Lead halide perovskite (LHP) nanocrystals have been intensely studied as photocatalysts for artificial photosynthesis in recent years.However,the toxicity of lead in LHP seriously limits their potential for widespread...Lead halide perovskite (LHP) nanocrystals have been intensely studied as photocatalysts for artificial photosynthesis in recent years.However,the toxicity of lead in LHP seriously limits their potential for widespread applications.Herein,we first present the synthesis of 2D lead-free halide perovskite (Cs_(3)Bi_(2)I_(9)) nanosheets with self-template-oriented method,in which BiOI/Bi_(2)O_(2) nanosheets were used as the template and Bi ion source simultaneously.Through facile electrostatic self-assembly strategy,a Z-scheme heterojunction composed of Cs_(3)Bi_(2)I_(9)nanosheets and CeO_(2) nanosheets (Cs_(3)Bi_(2)I_(9)/CeO_(2)-3:1) was constructed as photocatalyst for the photo-reduction of CO_(2) coupled with the oxidation of H_(2)O.Due to the matching energy levels and the close interfacial contact between Cs_(3)Bi_(2)I_(9)and CeO_(2) nanosheets,the separation efficiency of the photogenerated carriers in Cs_(3)Bi_(2)I_(9)/CeO_(2)-3:1 composite was significantly improved.Consequently,the environment-friendly halide perovskite heterojunction Cs_(3)Bi_(2)I_(9)/CeO_(2)-3:1presents impressive photocatalytic activity for the reduction of CO_(2)to CH_(4)and CO with an electron consumption yield of 877.04μmol g^(-1),which is over 7 and 15 times higher than those of pristine Cs_(3)Bi_(2)I_(9)and CeO_(2)nanosheets,exceeding the yield of other reported bismuth-based perovskite for photocatalytic CO_(2)reduction.展开更多
The elaborate regulation of heterostructure interface to accelerate the interfacial charge separation is one of practicable approaches to improve the photocatalytic CO_(2)reduction performance of halide perovskite(HP)...The elaborate regulation of heterostructure interface to accelerate the interfacial charge separation is one of practicable approaches to improve the photocatalytic CO_(2)reduction performance of halide perovskite(HP) materials. Herein, we report an in-situ growth strategy for the construction of 2D CsPbBr_(3)based heterostructure with perovskite oxide(SrTiO_(3)) nanosheet as substrate(CsPbBr_(3)/SrTiO_(3)). Lattice matching and matchable energy band structures between CsPbBr_(3)and SrTiO_(3)endow CsPbBr_(3)/SrTiO_(3)heterostructure with an efficient interfacial charge separation. Moreover, the interfacial charge transfer rate can be further accelerated by etching SrTiO_(3)with NH_(4)F to form flat surface capped with Ti-O bonds. The resultant 2D/2D T-SrTiO_(3)/CsPbBr_(3)heterostructure exhibits an impressive photocatalytic activity for CO_(2)conversion with a CO yield of 120.2 ± 4.9 μmol g^(-1)h^(-1)at the light intensity of 100 m W/cm^(2)and water as electron source, which is about 10 and 7 times higher than those of the pristine SrTiO_(3)and CsPbBr_(3)nanosheets, surpassing the reported halide perovskite-based photocatalysts under the same conditions.展开更多
Regarding the utilization of semiconductor nanocrystals(NCs)in photocatalysis,the significant challenge is to eliminate the hindrance of decorated surface ligands on the photocarrier transport while maintaining their ...Regarding the utilization of semiconductor nanocrystals(NCs)in photocatalysis,the significant challenge is to eliminate the hindrance of decorated surface ligands on the photocarrier transport while maintaining their overall stability.Herein,we report a novel and stable catalyst comprising CdS NCs and surfacebound mono-(6-mercapto-6-deoxy)-β-cyclodextrin(HS-β-CD)molecules(denoted as CdS-CD),which could convert alcohols selectively into diols or aldehydes and H2 under visible light irradiation,with 100%atomutilization,using an aqueous medium as a green solvent.The decoratedβ-CD ligands did not only confer a good stability of CdS-CD in water but also showed a high host–guest affinity to the alcohol species,thereby,guaranteeing a close vicinity of alcohol molecules at the surface of CdS NCs and minimizing the hindrance of surface ligands on the photocarrier transport.As a result,the CdS-CD displayed much improved photocatalytic activity for the conversion of alcohols in aqueous media,compared with those of CdS-BF_(4)NCs.展开更多
