In this study, benzothiazole was entirely mineralized by an up-flow internal circulation microbial electrolysis reactor. The bioelectrochemical system was operated at ambient temperature under continuous-flow mode. Th...In this study, benzothiazole was entirely mineralized by an up-flow internal circulation microbial electrolysis reactor. The bioelectrochemical system was operated at ambient temperature under continuous-flow mode. The analysis of metabolite which was extracted by HPLC-MS from the bioreactor indicated that benzothiazole derivative ( BTH ) was firstly converted into 2-hydroxybenzothiazole in the microbial electrolysis cell (MEC) and then mineralized within three steps, i.e., the fracture of thiazole-ring through a series of oxidation and hydrolysis, the deamination and hydroxylation of 2-aminobenzenesulfonic acid, and the mineralization of various carboxylic acids to CO2 and H2O. Bacterial community analysis indicated that the applied electric field could selectively enrich certain species and the dominate bacteria on the electrodes belonged to Proteobacteria, Bacteroidetes, and Firmicutes. Results show that MEC can improve the degradation efficiency of BTH in wastewater, enable the microbiological reactor to satisfy the requirements of high loading rate, thereby fulfilling the scale-up of whole process in the future.展开更多
Incorporating a selenium(Se)positive electrode into aluminum(Al)-ion batteries is an effective strategy for improving the overall battery performance.However,the cycling stability of Se positive electrodes has challen...Incorporating a selenium(Se)positive electrode into aluminum(Al)-ion batteries is an effective strategy for improving the overall battery performance.However,the cycling stability of Se positive electrodes has challenges due to the dissolution of intermediate reaction products.In this work,we aim to harness the advantages of Se while reducing its limitations by preparing a core-shell mesoporous carbon hollow sphere with a titanium nitride(C@TiN)host to load 63.9wt%Se as the positive electrode material for Al-Se batteries.Using the physical and chemical confinement offered by the hollow mesoporous carbon and TiN,the obtained core-shell mesoporous carbon hollow spheres coated with Se(Se@C@TiN)display superior utilization of the active material and remarkable cycling stability.As a result,Al-Se batteries equipped with the as-prepared Se@C@TiN composite positive electrodes show an initial discharge specific capacity of 377 mAh·g^(-1)at a current density of 1000 mA·g^(-1)while maintaining a discharge specific capacity of 86.0 mAh·g^(-1)over 200 cycles.This improved cycling performance is ascribed to the high electrical conductivity of the core-shell mesoporous carbon hollow spheres and the unique three-dimensional hierarchical architecture of Se@C@TiN.展开更多
Despite the recent progress on controllable synthesis of alkynyl-protected Au nanoclusters,the effective synthetic means are very limited and the cluster formation process still remains puzzling.Here,we develop a nove...Despite the recent progress on controllable synthesis of alkynyl-protected Au nanoclusters,the effective synthetic means are very limited and the cluster formation process still remains puzzling.Here,we develop a novel synchronous nucleation and passivation strategy to fabricate Au36(PA)24(PA=phenylacetylenyl) nanoclusters with high yield.In Au36(PA)24formation process,Au22(PA)18as key intermediate was identified.Meanwhile,Au22(PA)18can be synthesized under a low amount of reductant,and by employing more reductants,Au22(PA)18can turn into Au36(PA)24eventually.Moreover,the structure evolution from Au22(PA)18to Au36(PA)24is proposed,where four Au13cuboctahedra can yield one Au28kernel.Finally,the ratiocination is verified by the good accordance between the predicted intermediate/product ratio and the experimental value.This study not only offers a novel synthetic strategy,but also sheds light on understanding the structural evolution process of alkynyl-protected Au nanoclusters at atomic level.展开更多
