The application of photocatalytic technology in algae killing is limited by the non-floatability and difficulty in recycling of the photocatalysts.Loading photocatalyst on magnetic or floatable carriers is the most po...The application of photocatalytic technology in algae killing is limited by the non-floatability and difficulty in recycling of the photocatalysts.Loading photocatalyst on magnetic or floatable carriers is the most popular method for overcoming the above inadequacies.In this work,a CdZnS/TiO_(2) membrane photocatalyst with adjustable suspended depth(include floating)and flexible assembly is designed,which is less prone to dislodgement due to in situ synthesis and has a wider range of applicability than previously reported photocatalysts.The photocatalytic removal of Microcystis aeruginosa revealed that the suspended depth and distribution format of the CdZnS/TiO_(2) membrane photocatalysts have striking effects on the photocatalytic removal performance of Microcystis aeruginosa,the photocatalytic removal efficiency of CdZnS/TiO_(2)-2 membrane photocatalysts for Microcystis aeruginosa could reach to 98.6%in 60 min when the photocatalysts assembled in the form of 3×3 arrays suspended at a depth of 2 cm from the liquid surface.A tiny amount of TiO_(2) loading allows the formation of Z-Scheme heterojunction,resulting in accelerating the separation efficiency of photogenerated carriers,preserving the photogenerated electrons and holes with stronger reduction and oxidation ability and inhabiting the photo-corrosion of CdZnS.展开更多
Aiming to develop a photocatalyst that can simultaneously produce valuable chemicals and clean H_(2) fuel for promoting the utilization efficiency of solar energy,herein,a sea-urchin-like CoP@Ni_(2)P binary nanojuncti...Aiming to develop a photocatalyst that can simultaneously produce valuable chemicals and clean H_(2) fuel for promoting the utilization efficiency of solar energy,herein,a sea-urchin-like CoP@Ni_(2)P binary nanojunction was employed as an efficient photothermal cocatalyst to couple with zero-dimensional CdZnS(CZS)solid solution for achieving superior coordinative redox reaction.The CoP@Ni_(2)P/CZS hybrid displayed a high solar-driven H_(2) generation rate of 40.92 mmol g^(–1) h^(–1) coupling with a benzaldehyde formation rate of 20.33 mmol g^(–1) h^(–1),which was 16.4 and 8.0 times higher than that of bare CZS.Furthermore,the CoP@Ni_(2)P/CZS hybrid also achieved a high photothermal H_(2) production under a broad light range from 420 to 720 nm,and the H_(2) production reached 44.48μmol g^(–1) h^(–1) under the 720 nm light illumination.The enhanced catalytic performance can be ascribed to that the CoP@Ni_(2)P nanojunction with photothermal effect can speed up the separation and transport of carriers,offer more catalytic active sites,and induce an increase in temperature to optimize reaction kinetics.This study may open a facile route to design novel binary metal phosphides with dual functions in photocatalysis for the full exploitation of solar energy.展开更多
The electron mediator can effectively improve the performance of the direct Z-scheme heterojunction photocatalysts. However, it is still a great challenge to select cheap and efficient electron mediators and to design...The electron mediator can effectively improve the performance of the direct Z-scheme heterojunction photocatalysts. However, it is still a great challenge to select cheap and efficient electron mediators and to design them into the Z-scheme photocatalytic system. In the present paper, the g-C_(3)N_(4)/CNTs/CdZnS Z-scheme photocatalyst was prepared using carbon nanotubes(CNTs) as the electron mediators, and its photocatalytic hydrogen production performance was studied. Compared with single-phase g-C_(3)N_(4),CdZnS and biphasic g-C_(3)N_(4)/CdZnS photocatalysts, the photocatalytic hydrogen production performance of the prepared g-C_(3)N_(4)/CNTs/CdZnS has been significantly enhanced. Meanwhile, g-C_(3)N_(4)/CNTs/CdZnS possesses very good photocatalytic hydrogen production stability. The enhanced photocatalytic hydrogen production performance of g-C_(3)N_(4)/CNTs/CdZnS is attributed to the fact that CNTs, as an electron mediator,can accelerate the recombination of the photogenerated holes in the valence band of g-C_(3)N_(4) and the photogenerated electrons in the conduction band of CdZnS, which makes the g-C_(3)N_(4)/CNTs/CdZnS Zscheme photocatalyst be easier to escape the photogenerated electrons, increases the concentration of the photogenerated carriers and prolongs the lifetime of the photogenerated carriers. This work provides a theoretical basis for the further development and design of CNTs as the intermediate electron mediator of the Z-scheme heterojunction photocatalyst.展开更多
