The concentration of atmospheric CO_(2)has exceeded 400 ppm,surpassing its natural variability and raising concerns about uncontrollable shifts in the carbon cycle,leading to significant climate and environmental impa...The concentration of atmospheric CO_(2)has exceeded 400 ppm,surpassing its natural variability and raising concerns about uncontrollable shifts in the carbon cycle,leading to significant climate and environmental impacts.A promising method to balance carbon levels and mitigate atmospheric CO_(2)rise is through photocatalytic CO_(2)reduction.Titanium dioxide(TiO_(2)),renowned for its affordability,stability,availability,and eco-friendliness,stands out as an exemplary catalyst in photocatalytic CO_(2)reduction.Various strategies have been proposed to modify TiO_(2)for photocatalytic CO_(2)reduction and improve catalytic activity and product selectivity.However,few studies have systematically summarized these strategies and analyzed their advantages,disadvantages,and current progress.Here,we comprehensively review recent advancements in TiO_(2)engineering,focusing on crystal engineering,interface design,and reactive site construction to enhance photocatalytic efficiency and product selectivity.We discuss how modifications in TiO_(2)'s optical characteristics,carrier migration,and active site design have led to varied and selective CO_(2)reduction products.These enhancements are thoroughly analyzed through experimental data and theoretical calculations.Additionally,we identify current challenges and suggest future research directions,emphasizing the role of TiO_(2)-based materials in understanding photocatalytic CO_(2)reduction mechanisms and in designing effective catalysts.This review is expected to contribute to the global pursuit of carbon neutrality by providing foundational insights into the mechanisms of photocatalytic CO_(2)reduction with TiO_(2)-based materials and guiding the development of efficient photocatalysts.展开更多
Antibiotic-resistant bacteria (ARB) and antibiotic resistance genes (ARGs) have been recognized as one of the biggest public health issues of the 21 st century. Both ARB and ARGs have been determined in water after tr...Antibiotic-resistant bacteria (ARB) and antibiotic resistance genes (ARGs) have been recognized as one of the biggest public health issues of the 21 st century. Both ARB and ARGs have been determined in water after treatment with conventional disinfectants. Ultraviolet (UV) technology has been seen growth in application to disinfect the water. However, UV method alone is not adequate to degrade ARGs in water. Researchers are investigating the combination of UV with other oxidants (chlorine, hydrogen peroxide (H2O2), peroxymonosulfate (PMS), and photocatalysts) to harness the high reactivity of produced reactive species (C1-, C1O -, Cl2-,-OH, and SO4-_) in such processes with constituents of cell (e.g., deoxyribonucleic acid (DNA) and its components) in order to increase the degradation efficiency of ARGs. This paper briefly reviews the current status of different UV-based treatments (UV/chlorination, UV/H2O2, UV/PMS, and UV-photocatalysis) to degrade ARGs and to control horizontal gene transfer (HGT) in water. The review also provides discussion on the mechanism of degradation of ARGs and application of q-PCR and gel electrophoresis to obtain insights of the fate of ARGs during UV-based treatment processes.展开更多
Bisphenol(BP)analogues in wastewater effluent and groundwater pose a potential threat to human health due to their ability to disrupt steroidogenesis.A new solar-assisted electrochemical process(SECP)was developed and...Bisphenol(BP)analogues in wastewater effluent and groundwater pose a potential threat to human health due to their ability to disrupt steroidogenesis.A new solar-assisted electrochemical process(SECP)was developed and evaluated for the degradation of BP analogues.The effects of quenchers,current density,initial pH,supporting electrolyte,and aqueous matrix on the removal kinetics of bisphenol AF(BPAF)and bisphenol A(BPA)were investigated.The kinetic constants of BPAF,BPA,and bisphenol S(BPS)in