基金financially supported by the Natural Science Foundation of Tianjin City (17JCJQJC43800, 19JCQNJC05500)the National Key R&D Program of China (2017YFA0700104)+1 种基金NSFC (21931007)the 111 Project of China (D17003)。
文摘Lead halide perovskite (LHP) nanocrystals have been intensely studied as photocatalysts for artificial photosynthesis in recent years.However,the toxicity of lead in LHP seriously limits their potential for widespread applications.Herein,we first present the synthesis of 2D lead-free halide perovskite (Cs_(3)Bi_(2)I_(9)) nanosheets with self-template-oriented method,in which BiOI/Bi_(2)O_(2) nanosheets were used as the template and Bi ion source simultaneously.Through facile electrostatic self-assembly strategy,a Z-scheme heterojunction composed of Cs_(3)Bi_(2)I_(9)nanosheets and CeO_(2) nanosheets (Cs_(3)Bi_(2)I_(9)/CeO_(2)-3:1) was constructed as photocatalyst for the photo-reduction of CO_(2) coupled with the oxidation of H_(2)O.Due to the matching energy levels and the close interfacial contact between Cs_(3)Bi_(2)I_(9)and CeO_(2) nanosheets,the separation efficiency of the photogenerated carriers in Cs_(3)Bi_(2)I_(9)/CeO_(2)-3:1 composite was significantly improved.Consequently,the environment-friendly halide perovskite heterojunction Cs_(3)Bi_(2)I_(9)/CeO_(2)-3:1presents impressive photocatalytic activity for the reduction of CO_(2)to CH_(4)and CO with an electron consumption yield of 877.04μmol g^(-1),which is over 7 and 15 times higher than those of pristine Cs_(3)Bi_(2)I_(9)and CeO_(2)nanosheets,exceeding the yield of other reported bismuth-based perovskite for photocatalytic CO_(2)reduction.
基金financially supported by the Natural Science Foundation of Tianjin City (No. 17JCJQJC_(4)3800)the National Key R&D Program of China (No. 2017YFA0700104)+1 种基金NSFC (Nos.21931007, U21A20286)the 111 Project of China (No. D17003)。
文摘The elaborate regulation of heterostructure interface to accelerate the interfacial charge separation is one of practicable approaches to improve the photocatalytic CO_(2)reduction performance of halide perovskite(HP) materials. Herein, we report an in-situ growth strategy for the construction of 2D CsPbBr_(3)based heterostructure with perovskite oxide(SrTiO_(3)) nanosheet as substrate(CsPbBr_(3)/SrTiO_(3)). Lattice matching and matchable energy band structures between CsPbBr_(3)and SrTiO_(3)endow CsPbBr_(3)/SrTiO_(3)heterostructure with an efficient interfacial charge separation. Moreover, the interfacial charge transfer rate can be further accelerated by etching SrTiO_(3)with NH_(4)F to form flat surface capped with Ti-O bonds. The resultant 2D/2D T-SrTiO_(3)/CsPbBr_(3)heterostructure exhibits an impressive photocatalytic activity for CO_(2)conversion with a CO yield of 120.2 ± 4.9 μmol g^(-1)h^(-1)at the light intensity of 100 m W/cm^(2)and water as electron source, which is about 10 and 7 times higher than those of the pristine SrTiO_(3)and CsPbBr_(3)nanosheets, surpassing the reported halide perovskite-based photocatalysts under the same conditions.
基金supported financially by the National Key R&D Program of China(2017YFA0700104),NSFC(21702146,21790052,and 21931007)111 Project of China(D17003)。
文摘Regarding the utilization of semiconductor nanocrystals(NCs)in photocatalysis,the significant challenge is to eliminate the hindrance of decorated surface ligands on the photocarrier transport while maintaining their overall stability.Herein,we report a novel and stable catalyst comprising CdS NCs and surfacebound mono-(6-mercapto-6-deoxy)-β-cyclodextrin(HS-β-CD)molecules(denoted as CdS-CD),which could convert alcohols selectively into diols or aldehydes and H2 under visible light irradiation,with 100%atomutilization,using an aqueous medium as a green solvent.The decoratedβ-CD ligands did not only confer a good stability of CdS-CD in water but also showed a high host–guest affinity to the alcohol species,thereby,guaranteeing a close vicinity of alcohol molecules at the surface of CdS NCs and minimizing the hindrance of surface ligands on the photocarrier transport.As a result,the CdS-CD displayed much improved photocatalytic activity for the conversion of alcohols in aqueous media,compared with those of CdS-BF_(4)NCs.
