Efficient and sustainable photocatalytic hydrogen peroxide(H2O2)synthesis is crucial due to its role as an eco-friendly oxidant and the limitations of conventional industrial methods.Graphitic carbon nitride(g-C...Efficient and sustainable photocatalytic hydrogen peroxide(H2O2)synthesis is crucial due to its role as an eco-friendly oxidant and the limitations of conventional industrial methods.Graphitic carbon nitride(g-C3N4)is a promising photocatalyst but suffers from inefficient charge separation and limited visible light absorption.This study introduces a dual-modified g-C3N4,incorporating Na+/K+ions and cyano groups,coupled with ultrathin BiOCl nanosheets to form an S-scheme heterojunction(CN-NH-NaK/BiOCl).The modification enhances the electronic structure,visible light absorption,and charge separation.The CN-NH-NaK/BiOCl photocatalyst achieved an outstanding H2O2production rate of 33.15 mmol·g-1·h-1under visible light(λ≥400 nm),outperforming pristine g-C3N4(118-fold)and BiOCl(83-fold),and surpassing all previously reported g-C3N4-and BiOCl-based photocatalysts.Even in pure water,the production rate reached 5.18 mmol·g-1·h-1,exceeding that of most previously reported catalysts.Comprehensive characterization revealed an efficient S-scheme charge transfer mechanism,enabling selective 2e-oxygen reduction reaction(94.06%selectivity)and water oxidation.The heterojunction demonstrated excellent stability,reusability,and enhanced degradation of tetracycline hydrochloride.This work provides a promising strategy for advanced S-scheme photocatalysts in sustainable H2O2production and environmental remediation.展开更多
Limited by secondary pollution of PMS and active species generation capacity,the development of photocatalytic PMS activation systems should focus on the improvement of PMS utilization efficiency.In this manuscript,S-...Limited by secondary pollution of PMS and active species generation capacity,the development of photocatalytic PMS activation systems should focus on the improvement of PMS utilization efficiency.In this manuscript,S-scheme MnO2/BiOCl heterojunction were constructed for various antibiotics and endocrine disruptors removal by photocatalytic peroxymonosulfate(PMS)activation.Under visible light and the low PMS concentration(0.08 mmol·L–1),the doxycycline hydrochloride(DXC)and bisphenol A oxidation performance of MnO2/BiOCl-2 composites have enhanced 16.3%and 67.2%compared with that of BiOCl materials.The photocatalytic PMS utilization efficiency of MOBC-2 composites reaches to 95.5%,wherein that of BiOCl materials is 36.1%.The PMS adsorption energy of MnO2/BiOCl composites by the density functional thoery calculation possess exceptional PMS activation ability ascribed to the coupling with MnO2.Furthermore,the calculation of electron spin-charge density and Gibbs free energy change demonstrates MnO2/BiOCl composites can react with PMS for1O2formation.The liquid chromatography-tandem mass spectrometry measurement and Fukui function has been employed for inferring the intermediates of DXC in PMS oxidation process.This manuscript provides research insights and scientific references for construction of S-scheme heterojunction to employ in visible-light-driven low-concentration PMS activation process.展开更多
Novel SiO2/BiOCl composites were fabricated by decorating BiOCl nanosheets with SiO2 nanoparticles via a simple hydrothermal process. The as-prepared pure BiOCl and SiO2/BiOCl composites were intensively characterized...Novel SiO2/BiOCl composites were fabricated by decorating BiOCl nanosheets with SiO2 nanoparticles via a simple hydrothermal process. The as-prepared pure BiOCl and SiO2/BiOCl composites were intensively characterized by various techniques such as XRD, FT-IR, SEM/TEM, BET, UV-vis, DRS, XPS, and photocurrent measurements. The SiO2/BiOCl composite nanosheets displayed high photocatalytic activity and excellent stability in the degradation of organic pollutants such as phenol, bisphenol A (BPA), and rhodamine B (RhB). With respect to those over bare BiOCl, the degradation rates of RhB, BPA, and phenol over 1.88% SiO2/BiOCl increased 16.5%, 29.0%, and 38.7%, respectively. Radical capturing results suggested that h^+ is the major reactive species and that hydroxyl (·OH) and superoxide (·O2^-) radicals could also be involved in the degradation of organic pollutants. The enhanced photocatalytic performances of SiO2/BiOCl composites can be mainly attributed to the improved texture and the formation of intimate SiO2/BiOCl interfaces, which largely promoted the adsorption of organic pollutants, enhanced the light harvesting, and accelerated the separation of e^– and h^+.展开更多
