Chemi-resistive sensors based on hybrid functional materials are promising candidates for gas sensing with high responsivity,good selectivity,fast response/recovery,great stability/repeatability,room-working temperatu...Chemi-resistive sensors based on hybrid functional materials are promising candidates for gas sensing with high responsivity,good selectivity,fast response/recovery,great stability/repeatability,room-working temperature,low cost,and easy-to-fabricate,for versatile applications.This progress report reviews the advantages and advances of these sensing structures compared with the single constituent,according to five main sensing forms:manipulating/constructing heterojunctions,catalytic reaction,charge transfer,charge carrier transport,molecular binding/sieving,and their combinations.Promises and challenges of the advances of each form are presented and discussed.Critical thinking and ideas regarding the orientation of the development of hybrid material-based gas sensor in the future are discussed.展开更多
A good method of synthesizing Ti_(3)C_(2)T_(x)(MXene)is critical for ensuring its success in practical applications,e.g.,electromagnetic interference shielding,electrochemical energy storage,catalysis,sensors,and biom...A good method of synthesizing Ti_(3)C_(2)T_(x)(MXene)is critical for ensuring its success in practical applications,e.g.,electromagnetic interference shielding,electrochemical energy storage,catalysis,sensors,and biomedicine.The main concerns focus on the moderation of the approach,yield,and product quality.Herein,a modified approach,organic solvent-assisted intercalation and collection,was developed to prepare Ti_(3)C_(2)T_(x) flakes.The new approach simultaneously solves all the concerns,featuring a low requirement for facility(centrifugation speed<4000 rpm in whole process),gram-level preparation with remarkable yield(46.3%),a good electrical conductivity(8672 S cm^(−1)),an outstanding capacitive performance(352 F g^(−1)),and easy control over the dimension of Ti_(3)C_(2)T_(x) flakes(0.47–4.60μm^(2)).This approach not only gives a superb example for the synthesis of other MXene materials in laboratory,but sheds new light for the future mass production of Ti_(3)C_(2)T_(x) MXene.展开更多
The challenge in synthesizing high-entropy ceramic(HEC)nanopowders is to suppress severe grain coarsening and particle agglomeration,which occur at elevated temperatures.This challenge could be addressed by the polyac...The challenge in synthesizing high-entropy ceramic(HEC)nanopowders is to suppress severe grain coarsening and particle agglomeration,which occur at elevated temperatures.This challenge could be addressed by the polyacrylamide gel method.In this work,single-phase high-entropy(Lao.2Ndo.2Smo.2Gdo.2 Ybo.2)2Zr2O7 and(Lao.2Ndo.2Yo.2Euo.2Gdo.2)2Zr2O7 nanopowders without agglomeration were successfully synthesized using the polyacrylamide gel method for the first time.The results showed that phase composition,particle size,and agglomeration degree of the nanopowders were greatly influenced by the molar ratio of acrylamide(AM)/Zr and calcination temperature.These as-synthesized high-entropy zirconate(HEZ)nanopowders could be sintered into fully dense ceramics at 1500 C for 2 h.These HEZ nanopowders showed a phase transformation from a defect-fluorite phase to a pyrochlore phase with the increase of sintering temperature.Additionally,two-step sintering of these nanopowders was conducted,and the HEZ ceramics with fine grains were prepared.The polyacrylamide gel method is simple and easily operated,which is a facile approach of producing the HEC nanopowders with excellent sinterability.展开更多
基金the Phase-II Grand Challenges Explorations award from the Bill,Melinda Gates Foundation(Grant ID:OPP1109493)International Research Fellow of the Japan Society of the Promotion of Science(JSPS,Postdoctoral Fellowships for Research in Japan(Standard),P18334)+2 种基金the National Natural Science Foundation of China(21801243)the Natural Science Foundation of Shaanxi province(2018JM6045,2018JM1046)Research funding was received from Shanghai Key Lab for Urban Ecological Processes and Eco-Restoration(SHUES2019A02).
文摘Chemi-resistive sensors based on hybrid functional materials are promising candidates for gas sensing with high responsivity,good selectivity,fast response/recovery,great stability/repeatability,room-working temperature,low cost,and easy-to-fabricate,for versatile applications.This progress report reviews the advantages and advances of these sensing structures compared with the single constituent,according to five main sensing forms:manipulating/constructing heterojunctions,catalytic reaction,charge transfer,charge carrier transport,molecular binding/sieving,and their combinations.Promises and challenges of the advances of each form are presented and discussed.Critical thinking and ideas regarding the orientation of the development of hybrid material-based gas sensor in the future are discussed.
基金This work was financially supported by National Natural Science Foundation of China(No.51903197)Wuhu and Xidian University special fund for industry-universityresearch cooperation(No.XWYCXY-012020012)+3 种基金Open Fund of Zhijiang Lab(2021MC0AB02)China Postdoctoral Science Foundation(2019TQ02422019M660061XB)the Fundamental Research Funds for the Central Universities(JC2110,JB211305).
文摘A good method of synthesizing Ti_(3)C_(2)T_(x)(MXene)is critical for ensuring its success in practical applications,e.g.,electromagnetic interference shielding,electrochemical energy storage,catalysis,sensors,and biomedicine.The main concerns focus on the moderation of the approach,yield,and product quality.Herein,a modified approach,organic solvent-assisted intercalation and collection,was developed to prepare Ti_(3)C_(2)T_(x) flakes.The new approach simultaneously solves all the concerns,featuring a low requirement for facility(centrifugation speed<4000 rpm in whole process),gram-level preparation with remarkable yield(46.3%),a good electrical conductivity(8672 S cm^(−1)),an outstanding capacitive performance(352 F g^(−1)),and easy control over the dimension of Ti_(3)C_(2)T_(x) flakes(0.47–4.60μm^(2)).This approach not only gives a superb example for the synthesis of other MXene materials in laboratory,but sheds new light for the future mass production of Ti_(3)C_(2)T_(x) MXene.
基金supported by the Key Research and Development Projects of Shaanxi Province(Grant No.2021GY-250)the Open Project of State Key Laboratory of Environment-Friendly Energy Materials(Grant No.20kfhg06)the Fundamental Research Funds for the Central Universities of China(Grant No.300102312406).
文摘The challenge in synthesizing high-entropy ceramic(HEC)nanopowders is to suppress severe grain coarsening and particle agglomeration,which occur at elevated temperatures.This challenge could be addressed by the polyacrylamide gel method.In this work,single-phase high-entropy(Lao.2Ndo.2Smo.2Gdo.2 Ybo.2)2Zr2O7 and(Lao.2Ndo.2Yo.2Euo.2Gdo.2)2Zr2O7 nanopowders without agglomeration were successfully synthesized using the polyacrylamide gel method for the first time.The results showed that phase composition,particle size,and agglomeration degree of the nanopowders were greatly influenced by the molar ratio of acrylamide(AM)/Zr and calcination temperature.These as-synthesized high-entropy zirconate(HEZ)nanopowders could be sintered into fully dense ceramics at 1500 C for 2 h.These HEZ nanopowders showed a phase transformation from a defect-fluorite phase to a pyrochlore phase with the increase of sintering temperature.Additionally,two-step sintering of these nanopowders was conducted,and the HEZ ceramics with fine grains were prepared.The polyacrylamide gel method is simple and easily operated,which is a facile approach of producing the HEC nanopowders with excellent sinterability.