The photodegradation of anthracene(AN)and benzo[a]pyrene(BaP),two priority polycyclic aromatic hydrocarbons(PAHs),was examined at ultra-trace levels in surface water to elucidate their behaviour under several irradian...The photodegradation of anthracene(AN)and benzo[a]pyrene(BaP),two priority polycyclic aromatic hydrocarbons(PAHs),was examined at ultra-trace levels in surface water to elucidate their behaviour under several irradiance values and types of radiation.The emitting flux and the spectrum of the lamps were found to develop a crucial role in AN and BaP degradation since removal efficiencies of the target contaminants higher than 99%were found after 15 min of irradiation under an ultraviolet C(UVC)irradiance of 0.63 mW/cm^2,corresponding to a fluence of 560.25 mJ/cm^2.On the other hand,although ultraviolet A(UVA)lamps exhibited a higher irradiance compared to that of UVC lamps,they were not efficient for degrading the target PAHs.The removal kinetic studies corroborated these findings,being the AN elimination rate in surface water higher than that in deionized water at optimal operating conditions.Disinfection potential was also measured.A rapid microbial load inactivation,in terms of total coliforms naturally contained in the water matrix studied,was evidenced within 15 min of treatment for the fluence referred.However,after 24 hr in the dark,a regrowth was observed.Additionally,photolysis products more toxic than the parent compounds were found,which were not removed even by extending the treatment time.In this regard,it can be concluded that the individual action of UVC light for removing AN and BaP with disinfection purposes is not an efficient treatment;therefore,the use of radiation in combination with other kinds of treatments is required.展开更多
Despite of the hazardous risk of Pb^(2+) leakage, lead dioxide has been attributed as a quasi-ideal anode material with high oxygen evolution potential, excellent conductivity, good stability and low cost in electroch...Despite of the hazardous risk of Pb^(2+) leakage, lead dioxide has been attributed as a quasi-ideal anode material with high oxygen evolution potential, excellent conductivity, good stability and low cost in electrochemical oxidation wastewater treatment technique. In this study, a novel Ti/PbO_(2) anode was fabricated by embedding raw materials that are readily and cheaply available, i.e., hairs. The structure-activity relationship of the new electrode was firstly revealed by material and electrochemical characterizations. Then different levels of pollutants (azo dye, phenol and maleic acid) were used to investigate the electrochemical oxidation performance of the new electrode. Finally, the accelerated electrode lifetime and Pb^(2+) leakage tests were carried out. Results showed that the embedded hairs changed the preferential crystallographic orientation of PbO_(2) and decreased the grain size. Hairs introduced additional roughness and active sites, and decreased the electrode impedance, especially under 5 mg/cm^(2) of embedding amount. The removal efficiencies of different target pollutants were enhanced more or less by embedding appropriate amount of hairs, depending on the current density, but loading excessive hairs had a negative effect. The accumulation of intermediate products during phenol degradation was also changed by the hairs. The new electrode could undergo ~550 h of harsh electrolysis. It is also relieved that the Pb^(2+) leakage was found to be suppressed during this long-term electrolysis process.展开更多
ZrB_(2)-Al_(2)O_(3)composite powders were synthesized at 1100℃using a novel ZrB_(2)precursor and Al powders as raw materials.The final ZrB_(2)-Al_(2)O_(3)composite powders consisted of submicron Al_(2)O_(3)and nanosi...ZrB_(2)-Al_(2)O_(3)composite powders were synthesized at 1100℃using a novel ZrB_(2)precursor and Al powders as raw materials.The final ZrB_(2)-Al_(2)O_(3)composite powders consisted of submicron Al_(2)O_(3)and nanosize ZrB_(2)(50-100 nm)particles,which were homogeneously mixed in microscale.Combined with thermodynamic calculation and experiment results,the formation mechanism of ZrB_(2)-Al_(2)O_(3)composite powders was proposed as follows:ZrB_(2)precursor first decomposed into ZrO_(2)and amorphousB2O3.Aluminothermic reduction of ZrO_(2) and B_(2)O_(3) generated Zr and B atoms and the coproducts Al_(2)O_(3),and then,a series of reactions between Zr atoms,B atoms and Al took place to form ZrB_(2)and Al_(3)Zr.Then,ZrB_(2),Al_(2)O_(3)and Al were obtained through a liquid-solid reaction between Al_(3)Zr andB2O3,which is the limiting step in the conversion process.When the Al_(3)Zr was exhausted,the reaction between Al,ZrO_(2)and B became the main reaction to obtain ZrB_(2)and Al_(2)O_(3).展开更多
