Developing highly efficient heterostructural photocatalysts for direct CO_(2)reduction coupled with water oxidation remains challenging,the key to which is to establish an efficient interfacial charge transport channe...Developing highly efficient heterostructural photocatalysts for direct CO_(2)reduction coupled with water oxidation remains challenging,the key to which is to establish an efficient interfacial charge transport channel.Herein,we present a Cs_(3)Sb_(2)Br_(9)/Sb–C_(3)N_(4)Z-scheme heterojunction prepared with an in-situ growth method based on the Sb atomic pinning effect.As revealed by the analysis of experimental and theoretical calculation results,the introduction of Sb anchors on C_(3)N_(4)leads to the formation of an Sb–N charge transfer bridge between Cs_(3)Sb_(2)Br_(9)and C_(3)N_(4),promoting interfacial charge communication over Cs_(3)Sb_(2)Br_(9)/Sb–C_(3)N_(4)heterojunction.Moreover,it can induce the heterojunction interfacial charge transfer pathway between Cs_(3)Sb_(2)Br_(9)and C_(3)N_(4)to change from type II to the type Z-scheme,enabling the change of the catalytic site from C_(3)N_(4)to Cs_(3)Sb_(2)Br_(9),thus promoting the CO_(2)activation.As a result,Cs_(3)Sb_(2)Br_(9)/Sb–C_(3)N_(4)achieves efficient CO_(2)to CO photocatalytic conversion using water as the electron source under simulated solar light irradiation(100 mW·cm^(−2)),with the yield of 198.4μmol·g^(−1)·h^(−1),which is nearly 3-fold and 9-fold over the counterpart synthesized catalyst without Sb anchors(Cs_(3)Sb_(2)Br_(9)/g–C_(3)N_(4))and pure g–C_(3)N_(4),respectively.This work provides a new alternative solution for the design of highly efficient heterojunction photocatalysts.展开更多
Converting hydrocarbons into aldehydes in a green and environmentally benign way is of great signif-icance in fine chemistry.In this work,all-inorganic Cs_(3)Bi_(2)B_(9) perovskite nanoparticles were uniformly loaded ...Converting hydrocarbons into aldehydes in a green and environmentally benign way is of great signif-icance in fine chemistry.In this work,all-inorganic Cs_(3)Bi_(2)B_(9) perovskite nanoparticles were uniformly loaded on BiOBr nanosheets via an in-situ growth method,which can selectivity photoactivate aromatic C(sp3)-H bond of toluene to generate benzaldehyde.According to the in-situ X-ray photoelectron spec-troscopy characterization,the photogenerated electrons of BiOBr transfer to Cs_(3)Bi_(2)B_(9) enforced by the in-ternal electric field under light irradiation,resulting in S-scheme heterojunction.Furthermore,theoretical calculations indicate that toluene molecules are inclined to adsorb on the BiOBr surface,subsequently in-volving the oxidation reaction to generate benzyl radical(PhCH_(2)·)by using the energetic holes of BiOBr,while the remaining photoinduced electrons in the conduction band(CB)of Cs_(3)Bi_(2)B_(9) with powerful reduction ability reduce O2 into·O_(2)^(-),which is the vital oxidative active species working on toluene selective oxidation process.Such an unexceptionable charge carrier utilization mode and tendentious ad-sorption behavior of reactants contribute to the optimized Cs_(3)Bi_(2)B_(9)/BiOBr heterojunction with excellent photocatalytic performance,achieving a maximum of 22.5%toluene conversion and 96.2%selectivity to-wards benzaldehyde formation.This work provides a rational photocatalyst heterojunction construction protocol for the selective oxidation of saturated aromatic C-H bonds.展开更多
Recently,the newly booming metal halide perovskites have attracted extensive attention worldwide due to their outstanding optoelectronic performance,and are expected to be ideal candidates for photodetectors(PDs).Howe...Recently,the newly booming metal halide perovskites have attracted extensive attention worldwide due to their outstanding optoelectronic performance,and are expected to be ideal candidates for photodetectors(PDs).However,there is still lack of perovskite PDs-based imaging devices coming into commercialization stage,due to some practical reasons including toxicity brought by lead-based perovskites and the large light current fluctuations.In this paper,for the first time we fabricate a lead-free Cs3Bi2Br9 perovskite PD,and build a prototype of this perovskite PD-based imaging system with diffuse reflection imaging mode.Moreover,we propose a new parameter F related to light current fluctuation to evaluate imaging performance of a PD especially for weak diffuse light condition,and prove its usability by comparison of unoptimized lead-free Cs3Bi2Br9 perovskite PD and atomic layer deposition(ALD)optimized Cs3Bi2 Br9 PD.ALD-optimization can improve the quality of perovskite film and suppress the dark current and current fluctuation.Finally,we obtain satisfactory diffuse reflection images of 2D and 3D objects with wide dynamic range.Therefore,the ALD-optimized Cs3Bi2Br9PD has addressed two major concerns about perovskite PDs-based imaging devices,that may extend application of perovskite materials and improve imaging quality.展开更多
