Bi/Bi_(2)Fe_(4)O_(9)nanocomposites consisting of Bi_(2)Fe_(4)O_(9)nanosheets decorated with Bi nanodots were synthesized by a hydrothermal method.The formation of Bi nanodots on the Bi_(2)Fe_(4)O_(9)nanosheet surfaces...Bi/Bi_(2)Fe_(4)O_(9)nanocomposites consisting of Bi_(2)Fe_(4)O_(9)nanosheets decorated with Bi nanodots were synthesized by a hydrothermal method.The formation of Bi nanodots on the Bi_(2)Fe_(4)O_(9)nanosheet surfaces was attributed to the reducibility of 2-methoxyethanol in the precursor solution.Comparative photocatalytic evaluation reveals that the Bi/Bi_(2)Fe_(4)O_(9)nanocomposites significantly enhance the degradation efficiency(99.0%)of bisphenol A compared with Bi_(2)Fe_(4)O_(9)nanosheets(64.2%)under 120 min simulated solar irradiation.This remarkable enhancement can be attributed to the established Bi/Bi_(2)Fe_(4)O_(9)heterojunction structure,which effectively facilitates the separation of photogenerated electron-hole pairs and accelerates interfacial charge transfer between the metallic Bi nanodots and semiconductor Bi_(2)Fe_(4)O_(9)nanosheets.The synergistic effects arising from this unique architecture ultimately lead to superior photocatalytic performance.展开更多
Zn-based thermal charging devices,utilizing the synergistic effect of ion thermoextraction and thermodiffusion,are able to efficiently convert thermal energy into electrical energy and storage in the devices,making th...Zn-based thermal charging devices,utilizing the synergistic effect of ion thermoextraction and thermodiffusion,are able to efficiently convert thermal energy into electrical energy and storage in the devices,making them a highly promising technology for low-grade heat recovery and utilization.However,the low output power density and energy conversion efficiency resulted by the slow diffusion kinetics of Zn^(2+)hinder their development.Herein,we present a highperformance thermal charging cell design using Zn^(2+)/NH_(4)^(+)hybrid ion electrolyte,which not only maintains the high output voltage of the Zn-based thermoelectric system,but also significantly enhances the output power density due to the fast diffusion kinetics of NH_(4)^(+).Based on this strategy,the thermal charging cell displays a high thermopower of 12.5 mV K^(-1)and an excellent normalized power density of 19.6 mW m^(-2)K^(-2)at a temperature difference of 35 K.The Carnot-relative efficiency is as high as 12.74%.Moreover,it can operate continuously for over 72 h when the temperature difference persists,achieving a balance between thermoelectric conversion and output.This work provides a simple and effective strategy for the design of high-performance thermal charging cells for low-grade heat conversion and utilization.展开更多
In order to improve the catalytic ozonation effect of resorcinol, the spinel CuFe_2O_4 was modified by doped CeO_2, and X-ray diffraction(XRD) and scanning electron microscopy(SEM) were used for characterization analy...In order to improve the catalytic ozonation effect of resorcinol, the spinel CuFe_2O_4 was modified by doped CeO_2, and X-ray diffraction(XRD) and scanning electron microscopy(SEM) were used for characterization analysis. The effects of composite catalyst CeO_2/CuFe_2O_4 dosage, ozone dosage, initial pH and reaction temperature on degradation were studied, and the stability of the catalyst was tested. The results showed that the composite effect of CeO_2/CuFe_2O_4 prepared by combustion method was good, and the catalyst presented a laminated structure, in which 30 wt% CeO_2/CuFe_2O_4 degradation effect was significant. The removal rate of resorcinol using CeO_2/CuFe_2O_4 composite catalyst was higher than that using ozone or CuFe_2O_4 separately by 41.8% and 11.9%, respectively. In a reaction with resorcinol concentration of 100 mg/L, the catalyst dosage of 1.0 g/L, the ozone dosage of 2.5 mg/(L·min), at pH=9, temperature of 20 ℃, for reaction time of 40 min, the resorcinol removal rate was 88.5%. The catalyst CeO_2/CuFe_2O_4 still showed good degradation effect after repeatedly using for 10 times, and the dissolution rate of metal ions was lower than that of CuFe_2O_4.展开更多
