanced applications,yet achieving high sensitivity and stability under elevated temperatures remains challenging.In this study,we employ a...High-temperature piezoelectric ceramics are critical for aerospace and other advanced applications,yet achieving high sensitivity and stability under elevated temperatures remains challenging.In this study,we employ a multi-element co-doping strategy combined with domain engineering to significantly enhance the piezoelectric performance and Curie temperature of Bi_(4)Ti_(3)O_(12)(BIT)-based ceramics.Using a solid-state reaction method,W^(6+)/Nb^(5+)/Ta^(5+)/Sb^(3+)non-equivalently co-doped BIT ceramics were synthesized,achieving a high piezoelectric coefficient(d33)of 35 pC N^(-1),an elevated Curie temperature of 687℃,and an increased resistivity of 2.9×10^(6)Ωcm at an optimal doping level of x=0.02.This study further reveals the impact of poling conditions on domain structure,providing new insights for enhancing piezoelectric properties through domain configuration.A second high-voltage,short-duration poling process promotes the formation of large domains,underscoring the role of domain rearrangement in augmenting piezoelectric activity.This work demonstrates the potential of BIT-based ceramics in hightemperature sensing and precision actuation applications,presenting a novel strategy for designing high-performance piezoelectric materials for extreme environments.展开更多
In this work,samples consisting of BiVO4 with exposed(040)facets coupled with Bi2S3(Bi2S3/BiVO4)were prepared through a one-pot hydrothermal method,using ethylenediaminetetraacetic acid as directing agent and L-cystei...In this work,samples consisting of BiVO4 with exposed(040)facets coupled with Bi2S3(Bi2S3/BiVO4)were prepared through a one-pot hydrothermal method,using ethylenediaminetetraacetic acid as directing agent and L-cysteine as sulfur source and soft template.X-ray diffraction,field emission scanning electron microscopy,and high-resolution transmission electron microscopy measurements indicated that the Bi2S3 content had a significant influence on the growth of(040)and(121)facets as well as on the morphology of the Bi2S3/BiVO4 samples.When the Bi2S3 content reached 1 mmol,the Bi2S3/BiVO4 samples exhibited a peony-like morphology.The results of transient photocurrent tests and electrochemical impedance spectroscopy measurements confirmed that a more effective charge separation and a faster interfacial charge transfer occurred in Bi2S3/BiVO4 than BiVO4.The enhanced photocatalytic activity of the Bi2S3/BiVO4 samples could be attributed to the improved absorption capability in the visible light region and the enhanced electron-hole pair separation efficiency due to the formation of the Bi2S3/BiVO4 heterostructure.In addition,the Bi2S3/BiVO4 samples showed relative stability and reusability.The simple method presented in this work could be used to fabricate composite photocatalysts with high activity for different applications,such as photocatalytic degradation of organic pollutants,photocatalytic splitting of water,and photocatalytic reduction of carbon dioxide.展开更多
As BiVO4 is one of the most popular visible-light-responding photocatalysts, it has been widely used for visiblelight-driven water splitting and environmental purification. However, the typical photocatalytic activity...As BiVO4 is one of the most popular visible-light-responding photocatalysts, it has been widely used for visiblelight-driven water splitting and environmental purification. However, the typical photocatalytic activity of unmodified BiVO4 for the degradation of organic pollutants is still not impressive. To address this limitation, we studied Fe2O3-modified porous BiVO4 nanoplates. Compared with unmodified BiVO4, the Fe2O3-modified porous Bi VO4 nanoplates showed significantly enhanced photocatalytic activities in decomposing both dye and colorless pollutant models, such as rhodamine B(Rh B) and phenol,respectively. The pseudo-first-order reaction rate constants for the degradation of RhB and phenol on Fe2O3-modified BiVO4 porous nanoplates are 27 and 31 times larger than that of pristine Bi VO4, respectively. We also found that the Fe2O3 may act as an efficient non-precious metal co-catalyst, which is responsible for the excellent photocatalytic activity of Fe2O3/BiVO4.Graphical Abstract Fe2O3, as a cheap and efficient co-catalyst, could greatly enhance the photocatalytic activity of Bi VO4 porous nanoplates in decomposing organic pollutants.展开更多
基金Funded by the National Natural Science Foundation of China(No.50902108)。
文摘Bi/Bi_(2)Fe_(4)O_(9)nanocomposites consisting of Bi_(2)Fe_(4)O_(9)nanosheets decorated with Bi nanodots were synthesized by a hydrothermal method.The formation of Bi nanodots on the Bi_(2)Fe_(4)O_(9)nanosheet surfaces was attributed to the reducibility of 2-methoxyethanol in the precursor solution.Comparative photocatalytic evaluation reveals that the Bi/Bi_(2)Fe_(4)O_(9)nanocomposites significantly enhance the degradation efficiency(99.0%)of bisphenol A compared with Bi_(2)Fe_(4)O_(9)nanosheets(64.2%)under 120 min simulated solar irradiation.This remarkable enhancement can be attributed to the established Bi/Bi_(2)Fe_(4)O_(9)heterojunction structure,which effectively facilitates the separation of photogenerated electron-hole pairs and accelerates interfacial charge transfer between the metallic Bi nanodots and semiconductor Bi_(2)Fe_(4)O_(9)nanosheets.The synergistic effects arising from this unique architecture ultimately lead to superior photocatalytic performance.