基金financially supported by the National Key R&D Program of China(2022YFA1502902)the National Natural Science Foundation of China(U21A20286 and 22305214)+2 种基金the Natural Science Foundation of Tianjin City(17JCJQJC43800)the 111 Project of Chinathe Jiangsu Funding Program for Excellent Postdoctoral Talent(2022ZB616)。
文摘Developing highly efficient heterostructural photocatalysts for direct CO_(2)reduction coupled with water oxidation remains challenging,the key to which is to establish an efficient interfacial charge transport channel.Herein,we present a Cs_(3)Sb_(2)Br_(9)/Sb–C_(3)N_(4)Z-scheme heterojunction prepared with an in-situ growth method based on the Sb atomic pinning effect.As revealed by the analysis of experimental and theoretical calculation results,the introduction of Sb anchors on C_(3)N_(4)leads to the formation of an Sb–N charge transfer bridge between Cs_(3)Sb_(2)Br_(9)and C_(3)N_(4),promoting interfacial charge communication over Cs_(3)Sb_(2)Br_(9)/Sb–C_(3)N_(4)heterojunction.Moreover,it can induce the heterojunction interfacial charge transfer pathway between Cs_(3)Sb_(2)Br_(9)and C_(3)N_(4)to change from type II to the type Z-scheme,enabling the change of the catalytic site from C_(3)N_(4)to Cs_(3)Sb_(2)Br_(9),thus promoting the CO_(2)activation.As a result,Cs_(3)Sb_(2)Br_(9)/Sb–C_(3)N_(4)achieves efficient CO_(2)to CO photocatalytic conversion using water as the electron source under simulated solar light irradiation(100 mW·cm^(−2)),with the yield of 198.4μmol·g^(−1)·h^(−1),which is nearly 3-fold and 9-fold over the counterpart synthesized catalyst without Sb anchors(Cs_(3)Sb_(2)Br_(9)/g–C_(3)N_(4))and pure g–C_(3)N_(4),respectively.This work provides a new alternative solution for the design of highly efficient heterojunction photocatalysts.
基金National Natural Science Foundation of China(Nos.21905209,52171145,and 51973078)Natural Science Foundation of Xinjiang Uygur Autonomous Region(No.2020D01B25).
文摘Converting hydrocarbons into aldehydes in a green and environmentally benign way is of great signif-icance in fine chemistry.In this work,all-inorganic Cs_(3)Bi_(2)B_(9) perovskite nanoparticles were uniformly loaded on BiOBr nanosheets via an in-situ growth method,which can selectivity photoactivate aromatic C(sp3)-H bond of toluene to generate benzaldehyde.According to the in-situ X-ray photoelectron spec-troscopy characterization,the photogenerated electrons of BiOBr transfer to Cs_(3)Bi_(2)B_(9) enforced by the in-ternal electric field under light irradiation,resulting in S-scheme heterojunction.Furthermore,theoretical calculations indicate that toluene molecules are inclined to adsorb on the BiOBr surface,subsequently in-volving the oxidation reaction to generate benzyl radical(PhCH_(2)·)by using the energetic holes of BiOBr,while the remaining photoinduced electrons in the conduction band(CB)of Cs_(3)Bi_(2)B_(9) with powerful reduction ability reduce O2 into·O_(2)^(-),which is the vital oxidative active species working on toluene selective oxidation process.Such an unexceptionable charge carrier utilization mode and tendentious ad-sorption behavior of reactants contribute to the optimized Cs_(3)Bi_(2)B_(9)/BiOBr heterojunction with excellent photocatalytic performance,achieving a maximum of 22.5%toluene conversion and 96.2%selectivity to-wards benzaldehyde formation.This work provides a rational photocatalyst heterojunction construction protocol for the selective oxidation of saturated aromatic C-H bonds.
基金the National Natural Science Foundation of China(61604061,51772135,and 61875074)the Natural Science Foundation of Guangdong Province(2017A020215135,2018A030310659,and 2019A1515010482)+1 种基金the Science and Technology Program of Guangzhou,China(201804010432)the China Postdoctoral Science Foundation(2019M663363)。
文摘Recently,the newly booming metal halide perovskites have attracted extensive attention worldwide due to their outstanding optoelectronic performance,and are expected to be ideal candidates for photodetectors(PDs).However,there is still lack of perovskite PDs-based imaging devices coming into commercialization stage,due to some practical reasons including toxicity brought by lead-based perovskites and the large light current fluctuations.In this paper,for the first time we fabricate a lead-free Cs3Bi2Br9 perovskite PD,and build a prototype of this perovskite PD-based imaging system with diffuse reflection imaging mode.Moreover,we propose a new parameter F related to light current fluctuation to evaluate imaging performance of a PD especially for weak diffuse light condition,and prove its usability by comparison of unoptimized lead-free Cs3Bi2Br9 perovskite PD and atomic layer deposition(ALD)optimized Cs3Bi2 Br9 PD.ALD-optimization can improve the quality of perovskite film and suppress the dark current and current fluctuation.Finally,we obtain satisfactory diffuse reflection images of 2D and 3D objects with wide dynamic range.Therefore,the ALD-optimized Cs3Bi2Br9PD has addressed two major concerns about perovskite PDs-based imaging devices,that may extend application of perovskite materials and improve imaging quality.
