Semiconductor photocatalysts are extensively applied in environmental treatment and energy conversion.However,one of their major disadvantages is their relatively low photocatalytic performance owing to the recombinat...Semiconductor photocatalysts are extensively applied in environmental treatment and energy conversion.However,one of their major disadvantages is their relatively low photocatalytic performance owing to the recombination of generated electron-hole pairs.The presence of the phase junction is an effective way to promote the photocatalytic activity by increasing the separation efficiency of the electron-hole pairs.Accordingly,extensive research has been conducted on the design of phase junctions of photocatalysts to improve their charge transfer properties and efficiencies.Therefore,for the design of an appropriate phase junction and the understanding of the mechanism of electron-hole separation,the development of the photocatalytic phase junction,including the preparation methods of the heterogeneous materials,is tremendously important and helpful.Herein,the commonly used,externally induced phase transformation fabrication techniques and the primary components of the semiconductors are reviewed.Future directions will still focus on the design and optimization of the phase junction of photocatalytic materials according to the phase transition with higher efficiencies for broadband responses and solar energy utilization.Additionally,the most popular phase transformation fabrication techniques of phase junctions are briefly reviewed from the application viewpoint.展开更多
Rational engineering of semiconductor photocatalysts for efficient hydrogen production is of great significance but still challenging,primarily due to the limitations in charge transfer kinetics.Herein,a fascinating p...Rational engineering of semiconductor photocatalysts for efficient hydrogen production is of great significance but still challenging,primarily due to the limitations in charge transfer kinetics.Herein,a fascinating plasmonic tandem heterojunction with the hc-CdS/Mo_(2)C@C heterostructure is aimfully prepared for effectively promoting the charge separation kinetics of the CdS photocatalyst via the synergistic strategy of phase junction,Schottky junction,and photothermal effect.The difference in atomic configuration between cubic-CdS (c-CdS) and hexagonal-CdS (h-CdS) leads to effective charge separation through a typical Ⅱ charge transfer mechanism,and plasmonic Schottky junction further extracts the electrons in the hc-CdS phase junction to realize gradient charge transfer.Besides,the photothermal effect of Mo_(2)C@C helps to expand the light absorption,accelerate charge transfer kinetics,and reduce the hydrogen evolution energy barrier.The carbon layer provides a fast channel for charge transfer and protects the photocatalyst from photocorrosion.As a result,the optimized hc-CMC photocatalyst exhibits a significantly high photocatalytic H_(2)production activity of 28.63 mmol/g/h and apparent quantum efficiency of 61.8%,surpassing most of the reported photocatalysts.This study provides a feasible strategy to enhance the charge transfer kinetics and photocatalytic activity of CdS by constructing plasmonic tandem heterogeneous junctions.展开更多
In order to boost power conversion efficiency(PCE) and operation stability of organic solar cells(OSCs),we propose a new idea of phase junction materials(PJMs) used as a photoactive layer component to improve device p...In order to boost power conversion efficiency(PCE) and operation stability of organic solar cells(OSCs),we propose a new idea of phase junction materials(PJMs) used as a photoactive layer component to improve device performance and stability.For this purpose,a novel PJM of H-TRC8 based on rhodanine unit was designed with a conjugated AH-D-A framework.Here,AH is a hydrogen-donating electron acceptor unit,D-A is an electron donor-acceptor unit.It is found that H-TRC8 has a good carriertransporting ability,as well as definite hydrogen-bond and D-A interaction with donor/acceptor materials.While H-TRC8 is added into the PBDB-T/PC60BM blend film with 1.0 vol% DIO(1,8-diiodooctane),the resulting blend film exhibited an enhanced absorption and improved morphology.The intermolecular hydrogen bond between H-TRC8 and PBDB-T plays an important role for them,which is confirmed via FT-IR spectra and 2D 1H NMR.As a result,the PBDB-T/PC60BM-based devices with 1.25 wt%H-TRC8 and 1.0 vol% DIO exhibit a significantly improved PCE of 8.06%,which is increased by 20.6% in comparison to that in the binary devices with 1.0 vol% DIO only(PCE=6.68%).Furthermore,the device stability is significantly enhanced with only 43% PCE roll-off at 150℃ for 120 h.This work indicates that AH-D-A-type PJMs are promising photovoltaic materials used as photoactive-layer components to achieve high-performance fullerene OSCs with high device stability.展开更多
On the assumption that a Cooper pair acts as a Bose particle and based on the newly established <η|representation, which is the common eigenvector of two particles' relative position and total momentum, we int...On the assumption that a Cooper pair acts as a Bose particle and based on the newly established <η|representation, which is the common eigenvector of two particles' relative position and total momentum, we introduce a mesoscopic Josephson junction Hamiltonian constituted by two-mode Bose phase operator and number-difference operator. The number-difference-phase uncertainty relation can then be set up, which implies the existence of Josephson current.展开更多