基金financially supported by the National Natural Science Foundation of China(No.52172135)the Youth Top Talent Project of the National Special Support Program(No.2021-527-07)+1 种基金the Leading Talent Project of the National Special Support Program(No.2022WRLJ003)Guangdong Basic and Applied Basic Research Foundation for Distinguished Young Scholars(Nos.2022B1515020070 and 2021B1515020083)
文摘High-temperature piezoelectric ceramics are critical for aerospace and other advanced applications,yet achieving high sensitivity and stability under elevated temperatures remains challenging.In this study,we employ a multi-element co-doping strategy combined with domain engineering to significantly enhance the piezoelectric performance and Curie temperature of Bi_(4)Ti_(3)O_(12)(BIT)-based ceramics.Using a solid-state reaction method,W^(6+)/Nb^(5+)/Ta^(5+)/Sb^(3+)non-equivalently co-doped BIT ceramics were synthesized,achieving a high piezoelectric coefficient(d33)of 35 pC N^(-1),an elevated Curie temperature of 687℃,and an increased resistivity of 2.9×10^(6)Ωcm at an optimal doping level of x=0.02.This study further reveals the impact of poling conditions on domain structure,providing new insights for enhancing piezoelectric properties through domain configuration.A second high-voltage,short-duration poling process promotes the formation of large domains,underscoring the role of domain rearrangement in augmenting piezoelectric activity.This work demonstrates the potential of BIT-based ceramics in hightemperature sensing and precision actuation applications,presenting a novel strategy for designing high-performance piezoelectric materials for extreme environments.
文摘In this work,samples consisting of BiVO4 with exposed(040)facets coupled with Bi2S3(Bi2S3/BiVO4)were prepared through a one-pot hydrothermal method,using ethylenediaminetetraacetic acid as directing agent and L-cysteine as sulfur source and soft template.X-ray diffraction,field emission scanning electron microscopy,and high-resolution transmission electron microscopy measurements indicated that the Bi2S3 content had a significant influence on the growth of(040)and(121)facets as well as on the morphology of the Bi2S3/BiVO4 samples.When the Bi2S3 content reached 1 mmol,the Bi2S3/BiVO4 samples exhibited a peony-like morphology.The results of transient photocurrent tests and electrochemical impedance spectroscopy measurements confirmed that a more effective charge separation and a faster interfacial charge transfer occurred in Bi2S3/BiVO4 than BiVO4.The enhanced photocatalytic activity of the Bi2S3/BiVO4 samples could be attributed to the improved absorption capability in the visible light region and the enhanced electron-hole pair separation efficiency due to the formation of the Bi2S3/BiVO4 heterostructure.In addition,the Bi2S3/BiVO4 samples showed relative stability and reusability.The simple method presented in this work could be used to fabricate composite photocatalysts with high activity for different applications,such as photocatalytic degradation of organic pollutants,photocatalytic splitting of water,and photocatalytic reduction of carbon dioxide.
基金partial financial support from NSFC(51372173,51002107,and21173159)NSFC for Distinguished Young Scholars(51025207)+3 种基金Research Climb Plan of ZJED(pd2013383)Opening Project of State Key Laboratory of High Performance Ceramics and Superfine Microstructure(SKL201409SIC)Xinmiao talent project of Zhejiang Province(2013R424060)College Students Research Project of Wenzhou University(14xk193)
文摘As BiVO4 is one of the most popular visible-light-responding photocatalysts, it has been widely used for visiblelight-driven water splitting and environmental purification. However, the typical photocatalytic activity of unmodified BiVO4 for the degradation of organic pollutants is still not impressive. To address this limitation, we studied Fe2O3-modified porous BiVO4 nanoplates. Compared with unmodified BiVO4, the Fe2O3-modified porous Bi VO4 nanoplates showed significantly enhanced photocatalytic activities in decomposing both dye and colorless pollutant models, such as rhodamine B(Rh B) and phenol,respectively. The pseudo-first-order reaction rate constants for the degradation of RhB and phenol on Fe2O3-modified BiVO4 porous nanoplates are 27 and 31 times larger than that of pristine Bi VO4, respectively. We also found that the Fe2O3 may act as an efficient non-precious metal co-catalyst, which is responsible for the excellent photocatalytic activity of Fe2O3/BiVO4.Graphical Abstract Fe2O3, as a cheap and efficient co-catalyst, could greatly enhance the photocatalytic activity of Bi VO4 porous nanoplates in decomposing organic pollutants.
基金supported by the National Natural Science Foundation of China(21407059,61308095)Science Development Project of Jilin Province,China(20130522071JH,20130102004JC,20140101160JC)~~