The low photoelectric conversion efficiency of photoelectrode is an important factor that limits the application in photoelectrochemical cathodic protection(PECCP)field for marine anti-corrosion of metallic structures...The low photoelectric conversion efficiency of photoelectrode is an important factor that limits the application in photoelectrochemical cathodic protection(PECCP)field for marine anti-corrosion of metallic structures.In this work,a photoelectrode of TiO_(2)/CdZnS/ZnS triple-phase heterojunction was fabricated by loading the narrow-band CdZnS associated with the broad-band ZnS via hydrothermal and continuous ion layer adsorption methods,respectively.The composite of CdZnS enhances the photoelectric conversion ability of TiO_(2),while the ZnS composite can prevent the CdZnS from photo-corrosion and suppress the spillover of the photogenerated electrons.The three-phase heterostructure effectively improves the PECCP performance on 316 L stainless steel(SS)under simulated solar irradiation,especially in 3.5 wt%NaCl solution without the sacrificial agent.In addition,the prepared TiO_(2)/CdZnS/ZnS photoelectrode also performs anti-biofouling effect evidenced by the high removal efficiency of Pseudomonas aeruginosa(P.aeruginosa),which can be attributed to the oxidizability of photogenerated holes.The TiO_(2)/CdZnS/ZnS triple-phase heterojunction with desirable performance is a promising semiconductor material for the applications of PECCP and anti-biofouling.展开更多
Semiconductor colloidal quantum wells(CQWs)with atomic-precision layer thickness are rapidly gaining attention for next-generation optoelectronic applications due to their tunable optical and electronic properties.In ...Semiconductor colloidal quantum wells(CQWs)with atomic-precision layer thickness are rapidly gaining attention for next-generation optoelectronic applications due to their tunable optical and electronic properties.In this study,we investigate the dielectric and optical characteristics of CdSe CQWs with monolayer numbers ranging from 2 to 7,synthesized via thermal injection and atomic layer(c-ALD)deposition techniques.Through a combination of spectroscopic ellipsometry(SE)and first-principles calculations,we demonstrate the significant tunability of the bandgap,refractive index,and extinction coefficient,driven by quantum confinement effects.Our results show a decrease in bandgap from 3.1 to 2.0 eV as the layer thickness increases.Furthermore,by employing a detailed analysis of the absorption spectra,accounting for exciton localization and asymmetric broadening,we precisely capture the relationship between monolayer number and exciton binding energy.These findings offer crucial insights for optimizing CdSe CQWs in optoelectronic device design by leveraging their layer-dependent properties.展开更多
CdSe nanoplatelets(NPLs)are promising candidates for on-chip light sources,yet their performance is hindered by surface defects and inefficient optical gain.Herein,we demonstrate that CdSeS crown passivation significa...CdSe nanoplatelets(NPLs)are promising candidates for on-chip light sources,yet their performance is hindered by surface defects and inefficient optical gain.Herein,we demonstrate that CdSeS crown passivation significantly enhances the photophysical property of CdSe NPLs.Laser spectroscopy techniques reveal suppressed electronic and hole trapping at lateral surfaces,leading to a 4.2-fold increase in photoluminescence quantum yield and a shortened emission lifetime from13.5 to 4.8 ns.In addition,amplified spontaneous emission is achieved under nanosecond pulse pumping,with thresholds of0.75 to 0.16 mJ/cm^(2)for CdSe and CdSe/CdSeS NPLs,respectively.By integrating CdSe/CdSeS NPLs with high-refractiveindex SiO2scatters,coherent random lasing is realized at a threshold of 0.21 mJ/cm^(2).These findings highlight the critical role of lateral surface passivation in optimizing optical gain and pave the way for low-cost,multifunctional nanophotonic devices.展开更多
基金financially supported by the Natural Science Foundation of ShanDong(Nos.ZR2023QD152 and ZR2021MD002).