基金Sponsored by the National Natural Science Foundation of China(Grant No.51778175)the National Key R&D Plan(Grant No.2016YFC0401105)+1 种基金the Natural Science Foundation of Heilongjiang Province(Grant No.E2016039)the National Water Pollution Control and Management Technology Major Projects(Grant No.2013ZX07201007)
文摘In this study, benzothiazole was entirely mineralized by an up-flow internal circulation microbial electrolysis reactor. The bioelectrochemical system was operated at ambient temperature under continuous-flow mode. The analysis of metabolite which was extracted by HPLC-MS from the bioreactor indicated that benzothiazole derivative ( BTH ) was firstly converted into 2-hydroxybenzothiazole in the microbial electrolysis cell (MEC) and then mineralized within three steps, i.e., the fracture of thiazole-ring through a series of oxidation and hydrolysis, the deamination and hydroxylation of 2-aminobenzenesulfonic acid, and the mineralization of various carboxylic acids to CO2 and H2O. Bacterial community analysis indicated that the applied electric field could selectively enrich certain species and the dominate bacteria on the electrodes belonged to Proteobacteria, Bacteroidetes, and Firmicutes. Results show that MEC can improve the degradation efficiency of BTH in wastewater, enable the microbiological reactor to satisfy the requirements of high loading rate, thereby fulfilling the scale-up of whole process in the future.
基金supported by the National Natural Science Foundation of China(No.52374350)China Postdoctoral Science Foundation(Nos.2020M680347 and 2021T140051)the Fundamental Research Funds for the Central Universities(No.FRF-TP-20-045A1)。
文摘Incorporating a selenium(Se)positive electrode into aluminum(Al)-ion batteries is an effective strategy for improving the overall battery performance.However,the cycling stability of Se positive electrodes has challenges due to the dissolution of intermediate reaction products.In this work,we aim to harness the advantages of Se while reducing its limitations by preparing a core-shell mesoporous carbon hollow sphere with a titanium nitride(C@TiN)host to load 63.9wt%Se as the positive electrode material for Al-Se batteries.Using the physical and chemical confinement offered by the hollow mesoporous carbon and TiN,the obtained core-shell mesoporous carbon hollow spheres coated with Se(Se@C@TiN)display superior utilization of the active material and remarkable cycling stability.As a result,Al-Se batteries equipped with the as-prepared Se@C@TiN composite positive electrodes show an initial discharge specific capacity of 377 mAh·g^(-1)at a current density of 1000 mA·g^(-1)while maintaining a discharge specific capacity of 86.0 mAh·g^(-1)over 200 cycles.This improved cycling performance is ascribed to the high electrical conductivity of the core-shell mesoporous carbon hollow spheres and the unique three-dimensional hierarchical architecture of Se@C@TiN.
基金This work was supported by Guangdong Natural Science Funds for Distinguished Young Scholars(2015A030306006)Guangzhou Science and Technology Plan Projects(201804010323)+1 种基金the fundamental funds for central universities(SCUT,2018ZD022)the National Natural Science Foundation of China(21971070).
文摘Despite the recent progress on controllable synthesis of alkynyl-protected Au nanoclusters,the effective synthetic means are very limited and the cluster formation process still remains puzzling.Here,we develop a novel synchronous nucleation and passivation strategy to fabricate Au36(PA)24(PA=phenylacetylenyl) nanoclusters with high yield.In Au36(PA)24formation process,Au22(PA)18as key intermediate was identified.Meanwhile,Au22(PA)18can be synthesized under a low amount of reductant,and by employing more reductants,Au22(PA)18can turn into Au36(PA)24eventually.Moreover,the structure evolution from Au22(PA)18to Au36(PA)24is proposed,where four Au13cuboctahedra can yield one Au28kernel.Finally,the ratiocination is verified by the good accordance between the predicted intermediate/product ratio and the experimental value.This study not only offers a novel synthetic strategy,but also sheds light on understanding the structural evolution process of alkynyl-protected Au nanoclusters at atomic level.