the SECP with irradiation intensity of 500 mW cm^(-2) were 0.017±0.002 min^(-1),0.022±0.002 min^(-1),and 0.012±0.001 min^(-1),respectively.The changes in the degradation rates of BPAF,BPA,and BPS in the presence of quenchers indicated the relative contribution of hydroxyl radical(·OH)oxidation,anodic electrolysis,and singlet(^(1)O_(2))oxygenation in the degradation of BPs in the SECP.The enhanced rate of generation of ·OH and ^(1)O_(2) was observed in the SECP compared with those in the conventional electrochemical system.The identification of the transformation products(TPs)of BPAF demonstrated that hydroxylation,ring cleavage,b-scission,and defluorination were the major processes during the oxidation in the SECP.The conversion to fluoride ions(76%)and mineralization of total organic carbon(72%)in the SECP indicated further degradation of TPs.The results from this study improved our understanding of the degradation of BP analogues in the electrooxidation irradiated by solar light and help to establish the application potential of the SECP for the effective degradation of emerging contaminants in wastewater.展开更多
A series of unique 3D flower-like Bi_(2)MoO_(6)(BMO)/reduced graphene oxide(rGO)heterostructured composites decorated with varying amounts of Ag nanoparticles(NPs)were fabricated.Their morphological characteristics,st...A series of unique 3D flower-like Bi_(2)MoO_(6)(BMO)/reduced graphene oxide(rGO)heterostructured composites decorated with varying amounts of Ag nanoparticles(NPs)were fabricated.Their morphological characteristics,structural features,energy band structures and photoelectrochemical properties were systematically studied.All the Ag/BMO/rGO ternary composites(AgBGy;y=1%,2%and 3%)demonstrated greater photocatalytic activity towards efficient removal of our selected organic models[methyl orange(MO),rhodamine B(RhB)and phenol],as compared with the BMO/rGO binary composites(BG-x;x=0.25,2,4 and 5).Particularly,AgBG-2%,which was synthesized with the addition of 2 wt% rGO and 2 wt%Ag in BMO,possessed superior photocatalytic activity.The fitted rate constants(k)for the photocatalytic degradation of RhB,MO and phenol using AgBG-2% were estimated to be 0.0286,0.0301 and 0.0165 min^(-1),respectively,which were over one order of magnitude greater than those obtained using pure BMO.Several factors may contribute to the observed enhancement,including greater specific surface area,enhanced light absorption,promoted spatial separation of electronhole(e^(-)-h^(+))pairs and their suppressed recombination,especially benefiting from the synergistic effects among BMO,rGO and Ag NPs.Our work suggests that the rational design of BMO/rGO/Ag ternary composite was an effective strategy to boost the photocatalytic activity of the resulting catalyst towards the highly efficient removal of organic pollutants from water.展开更多
The design of van der Waals heterojunctions with S-scheme charge transfer pathway is expected to be an effective strategy for improvement of photocatalytic performance.Herein,two-dimensional(2D)phosphorus-doped g-C_(3...The design of van der Waals heterojunctions with S-scheme charge transfer pathway is expected to be an effective strategy for improvement of photocatalytic performance.Herein,two-dimensional(2D)phosphorus-doped g-C_(3)N_(4)/Bi_(5)O_(7)Ivan der Waals heterojunctions with reduced graphene oxide as electron bridge(PCN/RGO/Bi_(5O)_(7)I)were successfully synthesized via hydrothermal method.The van der Waals interaction endowed 2D PCN/RGO/Bi_(5O)_(7)I with intimate contact interface,lattice match,tunable band structure,and internal electric field,which efficiently promoted interfacial charge separation and enhanced redox ability of photogenerated charge carriers.As a result,the S-scheme PCN/RGO/Bi_5O_7I van der Waals heterojunctions exhibited superior photocatalytic performance in ciprofloxacin degradation and real pharmaceutical wastewater treatment.The optimized 12%PCN/RGO/Bi_5O_7I displayed the highest photocatalytic activity with 92%removal of ciprofloxacin.Importantly,the COD removal efficiency and extent of mineralization of real pharmaceutical wastewater reached 66.9%and 59.8%,respectively,and the biodegradability of pharmaceutical wastewater was significantly improved.The photocatalytic mechanism of the S-scheme PCN/RGO/Bi_(5)O_(7)I van der Waals heterojunctions based on the analysis of reactive species,work function,and internal electric field was presented.This study provides fresh insights into plausible design of S-scheme van der Waals heterojunction to enhance photocatalytic redox ability.展开更多