文摘The application of photocatalytic technology in algae killing is limited by the non-floatability and difficulty in recycling of the photocatalysts.Loading photocatalyst on magnetic or floatable carriers is the most popular method for overcoming the above inadequacies.In this work,a CdZnS/TiO_(2) membrane photocatalyst with adjustable suspended depth(include floating)and flexible assembly is designed,which is less prone to dislodgement due to in situ synthesis and has a wider range of applicability than previously reported photocatalysts.The photocatalytic removal of Microcystis aeruginosa revealed that the suspended depth and distribution format of the CdZnS/TiO_(2) membrane photocatalysts have striking effects on the photocatalytic removal performance of Microcystis aeruginosa,the photocatalytic removal efficiency of CdZnS/TiO_(2)-2 membrane photocatalysts for Microcystis aeruginosa could reach to 98.6%in 60 min when the photocatalysts assembled in the form of 3×3 arrays suspended at a depth of 2 cm from the liquid surface.A tiny amount of TiO_(2) loading allows the formation of Z-Scheme heterojunction,resulting in accelerating the separation efficiency of photogenerated carriers,preserving the photogenerated electrons and holes with stronger reduction and oxidation ability and inhabiting the photo-corrosion of CdZnS.
基金supported by the Program for the National Natural Science Foundation of China(No.21972058)Prof.H.Tang also appreciates the support from the Taishan Youth Scholar Program of Shandong Province.
文摘Aiming to develop a photocatalyst that can simultaneously produce valuable chemicals and clean H_(2) fuel for promoting the utilization efficiency of solar energy,herein,a sea-urchin-like CoP@Ni_(2)P binary nanojunction was employed as an efficient photothermal cocatalyst to couple with zero-dimensional CdZnS(CZS)solid solution for achieving superior coordinative redox reaction.The CoP@Ni_(2)P/CZS hybrid displayed a high solar-driven H_(2) generation rate of 40.92 mmol g^(–1) h^(–1) coupling with a benzaldehyde formation rate of 20.33 mmol g^(–1) h^(–1),which was 16.4 and 8.0 times higher than that of bare CZS.Furthermore,the CoP@Ni_(2)P/CZS hybrid also achieved a high photothermal H_(2) production under a broad light range from 420 to 720 nm,and the H_(2) production reached 44.48μmol g^(–1) h^(–1) under the 720 nm light illumination.The enhanced catalytic performance can be ascribed to that the CoP@Ni_(2)P nanojunction with photothermal effect can speed up the separation and transport of carriers,offer more catalytic active sites,and induce an increase in temperature to optimize reaction kinetics.This study may open a facile route to design novel binary metal phosphides with dual functions in photocatalysis for the full exploitation of solar energy.
基金financially supported by National Natural Science Foundation of China(Grant Nos.41976036,41676069,41906034)Key Research and Development Program of Shandong Province(Grant Nos.2019GHY112066,2019GHY112085)the Research Fund of State Key Laboratory for Marine Corrosion and Protection of Luoyang Ship Material Research Institute(LSMRI)under the contract No.KF190408。
文摘The electron mediator can effectively improve the performance of the direct Z-scheme heterojunction photocatalysts. However, it is still a great challenge to select cheap and efficient electron mediators and to design them into the Z-scheme photocatalytic system. In the present paper, the g-C_(3)N_(4)/CNTs/CdZnS Z-scheme photocatalyst was prepared using carbon nanotubes(CNTs) as the electron mediators, and its photocatalytic hydrogen production performance was studied. Compared with single-phase g-C_(3)N_(4),CdZnS and biphasic g-C_(3)N_(4)/CdZnS photocatalysts, the photocatalytic hydrogen production performance of the prepared g-C_(3)N_(4)/CNTs/CdZnS has been significantly enhanced. Meanwhile, g-C_(3)N_(4)/CNTs/CdZnS possesses very good photocatalytic hydrogen production stability. The enhanced photocatalytic hydrogen production performance of g-C_(3)N_(4)/CNTs/CdZnS is attributed to the fact that CNTs, as an electron mediator,can accelerate the recombination of the photogenerated holes in the valence band of g-C_(3)N_(4) and the photogenerated electrons in the conduction band of CdZnS, which makes the g-C_(3)N_(4)/CNTs/CdZnS Zscheme photocatalyst be easier to escape the photogenerated electrons, increases the concentration of the photogenerated carriers and prolongs the lifetime of the photogenerated carriers. This work provides a theoretical basis for the further development and design of CNTs as the intermediate electron mediator of the Z-scheme heterojunction photocatalyst.
