A graphite carbon nitride(g-C3N4)modified Bi4O5I2 composite was successfully prepared insitu via the thermal treatment of a g-C3N4/Bi OI precursor at 400°C for 3 hr.The as-prepared g-C3N4/Bi4O5I2 showed high phot...A graphite carbon nitride(g-C3N4)modified Bi4O5I2 composite was successfully prepared insitu via the thermal treatment of a g-C3N4/Bi OI precursor at 400°C for 3 hr.The as-prepared g-C3N4/Bi4O5I2 showed high photocatalytic performance in Methyl Orange(MO)degradation under visible light.The best sample presented a degradation rate of 0.164 min^-1,which is 3.2 and 82 times as high as that of Bi4O5I2 and g-C3N4,respectively.The g-C3N4/Bi4O5I2 was characterized by X-ray powder diffractometer(XRD),scanning electron microscopy(SEM),transmission electron microscopy(TEM),Raman,X-ray photoelectron spectroscopy(XPS),ultraviolet-visible diffuse reflectance spectra(DRS),electrochemical impedance spectroscopy(EIS)and transient photocurrent response in order to explain the enhanced photoactivity.Results indicated that the decoration with a small amount of g-C3N4 influenced the specific surface area only slightly.Nevertheless,the capability for absorbing visible light was improved measurably,which was beneficial to the MO degradation.On top of that,a strong interaction between g-C3N4 and Bi4O5I2 was detected.This interplay promoted the formation of a favorable heterojunction structure and thereby enhanced the charge separation.Thus,the g-C3N4/Bi4O5I2 composite presented greater charge separation efficiency and much better photocatalytic performance than Bi4O5I2.Additionally,g-C3N4/Bi4O5I2 also presented high stability.·O2^- and holes were verified to be the main reactive species.展开更多
Inverted perovskite solar cells(PSCs)have emerged as promising photovoltaic candidates because of their high efficiency and cost-effective fabrication.However,abundant defects and inefficient charge transport critical...Inverted perovskite solar cells(PSCs)have emerged as promising photovoltaic candidates because of their high efficiency and cost-effective fabrication.However,abundant defects and inefficient charge transport critically compromise the device efficiency and stability.Phosphonic acid-based multifunctional molecules,mainly as self-assemble monolayer,have recently been demonstrated to be useful in improving the device performance of the inverted PSCs.Herein,we designed and synthesized a new multifunctional molecule,(2-(3,6-bis(trifluoromethoxy)-9H-carbazol-9-yl)ethyl)phosphonic acid(M28)as additive in perovskite precursor solution to fabricate high-efficiency and stable inverted PSCs.Through spontaneous segregation toward the buried interface and grain boundaries(GBs),M28 affords threefold roles in enhancing device performance:(1)slowing the crystallization rate and enlarging the grain sizes to improve the perovskite film quality,(2)passivating the defects at buried interface and GBs to suppress charge recombination,(3)inducing an extra electric field at the buried interface through p-type doping to promote hole transport.The resulting devices thus achieved a remarkable power conversion efficiency of 25.96%and impressive long-term operational stability:maintaining 80%of their initial efficiency after 1500 h tracking at the maximum power point.This work emphasizes the importance of exploration of new types of functional molecules in advancing PSCs.展开更多
基金financially supported by National Undergraduate Training Program for Innovation and Entrepreneurship(Nos.201810345012 and 201810345051)
文摘A graphite carbon nitride(g-C3N4)modified Bi4O5I2 composite was successfully prepared insitu via the thermal treatment of a g-C3N4/Bi OI precursor at 400°C for 3 hr.The as-prepared g-C3N4/Bi4O5I2 showed high photocatalytic performance in Methyl Orange(MO)degradation under visible light.The best sample presented a degradation rate of 0.164 min^-1,which is 3.2 and 82 times as high as that of Bi4O5I2 and g-C3N4,respectively.The g-C3N4/Bi4O5I2 was characterized by X-ray powder diffractometer(XRD),scanning electron microscopy(SEM),transmission electron microscopy(TEM),Raman,X-ray photoelectron spectroscopy(XPS),ultraviolet-visible diffuse reflectance spectra(DRS),electrochemical impedance spectroscopy(EIS)and transient photocurrent response in order to explain the enhanced photoactivity.Results indicated that the decoration with a small amount of g-C3N4 influenced the specific surface area only slightly.Nevertheless,the capability for absorbing visible light was improved measurably,which was beneficial to the MO degradation.On top of that,a strong interaction between g-C3N4 and Bi4O5I2 was detected.This interplay promoted the formation of a favorable heterojunction structure and thereby enhanced the charge separation.Thus,the g-C3N4/Bi4O5I2 composite presented greater charge separation efficiency and much better photocatalytic performance than Bi4O5I2.Additionally,g-C3N4/Bi4O5I2 also presented high stability.·O2^- and holes were verified to be the main reactive species.
基金financially supported by the Yunnan Provincial Science and Technology Project at Southwest United Graduate School(202302AO370013)Yunnan Provincial Science and Technology Project of Key Research and Development Plan(202403AC100030)+2 种基金Yunnan Fundamental Research Projects(202401AU070200,202501AT070204)State Key Laboratory of Photoelectric Conversion and Utilization of Solar Energy(Innovation Fund Project SKLPCU24OP004)Natural Science Founda-tion of Xinjiang Uygur Autonomous Region(2022D01D079)。
文摘Inverted perovskite solar cells(PSCs)have emerged as promising photovoltaic candidates because of their high efficiency and cost-effective fabrication.However,abundant defects and inefficient charge transport critically compromise the device efficiency and stability.Phosphonic acid-based multifunctional molecules,mainly as self-assemble monolayer,have recently been demonstrated to be useful in improving the device performance of the inverted PSCs.Herein,we designed and synthesized a new multifunctional molecule,(2-(3,6-bis(trifluoromethoxy)-9H-carbazol-9-yl)ethyl)phosphonic acid(M28)as additive in perovskite precursor solution to fabricate high-efficiency and stable inverted PSCs.Through spontaneous segregation toward the buried interface and grain boundaries(GBs),M28 affords threefold roles in enhancing device performance:(1)slowing the crystallization rate and enlarging the grain sizes to improve the perovskite film quality,(2)passivating the defects at buried interface and GBs to suppress charge recombination,(3)inducing an extra electric field at the buried interface through p-type doping to promote hole transport.The resulting devices thus achieved a remarkable power conversion efficiency of 25.96%and impressive long-term operational stability:maintaining 80%of their initial efficiency after 1500 h tracking at the maximum power point.This work emphasizes the importance of exploration of new types of functional molecules in advancing PSCs.