Heterojunction has been widely used in vibration-driven piezocatalysis for enhanced charges separation,while the weak interfaces seriously affect the efficiency during mechanical deformations due to prepared by tradit...Heterojunction has been widely used in vibration-driven piezocatalysis for enhanced charges separation,while the weak interfaces seriously affect the efficiency during mechanical deformations due to prepared by traditional step-by-step methods.Herein,the intimate contact interfaces with shared S atoms are ingeniously constructed in SnS_(2)/SnS anchored on porous carbon by effective interface engineering,which is in-situ derived from temperature-dependent self-transformation of SnS_(2).Benefiting from intimate contact interfaces,the piezoelectricity is remarkably improved due to the larger interfacial dipole moment caused by uneven distribution of charges.Importantly,vibration-induced piezoelectric polarization field strengthens the interfacial electric field to further promote the separation and migration of charges.The dynamic charges then transfer in porous carbon with high conductivity and adsorption for significantly improved piezocatalytic activity.The degradation efficiency of bisphenol A(BPA)is 6.3 times higher than SnS_(2) and H_(2) evolution rate is increased by 3.8 times.Compared with SnS_(2)/SnS prepared by two-step solvothermal method,the degradation efficiency of BPA and H2 evolution activity are increased by 3 and 2 times,respectively.It provides a theoretical guidance for developing various multiphase structural piezocatalyst with strong interface interactions to improve the piezocatalytic efficiency.展开更多
A series of WO3 samples with different crystalline phases were prepared by the thermal decomposition method from ammonium tungstate hydrate.X-ray diffraction（XRD）,scanning electron microscopy（SEM）,high-resolution ...A series of WO3 samples with different crystalline phases were prepared by the thermal decomposition method from ammonium tungstate hydrate.X-ray diffraction（XRD）,scanning electron microscopy（SEM）,high-resolution transmission electron microscopy（HRTEM）,X-ray photoelectron spectroscopy,and N2 adsorption-desorption were used to characterize the crystalline phase,morphology,particle size,chemical composition,and surface area of the WO3 samples.The formation of hexagonal（h-WO3） and monoclinic（m-WO3） crystal structures of WO3 at different temperatures or different times was confirmed by XRD.m-WO3 is formed at 600 ℃,while m-WO3 starts to transform into h-WO3 at 800℃.However,h-WO3,which forms at 800℃,may transform into m-WO3 by increasing the calcination temperature to 1000℃.SEM results indicate that m-WO3 particles exhibit a bulky shape with heavy aggregates,while h-WO3 particles exhibit a rod-like shape.Moreover,m-WO3 crystals are sporadically patched on the surface of the h-WO3 rod-like particles,resulting in the exposure of both m-WO3 and h-WO3 on the surface.It is observed that the monoclinic phase（m-WO3）/hexagonal phase（h-WO3） junction was fabricated by tuning the calcination temperature and calcination time.The relative ratios between m-WO3 and h-WO3 in the phase junction can readily be tailored by control of the calcination time.The photocatalytic activities of WO3 with different crystalline phases were evaluated by the photocatalytic degradation of rhodamine B as a model pollutant.A higher photocatalytic activity was observed in the WO3 sample with the m-WO3/h-WO3junction as compared with the sample with only m-WO3.The improvement of photocatalytic activity can be attributed to the reduction of the electron-hole recombination rate owing to the formation of the phase junction,whose presence has been confirmed by HRTEM and photoluminescence spectra.展开更多
基金supported by the National Natural Science Foundation of China(21707055,21567008,21607064)Program of Qingjiang Excellent Young Talents,Jiangxi University of Science and Technology,Program of 5511 Talents in Scientific and Technological Innovation of Jiangxi Province(20165BCB18014)+3 种基金Academic and Technical Leaders of the Main Disciplines in Jiangxi Province(20172BCB22018)Jiangxi Province Natural Science Foundation(20161BAB203090,20181BAB213010,20181BAB203018)Young Science Foundation of Jiangxi Province Education Office(GJJ160671)Open Project Program of the State Key Laboratory of Photocatalysis on Energy and Environment(SKLPEE-KF201712)in Fuzhou University基金来源:国家自然科学基金(21707055,21567008,21607064)~~
文摘Semiconductor photocatalysts are extensively applied in environmental treatment and energy conversion.However,one of their major disadvantages is their relatively low photocatalytic performance owing to the recombination of generated electron-hole pairs.The presence of the phase junction is an effective way to promote the photocatalytic activity by increasing the separation efficiency of the electron-hole pairs.Accordingly,extensive research has been conducted on the design of phase junctions of photocatalysts to improve their charge transfer properties and efficiencies.Therefore,for the design of an appropriate phase junction and the understanding of the mechanism of electron-hole separation,the development of the photocatalytic phase junction,including the preparation methods of the heterogeneous materials,is tremendously important and helpful.Herein,the commonly used,externally induced phase transformation fabrication techniques and the primary components of the semiconductors are reviewed.Future directions will still focus on the design and optimization of the phase junction of photocatalytic materials according to the phase transition with higher efficiencies for broadband responses and solar energy utilization.Additionally,the most popular phase transformation fabrication techniques of phase junctions are briefly reviewed from the application viewpoint.