Hydroxyl radicals(HO*)show low reactivity with perchlorinated hydrocarbons,such as carbon tetrachloride(CT),in conventional Fenton reactions,therefore,the generation of reductive radicals has attracted increasing atte...Hydroxyl radicals(HO*)show low reactivity with perchlorinated hydrocarbons,such as carbon tetrachloride(CT),in conventional Fenton reactions,therefore,the generation of reductive radicals has attracted increasing attention.This study investigated the enhancement of CT degradation by the synergistic effects of hydroxylamine(HA)and formic acid(FA)(initial[CT]=0.13 mmol/L)in a Fe(il)activated calcium peroxide(CP)fenton process.CT degradation increased from 56.6%to 99.9%with the addition of 0.78 mmol/L HA to the CP/Fe(II)/FA/CT process in a molar ratio o f 12/6/12/1.The results also showed that the presence of HA enhanced the regeneration of Fe(II)from Fe(III),and the production of HO*increased one-fold when employing benzoic acid as the HO*probe.Additionally,FA slightly improves the production of HO*.A study of the mechanism confirmed that the carbon dioxide radical(C02·),a strong reductant generated by the reaction between FA and HO*,was the dominant radical responsible for CT degradation.Almost complete CT dechlorination was achieved in the process.The presence of humic acid and chloride ion slightly decreased CT removal,while high doses of bicarbonate and high pH inhibited CT degradation.This study helps us to better understand the synergistic roles of FA and HA for HO·and C02·^-generation and the removal of perchlorinated hydrocarbons in modified Fenton systems.展开更多
基金financially supported by the National Natural Science Foundation of China(22005123,22188102)the Natural Science Foundation of Shandong Province,China(ZR2023MB049)+1 种基金China Postdoctoral Science Foundation(2020M670483)the Key Project of Natural Science Foundation of Tianjin City(Contract No.22JCZDJC00510).
文摘The concentration of atmospheric CO_(2)has exceeded 400 ppm,surpassing its natural variability and raising concerns about uncontrollable shifts in the carbon cycle,leading to significant climate and environmental impacts.A promising method to balance carbon levels and mitigate atmospheric CO_(2)rise is through photocatalytic CO_(2)reduction.Titanium dioxide(TiO_(2)),renowned for its affordability,stability,availability,and eco-friendliness,stands out as an exemplary catalyst in photocatalytic CO_(2)reduction.Various strategies have been proposed to modify TiO_(2)for photocatalytic CO_(2)reduction and improve catalytic activity and product selectivity.However,few studies have systematically summarized these strategies and analyzed their advantages,disadvantages,and current progress.Here,we comprehensively review recent advancements in TiO_(2)engineering,focusing on crystal engineering,interface design,and reactive site construction to enhance photocatalytic efficiency and product selectivity.We discuss how modifications in TiO_(2)'s optical characteristics,carrier migration,and active site design have led to varied and selective CO_(2)reduction products.These enhancements are thoroughly analyzed through experimental data and theoretical calculations.Additionally,we identify current challenges and suggest future research directions,emphasizing the role of TiO_(2)-based materials in understanding photocatalytic CO_(2)reduction mechanisms and in designing effective catalysts.This review is expected to contribute to the global pursuit of carbon neutrality by providing foundational insights into the mechanisms of photocatalytic CO_(2)reduction with TiO_(2)-based materials and guiding the development of efficient photocatalysts.