Photo-assisted Li–O2batteries present a promising avenue for reducing overpotential and enhancing the capacity of next-generation energy storage devices.In this study,we introduce a novel photo-assisted Li–O2s...Photo-assisted Li–O2batteries present a promising avenue for reducing overpotential and enhancing the capacity of next-generation energy storage devices.In this study,we introduce a novel photo-assisted Li–O2system featuring a Z-scheme In2S3/MnO2/BiOCl heterojunction as a photocathode.This innovative design significantly boosts visible light absorption and facilitates the spatial separation of photogenerated electron-hole pairs.The Z-scheme charge transfer pathway establishes efficient channels for enhancing electron transfer and charge separation,thereby fostering high photocatalytic efficiency.During illumination,photo-generated electrons traverse within the band structure,participating in the Oxygen Reduction Reaction(ORR)during discharging,while photo-induced holes in the valence band facilitate the oxidation reaction of discharge products during the charging process.Under illumination,the surface electrons of In2S3/MnO2/BiOCl modify the morphology of the discharge product(Li2O2),leading to accelerated decomposition kinetics of Li2O2during charging.Remarkably,the In2S3/MnO2/BiOCl photoelectrode exhibits a high specific capacity of 19330 mAh/g under illumination,surpassing performance in the dark by a significant margin.This results in an ultranarrow discharge/charge overpotential of 0.19/0.16 V,coupled with excellent cyclic stability and a long cycle life of 1500 h at 200 mA/g.Further surface tests on the photoelectrode demonstrate that light energy application promotes the decomposition of Li2O2,corroborated by density function theory(DFT)theoretical calculations.This study of Z-scheme heterostructured photocathodes sheds light on the mechanism of photo-generated charge carriers in Li–O2batteries,providing valuable insights into their functionality and potential for future battery technologies.展开更多
Efficient CO2photoreduction to produce fuel remains a great challenge,due to the fast recombination of photogenerated charge carriers and the lack of effective reactive sites in the developed photocatalysts.Herein,...Efficient CO2photoreduction to produce fuel remains a great challenge,due to the fast recombination of photogenerated charge carriers and the lack of effective reactive sites in the developed photocatalysts.Herein,single Co atoms(CoSA)were highly dispersed on hydrothermally synthesized BiOCl nanosheets(BOC)by a facile two-step electrostatic self-assembly and pyrolysis method.The obtained CoSA-BOC could be performed for efficient CO2photoreduction to stoichiometrically produce CO and O2at the ratio of 2:1,with the CO evolution rate reaching 45.93 μmol g-1h-1,~4 times that of the pristine BOC.This distinctly improved photocatalytic performance for CoSA-BOC should benefit from the introduction of atomically dispersed Co–O4coordination structures,which could accelerate the migration of photogenerated charge carriers to surface by creating an impurity energy level in the forbidden band,and act as the reactive sites to deliver the photogenerated electrons to activate CO2molecules for CO production.This work provides a facile and reliable strategy to highly disperse single atoms on low-dimensional semiconductors for efficient CO2photoreduction to selectively produce CO.展开更多