基金National Natural Science Foundation of China (Nos. 22371165, 22209098 and 21971143)111 Project (D20015)Opening Found of Hubei Three Gorges Laboratory (SC232001, SK213002)。
文摘Rational engineering of semiconductor photocatalysts for efficient hydrogen production is of great significance but still challenging,primarily due to the limitations in charge transfer kinetics.Herein,a fascinating plasmonic tandem heterojunction with the hc-CdS/Mo_(2)C@C heterostructure is aimfully prepared for effectively promoting the charge separation kinetics of the CdS photocatalyst via the synergistic strategy of phase junction,Schottky junction,and photothermal effect.The difference in atomic configuration between cubic-CdS (c-CdS) and hexagonal-CdS (h-CdS) leads to effective charge separation through a typical Ⅱ charge transfer mechanism,and plasmonic Schottky junction further extracts the electrons in the hc-CdS phase junction to realize gradient charge transfer.Besides,the photothermal effect of Mo_(2)C@C helps to expand the light absorption,accelerate charge transfer kinetics,and reduce the hydrogen evolution energy barrier.The carbon layer provides a fast channel for charge transfer and protects the photocatalyst from photocorrosion.As a result,the optimized hc-CMC photocatalyst exhibits a significantly high photocatalytic H_(2)production activity of 28.63 mmol/g/h and apparent quantum efficiency of 61.8%,surpassing most of the reported photocatalysts.This study provides a feasible strategy to enhance the charge transfer kinetics and photocatalytic activity of CdS by constructing plasmonic tandem heterogeneous junctions.
基金financial support from the National Natural Science Foundation of China(Nos.51673031,51573154)the Major Program of the Natural Science Research of Jiangsu Higher Education Institutions(No.18KJA480001)+3 种基金the Top-Notch Academic Programs Project(TAPP)for Polymeric Materials Science and Technologythe Priority Academic Program Development(PAPD)of Jiangsu Higher Education InstitutionsJiangsu Provincial Talents Project of High-Level Innovation and Entrepreneurshipthe Talent Project of Jiangsu Specially-Appointed Professor。
文摘In order to boost power conversion efficiency(PCE) and operation stability of organic solar cells(OSCs),we propose a new idea of phase junction materials(PJMs) used as a photoactive layer component to improve device performance and stability.For this purpose,a novel PJM of H-TRC8 based on rhodanine unit was designed with a conjugated AH-D-A framework.Here,AH is a hydrogen-donating electron acceptor unit,D-A is an electron donor-acceptor unit.It is found that H-TRC8 has a good carriertransporting ability,as well as definite hydrogen-bond and D-A interaction with donor/acceptor materials.While H-TRC8 is added into the PBDB-T/PC60BM blend film with 1.0 vol% DIO(1,8-diiodooctane),the resulting blend film exhibited an enhanced absorption and improved morphology.The intermolecular hydrogen bond between H-TRC8 and PBDB-T plays an important role for them,which is confirmed via FT-IR spectra and 2D 1H NMR.As a result,the PBDB-T/PC60BM-based devices with 1.25 wt%H-TRC8 and 1.0 vol% DIO exhibit a significantly improved PCE of 8.06%,which is increased by 20.6% in comparison to that in the binary devices with 1.0 vol% DIO only(PCE=6.68%).Furthermore,the device stability is significantly enhanced with only 43% PCE roll-off at 150℃ for 120 h.This work indicates that AH-D-A-type PJMs are promising photovoltaic materials used as photoactive-layer components to achieve high-performance fullerene OSCs with high device stability.
