In this paper,the Pt/SnO2 nanostructures were prepared via a facile one-step microwave assisted hydrothermal route.The structure of the introduced Pt/SnO2 and its gas-sensing properties toward CO were investigated.The...In this paper,the Pt/SnO2 nanostructures were prepared via a facile one-step microwave assisted hydrothermal route.The structure of the introduced Pt/SnO2 and its gas-sensing properties toward CO were investigated.The results from the TEM test reveal that Pt grows on the SnO2 nanostructure,which was not found for bulk in this situ method,constructing Pt/SnO2.The results indicated that the sensor using 3.0 wt%Pt/SnO2 to 100 ppm carbon monoxide performed a superior sensing properties compared to 1.5 wt%and 4.5 wt%Pt/SnO2 at 225℃.The response time of 3.0 wt%sensor is 16 s to 100 ppm CO at225℃.Such enhanced gas sensing performances could be attributed to the chemical and electrical factors.In view of chemical factors,the presence of Pt facilitates the surface reaction,which will improve the gas sensing properties.With respect to the electrical factors,the Pt/SnO2 plays roles in increasing the sensor’s response due to its characteristic configuration.In addition,the one-step in situ microwave assisted process provides a promising and versatile choice for the preparation of gas sensing materials.展开更多
Fe-Based MOFs can serve as low cost,stable,eco-friendly and visible light-driven photocatalysts,exhibiting promising applications in a broad range of fields.However,the present modification or semiconductor-coupling r...Fe-Based MOFs can serve as low cost,stable,eco-friendly and visible light-driven photocatalysts,exhibiting promising applications in a broad range of fields.However,the present modification or semiconductor-coupling routes are still unable to extend their light response to the NIR region.Herein we present a microwave-assisted method to prepare MIL-53(Fe)octahedra with uniform concave facets.This unique structural geometry enables MIL-53(Fe)to trap upconversion nanocrystals(UCNPs)on their concave surface with a stable morphology.The developed MIL-53(Fe)/UCNP composites exhibit remarkable photocatalytic activity under NIR light and enhanced performance under Vis-NIR light.Through modifying the organic linkers with amino groups,both light absorption and utilization of upconverted emission of the composites can be enhanced,showing an improved activity.The formation and working mechanisms of the MOF/UCNP composite photocatalysts are also explored.展开更多
Silicoaluminophosphate(SAPO)zeolites with small pores(8-ring window),such as SAPO-34,SAPO-17,and SAPO-RHO,have attracted a lot of attention due to their unique structural features,and their appli-cations in the field ...Silicoaluminophosphate(SAPO)zeolites with small pores(8-ring window),such as SAPO-34,SAPO-17,and SAPO-RHO,have attracted a lot of attention due to their unique structural features,and their appli-cations in the field of small-molecule gas adsorption and separation.However,the fast,efficient and green synthesis of SAPO zeolites remains a great challenge.In this work,SAPO-17 zeolites were syn-thesized within 1 min for the first time by a seed-assisted microwave method,and the resulting samples possessed excellent performance in the application of CO_(2)adsorption and separation for flue gas and natural gas.The microwave-assisted route can shorten the crystallization time of traditional hydrothermal methods from a few hours to 30 min.Furthermore,the crystallization time could be drastically shortened to 1 min with the addition of seeds,which represents the shortest time for the preparation of a SAPO-17 zeolite up to now.SAPO-17 synthesized within 1 min(SAPO-17-S-1)possessed the smallest crystal size,and the largest micropore volume and specific surface area among all the samples,which enhanced mass transfer and exposed more active sites,and thus it possessed prominent performance for CO_(2)adsorption(3.47 mmol g^(−1)at 273 K and 1 bar)and gas separation.At 298 K and 100 kPa,SAPO-17-S-1 exhibited the highest gas selectivity for CO_(2)/N_(2)(276)and CO_(2)/CH_(4)(63)over the other samples,which were syn-thesized in a relatively long time.Transient binary breakthrough experiments on SAPO-17-S-1 further verified the highly-efficient gas separation performance.This work proposes a green and ultrafast strategy for the synthesis of SAPO-17 zeolites with highly selective CO_(2)adsorption over N_(2)and CH_(4).展开更多
