Artificial photosynthesis of valuable chemicals from CO_(2)is a potential way to achieve sustainable carbon cycle.The CO_(2)conversion activity is still inhibited by the sluggish charge kinetics and poor CO_(2)activat...Artificial photosynthesis of valuable chemicals from CO_(2)is a potential way to achieve sustainable carbon cycle.The CO_(2)conversion activity is still inhibited by the sluggish charge kinetics and poor CO_(2)activation.Herein,Ag nanoparticles coupled Bi OBr have been constructed by in-situ photoreduction strategy.The crafting of interface between Ag nanoparticles and Bi OBr nanosheets,achieving an ultra-fast charge transfer.The Bi OBr semiconductor excited electrons and plasmonic Ag nanoparticles generated high-energy hot electrons synchronous accelerates the C=O double bond activation.Thus,the optimized Ag/BiOBr-2 heterostructure shows excellent CO_(2)photoreduction activity with CO production of 133.75 and 6.83μmol/g under 5 h of 300 W Xe lamp and visible light(λ>400 nm)irradiation,which is 1.51 and 2.81 folds versus the pristine Bi OBr,respectively.The mechanism of CO_(2)photoreduction was in-depth understood through in-situ FT-IR spectrum and density functional theory calculations.This study provides some new perspectives into efficient photocatalytic CO_(2)reduction.展开更多
Designing simple, efficient, and environmentally friendly methods to construct high-efficient photocatalysts is an important strategy to promote the further development of the field of photocatalysis. Herein, flower-l...Designing simple, efficient, and environmentally friendly methods to construct high-efficient photocatalysts is an important strategy to promote the further development of the field of photocatalysis. Herein, flower-like carbon quantum dots(CQDs)/Bi OBr composite photocatalysts have been prepared via in-situ synthesis by mechanical ball milling in the existence of ionic liquid. The CQDs/Bi OBr composites exhibit higher photo-degradation performance for tetracycline(TC) than Bi OBr monomer and the commercial Bi_(2)O_(3) under visible light irradiation. For comparison, the different Br sources and synthetic methods are chosen to prepare Bi OBr and CQDs/Bi OBr composites. Photocatalysts prepared by ball milling and ionic liquid present significantly enhanced photocatalytic performance for removing TC. In addition, the introduction of CQDs could distinctly enhance the photocatalytic performances of pure Bi OBr. The reason is that CQDs as electron acceptor effectively separate electrons and holes and inhibit their recombination. The intermediates during photocatalytic degradation were tested using liquid chromatography-mass spectrometry(LC-MS) and possible degradation pathways were given. During degradation, ·OH, O_(2)^(·-)and h^(+) were identified to be the main active species based on electron spin resonance(ESR) spectra and free radical trapping experiments. A possible mechanism of CQDs/Bi OBr with enhanced photocatalytic performances was further proposed.展开更多
基金financially supported by the National Natural Science Foundation of China(Nos.22108106,21878134,21576123)China Postdoctoral Science Foundation(No.2020M680065)+1 种基金Hong Kong Scholar Program(No.XJ2021021)Key Laboratory of Electrochemical Energy Storage and Energy Conversion of Hainan Province(No.KFKT2021005)。
文摘Artificial photosynthesis of valuable chemicals from CO_(2)is a potential way to achieve sustainable carbon cycle.The CO_(2)conversion activity is still inhibited by the sluggish charge kinetics and poor CO_(2)activation.Herein,Ag nanoparticles coupled Bi OBr have been constructed by in-situ photoreduction strategy.The crafting of interface between Ag nanoparticles and Bi OBr nanosheets,achieving an ultra-fast charge transfer.The Bi OBr semiconductor excited electrons and plasmonic Ag nanoparticles generated high-energy hot electrons synchronous accelerates the C=O double bond activation.Thus,the optimized Ag/BiOBr-2 heterostructure shows excellent CO_(2)photoreduction activity with CO production of 133.75 and 6.83μmol/g under 5 h of 300 W Xe lamp and visible light(λ>400 nm)irradiation,which is 1.51 and 2.81 folds versus the pristine Bi OBr,respectively.The mechanism of CO_(2)photoreduction was in-depth understood through in-situ FT-IR spectrum and density functional theory calculations.This study provides some new perspectives into efficient photocatalytic CO_(2)reduction.
基金financially supported by the National Natural Science Foundation of China (Nos. 22108106, 22108108, 22109055, 21878134)Natural Science Foundation of Jiangsu Province (BK20210742)+2 种基金China Postdoctoral Science Foundation (No. 2020M680065)Hong Kong Scholar Program (No. XJ2021021)Key Laboratory of Electrochemical Energy Storage and Energy Conversion of Hainan Province (No. KFKT2021005)。
文摘Designing simple, efficient, and environmentally friendly methods to construct high-efficient photocatalysts is an important strategy to promote the further development of the field of photocatalysis. Herein, flower-like carbon quantum dots(CQDs)/Bi OBr composite photocatalysts have been prepared via in-situ synthesis by mechanical ball milling in the existence of ionic liquid. The CQDs/Bi OBr composites exhibit higher photo-degradation performance for tetracycline(TC) than Bi OBr monomer and the commercial Bi_(2)O_(3) under visible light irradiation. For comparison, the different Br sources and synthetic methods are chosen to prepare Bi OBr and CQDs/Bi OBr composites. Photocatalysts prepared by ball milling and ionic liquid present significantly enhanced photocatalytic performance for removing TC. In addition, the introduction of CQDs could distinctly enhance the photocatalytic performances of pure Bi OBr. The reason is that CQDs as electron acceptor effectively separate electrons and holes and inhibit their recombination. The intermediates during photocatalytic degradation were tested using liquid chromatography-mass spectrometry(LC-MS) and possible degradation pathways were given. During degradation, ·OH, O_(2)^(·-)and h^(+) were identified to be the main active species based on electron spin resonance(ESR) spectra and free radical trapping experiments. A possible mechanism of CQDs/Bi OBr with enhanced photocatalytic performances was further proposed.