Effect of divalent dopants, Zn2+ ion, on the high-order photon avalanche (PA) upconversion (UC) emission of Er3+ doped BiOCl microcrystals was investigated. XRD results indicated that Zn2+ ion dopants would mos...Effect of divalent dopants, Zn2+ ion, on the high-order photon avalanche (PA) upconversion (UC) emission of Er3+ doped BiOCl microcrystals was investigated. XRD results indicated that Zn2+ ion dopants would mostly enter into the lattice space at low and moderate doping concentration, and began to substitute Bi3+ ion gradually at heavily doping level. Under exaction at 980 nm, the PA UC of violet, green and red emission of Er3+ ions could be observed, and the UC emission intensity increased with increasing the Zn2+ addition below 8 mol.%, then decreased with further addition. Power dependence study showed that the dopant concentration of Zn2+ had no obviously negative effect on the occurrence of PA emission. On the bases of results investigated herein, we considered that the lattice distortion by Zn2+ doping could not directly change the special PA emission of BiOCI:Er3+, but would improve the emission intensity when used as lattice modifier.展开更多
Given the limited exposure of active sites and the retarded separation of photogenerated charge carriers in those developed photocata-lysts,photocatalyticCO2splitting into value-added chemicals has suffered from th...Given the limited exposure of active sites and the retarded separation of photogenerated charge carriers in those developed photocata-lysts,photocatalyticCO2splitting into value-added chemicals has suffered from the poor activity and remained in great challenge for real application.Herein,hydrothermally synthesized BiOCl with layered structure(BOC-NSs)was exfoliated into thickness reduced nanosheets(BOCNSs-w)and even atomic layers(BOCNSs-i)via ultrasonication in water and isopro-panol,respectively.In comparison with the pristine BOCNSs,the exfoli-ated BiOCl,especially BOCNSs-i with atomically layered structure,exhibits much improved photocatalytic activity forCO2overall splitting to produce CO andO2 at a stoichiometric ratio of 2:1,with CO evolution rate reaching 134.8µmolg-1h-1 under simulated solar light(1.7 suns).By surpassing the photocatalytic performances of the state-of-the-artBilOmXn(X:Cl,Br,I)based photocatalysts,the CO evolution rate is further increased by 99 times,reaching 13.3 mmolg-1h-1 under concentrated solar irradiation(34 suns).This excellent photocatalytic performance achieved over BOCNSs-i should be benefited from the shortened transfer distance and the increased built-in electric field intensity,which acceler-ates the migration of photogenerated charge carriers to surface.Moreover,with oxygen vacancies(VO)introduced into the atomic layers,BOCNSs-i is exposed with the electrons enriched Bi active sites that could transfer electrons to activateCO2molecules for highly efficient and selective CO production,by lowering the energy barrier of rate-determining step(RDS),*OH+*CO2-→HCO3-.It is also realized that theH2O vapor supplied during photocatalytic reaction would exchange oxygen atoms withCO2,which could alter the reaction path-ways and further reduce the energy barrier of RDS,contributing to the dramatically improved photocatalytic performance forCO2overall splitting to CO andO2.展开更多
摘要Efficient and sustainable photocatalytic hydrogen peroxide(H2O2)synthesis is crucial due to its role as an eco-friendly oxidant and the limitations of conventional industrial methods.Graphitic carbon nitride(g-C3N4)is a promising photocatalyst but suffers from inefficient charge separation and limited visible light absorption.This study introduces a dual-modified g-C3N4,incorporating Na+/K+ions and cyano groups,coupled with ultrathin BiOCl nanosheets to form an S-scheme heterojunction(CN-NH-NaK/BiOCl).The modification enhances the electronic structure,visible light absorption,and charge separation.The CN-NH-NaK/BiOCl photocatalyst achieved an outstanding H2O2production rate of 33.15 mmol·g-1·h-1under visible light(λ≥400 nm),outperforming pristine g-C3N4(118-fold)and BiOCl(83-fold),and surpassing all previously reported g-C3N4-and BiOCl-based photocatalysts.Even in pure water,the production rate reached 5.18 mmol·g-1·h-1,exceeding that of most previously reported catalysts.Comprehensive characterization revealed an efficient S-scheme charge transfer mechanism,enabling selective 2e-oxygen reduction reaction(94.06%selectivity)and water oxidation.The heterojunction demonstrated excellent stability,reusability,and enhanced degradation of tetracycline hydrochloride.This work provides a promising strategy for advanced S-scheme photocatalysts in sustainable H2O2production and environmental remediation.