基金supported by the National Natural Science Foundation of China (No.61803172)the Start-up Research Foundation of Hainan University (No.KYQD(ZR)1910)。
文摘In this paper,the Pt/SnO2 nanostructures were prepared via a facile one-step microwave assisted hydrothermal route.The structure of the introduced Pt/SnO2 and its gas-sensing properties toward CO were investigated.The results from the TEM test reveal that Pt grows on the SnO2 nanostructure,which was not found for bulk in this situ method,constructing Pt/SnO2.The results indicated that the sensor using 3.0 wt%Pt/SnO2 to 100 ppm carbon monoxide performed a superior sensing properties compared to 1.5 wt%and 4.5 wt%Pt/SnO2 at 225℃.The response time of 3.0 wt%sensor is 16 s to 100 ppm CO at225℃.Such enhanced gas sensing performances could be attributed to the chemical and electrical factors.In view of chemical factors,the presence of Pt facilitates the surface reaction,which will improve the gas sensing properties.With respect to the electrical factors,the Pt/SnO2 plays roles in increasing the sensor’s response due to its characteristic configuration.In addition,the one-step in situ microwave assisted process provides a promising and versatile choice for the preparation of gas sensing materials.
基金financial support from the National Natural Science Foundation of China(no.21273203)Natural Science Foundation of Zhejiang Province(no.R15B010001).
文摘Fe-Based MOFs can serve as low cost,stable,eco-friendly and visible light-driven photocatalysts,exhibiting promising applications in a broad range of fields.However,the present modification or semiconductor-coupling routes are still unable to extend their light response to the NIR region.Herein we present a microwave-assisted method to prepare MIL-53(Fe)octahedra with uniform concave facets.This unique structural geometry enables MIL-53(Fe)to trap upconversion nanocrystals(UCNPs)on their concave surface with a stable morphology.The developed MIL-53(Fe)/UCNP composites exhibit remarkable photocatalytic activity under NIR light and enhanced performance under Vis-NIR light.Through modifying the organic linkers with amino groups,both light absorption and utilization of upconverted emission of the composites can be enhanced,showing an improved activity.The formation and working mechanisms of the MOF/UCNP composite photocatalysts are also explored.
基金supported by the Jilin Province Science and Technology Development Plan(20220101048JC and 20210101112JC)the National Natural Science Foundation of China(22288101)the 111 Project of the Ministry of Education of China(B17020).
文摘Silicoaluminophosphate(SAPO)zeolites with small pores(8-ring window),such as SAPO-34,SAPO-17,and SAPO-RHO,have attracted a lot of attention due to their unique structural features,and their appli-cations in the field of small-molecule gas adsorption and separation.However,the fast,efficient and green synthesis of SAPO zeolites remains a great challenge.In this work,SAPO-17 zeolites were syn-thesized within 1 min for the first time by a seed-assisted microwave method,and the resulting samples possessed excellent performance in the application of CO_(2)adsorption and separation for flue gas and natural gas.The microwave-assisted route can shorten the crystallization time of traditional hydrothermal methods from a few hours to 30 min.Furthermore,the crystallization time could be drastically shortened to 1 min with the addition of seeds,which represents the shortest time for the preparation of a SAPO-17 zeolite up to now.SAPO-17 synthesized within 1 min(SAPO-17-S-1)possessed the smallest crystal size,and the largest micropore volume and specific surface area among all the samples,which enhanced mass transfer and exposed more active sites,and thus it possessed prominent performance for CO_(2)adsorption(3.47 mmol g^(−1)at 273 K and 1 bar)and gas separation.At 298 K and 100 kPa,SAPO-17-S-1 exhibited the highest gas selectivity for CO_(2)/N_(2)(276)and CO_(2)/CH_(4)(63)over the other samples,which were syn-thesized in a relatively long time.Transient binary breakthrough experiments on SAPO-17-S-1 further verified the highly-efficient gas separation performance.This work proposes a green and ultrafast strategy for the synthesis of SAPO-17 zeolites with highly selective CO_(2)adsorption over N_(2)and CH_(4).