文摘Antibiotic-resistant bacteria (ARB) and antibiotic resistance genes (ARGs) have been recognized as one of the biggest public health issues of the 21 st century. Both ARB and ARGs have been determined in water after treatment with conventional disinfectants. Ultraviolet (UV) technology has been seen growth in application to disinfect the water. However, UV method alone is not adequate to degrade ARGs in water. Researchers are investigating the combination of UV with other oxidants (chlorine, hydrogen peroxide (H2O2), peroxymonosulfate (PMS), and photocatalysts) to harness the high reactivity of produced reactive species (C1-, C1O -, Cl2-,-OH, and SO4-_) in such processes with constituents of cell (e.g., deoxyribonucleic acid (DNA) and its components) in order to increase the degradation efficiency of ARGs. This paper briefly reviews the current status of different UV-based treatments (UV/chlorination, UV/H2O2, UV/PMS, and UV-photocatalysis) to degrade ARGs and to control horizontal gene transfer (HGT) in water. The review also provides discussion on the mechanism of degradation of ARGs and application of q-PCR and gel electrophoresis to obtain insights of the fate of ARGs during UV-based treatment processes.
基金the support from the State Key Laboratory of Urban Water Resource and Environment(QA201926)Youth program of the National Natural Science Foundation of China(51908164)+1 种基金support from the University of Cincinnati through a UNESCO co-Chair Professor position on“Water Access and Sustainability”the Herman Schneider Professorship in the College of Engineering and Applied Sciences.
文摘Bisphenol(BP)analogues in wastewater effluent and groundwater pose a potential threat to human health due to their ability to disrupt steroidogenesis.A new solar-assisted electrochemical process(SECP)was developed and evaluated for the degradation of BP analogues.The effects of quenchers,current density,initial pH,supporting electrolyte,and aqueous matrix on the removal kinetics of bisphenol AF(BPAF)and bisphenol A(BPA)were investigated.The kinetic constants of BPAF,BPA,and bisphenol S(BPS)in the SECP with irradiation intensity of 500 mW cm^(-2) were 0.017±0.002 min^(-1),0.022±0.002 min^(-1),and 0.012±0.001 min^(-1),respectively.The changes in the degradation rates of BPAF,BPA,and BPS in the presence of quenchers indicated the relative contribution of hydroxyl radical(·OH)oxidation,anodic electrolysis,and singlet(^(1)O_(2))oxygenation in the degradation of BPs in the SECP.The enhanced rate of generation of ·OH and ^(1)O_(2) was observed in the SECP compared with those in the conventional electrochemical system.The identification of the transformation products(TPs)of BPAF demonstrated that hydroxylation,ring cleavage,b-scission,and defluorination were the major processes during the oxidation in the SECP.The conversion to fluoride ions(76%)and mineralization of total organic carbon(72%)in the SECP indicated further degradation of TPs.The results from this study improved our understanding of the degradation of BP analogues in the electrooxidation irradiated by solar light and help to establish the application potential of the SECP for the effective degradation of emerging contaminants in wastewater.
基金financially supported by National Natural Science Foundation of China(Nos.21607064 and 21707055)the Youth Key Project of Nature Science Foundation of Jiangxi Province(Nos.20192ACBL20014 and 20192ACBL21011)+2 种基金the Natural Science Foundation of Jiangxi Province(Nos.20181BAB203018 and 20181BAB213010)Qingjiang Youth Talent Program(No.JXUSTQJYX20170005)the scholarship under China S cholarship Council(No.201803000004)。
文摘A series of unique 3D flower-like Bi_(2)MoO_(6)(BMO)/reduced graphene oxide(rGO)heterostructured composites decorated with varying amounts of Ag nanoparticles(NPs)were fabricated.Their morphological characteristics,structural features,energy band structures and photoelectrochemical properties were systematically studied.All the Ag/BMO/rGO ternary composites(AgBGy;y=1%,2%and 3%)demonstrated greater photocatalytic activity towards efficient removal of our selected organic models[methyl orange(MO),rhodamine B(RhB)and phenol],as compared with the BMO/rGO binary composites(BG-x;x=0.25,2,4 and 5).Particularly,AgBG-2%,which was synthesized with the addition of 2 wt% rGO and 2 wt%Ag in BMO,possessed superior photocatalytic activity.The fitted rate constants(k)for the photocatalytic degradation of RhB,MO and phenol using AgBG-2% were estimated to be 0.0286,0.0301 and 0.0165 min^(-1),respectively,which were over one order of magnitude greater than those obtained using pure BMO.Several factors may contribute to the observed enhancement,including greater specific surface area,enhanced light absorption,promoted spatial separation of electronhole(e^(-)-h^(+))pairs and their suppressed recombination,especially benefiting from the synergistic effects among BMO,rGO and Ag NPs.Our work suggests that the rational design of BMO/rGO/Ag ternary composite was an effective strategy to boost the photocatalytic activity of the resulting catalyst towards the highly efficient removal of organic pollutants from water.