文摘On the assumption that a Cooper pair acts as a Bose particle and based on the newly established <η|representation, which is the common eigenvector of two particles' relative position and total momentum, we introduce a mesoscopic Josephson junction Hamiltonian constituted by two-mode Bose phase operator and number-difference operator. The number-difference-phase uncertainty relation can then be set up, which implies the existence of Josephson current.
文摘Heterojunction has been widely used in vibration-driven piezocatalysis for enhanced charges separation,while the weak interfaces seriously affect the efficiency during mechanical deformations due to prepared by traditional step-by-step methods.Herein,the intimate contact interfaces with shared S atoms are ingeniously constructed in SnS_(2)/SnS anchored on porous carbon by effective interface engineering,which is in-situ derived from temperature-dependent self-transformation of SnS_(2).Benefiting from intimate contact interfaces,the piezoelectricity is remarkably improved due to the larger interfacial dipole moment caused by uneven distribution of charges.Importantly,vibration-induced piezoelectric polarization field strengthens the interfacial electric field to further promote the separation and migration of charges.The dynamic charges then transfer in porous carbon with high conductivity and adsorption for significantly improved piezocatalytic activity.The degradation efficiency of bisphenol A(BPA)is 6.3 times higher than SnS_(2) and H_(2) evolution rate is increased by 3.8 times.Compared with SnS_(2)/SnS prepared by two-step solvothermal method,the degradation efficiency of BPA and H2 evolution activity are increased by 3 and 2 times,respectively.It provides a theoretical guidance for developing various multiphase structural piezocatalyst with strong interface interactions to improve the piezocatalytic efficiency.
基金supported by the National Natural Science Foundation of China (21573101)the Liaoning Provincial Natural Science Foundation(2014020107)+2 种基金the Program for Liaoning Excellent Talents in University (LJQ2014041)the Scientific Research Foundation for the Returned Overseas Chinese Scholars, State Education Ministry ([2013]1792)the Opening Project of Key Laboratory of Photochemical Conversion and Optoelectronic Materials, TIPC, CAS,the Opening Project of State Key Laboratory of Catalysis, DICP, CAS (N-09-06)~~
文摘A series of WO3 samples with different crystalline phases were prepared by the thermal decomposition method from ammonium tungstate hydrate.X-ray diffraction（XRD）,scanning electron microscopy（SEM）,high-resolution transmission electron microscopy（HRTEM）,X-ray photoelectron spectroscopy,and N2 adsorption-desorption were used to characterize the crystalline phase,morphology,particle size,chemical composition,and surface area of the WO3 samples.The formation of hexagonal（h-WO3） and monoclinic（m-WO3） crystal structures of WO3 at different temperatures or different times was confirmed by XRD.m-WO3 is formed at 600 ℃,while m-WO3 starts to transform into h-WO3 at 800℃.However,h-WO3,which forms at 800℃,may transform into m-WO3 by increasing the calcination temperature to 1000℃.SEM results indicate that m-WO3 particles exhibit a bulky shape with heavy aggregates,while h-WO3 particles exhibit a rod-like shape.Moreover,m-WO3 crystals are sporadically patched on the surface of the h-WO3 rod-like particles,resulting in the exposure of both m-WO3 and h-WO3 on the surface.It is observed that the monoclinic phase（m-WO3）/hexagonal phase（h-WO3） junction was fabricated by tuning the calcination temperature and calcination time.The relative ratios between m-WO3 and h-WO3 in the phase junction can readily be tailored by control of the calcination time.The photocatalytic activities of WO3 with different crystalline phases were evaluated by the photocatalytic degradation of rhodamine B as a model pollutant.A higher photocatalytic activity was observed in the WO3 sample with the m-WO3/h-WO3junction as compared with the sample with only m-WO3.The improvement of photocatalytic activity can be attributed to the reduction of the electron-hole recombination rate owing to the formation of the phase junction,whose presence has been confirmed by HRTEM and photoluminescence spectra.