基金financial support obtained from the Colombian Administrative Department of Science,Technology and Innovation(COLCIENCIAS)。
文摘The photodegradation of anthracene(AN)and benzo[a]pyrene(BaP),two priority polycyclic aromatic hydrocarbons(PAHs),was examined at ultra-trace levels in surface water to elucidate their behaviour under several irradiance values and types of radiation.The emitting flux and the spectrum of the lamps were found to develop a crucial role in AN and BaP degradation since removal efficiencies of the target contaminants higher than 99%were found after 15 min of irradiation under an ultraviolet C(UVC)irradiance of 0.63 mW/cm^2,corresponding to a fluence of 560.25 mJ/cm^2.On the other hand,although ultraviolet A(UVA)lamps exhibited a higher irradiance compared to that of UVC lamps,they were not efficient for degrading the target PAHs.The removal kinetic studies corroborated these findings,being the AN elimination rate in surface water higher than that in deionized water at optimal operating conditions.Disinfection potential was also measured.A rapid microbial load inactivation,in terms of total coliforms naturally contained in the water matrix studied,was evidenced within 15 min of treatment for the fluence referred.However,after 24 hr in the dark,a regrowth was observed.Additionally,photolysis products more toxic than the parent compounds were found,which were not removed even by extending the treatment time.In this regard,it can be concluded that the individual action of UVC light for removing AN and BaP with disinfection purposes is not an efficient treatment;therefore,the use of radiation in combination with other kinds of treatments is required.
基金financed by the National Natural Science Foundation of China (No. 21706153)Natural Science Basic Research Plan in Shaanxi Province of China (No. 2018JQ2066)。
文摘Despite of the hazardous risk of Pb^(2+) leakage, lead dioxide has been attributed as a quasi-ideal anode material with high oxygen evolution potential, excellent conductivity, good stability and low cost in electrochemical oxidation wastewater treatment technique. In this study, a novel Ti/PbO_(2) anode was fabricated by embedding raw materials that are readily and cheaply available, i.e., hairs. The structure-activity relationship of the new electrode was firstly revealed by material and electrochemical characterizations. Then different levels of pollutants (azo dye, phenol and maleic acid) were used to investigate the electrochemical oxidation performance of the new electrode. Finally, the accelerated electrode lifetime and Pb^(2+) leakage tests were carried out. Results showed that the embedded hairs changed the preferential crystallographic orientation of PbO_(2) and decreased the grain size. Hairs introduced additional roughness and active sites, and decreased the electrode impedance, especially under 5 mg/cm^(2) of embedding amount. The removal efficiencies of different target pollutants were enhanced more or less by embedding appropriate amount of hairs, depending on the current density, but loading excessive hairs had a negative effect. The accumulation of intermediate products during phenol degradation was also changed by the hairs. The new electrode could undergo ~550 h of harsh electrolysis. It is also relieved that the Pb^(2+) leakage was found to be suppressed during this long-term electrolysis process.
基金the National Natural Science Foundation of China(Nos.51672170 and 51702206)Shanghai Science and Technology Commission Research Project(No.17XD1424700)。
文摘ZrB_(2)-Al_(2)O_(3)composite powders were synthesized at 1100℃using a novel ZrB_(2)precursor and Al powders as raw materials.The final ZrB_(2)-Al_(2)O_(3)composite powders consisted of submicron Al_(2)O_(3)and nanosize ZrB_(2)(50-100 nm)particles,which were homogeneously mixed in microscale.Combined with thermodynamic calculation and experiment results,the formation mechanism of ZrB_(2)-Al_(2)O_(3)composite powders was proposed as follows:ZrB_(2)precursor first decomposed into ZrO_(2)and amorphousB2O3.Aluminothermic reduction of ZrO_(2) and B_(2)O_(3) generated Zr and B atoms and the coproducts Al_(2)O_(3),and then,a series of reactions between Zr atoms,B atoms and Al took place to form ZrB_(2)and Al_(3)Zr.Then,ZrB_(2),Al_(2)O_(3)and Al were obtained through a liquid-solid reaction between Al_(3)Zr andB2O3,which is the limiting step in the conversion process.When the Al_(3)Zr was exhausted,the reaction between Al,ZrO_(2)and B became the main reaction to obtain ZrB_(2)and Al_(2)O_(3).
