Mechanoredox chemistry that uses highly polarized piezoelectric materials as mechanoredox catalysts to promote redox reactions has emerged recently.It provides an alternative approach alongside the existing polymeriza...Mechanoredox chemistry that uses highly polarized piezoelectric materials as mechanoredox catalysts to promote redox reactions has emerged recently.It provides an alternative approach alongside the existing polymerization methods.Despite recent accomplishments,determining the quantitative relationship between the structure of ZnO and its catalytic performance for polymerization is still challenging.Herein,we prepared various ZnO crystals with different polar facets ratios to achieve efficient mechanically induced reversible addition-fragmentation chain transfer polymerization(mechano-RAFT).ZnO prepared from Zn(NO3)2 showed a high polar facet ratio of 1.66 and offered the highest catalytic activity among all ZnO samples.A near-quantitative initiator efficiency of 99.5%and narrow molecular weight distribution were achieved for the polymerization of n-butyl acrylate.Furthermore,the high chain-end fidelity and chain extension capability were also evidenced by MALDI-TOF MS and GPC analysis.This work highlighted the significant contribution of polar facets in ZnO to its catalytic activity and will guide the design of mechanoredox catalysis with superior catalytic performance in the future.展开更多
ZnO single crystals were grown by vapor phase reaction of Zno powder with active carbon powdei at an elevated temperature The typical crystals were colorless and transparent with maximum size o4 0.1 mm in diameter and...ZnO single crystals were grown by vapor phase reaction of Zno powder with active carbon powdei at an elevated temperature The typical crystals were colorless and transparent with maximum size o4 0.1 mm in diameter and 25 mm in length, The gas-sensing characteristics of Na+-doped anc undoped single crystals were investigated in 1 %H2. Co and CH, in air between 1 50 and 600℃. It was found that the undoped ZnO single crystals showed little gas sensitivity in air. and Na+-doping can greatly enhance the senstivity by increasing the resistivities. The maximum sensitivity of the samples is 22 (Ra/ Rg) for H2. 1 2 for CO and 4 for CH4展开更多
Nano-floating gate memory devices with ZnO nano-crystals as charge storage layers are fabricated,and the influence of post-deposition annealing temperature and thickness of the ZnO layer are investigated.Atomic force ...Nano-floating gate memory devices with ZnO nano-crystals as charge storage layers are fabricated,and the influence of post-deposition annealing temperature and thickness of the ZnO layer are investigated.Atomic force microscopy and scanning electron microscopy reveal the morphology of discrete ZnO nano-crystals.For capacitance-voltage measurements,it is found that the memory device with 1.5 nm ZnO and annealed at 700℃shows a larger memory window of 4.3 V（at±6 V）and better retention characteristics than memoriy devices with2.5 nm ZnO or annealed at other temperatures.These results indicate that the nano-floating gate memory with ZnO nano-crystals can obtain good trade-off memory properties.展开更多
基金This work was supported by the National Natural Science Foundation of China(22101195 and 21925107)the Natural Science Foundation of Jiangsu Province(BK20210732)+1 种基金the Suzhou Science&Technology NOVA Program(ZXL2022480)the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)and the Program of Innovative Research Team of Soochow University。
文摘Mechanoredox chemistry that uses highly polarized piezoelectric materials as mechanoredox catalysts to promote redox reactions has emerged recently.It provides an alternative approach alongside the existing polymerization methods.Despite recent accomplishments,determining the quantitative relationship between the structure of ZnO and its catalytic performance for polymerization is still challenging.Herein,we prepared various ZnO crystals with different polar facets ratios to achieve efficient mechanically induced reversible addition-fragmentation chain transfer polymerization(mechano-RAFT).ZnO prepared from Zn(NO3)2 showed a high polar facet ratio of 1.66 and offered the highest catalytic activity among all ZnO samples.A near-quantitative initiator efficiency of 99.5%and narrow molecular weight distribution were achieved for the polymerization of n-butyl acrylate.Furthermore,the high chain-end fidelity and chain extension capability were also evidenced by MALDI-TOF MS and GPC analysis.This work highlighted the significant contribution of polar facets in ZnO to its catalytic activity and will guide the design of mechanoredox catalysis with superior catalytic performance in the future.
文摘ZnO single crystals were grown by vapor phase reaction of Zno powder with active carbon powdei at an elevated temperature The typical crystals were colorless and transparent with maximum size o4 0.1 mm in diameter and 25 mm in length, The gas-sensing characteristics of Na+-doped anc undoped single crystals were investigated in 1 %H2. Co and CH, in air between 1 50 and 600℃. It was found that the undoped ZnO single crystals showed little gas sensitivity in air. and Na+-doping can greatly enhance the senstivity by increasing the resistivities. The maximum sensitivity of the samples is 22 (Ra/ Rg) for H2. 1 2 for CO and 4 for CH4
基金Supported by the National Natural Science Foundation of China under Grant No 61404055
文摘Nano-floating gate memory devices with ZnO nano-crystals as charge storage layers are fabricated,and the influence of post-deposition annealing temperature and thickness of the ZnO layer are investigated.Atomic force microscopy and scanning electron microscopy reveal the morphology of discrete ZnO nano-crystals.For capacitance-voltage measurements,it is found that the memory device with 1.5 nm ZnO and annealed at 700℃shows a larger memory window of 4.3 V（at±6 V）and better retention characteristics than memoriy devices with2.5 nm ZnO or annealed at other temperatures.These results indicate that the nano-floating gate memory with ZnO nano-crystals can obtain good trade-off memory properties.