基金the National Natural Science Foundation of China(Grant Nos.51978324,51720105001,and 51962023)the Natural Science Foundation of Jiangxi Province(Grant Nos.20213BCJL22053,20192ACBL20043,and 20212BAB204045)+1 种基金the Department of Education Fund of Jiangxi Province(Grant No.GJJ210913)Graduate Innovation Fund(Grant No.YC2021-011)。
文摘The design of van der Waals heterojunctions with S-scheme charge transfer pathway is expected to be an effective strategy for improvement of photocatalytic performance.Herein,two-dimensional(2D)phosphorus-doped g-C_(3)N_(4)/Bi_(5)O_(7)Ivan der Waals heterojunctions with reduced graphene oxide as electron bridge(PCN/RGO/Bi_(5O)_(7)I)were successfully synthesized via hydrothermal method.The van der Waals interaction endowed 2D PCN/RGO/Bi_(5O)_(7)I with intimate contact interface,lattice match,tunable band structure,and internal electric field,which efficiently promoted interfacial charge separation and enhanced redox ability of photogenerated charge carriers.As a result,the S-scheme PCN/RGO/Bi_5O_7I van der Waals heterojunctions exhibited superior photocatalytic performance in ciprofloxacin degradation and real pharmaceutical wastewater treatment.The optimized 12%PCN/RGO/Bi_5O_7I displayed the highest photocatalytic activity with 92%removal of ciprofloxacin.Importantly,the COD removal efficiency and extent of mineralization of real pharmaceutical wastewater reached 66.9%and 59.8%,respectively,and the biodegradability of pharmaceutical wastewater was significantly improved.The photocatalytic mechanism of the S-scheme PCN/RGO/Bi_(5)O_(7)I van der Waals heterojunctions based on the analysis of reactive species,work function,and internal electric field was presented.This study provides fresh insights into plausible design of S-scheme van der Waals heterojunction to enhance photocatalytic redox ability.
基金a grant from the National Key R&D Program of China(No.2018YFC1802500)Chinese Scholar Council(CSC,No.201806740035)。
文摘Hydroxyl radicals(HO*)show low reactivity with perchlorinated hydrocarbons,such as carbon tetrachloride(CT),in conventional Fenton reactions,therefore,the generation of reductive radicals has attracted increasing attention.This study investigated the enhancement of CT degradation by the synergistic effects of hydroxylamine(HA)and formic acid(FA)(initial[CT]=0.13 mmol/L)in a Fe(il)activated calcium peroxide(CP)fenton process.CT degradation increased from 56.6%to 99.9%with the addition of 0.78 mmol/L HA to the CP/Fe(II)/FA/CT process in a molar ratio o f 12/6/12/1.The results also showed that the presence of HA enhanced the regeneration of Fe(II)from Fe(III),and the production of HO*increased one-fold when employing benzoic acid as the HO*probe.Additionally,FA slightly improves the production of HO*.A study of the mechanism confirmed that the carbon dioxide radical(C02·),a strong reductant generated by the reaction between FA and HO*,was the dominant radical responsible for CT degradation.Almost complete CT dechlorination was achieved in the process.The presence of humic acid and chloride ion slightly decreased CT removal,while high doses of bicarbonate and high pH inhibited CT degradation.This study helps us to better understand the synergistic roles of FA and HA for HO·and C02·^-generation and the removal of perchlorinated hydrocarbons in modified Fenton systems.