摘要Limited by secondary pollution of PMS and active species generation capacity,the development of photocatalytic PMS activation systems should focus on the improvement of PMS utilization efficiency.In this manuscript,S-scheme MnO2/BiOCl heterojunction were constructed for various antibiotics and endocrine disruptors removal by photocatalytic peroxymonosulfate(PMS)activation.Under visible light and the low PMS concentration(0.08 mmol·L–1),the doxycycline hydrochloride(DXC)and bisphenol A oxidation performance of MnO2/BiOCl-2 composites have enhanced 16.3%and 67.2%compared with that of BiOCl materials.The photocatalytic PMS utilization efficiency of MOBC-2 composites reaches to 95.5%,wherein that of BiOCl materials is 36.1%.The PMS adsorption energy of MnO2/BiOCl composites by the density functional thoery calculation possess exceptional PMS activation ability ascribed to the coupling with MnO2.Furthermore,the calculation of electron spin-charge density and Gibbs free energy change demonstrates MnO2/BiOCl composites can react with PMS for1O2formation.The liquid chromatography-tandem mass spectrometry measurement and Fukui function has been employed for inferring the intermediates of DXC in PMS oxidation process.This manuscript provides research insights and scientific references for construction of S-scheme heterojunction to employ in visible-light-driven low-concentration PMS activation process.
基金funding from the National Natural Science Foundation of China (21567008, 21707055)the Program for Innovative Research Team of Guangdong University of Petrochemical Technology+4 种基金the Yangfan talents Project of Guangdong Provincethe Innovation-driven “5511” Program in Jiangxi Province (20165BCB18014)the Funding Program for Academic and Technological Leaders of Major Disciplines in Jiangxi Province (20172BCB22018)the Program for New Century Excellent Talents in Fujian Province Universitythe Natural Science Foundation for Distinguished Young Scholars of Hunan Province, China (2017JJ1026)~~
摘要Novel SiO2/BiOCl composites were fabricated by decorating BiOCl nanosheets with SiO2 nanoparticles via a simple hydrothermal process. The as-prepared pure BiOCl and SiO2/BiOCl composites were intensively characterized by various techniques such as XRD, FT-IR, SEM/TEM, BET, UV-vis, DRS, XPS, and photocurrent measurements. The SiO2/BiOCl composite nanosheets displayed high photocatalytic activity and excellent stability in the degradation of organic pollutants such as phenol, bisphenol A (BPA), and rhodamine B (RhB). With respect to those over bare BiOCl, the degradation rates of RhB, BPA, and phenol over 1.88% SiO2/BiOCl increased 16.5%, 29.0%, and 38.7%, respectively. Radical capturing results suggested that h^+ is the major reactive species and that hydroxyl (·OH) and superoxide (·O2^-) radicals could also be involved in the degradation of organic pollutants. The enhanced photocatalytic performances of SiO2/BiOCl composites can be mainly attributed to the improved texture and the formation of intimate SiO2/BiOCl interfaces, which largely promoted the adsorption of organic pollutants, enhanced the light harvesting, and accelerated the separation of e^– and h^+.
基金funded by the Natural Science Project of the Zhengzhou Science and Technology Bureau(No.22ZZRDZX04).
摘要Photo-assisted Li–O2batteries present a promising avenue for reducing overpotential and enhancing the capacity of next-generation energy storage devices.In this study,we introduce a novel photo-assisted Li–O2system featuring a Z-scheme In2S3/MnO2/BiOCl heterojunction as a photocathode.This innovative design significantly boosts visible light absorption and facilitates the spatial separation of photogenerated electron-hole pairs.The Z-scheme charge transfer pathway establishes efficient channels for enhancing electron transfer and charge separation,thereby fostering high photocatalytic efficiency.During illumination,photo-generated electrons traverse within the band structure,participating in the Oxygen Reduction Reaction(ORR)during discharging,while photo-induced holes in the valence band facilitate the oxidation reaction of discharge products during the charging process.Under illumination,the surface electrons of In2S3/MnO2/BiOCl modify the morphology of the discharge product(Li2O2),leading to accelerated decomposition kinetics of Li2O2during charging.Remarkably,the In2S3/MnO2/BiOCl photoelectrode exhibits a high specific capacity of 19330 mAh/g under illumination,surpassing performance in the dark by a significant margin.This results in an ultranarrow discharge/charge overpotential of 0.19/0.16 V,coupled with excellent cyclic stability and a long cycle life of 1500 h at 200 mA/g.Further surface tests on the photoelectrode demonstrate that light energy application promotes the decomposition of Li2O2,corroborated by density function theory(DFT)theoretical calculations.This study of Z-scheme heterostructured photocathodes sheds light on the mechanism of photo-generated charge carriers in Li–O2batteries,providing valuable insights into their functionality and potential for future battery technologies.
