First-principles calculations based on van der Waals(vdW) corrected density functional theory(DFT) are firstly employed to investigate the adsorption of methanol(CH_3OH) gas molecule on pristine and Xdoped phosphorene...First-principles calculations based on van der Waals(vdW) corrected density functional theory(DFT) are firstly employed to investigate the adsorption of methanol(CH_3OH) gas molecule on pristine and Xdoped phosphorene( =B, C, N and O). The CH_3OH gas molecule is placed on the top of different phosphorene surfaces, the whole adsorption systems are fully optimized by using Vienna ab initio simulation package(VASP). The calculation results demonstrate that both pristine and heteroatomdoped phosphorene are sensitive to CH_3OH gas molecule with a moderate adsorption energy and an excellent charge transfer. Among all the investigated adsorption configurations, CH_3OH gas molecule is physically absorbed on pristine phosphorene and heteroatom-doped phosphorene. The N and O doping improve the adsorption of phosphorene with CH_3OH gas molecule, while B and C doping are almost not beneficial compared to the pristine phosphorene. The results suggest that N-doped and O-doped phosphorene are ideal candidates used for CH_3OH gas sensing.展开更多
A template-free carbonization-activation route is developed to fabricate sub-nanopore-containing porous carbon by using a novel polypyrrole(PPy)hydrogel as a precursor.This design of PPy hydrogel precursor containing ...A template-free carbonization-activation route is developed to fabricate sub-nanopore-containing porous carbon by using a novel polypyrrole(PPy)hydrogel as a precursor.This design of PPy hydrogel precursor containing molecular-scale grids(diameter~2.0 nm)allows for homogeneous N,O-codoping into the porous carbon scaffold during the pyrolysis process.A subsequent activation step produces activated porous carbons(APCs)with tailored pore structures,which renders the APCs abundant subnanopores on their surface to increase the specific capacitance as extra capacitance sites.Coupled with large specific surface area and abundant heteroatoms,the optimized APC4/1 displays excellent specific capacitance of 379 F/g for liquid-state supercapacitor and 230 F/g for solid-state supercapacitor.The solid-state supercapacitor shows a high energy density of 22.99 Wh/kg at power density of 420 W/kg,which is higher than most reported porous carbon materials and satisfy the urgent requirements of elementary power source for electric vehicles.Moreover,this method can be easily modified to fabricate sub-nanopore-containing porous carbons with preferred structures and compositions for many applications.展开更多
基金supported by the National Natural Science Foundation of China (Nos. 21701043, 21573066, 51402100)the Provincial Natural Science Foundation of Hunan (Nos 2016JJ1006, 2016TP1009)the Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province and Shenzhen Science and Technology Program (No JCYJ20170306141659388)
文摘First-principles calculations based on van der Waals(vdW) corrected density functional theory(DFT) are firstly employed to investigate the adsorption of methanol(CH_3OH) gas molecule on pristine and Xdoped phosphorene( =B, C, N and O). The CH_3OH gas molecule is placed on the top of different phosphorene surfaces, the whole adsorption systems are fully optimized by using Vienna ab initio simulation package(VASP). The calculation results demonstrate that both pristine and heteroatomdoped phosphorene are sensitive to CH_3OH gas molecule with a moderate adsorption energy and an excellent charge transfer. Among all the investigated adsorption configurations, CH_3OH gas molecule is physically absorbed on pristine phosphorene and heteroatom-doped phosphorene. The N and O doping improve the adsorption of phosphorene with CH_3OH gas molecule, while B and C doping are almost not beneficial compared to the pristine phosphorene. The results suggest that N-doped and O-doped phosphorene are ideal candidates used for CH_3OH gas sensing.
基金financial support from National Natural Science Foundation of China(Nos.51902222,51603142,U1610255)Key Laboratory of Yarn Materials Forming and Composite Processing Technology,Zhejiang Province(No.MTC2019-03)+2 种基金Scientific and Technological Innovation Programs of Higher Education Institutions in Shanxi(Nos.2019L0164 and 2019L0255)the Shanxi Provincial Key Innovative Research Team in Science and Technology(Nos.2015013002-10 and 201605D131045-10)Key R&D Program of Shanxi Province(International Cooperation,No.201903D421077)。
文摘A template-free carbonization-activation route is developed to fabricate sub-nanopore-containing porous carbon by using a novel polypyrrole(PPy)hydrogel as a precursor.This design of PPy hydrogel precursor containing molecular-scale grids(diameter~2.0 nm)allows for homogeneous N,O-codoping into the porous carbon scaffold during the pyrolysis process.A subsequent activation step produces activated porous carbons(APCs)with tailored pore structures,which renders the APCs abundant subnanopores on their surface to increase the specific capacitance as extra capacitance sites.Coupled with large specific surface area and abundant heteroatoms,the optimized APC4/1 displays excellent specific capacitance of 379 F/g for liquid-state supercapacitor and 230 F/g for solid-state supercapacitor.The solid-state supercapacitor shows a high energy density of 22.99 Wh/kg at power density of 420 W/kg,which is higher than most reported porous carbon materials and satisfy the urgent requirements of elementary power source for electric vehicles.Moreover,this method can be easily modified to fabricate sub-nanopore-containing porous carbons with preferred structures and compositions for many applications.