基金Funded by the National Natural Science Foundation of China(No.50902108)。
文摘Bi/Bi_(2)Fe_(4)O_(9)nanocomposites consisting of Bi_(2)Fe_(4)O_(9)nanosheets decorated with Bi nanodots were synthesized by a hydrothermal method.The formation of Bi nanodots on the Bi_(2)Fe_(4)O_(9)nanosheet surfaces was attributed to the reducibility of 2-methoxyethanol in the precursor solution.Comparative photocatalytic evaluation reveals that the Bi/Bi_(2)Fe_(4)O_(9)nanocomposites significantly enhance the degradation efficiency(99.0%)of bisphenol A compared with Bi_(2)Fe_(4)O_(9)nanosheets(64.2%)under 120 min simulated solar irradiation.This remarkable enhancement can be attributed to the established Bi/Bi_(2)Fe_(4)O_(9)heterojunction structure,which effectively facilitates the separation of photogenerated electron-hole pairs and accelerates interfacial charge transfer between the metallic Bi nanodots and semiconductor Bi_(2)Fe_(4)O_(9)nanosheets.The synergistic effects arising from this unique architecture ultimately lead to superior photocatalytic performance.
基金supported by the Leading Edge Technology of Jiangsu Province(BK20222009-X.Z.,BK20202008-X.Z.)Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)National Undergraduate Innovation Training Program of NUAA(202410287179Y).
文摘Zn-based thermal charging devices,utilizing the synergistic effect of ion thermoextraction and thermodiffusion,are able to efficiently convert thermal energy into electrical energy and storage in the devices,making them a highly promising technology for low-grade heat recovery and utilization.However,the low output power density and energy conversion efficiency resulted by the slow diffusion kinetics of Zn^(2+)hinder their development.Herein,we present a highperformance thermal charging cell design using Zn^(2+)/NH_(4)^(+)hybrid ion electrolyte,which not only maintains the high output voltage of the Zn-based thermoelectric system,but also significantly enhances the output power density due to the fast diffusion kinetics of NH_(4)^(+).Based on this strategy,the thermal charging cell displays a high thermopower of 12.5 mV K^(-1)and an excellent normalized power density of 19.6 mW m^(-2)K^(-2)at a temperature difference of 35 K.The Carnot-relative efficiency is as high as 12.74%.Moreover,it can operate continuously for over 72 h when the temperature difference persists,achieving a balance between thermoelectric conversion and output.This work provides a simple and effective strategy for the design of high-performance thermal charging cells for low-grade heat conversion and utilization.
基金Supported by the National Natural Science Foundation of China(41772240)
文摘In order to improve the catalytic ozonation effect of resorcinol, the spinel CuFe_2O_4 was modified by doped CeO_2, and X-ray diffraction(XRD) and scanning electron microscopy(SEM) were used for characterization analysis. The effects of composite catalyst CeO_2/CuFe_2O_4 dosage, ozone dosage, initial pH and reaction temperature on degradation were studied, and the stability of the catalyst was tested. The results showed that the composite effect of CeO_2/CuFe_2O_4 prepared by combustion method was good, and the catalyst presented a laminated structure, in which 30 wt% CeO_2/CuFe_2O_4 degradation effect was significant. The removal rate of resorcinol using CeO_2/CuFe_2O_4 composite catalyst was higher than that using ozone or CuFe_2O_4 separately by 41.8% and 11.9%, respectively. In a reaction with resorcinol concentration of 100 mg/L, the catalyst dosage of 1.0 g/L, the ozone dosage of 2.5 mg/(L·min), at pH=9, temperature of 20 ℃, for reaction time of 40 min, the resorcinol removal rate was 88.5%. The catalyst CeO_2/CuFe_2O_4 still showed good degradation effect after repeatedly using for 10 times, and the dissolution rate of metal ions was lower than that of CuFe_2O_4.