基金the National Natural Science Foundation of China(52225606,52488201)the"Fundamental Research Funds for the Central Universities".
摘要Efficient CO2photoreduction to produce fuel remains a great challenge,due to the fast recombination of photogenerated charge carriers and the lack of effective reactive sites in the developed photocatalysts.Herein,single Co atoms(CoSA)were highly dispersed on hydrothermally synthesized BiOCl nanosheets(BOC)by a facile two-step electrostatic self-assembly and pyrolysis method.The obtained CoSA-BOC could be performed for efficient CO2photoreduction to stoichiometrically produce CO and O2at the ratio of 2:1,with the CO evolution rate reaching 45.93 μmol g-1h-1,~4 times that of the pristine BOC.This distinctly improved photocatalytic performance for CoSA-BOC should benefit from the introduction of atomically dispersed Co–O4coordination structures,which could accelerate the migration of photogenerated charge carriers to surface by creating an impurity energy level in the forbidden band,and act as the reactive sites to deliver the photogenerated electrons to activate CO2molecules for CO production.This work provides a facile and reliable strategy to highly disperse single atoms on low-dimensional semiconductors for efficient CO2photoreduction to selectively produce CO.
基金Project supported by the National Natural Science Foundation of China(61465006,61265007)
摘要Effect of divalent dopants, Zn2+ ion, on the high-order photon avalanche (PA) upconversion (UC) emission of Er3+ doped BiOCl microcrystals was investigated. XRD results indicated that Zn2+ ion dopants would mostly enter into the lattice space at low and moderate doping concentration, and began to substitute Bi3+ ion gradually at heavily doping level. Under exaction at 980 nm, the PA UC of violet, green and red emission of Er3+ ions could be observed, and the UC emission intensity increased with increasing the Zn2+ addition below 8 mol.%, then decreased with further addition. Power dependence study showed that the dopant concentration of Zn2+ had no obviously negative effect on the occurrence of PA emission. On the bases of results investigated herein, we considered that the lattice distortion by Zn2+ doping could not directly change the special PA emission of BiOCI:Er3+, but would improve the emission intensity when used as lattice modifier.
基金the financial support from the National Key R&D Program of China(2024YFF0506100)the National Natural Science Foundation of China(52225606 and 52488201).
摘要Given the limited exposure of active sites and the retarded separation of photogenerated charge carriers in those developed photocata-lysts,photocatalyticCO2splitting into value-added chemicals has suffered from the poor activity and remained in great challenge for real application.Herein,hydrothermally synthesized BiOCl with layered structure(BOC-NSs)was exfoliated into thickness reduced nanosheets(BOCNSs-w)and even atomic layers(BOCNSs-i)via ultrasonication in water and isopro-panol,respectively.In comparison with the pristine BOCNSs,the exfoli-ated BiOCl,especially BOCNSs-i with atomically layered structure,exhibits much improved photocatalytic activity forCO2overall splitting to produce CO andO2 at a stoichiometric ratio of 2:1,with CO evolution rate reaching 134.8µmolg-1h-1 under simulated solar light(1.7 suns).By surpassing the photocatalytic performances of the state-of-the-artBilOmXn(X:Cl,Br,I)based photocatalysts,the CO evolution rate is further increased by 99 times,reaching 13.3 mmolg-1h-1 under concentrated solar irradiation(34 suns).This excellent photocatalytic performance achieved over BOCNSs-i should be benefited from the shortened transfer distance and the increased built-in electric field intensity,which acceler-ates the migration of photogenerated charge carriers to surface.Moreover,with oxygen vacancies(VO)introduced into the atomic layers,BOCNSs-i is exposed with the electrons enriched Bi active sites that could transfer electrons to activateCO2molecules for highly efficient and selective CO production,by lowering the energy barrier of rate-determining step(RDS),*OH+*CO2-→HCO3-.It is also realized that theH2O vapor supplied during photocatalytic reaction would exchange oxygen atoms withCO2,which could alter the reaction path-ways and further reduce the energy barrier of RDS,contributing to the dramatically improved photocatalytic performance forCO2overall splitting to CO andO2.