Abstract
Converting hydrocarbons into aldehydes in a green and environmentally benign way is of great signif-icance in fine chemistry.In this work,all-inorganic Cs3Bi2Br9 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 Cs3Bi2Br9 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(PhCH2·)by using the energetic holes of BiOBr,while the remaining photoinduced electrons in the conduction band(CB)of Cs3Bi2Br9 with powerful reduction ability reduce O2 into·O2-,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 Cs3Bi2Br9/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.
基金项目
国家自然科学基金(21905209)
国家自然科学基金(52171145)
国家自然科学基金(51973078)
新疆维吾尔自治区自然科学基金(2020D01B25)
NETL
NSTL
万方数据