基金financially supported by the Natural Science Foundation of Shandong(No.ZR2021MD002)the National Natural Science Foundation of China(Nos.42106051 and U2106206).
文摘The low photoelectric conversion efficiency of photoelectrode is an important factor that limits the application in photoelectrochemical cathodic protection(PECCP)field for marine anti-corrosion of metallic structures.In this work,a photoelectrode of TiO_(2)/CdZnS/ZnS triple-phase heterojunction was fabricated by loading the narrow-band CdZnS associated with the broad-band ZnS via hydrothermal and continuous ion layer adsorption methods,respectively.The composite of CdZnS enhances the photoelectric conversion ability of TiO_(2),while the ZnS composite can prevent the CdZnS from photo-corrosion and suppress the spillover of the photogenerated electrons.The three-phase heterostructure effectively improves the PECCP performance on 316 L stainless steel(SS)under simulated solar irradiation,especially in 3.5 wt%NaCl solution without the sacrificial agent.In addition,the prepared TiO_(2)/CdZnS/ZnS photoelectrode also performs anti-biofouling effect evidenced by the high removal efficiency of Pseudomonas aeruginosa(P.aeruginosa),which can be attributed to the oxidizability of photogenerated holes.The TiO_(2)/CdZnS/ZnS triple-phase heterojunction with desirable performance is a promising semiconductor material for the applications of PECCP and anti-biofouling.
基金supported by the National Natural Science Foundation of China(62205180)the Natural Science Foundation of Shandong Province(ZR2022QF029)the Taishan Scholar Program of Shandong Province(Young Scientist).
文摘Semiconductor colloidal quantum wells(CQWs)with atomic-precision layer thickness are rapidly gaining attention for next-generation optoelectronic applications due to their tunable optical and electronic properties.In this study,we investigate the dielectric and optical characteristics of CdSe CQWs with monolayer numbers ranging from 2 to 7,synthesized via thermal injection and atomic layer(c-ALD)deposition techniques.Through a combination of spectroscopic ellipsometry(SE)and first-principles calculations,we demonstrate the significant tunability of the bandgap,refractive index,and extinction coefficient,driven by quantum confinement effects.Our results show a decrease in bandgap from 3.1 to 2.0 eV as the layer thickness increases.Furthermore,by employing a detailed analysis of the absorption spectra,accounting for exciton localization and asymmetric broadening,we precisely capture the relationship between monolayer number and exciton binding energy.These findings offer crucial insights for optimizing CdSe CQWs in optoelectronic device design by leveraging their layer-dependent properties.
基金supported by the National Natural Science Foundation of China(Grant No.62174079)Guangdong Provincial Quantum Science Strategic Initiative(Grant No.GDZX2404006)Science,Technology and Innovation Commission of Shenzhen Municipality(Grant No.JCYJ20220530113015035)。
文摘CdSe nanoplatelets(NPLs)are promising candidates for on-chip light sources,yet their performance is hindered by surface defects and inefficient optical gain.Herein,we demonstrate that CdSeS crown passivation significantly enhances the photophysical property of CdSe NPLs.Laser spectroscopy techniques reveal suppressed electronic and hole trapping at lateral surfaces,leading to a 4.2-fold increase in photoluminescence quantum yield and a shortened emission lifetime from13.5 to 4.8 ns.In addition,amplified spontaneous emission is achieved under nanosecond pulse pumping,with thresholds of0.75 to 0.16 mJ/cm^(2)for CdSe and CdSe/CdSeS NPLs,respectively.By integrating CdSe/CdSeS NPLs with high-refractiveindex SiO2scatters,coherent random lasing is realized at a threshold of 0.21 mJ/cm^(2).These findings highlight the critical role of lateral surface passivation in optimizing optical gain and pave the way for low-cost,multifunctional nanophotonic devices.
